Have you used Race gas?

[BillyGman]

I've started this poll because of my curiosity, but I also believe that if many of you participate in it, that it will provide some good information for everyone here. This is a topic that most hi-perf car enthusiasts don't care to talk about. However, I don't see it as being advantagous to us as a group if people conceal things like this. So please participate. particularly if you've made modifications to your Marauder, and have Dynoed it, and/or raced it at the drag strip. This is a public poll, so everyone will be able to see your vote. I don't see why there should be any problem with that though..... BTW, it will be interesting to see how many guys who have some type of forced induction will participate in this poll.......I'm hoping that they all will.

[SergntMac]

Yes, I use race gas for the track, and Zack tells me I'm wasting my money. Perhaps I am, but it makes me feel a bit better about hitting the throttle hard. Pump gas around Chicagoland leaves much to be desired, I feel better with some 100 octane on board.

I try to get to the track with a 1/4 tank of my customary 93 octane pump gas, and add 3-4 gallons at the track, for near a third of a tank. 100 octane unleaded, and I won't race with less than a 1/4 tank of fuel because of fuel system issues inherrent to the MM. The last time I bought race gas, it was at Gainsville, FL. last week and it was 6 bucks a gallon. It's usually 4.59 locally, have to check out local prices again.

Zack has tried a few race tunes that should have taken advantage of the higher octane, but I have no positive results to report. Race gas doesn't seem to make any performance difference in my MM, the car runs 12.4x all day long. It's best time this season was on my "stock" street tune ala Sutton Ford/Jerry VanDerlinde.

I'm not suggesting using race gas is a myth, but I can't say it helps me any. Your results may be vary, I imagine N/A cars benefit nicely.

[Deebar]

I use 100 unleaded EXCLUSIVELY. I know it sounds strange, but with cam 2 and my race gas tune from lidio, I think my car has paid for all of my mods (exept the blower). I HIGHLY recommend anyone with an sc'd MM look into a race gas tune, particularly if you run on the uhh "private track". Believe me, there are plenty of 'Benjamins' to be made before the word on these cars potential really gets out, your fuel will pay for itself IF you race.

[Captain Steve]

I tried out race gas with no tune at all. It didn't do squat.

It may in fact have hurt my times some, since my car is tuned for 91 octane from the factory. 100 octane has less energy per volume than 93 octane which may explain it.

[Smokie]

I have the tune that came with the base T-Kit, never used race gas when I ran N/A, Gainsville was the first track outing since the T-Kit. I arrived at the track with less then 1/4 tank and was concerned about fuel sloshing, I purchased 4 gallons of race fuel, no gas stations nearby.

My answer on the poll will be NO RACE GAS. I do not have the tune for it, and will not pay for race fuel again.

PS: I saw a member run alongside me with pump gas and regular tune, then he switched to race gas/race tune and ran slower. If race gas makes you go faster, I didn't see it.

[Deebar]

Race fuel by itself does nothing for your performance. You need a tune to benefit from it. Think of it as anti-knock for an agressively tuned/ boosted engine.

[Jeff03]

Yes I use race gas along with Lidio's tune when I'm at the track and I have to say that the results are good ... at least I think that there not to bad 12.06 at 112 mph with stock gear , 1/2 tank full and 3.0 pulley , K&N filter kit .:burnout:

[MI2QWK4U]

Race fuel by itself does nothing for your performance. You need a tune to benefit from it. Think of it as anti-knock for an agressively tuned/ boosted engine.

D is right, you need to tune around the race gas for the best results. Race Gas use is another area that most members dont have a clue about. For someone to pump in some 100 octane gas, run at the strip in their stock marauder without a tune to benefit from it will not see any return for their investment. I can only speak for using race gas in a trilogy equipped Marauder. The difference is very obvious, both at the track and the dyno. The higher octane allows for tuning more aggressivly. The best I could do on the dyno with 94 octane was around 425 at the wheel. Adding 100 octane allowed for a more agressive tune and yielded me 485 rwhp. Do the math, that is 60 RWHP in the hands of a capable tuner. I can feel the difference. I have seen this repeated on Lidios, Jerrys, Dees, Mike and Mikes, etc etc.
If someone says race gas isnt worth it is full of ***** and doesnt know what they are talking about...again. It wont help a lot with a NA car, but for a supercharged application, its like night and day. So dont use it...and give people like D and myself an awesome advantage.

[MikesMerc]

Billy, you need another vote option...."Race gas every day"

Race gas here used exclusively as well.

As Dave and Deebar have said, you have to have the tune to take advantage of it. The higher octane allows for much more spark to be used safely.

Furthermore, if you ask around and talk to the hardcore racers and tuners, they will tell you that it is actually safer to run a more powerful tune with race gas, then a softer tune with pump gas. I've heard that from nearly every competent tuner I've talked to. Pump gas is subject to much more variation in quality. Consequently, it is subject to more detonation issues. The only way around it is to tune things VERY soft to accomodate for the crap the local station might be pumping.

Race gas, on the other hand, tends to be more consistent in quality and true octane. It not only allows for a more aggressive tune, but you don't get the variation either. That's a serious increase in safety under forced induction conditions.

Race gas is worth 70 peak rwhp for me. But, more importantly, race gas is good for 50 ft lbs of peak rwtq, and more than that at other areas in the power curve. IMO, running forced induction without race gas is like leaving power and safety on the table.

I have a 94 Octane tune on my flip chip for emergencies and long trips...I just haven't used it in over a year.

[Bradley G]

Both track and street.

Ran half race fuel At MVIII, no other time to compare that to.Half 110 and half 93.
Once on the street.
No seat of the pants increase.
It felt slower to me.

[BillyGman]

IMO, running forced induction without race gas is like leaving power and safety on the table.

. Unless you have the stock Trilogy engine tune, because it's a very conservative tune according to Lidio. In that case you're only leaving POWER on the table by using 93 octane pump gas (as I am ) but not safety. ;) I have a daily driver that's S/Ced, so it would be difficult for me to run race gas because of the extra expense. I bought my Marauder 27 months ago brand new, and it has 34,000 miles on it because of daily use, and some trips too.

Thanks for everyone's honest and straight forward answers so far, as well as your participation in the poll. :up:

[MikesMerc]

Both track and street.
It felt slower to me.

Brad, I assume you didn't have a race gas tune?

[MikesMerc]

Unless you have the stock Trilogy engine tune, because it's a very conservative tune according to Lidio. In that case you're only leaving POWER on the table by using 93 octane pump gas (as I am ) but not safety.

