Safe RPM for rev limiter???

[BillyGman]

I'm looking for some educated opinions about exactly what is the highest RPM that would still be safe to have the rev limiter set at in our Marauders.
The reason for my question is simply that once in awhile when I get a little crazy behind the wheel, and I decide to make a spectacle by leaving rubber from a dead punch, my MM spins the tires right up to 6200RPM's in first gear and I hear the engine breaking up indicating that it's getting into the rev limiter just before it hits second gear.

So I was considering having the chip re-burned in order to reset the rev limiter to 6500 RPM. But I'm wondering if that would be high enough to avoid getting into the rev limiter while doing a burnout. So I've been thinking about having it set to 6800 RPM instead. However I'm not sure if 6800 RPM would be safe. I'm wondering if anything over 6500 would open up the possibility of valve float.

[Fourth Horseman]

:eek: Yikes! I'll be the first to admit that I'm a big sissy, but I turned my motor to 6000 once and swore I'd never do it again. Even when goofing off I keep my RPMs to the low 5000s. You're a braver man than I am. :)

[BillyGman]

:eek: Yikes! I'll be the first to admit that I'm a big sissy, but I turned my motor to 6000 once and swore I'd never do it again. Even when goofing off I keep my RPMs to the low 5000s. You're a braver man than I am. :)

Well thanks for your honesty. I've had my 73 Vette for 6 years, and over those 6 years, I've done countless 6000RPM burnouts. The engine now has well over 100k on it, and I've never done any engine damage to it driving it hard like that. I recently blew my clutch doing that, but because it also had over 100k on it, then it had seen it's better days anyway.

This isn't something that I do every day,or even every week, but when I do show off w/my car, I don't want it to be limited because it's getting into the rev limiter.

Anyone else on the rev limiter question?

[Fourth Horseman]

Wasn't trying to say you're doing anything wrong. :) I just don't have the cajones for the high-RPM stuff. If it wasn't my daily driver that I depend on I'd probably feel differently.

[BillyGman]

Wasn't trying to say you're doing anything wrong. :) I just don't have the cajones for the high-RPM stuff. If it wasn't my daily driver that I depend on I'd probably feel differently.

It's all cool FH. I wasn't offended at all by your comments. I understand and respect your viewpoint on that. As for me, my Marauder is my daily driver too. But if I didn't want to use ALL of the power this car has to offer, then i would've just purchased the Black crown Vic that I test drove just before I purchased this car. And if you look at the list of the modifications I've made to this car, then maybe you can see where I'm coming from.

my viewpoint is that I wouldn't have bothered spending $800 for an aftermarket Torque converter, $1600 for Headers, and aftermarket exhaust system, and another couple hundred for 4.56 ratio rear end gears, if I simply wanted to drive my MM mellow.

That isn't to say that your viewpoint is neccessarily wrong. It's just that some of us are more performance oriented than others. That's all. Thanks for your opinion. Nuthin wrong w/sharing. ;)

[Fourth Horseman]

my viewpoint is that I wouldn't have bothered spending $800 for an aftermarket Torque converter, $1600 for Headers, and aftermarket exhaust system, and another couple hundred for 4.56 ratio rear end gears, if I simply wanted to drive my MM mellow.

All good points. I'll probably romp on it more once I get out of warranty and start to mod my power train. I now return your thread to it's intended subject matter. :P

[BillyGman]

All good points. I'll probably romp on it more once I get out of warranty and start to mod my power train. I now return your thread to it's intended subject matter. :P

LOL.........

[cyclone03]

Billy,
You,like I,have removed the reason for the 6200rpm rev limit,the Torque Converter.Our new ones are now good to 9500rpm(!).
The Mach 1's with stick shifts are limited to 7200rpm but they have steel cranks too(Cobra).
Being the top end is the same as the 5spd Machs I dont think the valve train is the limit.
I too would like to raise the rev limit in the search for improved ET's,I know slightly less vain than your reason,but thats just me.I think with our exhaust there is power to be had above 6000rpm,and improved ET.

