Race fuel question

[ultravorx]

Hey everyone, i was wondering what steps are needed to run the 100 race fuel in our marauders. I have the SCT with the race fuel program, and im going to the track next month, so i was wondering what steps i need to use the race fuel. Do i first reprogram the car, then dump in the race fuel.
Also, when do i return the car back to normal gas? when im done racing, or just when i do my next normal fill up.
Thanks in advance,
Frank

[woaface]

I've talked to some guys who have run 100 octane in their Mustangs on tracks. The one individual I've talked to at length about the 4.6 and racing fuel and all, said he hasn't had any gain with it. I've yet to hear of any gain from it either...

But I'm real jealous of your car either way:lol:

[SergntMac]

I'm not sure if the gain is there, but the extra safety against leaning out under severe conditions must be some benefit.

[TooManyFords]

Mac, I'm not sure that octane has anything to do with a "leaning out." Octane is a measurment of rate of burn and Lean is a measurment of air/fuel ratio. You can run AvGas and still run lean if you don't put enough in with the air.

Apples and Oranges.

John

[carfixer]

I have the SCT 9100 tuner from Dennis. He put the premium fuel and race gas programs in. I went to the track last month with almost no gas in the tank. It was so low, the low fuel light was on. I made about 8 passes which were all around 14.4 with a best of 14.29. I then put in 5 gallons of 100 octane unleaded race gas in and tuned in the race gas program. 4 passes later, I was still averageing in the 14.4's with a best around 14.41. Moral of the story, the $25 I spent on race gas was a waste of $$$$.

I imagine the race gas program has a more aggressive timing curve but it didn't help with my 1/4 mile times.

[jspradii]

I have the SCT 9100 tuner from Dennis. He put the premium fuel and race gas programs in. I went to the track last month with almost no gas in the tank. It was so low, the low fuel light was on. I made about 8 passes which were all around 14.4 with a best of 14.29. I then put in 5 gallons of 100 octane unleaded race gas in and tuned in the race gas program. 4 passes later, I was still averageing in the 14.4's with a best around 14.41. Moral of the story, the $25 I spent on race gas was a waste of $$$$.

I imagine the race gas program has a more aggressive timing curve but it didn't help with my 1/4 mile times.

If you're running a power adder (blower or nitrous), the higher octane will lower the chance of detonation, which of course is quite nasty to pistons and other rotating things. I run nitrous with mine, and for an all out application (150-300hp shot) I have to run V/P C-16 (116 octane) or equivalent in order to make sure detonation doesn't occur, even with up to a 10-12 degree timing retard. Higher octane fuel on an otherwise stock engine will not yield significant increases in anything except the price you pay for gas. :banana2:

[sailsmen]

Race Gas is mfg to a higher quality and consistancy. If you consistantly use race fuel you will have more consistant runs.

[SergntMac]

Mac, I'm not sure that octane has anything to do with a "leaning out." Octane is a measurment of rate of burn and Lean is a measurment of air/fuel ratio. You can run AvGas and still run lean if you don't put enough in with the air. Apples and Oranges. John
As the first to step up and into this discussion, John, alphabetically speaking, I'm the apple. No problem, I offered what I knew. Race gas may be in my very new and very near future, John, and not for performance. Maybe as a safety blankie...?

If you're running a power adder (blower or nitrous), the higher octane will lower the chance of detonation, which of course is quite nasty to pistons and other rotating things. I run nitrous with mine, and for an all out application (150-300hp shot) I have to run V/P C-16 (116 octane) or equivalent in order to make sure detonation doesn't occur, even with up to a 10-12 degree timing retard. Higher octane fuel on an otherwise stock engine will not yield significant increases in anything except the price you pay for gas.
Well, John, you're the "orange" here, right?

Ummm...I believe a few more questions on this race gas topic will be posted, so, I'm going to acknowledge my senior. That a more experienced and knowledgeable voice is present among us, now that you have joined us, John. A voice more willing (and quick) to guide us all towards more correct 411 than I alone can offer here.

Please, before y'all post, know your flavors, K?

[Effster]

Vp makes a 100 octane unleaded.its available in 5 gallon containers.100 is more than enough octane to drag race it

[BillyGman]

I would contact the place where you bought this Tuner that came w/the so called race fuel program in it, to ask them exactly why this was included in it, and what it's intended for. Otherwise, generally speaking, if your car only requires 92 or 93 octane, and it runs fine on pump gas, then going to 100 octane will usually do absolutely nothing other than drain your wallet.

But I won't pretend to know why the tuner comes w/a race program in it in the first place. Either that's simply a gimmick, or there has been some extreme ignition timing advance programmed in that file specifically for a certain octane. But even if the latter is the case, you'll still need to contact the people it was purchased from.