Technically speaking, running 100 octane would be even safer simply due to the reduced chance of detonation:) LOL...but I know what you mean Billy. It would indeed be overkill and a waste of money running race gas on the stock Trilogy tune.


I have a daily driver that's S/Ced, so it would be difficult for me to run race gas because of the extra expense. I bought my Marauder 27 months ago brand new, and it has 34,000 miles on it because of daily use, and some trips too.


I hear you loud and clear. Race gas is not an option for everyone. If I drove as money miles as you do, most of it would be on 93/94 for sure.

Just, FYI, though. A race gas tune with the stock 9.5 psi is worth about 45 rwhp. For sunny days and track trips it might be worth it to get a race gas tune just to play with:)

[BillyGman]

Just, FYI, though. A race gas tune with the stock 9.5 psi is worth about 45 rwhp.Yeah, that's what I kinda thopught Mike. It's definately tempting!! For sunny days and track trips it might be worth it to get a race gas tune just to play with:) Thanks for that suggestion Mike....I guess the main reason why I've never opted for a race gas tune is because I've always wanted to tell people when they've asked about my car that it runs the same on the street and also has just as much power, as it does at the track. And I CAN say that because I've never used anything but 93 octane. The only thing that has ever been in the gas tank of my Marauder besides 93 octane pump gas anywhere is fuel injector cleaner once, and 92 octane once when I was in NJ and 93 octane wasn't available then.

That's also one of the reasons why I chose the S/Cer instead of Nitrous oxide injection. It's the same all the time, and how my car performs and how fast it is any given day is never dependent on what type of fuel I have onboard or in the tank. The car runs the same regardless of where I am, or when you happen to challenge me. The only thing that alters that somewhat will be the outside air temperatures, as well as elevation, and eveybody's car is subject to that.

[CRUZTAKER]

I have an aggressive N/A tune for race gas available to me. And yes, it works.
Obviously, consistently running 13.1 - 13.4 naturally aspirated on race fuel justifies the use of it. However, I sometimes add 100 or higher and occationally leaded if that's all there is available.

When I use a shot of juice, it is imperative I use good fuel, in my case, a setting for 94, or 100+ is available, and the race fuel pretty much covers me from the possibility of life ending 'knock/ping' during spray.

[Cobra25]

I have never used race gas & can't see a advantage to putting it in unless you have a special custom tune for it. I for one am happy with my present Custom tune and wouldn't want to change a thing.

[MarauderMark]

I haven't use race gas yet but after watching Cruztaker and Jet use it i will most certainly give it a try since Dennis has given me the tune to do it with..:burn: :D

[Glenn]

So how many HP is a Race gas tune worth on the track for a N/A MM??? I was once told only 10HP?? Anyone have any experience to share.

Glenn

[martyo]

Billy, you need another vote option...."Race gas every day"

Race gas here used exclusively as well.


Me too, but I use nickel plated race gas! :D :P

^^^ The nickel plated part is a joke, in case someone doesn't get my sense of humor.

[HwyCruiser]

I've mixed 100 octane with 92 octane for the street. Not every tank, probably once a month or so, when I feel the need to put a real spanking on the motor. Probably the same concerns as Mac's over quality and consistency.

I have not run race gas at the track. I don't have a race fuel tune to take advantage of it anyway. My dyno tune was done on 91 octane (the highest octane available at the time) with a few gallons of 92 octane left over from the trip to the tuner. At 450 rwhp, I'm not really looking for any more.

EDIT: Since there wasn't a poll option for this, I didn't vote.

[stevengerard]

Tell us how you really feel!

I use it at the track but without a specific race tune, just for safety, one day I'll get the additional race tune added and try it sounds fun. I often put it into the 442 during hot months, helps a lot with the old engines.

[MI2QWK4U]

Tell us how you really feel!

I use it at the track but without a specific race tune, just for safety, one day I'll get the additional race tune added and try it sounds fun. I often put it into the 442 during hot months, helps a lot with the old engines.


Thanks Steve! Those that know me will attest to that!
Given the correct situation, equipment, and tune, the 100 octane will yield some very tangible and impressive results. Not to mention the overall quality of the 100 octane is much better and consistant, eliminating worries about not getting 93-94 at the pump. When I switch back to the 94 octane tune I can sure feel the missing 60-70 RWHP as well as the torque that goes with it.

[QWK SVT]

I've voted no, but have used it once, in a pinch. The gas station closest to one of the tracks I visit only sells 91 octane. I miscalculated my gas needs, and had to put some 91 in. I babied it to the track, and offset the 91 octane with a little race fuel, but I calculated to a average of 94 octane... I don't have a tune for it, so I don't need it.

So, technically, I've used it, but never for any realy benefit...

[SergntMac]

The nickel plated part is a joke, in case someone doesn't get my sense of humor.Hehehe...Another time, my friend.

Another time...

[teamrope]

I still had a little over 1/8 of a tank left in the tank when we got to the track during MMVIII so I put 1 gal of 110 and 4 gal of 100 before loading Lidio's race tune. I can tell you that I really felt a difference. 14.38 with nothing more than 4.10's, the tune and the fuel on a hot muggy day.

I'm hoping to get to Bremerton Raceway Park on a good cool day and see how much I can shave off of that. You can see the Sound from that track so the altitude is under 200 ft. :)

[Bradley G]

There is a simple way to settle our difference in opinion, and there are still race tracks open in our respective areas. Care to agree on test terms?{Quote}
This may be exactly what the Dr. ordered!
Hopeing out loud, the race is around here.

[MERCMAN]

Ahh, and I though S/C were the only threads that spoil faster tham mayo left out in a hot Georgia sun!!

DAVE- Your S?A comments to start off with were not needed, keep it to the topic

Zack and Mac,, your twisting ^^^ his tail for fun may amuse you, but does nothing but throw this thread farther into disarray.

Anyone else that wants to join into the fracas,, BE WARNED!!!!

I will be deleting the offending posts, but will keep this thread open for the information it is providing.

BE WARNED!! Keep it decent, or keep it off the board. BIG BROTHER is watching you!!

[MikesMerc]

There is no argument here in this thread...no credible argument anyway. To argue that there is no performance benefit to high octane race gas is to argue that the world is flat. The use of high octane gas in high compression engines is hotrod 101. And when you are running forced induction, all you are doing is raising effective compression.

Mac, you seem to be missing the point. It isn't the gas that's providing the power, its the tune. Race gas alone, without a tune that uses it, produces zero power gains. Zip, zilch, nada.

The higher octane gas simply allows for a more aggressive use of timing and fuel delivery that results in major power gain. The higher octane gas is more resisitant to detonation and allows for more spark. It also allows you to eliminate some of the over rich conditions some tuners use as a margin of safety with forced induction set ups.