I don't know if the best way to find the best upper limit is at the track or on the dyno.
I also don't know when the crank and rods will come flying out either,but my GUESS would be about 7500rpm.
So I'd go with 6800 to be safe and shift at what ever gives the best ET.

[BillyGman]

Yep, I'll admit that my reason is more vain like you said. Those are some interesting viewpoints you've shared about the mach I. What 'm interested in doing is to raise the rev limiter w/out raising the shift points. I'm pretty sure that can be done. I'm happy w/my ET's(atleast until marty beats them!), so the shift points I have no are fine. I just don't like hitting the rev limiter in first gear during a dead punch burnout. (call me Mr. Vanity....LOL).

[prchrman]

Billy if you have done a dyno...and see where you quit making power this might be a good rpm to set your limiter at because that is where the motor is starting to strain...my dad a master machanic always said it was not USUAL high reving that got motors and such but sudden jerks (like we all did in our younger days, neutral drops, reverse to forward or vice versa) is what kills motors, drive train and such...willie

[merc406]

I don't think you have to worry about valve float with OHC motors, and they are capable of higher RPM's in general.

[RF Overlord]

Gman:

I'm with Fourth on this one...I rarely run mine up that tight, but I understand your question...I think Dennis or Lidio would be the ones to answer it, though...

Would raising the rev limiter really buy you that much? I'd have to see a hp/torque curve...perhaps it falls off rapidly at much above 6200...

The other question is: will the lower end handle the increased revs? Remember, this motor has powdered-metal rods...

I know this isn't much help...just thinking out loud...

[FordNut]

Billy,
Good question and something I've been thinking about too. After I get the headers installed I may have the rev limiter set to 6500. I would like to do some experimenting with my chip's shift points too. If only I could setup 3 different programs. Maybe a flash on the PCM plus my delta chip with two different programs! Then one program to shift at 5800, another at 6000, and another at 6200. If the best times are at one of the end settings, I would try again at a 200 rpm change. I believe the shift points should be slightly higher than the peak power RPM so you don't drop off too many RPMs below the peak. But I don't know that anybody has done the dyno test at very high RPM (like 7000 or so) with the headers.

[Zack]

My rev limiter is set at 6500 with a S/C.
No problems yet.

And the Mach 1 crank is not steel, its cast and has a 7200rpm rev limit.
A good tune save you from a lot of potential problems.

[SergntMac]

BillyG...What are you trying to accomplish here? Looking for a better launch? Or, putting on a smoke show?

You can perform an impressive smoke show easy enough by locking the tranny in 1st gear, brake torque until the rear tires break loose, and ride on up to 4K RPM holding the brakes. You'll smoke 'em just fine right there, my friend, and not move too far forward while doing it. This is exactly how we clean and warm up our tires/slicks at the track, just before runnig a quarter mile race. Folks watching you will be coughing up rubber for hours, anyone passing by will want to dial 911...LOL! If this is your quest, Billy, go for it!

BTW y'all, I have 3 sets of Pirelli tires just waiting for this honorable epitath. Free too, but I need 40 bucks each tire for shipping anywhere in North America. Write to me at SergntMac@aol.com if your looking to put on a show.

[Krytin]

I had a 302 cu in w/ the 4V(enturi) heads in my '68 Cougar that I would rev to 6500 in first and second gear (60 mph in first gear - 0 to 60 5 sec flat high 12's 1/4 mi). I rev my stock 300 A up to 6000 - 6200 where the auto shifts itself to second. I don't do it every day but enough. 23 k mi and no problems yet (did it the first week driving out of the dealer's lot with the salesman in the car). Raising the rev limit up to 6300 or 6500 sounds like it shoould be ok.

[BillyGman]

Okay people. Thanks to everyone for your replies. Zack, that's some good info there. In light of what you've stated, I guess I atleast should be okay going to 6500RPM.