[TooManyFords]

That a more experienced and knowledgeable voice is present among us, now that you have joined us, John. A voice more willing (and quick) to guide us all towards more correct 411 than I alone can offer here.

I'm honored, Mac. I couldn't have typed it any better! :D

John

[SergntMac]

I'm honored, Mac. I couldn't have typed it any better! John
Don't underestimate yourself, John, you would. Now, how about answering the man's question...

Hey everyone, i was wondering what steps are needed to run the 100 race fuel in our marauders. I have the SCT with the race fuel program, and im going to the track next month, so i was wondering what steps i need to use the race fuel. Do i first reprogram the car, then dump in the race fuel. Also, when do i return the car back to normal gas? when im done racing, or just when i do my next normal fill up.
Thanks in advance, Frank

[TooManyFords]

Don't underestimate yourself, John, you would. Now, how about answering the man's question...

I'd love to Mac, but I didn't write the race fuel program for the SCT tuner so I don't know how it is setup. But, I have a good idea so I'll try to take this slow for ya, Mac...

The higher the octane means the fuel burns SLOWER to prevent things like detonation, pre-ignition, knock and ping. I can only -assume- that the 100 octane program in the tuner uses an advanced ignition timing curve that requires the fuel to burn slower to prevent the above conditions.

Since a tuner cannot change the compression ratio (another big reason to use higher octane), here's what I recommend:

1. Put the 100 octane gas in at least one full tank BEFORE switching to the new racing program. You should make sure that all the pre-100 octane gas is gone or you run the risk of deadly detonation and ping. Remember, your tank holds a gallon or two even when the "your empty" light is lit.

2. Switch to the new program.

3. Immediately switch back to the original program after racing and BEFORE the 100 octane is gone.


John

[TripleTransAm]

Isn't the big problem with running lean the fact that there is a greater chance of pre-ignition? (ie. mixture heated excessively because of lacking of cooling fuel in the mixture?)

So, wouldn't the higher octane serve to deliver (as Mac said) a safety blanket for such a scenario? My GTA has a high-RPM pinging problem... either it's a fuel pump weakness (very likely, will address this in my new house next winter) or a bad injector/regulator... and I can mask the symptom by feeding it 94 octane. Bad 92 octane is enough to make it ping in the above-mentioned scenario.

[Smokie]

Ultra, your question on the how to, has been covered with good advise.

I have observed this program and fuel used at the track, it did not make the car faster. It is quite an expensive experiment to fill your tank with 100 octane, but if you do, please let us know how much faster it made your car, best wishes.:burnout:

[SergntMac]

Okay...While I am pursuing this in another thread, I thought I'd stop back here with some notes from a pro.

Mike Lopez is a professional drag racer/builder, some of you here have been to his shop, High Speed Performance, for our local dyno tunes. I put the questions to him, and he thinks that mixing a 50/50 solution for the drag strip is a good way to go. Mike sells 100 octane race gas for 5 bucks a gallon, because he has to pay more for it in 5000 gallon lots. But, he thinks it can be had cheaper from larger vendors, like Speedway or Sunoco.

If you start out with a 1/4 tank of 93 pump gas, and add a 1/4 tank of 100 octane, you'll have a 1/2 tank of 96-97 gas on board. Mike says it won't "directly" enhance performance, like make a difference you can detect, but it will work to prevent detonation, the results of which are pulled timing and reduced spark, therefore less performance without it.

In this round about way, this mixed gas allows you to see your best performance from your MM, and that makes sense to me. Mike added that even on a bone stock MM shouldn't have to be retuned for this occassional bonus in octane, however, he added that if you're going to race like this with any frequency or regularity, getting you MM tuned for this mix is beneficial.

BTW, IMHO, I would not suggest anyone race with less that a half tank of gas in the MM. It's been shown that the fuel supply system drops pressure in the higher RPMs, which will also cause pulled timing, but not pulled spark. Much more lethal to the engine than just detonation, or, so I have been told by the pros, and the MM specialists both. As usual, just my .02C...

[BillyGman]

perhaps the next best thing to buying race gas simply to ensure that you're not getting a lesser octane than advertised, would be to always top-off your tank w/93 octane gas as soon as it gets to the halfway mark, and alternate between two or three gas stations every time you fill it. That way, even if one of the stations that you get gas at sneaks in some 87 octane gasoline in their 93 octane tanks, the worst that will happen is that you have half a tank of the 87 octane rather than a full tank. And ofcourse having a half tank of 93 octane, combined w/half a tank of 87, would yield about 90 octane.