Now, if anyone beleives that forced induction motors do not take advantage of high octane gas with the proper tune, well....they need to do some research. There is simply a ton of information about the benefits of using high octane race gas with forced induction. Just google it.

[Logan]

I agree, race gas along with an aggressive tune = lots more power.

Dumbasses from Detroit and Chicago being a bunch of juvenile idiots = A pissed off Logan.

Don't make me choose who gets the boot, as the easy answer in my mind is all of you.

You all SERIOUSLY need to get over yourselves.

[Glenn]

I ask again how many HP on a N/A MM with a race tune/gas. Can some of us N/A owners have a moment on the net with the big guys?

Glenn

[MikesMerc]

Sorry Glenn, it seems your post was lost in some of the heated debate.

Anyway, from what I have seen on two NA cars that had a race gas tune it was about 15-20 rwhp.

The issue with NA cars is that you're already running the motor at a 14:1 AFR and throwing lots of spark at it with the stock program. This is very different from blown cars that often pull spark out, and richen the AFR as boost builds. So, for NA cars, there just isn't much more spark advance that can be thrown in to produce any more power. Accordingly, race gas provides a limited benefit to the NA guys with stock compression.

I'm sure someone with an NA race gas tune will come along shortly. I know Mat Peirce has one. He may still be away on his honeymoon though:)

[BillyGman]

I'm going to make mention of something that is pretty much elementary to some of us, however, we cannot just assume that everyone is aware of the following.......


Please keep in mind that there is always extra power to be had by making the air/fuel ratio ("AFR") more lean ( ie. a greater air to gas ratio), as well as by increasing the ignition timing advance. For the most part, the leaner that the AFR is, the more power any internal combustion engine will make (atleast to a certain point). And probably to a lesser point, the more advanced ignition timing is set, the more power will be made also. However, the problem that arises is that this extra power from a leaner AFR as well as from a greater ignition timing advance, comes at a cost. A very great cost. That cost is engine detonation (ie. "pinging", "knocking", etc.).

As many of you already know, (but some of you may not) severe pinging can destroy your engine in short order. When that happens, usually the pistons melt or crack, or the head gaskets blow. But the best way to avoid the detonation in the first place, is with higher octane gasoline. Therefore, as Mike and others have pointed out already in this thread, using race gas will allow you to run your engine with a leaner AFR, as well as with a greater ignition timing advance, without the engine pinging ("detonating").

And as Mike has already stated, it's that greater ignition timing and leaner AFR that can safely be run with the use of 100+ octane gas, that will bring considerably more power to your engine. I just wanted to spell that out in very simple terms w/out all of the racing jargon that Mike used in his post, so that everyone who may be reading can fully understand what we've been talking about here. I hope this helps.

[SergntMac]

Hehehe...Ya kno, being a member of two National Champion Bagpipe bands teaches you something, something I forgot here. One band is Grade 2, the other is Grade 4.

As a sidedrummer (plays snare drum), I have to play a series of intricate rudiments. Not American rudiments, but Scotish, which are very tight, and very exact. Difficult, in the best of moods. Add to that flourishing and show, and it's all a very real contest. Any of y'all want to see more about drumming, just rent "Drum Line", and think ten times that precision, and show.

No one, anywhere in America, or, Scotland, can play such rudiments without professional instruction. "Training from the Masters" is the key. You can have the natural talent to play it all correctly, but if you have not been "trained by the Masters", no sense in goinjg on.

So...You have to go to school with them, in order to learn their precision ways, if you want to be a champion among drummers world-wide. You must have a degree from a Master Academy, ands which academy you attend will guide the competition judges on how much of their academy skill you really learned. Follow me on this?

Apprentice plumber?
Union Electrician?
Journeyman Card?

I am a Grade 2 sidedrummer, with my card. I studied with Carl Lenny, and I can roll out 9/8 beatings with flourishes that will chill your spine. Now that I have reflected on my sidedrummer experience and accomplishment, I have a better understanding of how this thread went south, and came to need moderator intervention.
Yes, I use race gas for the track, and Zack tells me I'm wasting my money. Perhaps I am, but it makes me feel a bit better about hitting the throttle hard. Pump gas around Chicagoland leaves much to be desired, I feel better with some 100 octane on board.

I try to get to the track with a 1/4 tank of my customary 93 octane pump gas, and add 3-4 gallons at the track, for near a third of a tank. 100 octane unleaded, and I won't race with less than a 1/4 tank of fuel because of fuel system issues inherrent to the MM. The last time I bought race gas, it was at Gainsville, FL. last week and it was 6 bucks a gallon. It's usually 4.59 locally, have to check out local prices again.

Zack has tried a few race tunes that should have taken advantage of the higher octane, but I have no positive results to report. Race gas doesn't seem to make any performance difference in my MM, the car runs 12.4x all day long. It's best time this season was on my "stock" street tune ala Sutton Ford/Jerry VanDerlinde.

I'm not suggesting using race gas is a myth, but I can't say it helps me any. Your results may be vary, I imagine N/A cars benefit nicely. Okay, I'm quoting myself here without any changes because I want to restart this discussion as an honest and viable resource.

I want more 411 on gas ands octane and please pour it on, but without wiseazzz commentary K?

BTW, I apologize for my previous posts now deleted by moderators, but smack me and you will get smacked back. That said, I want to know more about this race gas too, so, please don't make me duck a swing at the same time. Right here, I posted my thoughts, someone tell me what's wrong with my position, my thinking, and my experience?

I'm making 500 plus HP at the wheels on a dyno (which isn't important, just a test tool, IMHO) and running 12.4x on a race track. This is good performance from 93 octane, yes? But, if 100 octane is worth 55-70 RWHP at my level of mods, where am I going wrong?

When I add 100 octane to the mix, and retune for performance (add timing, and what ever), I get nothing performance-wise, that's worth the cost of the gas, or, the time to figure the tune.

I promise I will continue to add 100 octane race gas when heading to the track, but only for the reasons I've stated i.e. "emotional comfort" that I have a balanced load on board, and between 1/4 and 1/2 of a tank of fuel.

BTW, once we get past this octane discussion, we have on-board fuel system faults to discuss, y'all have been warned.

I'm not looking to break balls here, just trying to get a better handle on the "science" behind it all, eh?

Until I learn better, I stand by my original statement, as it's posted again right here as a quote. Rather than tell me how stupid I am in a public forum, please tell me why I need to learn more about this? Maybe if I ask these questions, it will help move this discussion forward?

How much is one full octane "notch" worth, in RWHP/RWTQ?