MAC, believe me, I've smoked up the tires a number of times in first and second gear at the track and on the street using the brake pedal. But you see, my car can also smoke them a bit w/out using the brake at all. Almost anyone can smoke the tires using the brake pedal as long as they have a hi-perf V8 engine under the hood. But I think it's even more impressive if you can do so w/out using the brakes. And that's what I want. My car can leave a 40-70ft. strip of rubber w/out the brake pedal being used depending on the road surface being level, or a hill. But I'm sure I can leave even more rubber from a dead punch if the rev limiter didn't kick in during first gear, because when that happens, it throws the RPM downward right as it's hitting second gear. So if I could avoid hitting that rev limiter while remaining at WOT in first, then the tires would have better momentum when the transmission hits second, and the revs would stay up better during second gear. And first gear will not get the tires spinning fast enough to really smoke em good. You need second gear for that.

From a dead punch my car can keep em spinning a little bit into second gear, but not long enough to really smoke em good. But I think it's only because of the engine's power being choked a bit in first gear due to the rev limiter. That's all I'm getting at here. I'm not really interested in raising the shift points at all because I like where there at right now. The car moves great. I just want to move up that rev limiter a few hundred RPM's. I guess I'll just try increasing it another 300 RPM to 6500, and see how that works.

I cannot look to my Dyno charts for additional power above 6100 RPM, because the test ended there because of the rev limiter kicking in and causing the power to drop way off.

[SergntMac]

Well then Billy, let me back out of here with my opinion. I read what you have posted here several times, and I still do not grasp what it is you are seeking. Carry on, someone with the right answer must be right around the corner, I'm sure.

[Petrograde]

My Rev Limit is set at 6500 rpm with my SCMT. I found this out yesterday on a utility road behind the airport where I work. :burnout: I was suprised it was set that high. In fact, I was so suprised I nearly forgot I was running against a Lightning! :nono: Oh well,... I knew I wouldn't win that one. But, it was fun,... and fairly close. :up:

Tom

[cyclone03]

The problem your having Billy is the RPM is climbing,(with the tires in flames)faster than normal.Remember the CPU calculates when to shift based on known programing.Same thing would happen with a gear change,the CPU says shift here so the rpm doesn't climb too high,but the egngine is revving so fast it bangs the limiter.

The cure may be 2 fold.
1. raise the limiter to,say 6800rpm.
2.lower the shift point 100-200 rpm to give more time for the shift.
I would just get the rev limiter out of the way myself.

The "trick" to setting shift points is the AFTER shift rpm,you want the after shift rpm to hit right at or a few rpm above the TORQUE peak.My guess is that number is in the 4000rpm range,3800 on my car is too low,I get a slight hesitation right after the 1-2 shift.

Just pull the shifter into "1"and burn baby burn those tires!!!! :banana2:

[BillyGman]

Petro, thanks for that info because that's another confirmation for me that it's safe to set the rev limiter to atleast 6500 RPM. I thought about going with the Superchips tuner so that I can play around w/shift points and w/the rev limiter too w/out having to send my computer chip back to be re-burned every time i wanted to make a change. But the SCT isn't an option for me since that product doesn't allow for speedo corrections for 4.56 gears.

Cyclone, it sounds to me like you understand what I'm getting at here. The reason I want to spin the tires better in second gear is because first gear doesn't really spin them fast enough to cook em up really good. I need second gear for that. The highest reading on my speedometer that I obtain while spinning the tires in first gear is only 40 MPH, and that's at redline. That's because of the 4.56 gears. And that's just not quite fast enough to smoke em up really good. They smoke a little at that speed, but it isn't a big white cloud. W/the 4.56's the car is able to break them loose better, but because of the top speed limitation that the 4.56 ratio creates, I need second gear to get that speedo up to 80 MPH which is what is needed to really smoke em good. But because the rev limiter is being hit in first gear, it robs the momentum of the tires, and kills the power, so that the engine is only reving at about 3500 RPM while the tires are spinning in second gear, and that isn't enough RPM's to keep em spinning in second for any length of time. I believe that if the rev limiter was out of the way for the burnout during first gear, then the car would continue to heat up the tires real good in second gear just like it does in first.