If I move up from a 93 octane "notch" to a 94 "notch", what should I expect in performance?

If I move up from a 94 "notch" to a 100 octane "notch", what should I expect?

How can a performance tune glean 55-70 RWHP from only 6-7 "notches" in octane? Can you, please, explain this?

How can I go faster with higher octane?

This is about as netural as I can get on this topic, I hope others posting here respect that I am, and have, tired to hunt down the 411.

Thanks to y'all, carry on...

[BillyGman]

MAC, have you seen my last post that I put up right before your last one? I'm asking you this, because I want to make sure that you understand the theory behind this. Now with that in mind, I'm a bit confused about your post that you have quoted, as compared to your last post. because I was under the impression by your quoted post, that you've been using race gas at the track, but merely with a 93 octane engine tune.


However, in your last post above, it seems that you're claiming that you've used a race gas engine tune along with the race gas. So which is it? have I missed something? I'm asking you that, because the bottom line is that you will never gain any HP or TQ from the use of higher octane gasoline, unless you also are running a special engine tune that tailored specifically for that higher octane. In fact, it is my understanding that obtaining a special engine tune for the race gas, will require you to get a dyno tune performed while you have nothing but the race gas in your tank. And unless you've had that done, then you'll never gain power from the use of race gas.

Guys like Barry, Dave, Mike, and others who have race gas engine tunes, either have a muliple position computer chip with a toggle switch that enables them to switch from their 93 octane tunes, to their race gas tunes at will, or they have the handheld tuners which include several tunes in them that they can use, one of them being specifically for 100+ octane gas. So do you have that? If not, then that's why you haven't obtained results from the use of 100+ octane gas. And BTW, if you do have a special tune for that, then you'll have to use straight race gas that's undiluted in your tank, and not a mixture.Because if you have an engine tune specifically for 100+ octane fuel, then anything less than that octane while using that tune, will result in severe engine pinging during hard acceleration. If it doesn't result in that with the use of 95 octane or 96 octane (ie. a mixture), then you don't have a race gas tune, and that's the reason why you don't see any power gain from the race gas.

[merc406]

No comment.................. :burnout:

[BillyGman]

No comment.................. :burnout:Yep, from what I've seen at the track, and the talk I've been exposed to in the staging lanes while waiting to race various times, I think that your comment above^ definately represents many amatuer drag racers' approach to this topic, and demonstrates how secretive and widespread the use of race gas at the track really is.

[merc406]

Not really sure what ya meant, but anyone that spends that much on race gas would more than likely know how to use it with their particular motor setup. :D

[MarauderMark]

Questions..
1) If i have a tune for 100 octane ,do i use it for 98 octane?

2) Same question goes .can a 100 octane tune be ok using 110 octane gas or would a 110 octane tune be needed?
i do have a race tune for my car but i think its only for 100 octane and want to know if using anything other than 100 octane will be worth it or make matters worst or just be a waste of money..Thanks
I hope i am not sounding dumb but i am reading all this and starting to understand a little more than i knew about a/f ratio..again thanks everyone..

[BillyGman]

[QUOTE=MarauderMark]Questions..
1) If i have a tune for 100 octane ,do i use it for 98 octane?my guess is that changing the octane by only two numbers might not make much differnce, but that might depend on how far on the edge the tune is. So it might have to do with who does the tune, and what his approach and tuning theories are.

2) Same question goes .can a 100 octane tune be ok using 110 octane gas or would a 110 octane tune be needed?
QUOTE]I think that's a good question, and one that I'd want to ask Lidio.

[BillyGman]

Not really sure what ya meant, but anyone that spends that much on race gas would more than likely know how to use it with their particular motor setup. :DExactly. I think some people simply play dumb in order to be secretive about this topic. Many of the people who use the race gas won't admit it.

[SergntMac]

I hear you, Billy, let me try to explain it again.

Over the years, I have sampled many dyno tunes from several professional tuners, each with their own spin on how to tune my Marauder. I have made many changes to the car, it's been a slow, but sure progression to where I am today.

Several times along this path, I have explored race gas in different octanes, with the appropriate tuning to exploit that. Once the gas was on board, albeit mixed with some pump gas (but as little as possible), and the EEC reprogramed, I didn't get any results that convinced me that race gas is sure path to solid and repeatable performance.

Yes, some of the folks you mention ^ there use race gas for their own reasons, and I'll agree that when using NOS, it's a must. However, IMHO, their performance is a product of NOS, not octane, and if they were to delete race gas, their performance would not suffer, though they would be flirting with a detonation edge. If someone can teach me differently, I'm ready to learn.

Today, I continue to use race gas at the track as a safety margin against the lower octane pump gas I may have on board, but no special tune for that octane. Zack says I'm wasting my money, but it's an emotional comfort for me. My MM is finely tuned at this point, and very sensitive to lower grades of pump gas, so, it's just insurance for the hard driving. I have been forced to use 91 octane due to lack of choice when traveling OTR, and my engine shows it's displeasure. All I can do is stay out of the deep end of the throttle until I burn it up. Moreover, if I change my tune, I can burn 87 octane safely, all I'll miss is my best performance.

Quite by accident, Zack and I proved something in this, but in a reverse manner. We ventured out to US 41 with 10 gallons of 100 octane on board, and spent the day twisting and tuning, with BFG drag radials in place. Consistent 12.4x/110+ MPH all day long, and I liked this repeatable performance. We called it quits, loaded up the floor jack, tool box, cooler, compressor, and restored the street tires and my street tune. Zack made one more pass while I drove an '03 Cobra, and I ended up racing my own Marauder. I beat Zack through the traps, but red lighted the race to him. My Marauder ran a 12.66/108 MPH.

So, I have tried race gas on the race track and on the dyno, and I never found a solid, tangible improvement to my individual performance. Again, if someone can show me otherwise, I'm willing to learn, new tricks in tuning are developing every day. If someone is interested in testing this, I'll offer my Marauder up as the test pig. Seems that all I do with it anyway, is try new stuff. If a tuner can get more that 10 RWHP out of 100 octane, or, more that 2/10 in my ET, I'll pay for the dyno tune as well. Considering the cost of race gas, and effort to exploit that.

These seem reasonable minimums to ask for before attaching a performance value to race gas, and if we achieve that, we can call it a mod worth installing for racing. I'd like to see everyone benefit from race gas, and I'm all for improved performance. I'm not ignoring this possibility, but I haven't seen it yet. Anyone game? If a tuner wants to invest his time, he'll benefit from the programming upgrades folks will be asking for.

[MI2QWK4U]

I will make an attempt to repost the informative portions of my posts that were deleted for whatever reason. Usually when I post information, especially lately, it is at the request of another member that honestly wants or needs to know something that I have personal real time experience with and feel like I can contribute or help. The facts I post are just that, facts that I can show or prove by various means. If people want to attack those facts, so be it. Those of you that really know me well know that I will help anyone out, weather by email, pm, or hours of chat on the phone. I have been fortunate to have been in on the ground floor of heavily modifying the Marauder. I have made some mistakes, and warn others of making the same mistakes, but I have also been on many "Firsts" lists. I pay a lot of attention and take a lot of time watching what is going on around me with respect to various Marauder Mods, and what those results are. Lidio has probably worked on more Marauders than any other vendor, save Dennis, and I had a front row seat taking notes and building my car.
The topic of race gas isnt taboo or secret. It is another tool used by experienced and knowledgeable racers to achieve better results. I will restate my original opinion in a different way, Anyone that says race gas isnt worth the money or doesnt yield better results, either lacks experience with tuning with race gas, or is misinformed. In most performance circles for modern cars, it is generally known that race gas refers to 100 octane sunoco or cam 2. There are other versions of race gas, higher octane and contain lead, but most of us dont use that, although there are a couple of folks using Turbo Blue 110 octane leaded race fuel!
Given the correct situation, equipment, and tune, the 100 octane will yield some very tangible and impressive results. Not to mention the overall quality of the 100 octane is much better and consistant, eliminating worries about not getting 93-94 at the pump. When I switch back to the 94 octane tune I can sure feel the missing 60 RWHP as well as the torque that goes with it. What started the ruckus earlier in the thread was a member discounting the concept of a 60 RWHP gain from using race gas and wanting to know if I was sober as I post that information. In my deleated posts, I made it clear that the results of race gas were specific to my car and my car alone. I would expand that to other Trilogy equipped Marauders that are simularly set up. I cannot attest to 100 octane in a vortech, procharger, or N/A Marauder. A N/A Marauder even with tuning wont appreciate the additional octane as much as a supercharged one will. It would be a waste of money. I run 100 octane in my 04 Mach 1 with a very agressive tune for the strip. It was worth maybe 2 tenths of a second, but the car felt a lot better throughout the RPM range with the 100 in the tank and the mid range torque also better. My results were well documented as was every mod ever made on the Marauder by being tested on the very same Dyno for as close to accuracy as possible.
I was hoping some folks with more experience would speak up and attest to the fact, that running race gas yields better performance in a supercharged application. It allows a competent tuner to play with spark and timing and produce a much more aggressive tune that is actually safer. Every point of octane equals so many degrees of timing, safe timing equals so much horsepower and torque. I dont recall what those numbers were, but thats not important. On 94 octane i was pulling about 420 RWHP, with the 100 octane and no other changes, it pulled about 470 RWHP. Its not a special tune, rather its a more agressive and responsive tune for whats in the tank. It seems that I am one of the only Super High powered Marauders out there running on a stock motor. I am right up there with some of the supercharged and nitroused Marauders.
So for all you that are wondering if race gas is worth it, it really depends on your setup and budget. With a race gas tune and good race gas, your Marauder will feel better, but not the same way putting a chip and 4:10s feels. For the Trilogy guys, its a done deal, try it. Several Trilogy guys are running so much better on race gas. I wont speak for any other setup, that can be for them to post on their own, and some has told their lack of success story using race gas. I will say it again....Capable tune to make the best of the race gas.
Anyone else with real experience care to speak up?

[Marauderjack]

No Race Gas experience here but I would like to know how you guys utilize the "100 octane tune" with less that 100 octane fuel?? Unless your tank is bone dry and you add 10 gallons of 100 octane....you ain't got 100 octane!! :rolleyes:

I had a 100 octane SCT tune on my 9100 and asked Dennis to remove it because I don't race and would rather have a tune I could use....plus I mentioned the above?? :o

Can you run a remote tank that has only Race Gas somehow with our cars or are you guys constantly flirting with disaster...DETONATION...with a 96 octane "Race Mixture"?? :coolman:

Just wondering how this Race Gas thing works?? :burnout:

Marauderjack :rasta:

[MI2QWK4U]

No Race Gas experience here but I would like to know how you guys utilize the "100 octane tune" with less that 100 octane fuel?? Unless your tank is bone dry and you add 10 gallons of 100 octane....you ain't got 100 octane!! :rolleyes:

I had a 100 octane SCT tune on my 9100 and asked Dennis to remove it because I don't race and would rather have a tune I could use....plus I mentioned the above?? :o

Can you run a remote tank that has only Race Gas somehow with our cars or are you guys constantly flirting with disaster...DETONATION...with a 96 octane "Race Mixture"?? :coolman:

Just wondering how this Race Gas thing works?? :burnout:

Marauderjack :rasta:


Some people commit to using 100 octane all the time. Others drain the tank, which is what I used to do. I was able to get all but a couple of ounces out, adding 5 or 6 gallons of race gas would easily dilute the 94 left over.

[MikesMerc]

Questions..
1) If i have a tune for 100 octane ,do i use it for 98 octane?

I wouldn't recommend it. Its no different than running 89 Octane in a stock MM that requires premium 93/94. The higher the octane, the slower burning the fuel, and the less chance of detonation (pinging). If you have a tune which has been programmed around the use of 100 octane, I wouldn't use it for anything with a lower octane rating.



2) Same question goes .can a 100 octane tune be ok using 110 octane gas or would a 110 octane tune be needed?

No. But for a different reason than you may be thinking.

Running higher octane than needed doesn't do anything except cost money for nothing. Running 110 octane on a 100 tune is like running 100 octane on a premium 93 tune. No gain. no harm. HOWEVER all 110 octane fuels contain lead. The lead drastically changes your effective AFR (air fuel ratio). So, if you want to run 110 leaded race fuel, you'll need a specific tune for it.

This also ignores the fact that the leaded fuel over time can hurt your cats.

So, the moral of the story is to have seperate tunes for the fuels you plan on running. For example I have the following 4 tunes on my flip chip:

93 pump gas tune
100 Octane race tune
110 Turbo Blue race tune
110 Turbo Blue race tune with NOS

The 93 tune is there for emergencies.
The 100 tune is my standard setting for street and strip
The turbo blue setting is for running at the track without nos
The turbo blue setting with nos is obviously for nos use.

The reason for all these tunes is to match the tune to the fuel being run.

[Logan]

Finally!!!! Sanity and reasonable conversations abound!!! Much better! Keep it up!

[MikesMerc]

How much is one full octane "notch" worth, in RWHP/RWTQ?