[cyclone03]

Billy,I don't think even with the shift hitting at 8000rpm you'll have enough torque to keep the tires burnin in second on dry pavement :D
But if your are hitting the limiter,as you say,at the top of the 1-2 shift then moving the limit up to say 6700-7000 MAY help you.

The way mine revs to 6000 with stock gearing and the PI3000 I can see how your hitting the limit. :banana2:

[TripleTransAm]

I too think it's the "revving too quick for the transmission to shift in time" issue that's getting you to rev limiter too quickly. Just remember that the 4R70W can be manually shifted to 2nd. If you feel the tires will keep spinning in 2nd, just manually shift to 2 before the engine revs too high.

[BillyGman]

I too think it's the "revving too quick for the transmission to shift in time" issue that's getting you to rev limiter too quickly. just manually shift to 2 before the engine revs too high.

Yep, I understand your point completely, and that's precisely why I've already tried shifting it manualy back in December. However it still will not shift into second before it hits the rev limiter in first. Even if you push the gear selector into second gear as soon as the tires begin to break loose it still will take a second or two before it actually obeys the command. Maybe because you guys don't have the 4.56's in the rear it's difficult for you to get a good picture in your mind about how quickly my car gets up to redline while spinning the tires in first gear. I mean it happenes immediately. I'm talking within one second or less!!

And then when it hits the rev limiter, the RPM's begin to drop BEFORE it even hits second gear, so that when it shifts, it's catching the RPM's going downward BEFORE the shift even takes place. I don't know how else I can explain it. Yes, the tires still keep spinning in second gear, and sometimes it's even enough to still get the car a little sideways while in second gear, but it isn't able to turn the tires fast enough to really smoke em good. I've found that while performing burnouts at the dragstrip using the brake pedal, I have to get the tires spinning fast enough to have the speedometer reading at atleast 80 MPH to really provide a healthy thick white smoke show. But when I'm doing a burnout on the street from simply a dead punch, the car will not get the tires past the 40 or 50 MPH mark since the revs are too low in second, and w/my car I believe that it's merely due to the rev limiter killing the power. I guess the proof is in the putting, so I'll just have to try getting the chip re-burned to take the rev limiter up to 6500 RPM w/out raising the shift points.

Now even though my Vette is a manual shift car, I did learn something w/it that can apply here. I installed an MSD ignition in that car that came w/various plugs to set the rev limiter anywhere from 3000-8000 RPM in 300 RPM increments. When doing a burnout, and dumping the clutch in first gear, the engine would hit the rev limiter when it was set to 6000 RPM, and that would compromise the car's ability to perform a real healthy smoke show. So I then changed it to 6500 RPM, and it would still hit the rev limiter in first gear. So then I set it to 6800 RPM, and now it never hits it at all during a burnout, because when I keep it pegged in first gear w/the tires spinning, the car only has the power to spin the tires up to 6500 RPM's in first gear w/the camshaft I have in it. Therefore w/the limit set to 6800 RPM, it never hits it while doing a burnout, but would still provide rev limit protection to the engine in the event I missed a shift during a race, or if I was to blow a u-joint.

So if my 311 RWHP Vette that's about 1000 LBS lighter than the Marauder has the power to spin the tires in first gear up to 6500 RPM's and doesn't go any higher, then perhaps I can assume that the heavy behemoth Marauder doesn't have the power to spin the tires any faster than that in first gear either. But that might depend on where in the RPM band the power actually falls off at w/the stock camshafts. Perhaps nobody would really be able to answer these questions anyway, unless they themselves had a Marauder w/4.56's in the rear like I have.