If I move up from a 93 octane "notch" to a 94 "notch", what should I expect in performance?

If I move up from a 94 "notch" to a 100 octane "notch", what should I expect?


I do not know this answer off the top of my head, but there are tuners that do have "rules of thumb" they follow. And it indeed goes something like "x degrees of timing for every octane point."

I again suggest you do some google searching and you'll find a ton of information of this.



How can a performance tune glean 55-70 RWHP from only 6-7 "notches" in octane? Can you, please, explain this?

Simple. The higher the octane the slower the fuel burns. Higher octane gas is harder to ignite. It resists detonation (being ignited before the spark plug fires).

As compression rises (as in high compression motors or forced induction set ups) it becomes prone for lower octane gas to detonate under the increased heat and compression. Tuners compensate for this by pulling timing out and/or richening up the AFR.

High octane gas is simply less prone to detonation. Accordingly you can run more timing and leaner AFR, which in turn produces a lot of extra power.

I don't think it can be explained any simpler than that.



How can I go faster with higher octane?

More power production from the motor = faster

[MikesMerc]

So, I have tried race gas on the race track and on the dyno, and I never found a solid, tangible improvement to my individual performance.

Mac,

I want to be very very careful on how I say this. So please do not be offended in any way.

That said, my only guess as to why you have seen no improvement in power numbers using race gas along with forced induction is that your tuner did not tune to take advantage of it. Simple as that.

Again, I ask you to pick up any issue of superford, or MM&FF, or just cruise the other internet forums and look at posts about using race gas with forced induction. You will see tons of information about the benefits. In fact, call Vortech or Procharger and ask them about the ability to run more aggressive tunes with race gas. Heck, some companies making kits based on the vortech units even offer off the shelf programs for race gas use when you buy the kit.

The physics of it all are very very simple. I doubt that there is a forced induction set up out there that would not benefit power wise from the use of race gas to due its ability to resist detonation in high heat and compression situations.

All that said, that doesn't mean race gas is for everyone. It takes a seperate tune for it. You also have to be willing to drain your tank and run it very low before fueling as "mixing" is a bad idea. Its one thing to run your 93 tune with some leftover 100 in the tank...no harm done. But it is a very bad thing to run your 100 tune if you left 93 in the tank before fueling with 100. So, practically speaking, its just not for everyone. But, if you want to make the commitment and have the discipline to be careful with whats in the tank, you can gain A LOT of power.

[MikesMerc]

No Race Gas experience here but I would like to know how you guys utilize the "100 octane tune" with less that 100 octane fuel?? Unless your tank is bone dry and you add 10 gallons of 100 octane....you ain't got 100 octane!! :rolleyes:

I had a 100 octane SCT tune on my 9100 and asked Dennis to remove it because I don't race and would rather have a tune I could use....plus I mentioned the above?? :o

Can you run a remote tank that has only Race Gas somehow with our cars or are you guys constantly flirting with disaster...DETONATION...with a 96 octane "Race Mixture"?? :coolman:

Just wondering how this Race Gas thing works?? :burnout:

Marauderjack :rasta:

Dave hit the nail on the head. It takes discipline to drain the tank and be sure of what you are running.

Some folks, like me and Deebar, run nothing but 100. This is a lot easier to deal with but isn't a problem expense wise as my car is no longer my daily driver (not to mention that the price difference between premium and 100 has shrank consideribly lately).

[MarauderMark]

So, the moral of the story is to have seperate tunes for the fuels you plan on running. .
I understand and thank you for the explaination..:up:
Only run 100 oct with the race tune that i have for it and nothing else..unless i wanna run the 98 with the 94 tune for safe measures.. :D

[Smokie]

Ok, my turn, just a couple of thoughts. Octane decreases the tendency of gasoline to self-ignite without a spark; as compression is increased.

Higher octane gasoline has less potential energy per unit of measure than lower octane gas. I do not question for a moment that by using a more agressive tune you increase power.

However do not allow the higher octane gas to give you a false sense of security. Look around you and compare which engines are blowing up.

The engines with a conservative tune on PUMP gas have a better record of safety than the agressive tune engines with RACE gas do.

Agressive tunes with race gas are not safer than conservative tunes on 93 octane pump gas.

Ok, let the arrows fly.:)

[MI2QWK4U]

Ok, my turn, just a couple of thoughts. Octane decreases the tendency of gasoline to self-ignite without a spark; as compression is increased.

Higher octane gasoline has less potential energy per unit of measure than lower octane gas. I do not question for a moment that by using a more agressive tune you increase power.

However do not allow the higher octane gas to give you a false sense of security. Look around you and compare which engines are blowing up.

The engines with a conservative tune on PUMP gas have a better record of safety than the agressive tune engines with RACE gas do.

Agressive tunes with race gas are not safer than conservative tunes on 93 octane pump gas.

Ok, let the arrows fly.:)

No arrows Smokie!
I do think that tuners that know better will argue that agressive tunes on race gas in a supercharged application are safer than you may think. Conservative tunes on a N/A car with 93 octane tunes are very save, however, on a supercharged Marauder on a 93 octane tune, the agressive 100 octane tune is safer. You could blow your motor if you get a bad tank of gas. This happened to me, on the way to Norwalk FFW last summer...thank God that Lidio TAUGHT me to recognize mild detonation, because it was spark knocking badly 1/2 mile from the gas station where I just bought supposedly 94 octane at a Sunoco station. I was running my 93 octane mild street tune, if I hadnt recognized the signs of detonation, and let it fully detonate, I would have blown the motor.

I have the highest RWHP/RWTorque supercharged Marauder with the stock block intact. Lidio insists that my tune is still safe if i use pure race gas, Lid has no reason to lie to me, he could tune the car any way he saw fit because I gave him the final say. Lidio is well known for being safe and conservative. Since I wont be adding NOS, I dont think I will have to worry about a new block for a while. Although we are working on a new mod that will make my setup even safer and add 35-55 RWHP and maybe 50 RWTorque. Stepping up to 560-575 at the wheels will be fun to say the least!

[Smokie]

No arrows Smokie!Dave I know there are no absolutes when it comes to "safe" tuning. I have a great deal of respect for Lidio's tuning ability, I also know that he would not tell you a lie.

I don't know how often you encounter "track" temps above 120 degrees (95*in the shade) but running 10 passes on days like that would sorely test the safety of any tune.

Dave I am sure you know that even master tuners sometimes have engines come apart at the track, you have a very powerful vehicle; my opinion is that you may riding on the edge of the envelope....this is a bit like weight lifting...no pain...no gain.

I wish the very best with your upcoming project. Javier.:)

[MikesMerc]

However do not allow the higher octane gas to give you a false sense of security. Look around you and compare which engines are blowing up.

The engines with a conservative tune on PUMP gas have a better record of safety than the agressive tune engines with RACE gas do.

Agressive tunes with race gas are not safer than conservative tunes on 93 octane pump gas.



Actually what we are doing here is mixing apples with oranges.

There are two main reasons why engines (short blocks) fail in boosted applications. One is that detonation destroys the motor. The other is that the motor is making more power than the block can handle. Both are VERY different reasons for the failure.

So the question is what is safer. A typical pump gas tune, or a more powerful race gas tune. Most tuners will tell you, that as long as overall power levels are kept at sane levels, the race gas tune making more power is safer. This is due to the protection from detonation with higher octane gas.

Of course, if a motor is tuned too aggressively, or you are making more power than the block can handle, no amount of race gas will save you.

Compare the engine failures accross the board, and you will find more failures from pump gas tunes that resulted in detonation under boost due to bad gas, and failures due to too much power being made, than any engines that burned down due to detonation with race gas.

The key, then, is to find the "sweet spot" where you can make more power with race gas without the fear of detonation, but limit the power to keep the block alive. Of course the safest thing to due is run race gas on a mild tune. But, that is overkill in the other direction.

I point to several long lived race gas tuned trilogy cars. Deebar, Jeff03, Dave, and myself just for starters. We all make good power and are keeping the motor alive. now, is Dave pushing the limits of the block...sure. That doesn't mean the race gas tune is not safe. It just means he has pushed his block to the limit power wise. Step that power down into 475rwhp range, and you have a very powerful yet reasonably safe tune.

Bottom line...more SC engines fail due to detonation problems more than anything else. So if you keep detonation at bay, you go a long way to keeping your SC motor intact....even if it means your getting more power. As long as the power level is sane, your actually safer then on pump gas which is notoriously varied in quality.

[MI2QWK4U]

Dave I know there are no absolutes when it comes to "safe" tuning. I have a great deal of respect for Lidio's tuning ability, I also know that he would not tell you a lie.

I don't know how often you encounter "track" temps above 120 degrees (95*in the shade) but running 10 passes on days like that would sorely test the safety of any tune.

Dave I am sure you know that even master tuners sometimes have engines come apart at the track, you have a very powerful vehicle; my opinion is that you may riding on the edge of the envelope....this is a bit like weight lifting...no pain...no gain.

I wish the very best with your upcoming project. Javier.:)


The only absolute is there are no absolutes! I have to put my trust in Lidios touch and feel for the car, it is uncanny to watch him work. I get lucky, when he feels something, he explains it to me so i know what he is talking about. I have seen engines come apart, thats life, speed costs. I may be on the edge, hopefully my chief engineer can hold her together like Scotty held the Enterprise's engines together. Cause I plan on pushing her even harder for the hell of it. Its fun..what can I say.

[Smokie]

I may be on the edge, hopefully my chief engineer can hold her together like Scotty held the Enterprise's engines together. Cause I plan on pushing her even harder for the hell of it. Its fun..what can I say.
Beats the hell out of staying at home don't it?!!!:D

[MI2QWK4U]

Beats the hell out of staying at home don't it?!!!:D

Yes Sir, I believe it does!

[CRUZTAKER]

No Race Gas experience here but I would like to know how you guys utilize the "100 octane tune" with less that 100 octane fuel?? Unless your tank is bone dry and you add 10 gallons of 100 octane....you ain't got 100 octane!! :rolleyes:

Some people commit to using 100 octane all the time. Others drain the tank, which is what I used to do. I was able to get all but a couple of ounces out, adding 5 or 6 gallons of race gas would easily dilute the 94 left over.
I too make it a point to run my tank to bone dry when I know I am off to the track. It's not always that easy. Particularly when I am out of my element, ie. racing at MV-III. At home, I know that if the 'Add Fuel' light comes on, I can go roughly 30 to 37 miles till the inevitable happens. If the light comes on when I reach downtown Cleveland from my house, I am good to go because it's 23 miles to the Speedway gas station. These are the things we learn when we use daily drivers as race cars on Friday nights. It's all planned out ahead of time. I know my fuel ranges well. Out of town it gets hairy...:P

As far as dilution of perhaps 2 gallons of 93...no problem. I always...I say ALWAYS...put atleast 2-3 gallons of 110 or better in the tank AT THE TRACK over the 100 mixture. Mainly to get the fuel tank to just over a quarter to avoid fuel starvation at the launch, add a little weight, and make sure the mix is indeed 100 or BETTER.;)

[MikesMerc]

I have seen engines come apart, thats life, speed costs.

No doubt. When you are pushing 500rwhp on the stock block, you are at the limits for sure. Even the safest tune cannot prevent the block from coming apart under those conditions if the motor is ready to let go. Those of us in the "upper" end fully realize this and accept the consequences.

But, like I said, there is indeed a large contingent of folks running safely in the 450 to 490 range doing great.

I'm not a betting man, but I would place my wager on the motor with the aggressive tune and race gas, over another with a milder tune and pump gas any day.

Sure, the bone stock program is fine and very safe for the stock SC kits. But when guys get into smaller pullies for more boost, it is much safer to go with race gas than run a softer pump gas tune.

[Lidio]

I’m sorry I’m getting in real late on this one guys... but for some to say that race fuel has no benefit is rather narrow minded thinking and not truly understanding what its capable of when taken advantage of.
Believe me 93 octane, if its even that most of the time, is not the end all for supercharged and non super charged applications in any way. I’m not gona get scientific about this cause I really don’t know all the science behind it all deep down, only what’s at hand for me and a lot of cars I’ve tuned.

N/A Marauders and many other cars for the most part don’t benefit from 100 unleaded or so because their just not volatile enough to take advantage of the increased octane. Even when you add some or lots of spark they just don’t respond to the race fuel cause its simply not justified in the combustion chamber at that level of power and compression. They do come to life a little but then reach a point of diminishing return.

Supercharged MM’s on the other hand Both roots type and centrifugal really can , and do come to life in a big way when switching to 100 unleaded and taking full advantage of it with the tune as well. When you take a 10.1 to 1 compression in our MM’s and then throw almost 10psi of Trilogy boost with a very efficient intercooler, this to some in the past was a total no-no in terms of boost vs. compression. But with today’s computers and competent tuning skills, we can manage spark and fuel like never before and combine a fair amount of boost with not so low of compression and make them run very good, and live long healthy lives very clear and free of detonation. But because of the fact that its fairly high compression with not so low of boost like 5-7psi… when you induce race fuel like 100 unleaded and do like I do and add as much as additional 5-7 degrees more spark at WOT….. now your talking!!
MM’s with Trilogy’s especially the ones that have a smaller then stock pulley and some sort of a better air-box and even some exhaust work… these baby’s can, do and will make as much as 40-60 more at the rear wheels easily, with no smoke and mirrors other then I also lean them out a bit with the race fuels by about a couple of percent, because you can.