But my original question was about how high would I safely be able to go w/the rev limiter, and I DO appreciate the response that I've received so far.

BTW, just for the record, I don't want anyone to think that I ever engaged in the practice of reving the engine in my Vette to 6000 RPM and then dumping the clutch all at once at that RPM, because that would likely result in some type of catastrophy somewhere in the drivetrain. What I do is rev it to about 4000-4500 RPM and then let go of the clutch pedal, which is plenty for getting those tires spinning, and then once I have the tires loose, I smash the gas padel to the floor which then brings the revs up to 6500 RPM in first gear(talk about smoke!). Then if i hit second gear, it's difficult to even keep the car on the road. I mean it gets sideways so much, that it isn't even a fishtail where the car swings like a pendulum to one side ot the other, but the whole car actually jumps sideways. If any of you guys ever had a Big Block w/a manual shift transmission in a car that was very light such as a Camaro, Firebird or Mustang, then perhaps you can relate to what I'm talking about.

[TAF]

Billy, Billy, Billy...my man!!!!

If you'd just go ahead and buy this...
http://www.magiccitymustangs.com/images/superbowl/FordGT_TheONE_FL.wmv (http://www.magiccitymustangs.com/images/superbowl/FordGT_TheONE_FL.wmv)
You wouldn't have to ask such silly questions...:nono:

I wanted to be sure you've seen this, my friend!!!:up:

[Petrograde]

Petro, thanks for that info because that's another confirmation for me that it's safe to set the rev limiter to atleast 6500 RPM..

ok today,.. leaving work again,.. same utility road, same Lightning... My RPMs topped out at 6100 when I hit 2nd. :confused: ..then 3rd gear,... at 6000 RPMs.. weird...

hmmm,.. I'm 99% sure I saw 6500 yesterday. I'll try it again tomorrow,.. since I have to work. :(

Tom

[Zack]

Billy, listen to this. Cyclone has some good info to listen to, but I feel that it only applies to having traction. I have been driving around with this S/C for 6,000 miles now and not once has the car shifted while spinning the tires. The cure you are looking for may not be attainable unless you convert the trans to a manual shifting valve body.
Believe me, I have had about 10-15 different computer programs to adjust shifting points and not one of them did NOT hit the limiter while spinning the tires. I know, its frustrating. Jerry W. also told me that its pretty much impossible to correct this.

[BillyGman]

Billy, Billy, Billy...my man!!!!

If you'd just go ahead and buy this...
http://www.magiccitymustangs.com/images/superbowl/FordGT_TheONE_FL.wmv (http://www.magiccitymustangs.com/images/superbowl/FordGT_TheONE_FL.wmv)
You wouldn't have to ask such silly questions...:nono:

I wanted to be sure you've seen this, my friend!!!:up:

WOW!!!!!!!! TAF, you're killing me!!!!!! I just got to a point where I thought that obsession about putting a lean on the house to try and get one of those GT's was almost behind me (sort of), but now I'm hooked all over again!!!!!! You're killin me Dude!!!!!! Man do I LUV that car!!!!!!!!!! :bigcry:

[BillyGman]

Zack, I'm very surprised to hear that. But having a S/C'd Marauder, I guess you oughta know, because I'm sure your car can spin em all over the place. But I wonder if you would've found something different, if you were to adjust the rev limiter up higher to about 6800 RPM instead of moving the shift points.

[BillyGman]

AAAAARRRRGGGGGGG!!!!!! TAF has got me nuts over that GT video!! I can't stop watching it!!! Did you see that thing rounding the track???? Did you hear the GGGGGRRRRRowl of that V8 engine??????????? I'm gonna wind up back in the funny farm over that video, and it's all TAF's fault!!!!!!!!!

[BillyGman]

"The Pace Car for an entire company"!!!!!!!! AAHHHHHH!!!!!!!! I gotta have one!!!!