Race fuels exist for a reason and they do work in the right application, and can be waist of money for some folks indeed.
Another thing is that when a guy pumps in some thing like the popular “Turbo Blue” that’s a leaded 110 octane race fuel. This stuff is so heavy that not only do you need to add even more spark then you normally would with 100 unleaded but I’ve found over the years on EFI cars that it will make the A/F on some application as much as 10-15% richer with out any other changes. So the tune really needs to be watched at first with this stuff to take advantage of it.

I don’t know how this could potentially be a Michigan vs. who ever again thread but I’ll throw in a dig any way once again against the centrifugal guys…
Like I always argue aside from not tuning correctly for the 100 unleaded, the centrifugal guys have less to gain on race fuel then the roots guys… think about it, they compress air for a shorter period of time, or don’t start to compress the air as early and as broad as the roots guys do. Plus if you’ve lowered your compression down from 10.1 to 1 to what ever other then stock, and the lack of boost down low in the revs, your really wont benefit from race fuel at least below 3500-4000rpms. So technically the Roots cars make better use of it over a longer rpm range.

Also if you tune aggressively, your not safe with any fuels at all depending on the application. You can burn down the best of them when your tune lean, and to much spark pretty much any engine.
Although in my circle you are much safer making more power with race fuels then less power with pump 93 octane fuels. I have countless 4.6L’s with stock non-forged bottom ends out side of the Marauder scene locally here that are making obscene power, RWHP numbers and very fast ¼ mile times with blowers, race fuel and are lasting much longer then they would have taking their chances with less reliable pump fuels and much, much less horsepower. The more of these blower 4.6L I do with stock non forged pistons, the more I learn that these pistons and even the rods don’t mind making some pretty big power for a long time. But the second you detonate them a little to hard and to long its all over.


As I always say “Its in the tune” and that statement is not limited to just spark and A/F, it includes octane as well.


Thanks

[BillyGman]

Higher octane gasoline has less potential energy per unit of measure than lower octane gas. .:)I've never heard that. I didn't think that it has less energy, but just that it's a bit harder to ignite than the lower octane is. As far as I know, once it IS ignited, it has just as much energy potential as the lower octane gas does. I believe that the only thing different with the high octane unleaded gas is that it takes more heat for ignition, but once ignition does occur, it yields the same amount of energy. BTW, thanks to Lidio for weighing in on this. ;)

[MI2QWK4U]

I’m sorry I’m getting in real late on this one guys... but for some to say that race fuel has no benefit is rather narrow minded thinking and not truly understanding what its capable of when taken advantage of.
Believe me 93 octane, if its even that most of the time, is not the end all for supercharged and non super charged applications in any way. I’m not gona get scientific about this cause I really don’t know all the science behind it all deep down, only what’s at hand for me and a lot of cars I’ve tuned.

N/A Marauders and many other cars for the most part don’t benefit from 100 unleaded or so because their just not volatile enough to take advantage of the increased octane. Even when you add some or lots of spark they just don’t respond to the race fuel cause its simply not justified in the combustion chamber at that level of power and compression. They do come to life a little but then reach a point of diminishing return.

Supercharged MM’s on the other hand Both roots type and centrifugal really can , and do come to life in a big way when switching to 100 unleaded and taking full advantage of it with the tune as well. When you take a 10.1 to 1 compression in our MM’s and then throw almost 10psi of Trilogy boost with a very efficient intercooler, this to some in the past was a total no-no in terms of boost vs. compression. But with today’s computers and competent tuning skills, we can manage spark and fuel like never before and combine a fair amount of boost with not so low of compression and make them run very good, and live long healthy lives very clear and free of detonation. But because of the fact that its fairly high compression with not so low of boost like 5-7psi… when you induce race fuel like 100 unleaded and do like I do and add as much as additional 5-7 degrees more spark at WOT….. now your talking!!
MM’s with Trilogy’s especially the ones that have a smaller then stock pulley and some sort of a better air-box and even some exhaust work… these baby’s can, do and will make as much as 40-60 more at the rear wheels easily, with no smoke and mirrors other then I also lean them out a bit with the race fuels by about a couple of percent, because you can.

Race fuels exist for a reason and they do work in the right application, and can be waist of money for some folks indeed.
Another thing is that when a guy pumps in some thing like the popular “Turbo Blue” that’s a leaded 110 octane race fuel. This stuff is so heavy that not only do you need to add even more spark then you normally would with 100 unleaded but I’ve found over the years on EFI cars that it will make the A/F on some application as much as 10-15% richer with out any other changes. So the tune really needs to be watched at first with this stuff to take advantage of it.

I don’t know how this could potentially be a Michigan vs. who ever again thread but I’ll throw in a dig any way once again against the centrifugal guys…
Like I always argue aside from not tuning correctly for the 100 unleaded, the centrifugal guys have less to gain on race fuel then the roots guys… think about it, they compress air for a shorter period of time, or don’t start to compress the air as early and as broad as the roots guys do. Plus if you’ve lowered your compression down from 10.1 to 1 to what ever other then stock, and the lack of boost down low in the revs, your really wont benefit from race fuel at least below 3500-4000rpms. So technically the Roots cars make better use of it over a longer rpm range.

Also if you tune aggressively, your not safe with any fuels at all depending on the application. You can burn down the best of them when your tune lean, and to much spark pretty much any engine.
Although in my circle you are much safer making more power with race fuels then less power with pump 93 octane fuels. I have countless 4.6L’s with stock non-forged bottom ends out side of the Marauder scene locally here that are making obscene power, RWHP numbers and very fast ¼ mile times with blowers, race fuel and are lasting much longer then they would have taking their chances with less reliable pump fuels and much, much less horsepower. The more of these blower 4.6L I do with stock non forged pistons, the more I learn that these pistons and even the rods don’t mind making some pretty big power for a long time. But the second you detonate them a little to hard and to long its all over.


As I always say “Its in the tune” and that statement is not limited to just spark and A/F, it includes octane as well.


Thanks

Thank God Lidio got in on this thread. A lot of what I was trying to explain is exactly what Lidio stated here. No Kool-Aid here folks, and Lid is as sober as I am!