[teamrope]

I have herd from a recently retired Ford mecanic that the dual cam 4.6 is safe up to 8000 rpms. Personally I would check with some of the venders that are offering the superchargers. I would trust their input more than anybodys.

[BillyGman]

Hmmm, not bad idea. thanks.

[Smokie]

Billy, have you considered changing the transmission shift point to about 6000 rpms, that would allow you to shift without hitting the rev limiter. And I believe it would increase the life of your transmission, the engine can safely handle 6500 rpm's, not so sure about the transmission.

[BillyGman]

Wow, this an old threadyou've summoned up Smokie. When I stsrted this thread my car wasn't yet S/Ced, but now it is, and the rev limiter is now set to 6600 RPMs. My shift points are still around 6100 RPM's but none of that matters when I punch it down to lay rubber because w/the S/Cer and the gears that I have those tires spin so quick and the engine reaches the redline so quick that the transmission does NOT have any hope of hitting 2nd gear before the engine begins to bounce off the rev limiter, and I've been told by Lidio that there's just no way to prevent that. So I'll simply live w/it. it's no biggie really. I just don't like the sound of the exhaust note when the rev limiter kicks in.


It's only momentary though. but you can hear it for yourself in that Godzilla burnout video that I've posted. Here it is again incase you forgot about it....

http://www.mercurygallery.net/mmnet/images/video.gif (http://www.mercurygallery.net/mmnet/showphoto.php/photo/3375/password/ca66a98a00c09c4685fdcfb9de4612 57/sort/1/cat/500/page/1)

[FordNut]

At my last dyno tune mine was set to 6800 but the hp and tq curves were on such a rapid downhill slope by then that the limit was set back a little, to 6500.

[Smokie]

those tires spin so quick and the engine reaches the redline so quick that the transmission does NOT have any hope of hitting 2nd gear before the engine begins to bounce off the rev limiterYeah, that is one hell of a problem....too much power.:lol:


Like the song says: " Oh Lord, won't you buy me a....supercharged Marauder "

[BillyGman]

Lol...........

[studio460]

But the SCT isn't an option for me since that product doesn't allow for speedo corrections for 4.56 gears.BillyG:

Depends on which SCT "tuner" you're talking about. I guess the cheapest one, the SCT Extreme Flash Tuner, comes pre-programmed with up to three custom files and allows the user to modify a few parameters right on the tuner without the use of desktop software. Next up, would be the SCT 9100 programmable tuner only. You can buy the SCT 9100 tuner without software (not sure why you would want to) and let the vendor reprogram your tuner from time to time. The 9100 can do nothing but "store" and "burn" or "flash" files (depending on which version you buy). You can't directly modify ANYTHING if all you have is the SCT 9100 tuner and no software. The one I recommend is the priciest, of course, and at $795, the SCT Pro Racer tuner package includes the SCT 9100 tuner and the SCT Advantage programming software for Windows so that you can modify your own files and burn your own chip (or flash your own PCM with the EEC-flasher version). I guess, I just assumed you had the SCT tuning software. Although it's not too user friendly, you can change EVERYTHING, and I HIGHLY recommend the Pro Racer package over either the Extreme or the 9100 without software, despite its user-unfriendlyness. Here's my values under the scalars/axle table shown in the SCT Advantage software:

axle_ratio 3.550
axle_ratio_switch 0.000
tire_revs_per_mile 770.0000 [revs per mile of my new Nitto 255/45/18 rears taken from the Nitto website vs. the stock revs of 723]
traction_control_switch 55.0000

You just open this table up in the SCT software and type in your own values, in your case, changing axle_ratio 3.550 to axle_ratio 4.560 (and set the tire_revs_per_mile to 722 to match your 305/45/18 Nitto NT-555Rs, which I assume someone had already burned for you on your chip).

Your scalars/axle table for your car's set-up would then look like this:

axle_ratio 4.560
axle_ratio_switch 0.000
tire_revs_per_mile 722.0000
traction_control_switch 55.0000

Perhaps, it's also worth clarifying here the difference between SCT and Superchips. SCT is a different (though related) company from Superchips. The older Superchips 1725 tuner for 4.6L DOHC Ford engines is NOT programmable and NOT upgradeable. The 1725 allows the user to directly modify several parameters without software, but there were several firmware versions of the 1725, and the older ones did not have the gear ratio feature (and can't be upgraded). SCT was started by the famed Jerry W. and rebrands the Superchips-manufactured hardware to "SCT" (Superchips Custom Tuning). Both the SCT Extreme and SCT 9100-series tuners are completely different animals from the Superchips 1725 tuners, in that the SCT tuners CAN be "loaded" with varying tuning files, whereas, the 1725 tuners use non-writable firmware which CANNOT be upgraded at all (Superchips says you just have to buy a whole new tuner).

As far as the rev limiter thing goes, Jerry from SCT changed all my default rev limiters to 6,500 RPM (I think 6,200 RPM is stock) when he performed my dynotune. I routinely go through my gears up to a hair over 6,000 before hitting the limiter in my N/A Marauder. Again, I would HIGHLY recommend you upgrade to the SCT Pro Racer package which includes the programmable SCT 9100 tuner, the SCT Advantage software, and necessary cables. Again, the software is cryptic and difficult to understand, but at least you have ALL the control of EVERY parameter right on your desktop. I guess since you already have a chip you would go for the chip burner SCT package. Since I never had a chip and wanted to preserve my PCM intact, I got the EEC-flasher SCT tuner which works great.

By the way, I totally understand what you're trying to achieve with your rev limiter setting. I would suggest that you buy the SCT Pro Racer package and call someone at SCT directly and describe what you're trying to do. They will be able to talk you through your table values either over the phone or via e-mail.

Good luck, Billy! And keep those tires smokin'!

[CRUZTAKER]

Currently with the new 3000 T/C mine shifts 1-2 at 6500 and 2-3 at 5800.....

Opinions wanted: Should I bump the 2-3 shift higher now?

[FordNut]

Currently with the new 3000 T/C mine shifts 1-2 at 6500 and 2-3 at 5800.....

Opinions wanted: Should I bump the 2-3 shift higher now?
I would set them both to 6000-6100.

[TripleTransAm]

NBC shooter,
Great detailed explanation. If the reputation function of this board's s/w was working right now, I'd definitely throw you a big thumbs up for that description. :up:

[cyclone03]

Currently with the new 3000 T/C mine shifts 1-2 at 6500 and 2-3 at 5800.....

Opinions wanted: Should I bump the 2-3 shift higher now?


What is the after shift RPM on the 2-3?
If it falls below 4200 rpm I would say Yes.

[Fourth Horseman]

Just out of curiosity, does anybody know what DR has been setting for the rev limit on the programs he's loading onto the 9100? I haven't been rich enough to pony up for the full software suite for the tuner yet, or I'd check myself.

[BillyGman]

Shooter, i wouldn't mess around w/anything like timing curves nor air/fuel ratios since I have a S/ced engine, and those parameters are critical to the health and longevity of an engine that's S/Ced. Lidio burned the chip for me as he does for every Trilogy kit, and I'm not going to try and change anything that he did. I began this thread before I ever seriously considered S/Cing my car.


Furthermore your car cannot spin the tires like mine could even when my car was N/A unless you had the 4.56's in the rear and all the other mods that I have besides the S/Cer. So that's why you don't hit the rev limiter like my car does. my rev limiter is set at 6600 RPM's and it hits that RPM almost immediately in first gear while the tires are spinning. But this only happens during a burnout. Tye engine doesn't bounce off the rev limiter like that when the tires get traction.

[David Morton]

...I'm wondering if anything over 6500 would open up the possibility of valve float.The 427 SOHC (Cammer) was Fords answer to getting higher revs before valve float occured. I've read articles that stated 10,000 rpm was about as high as that setup could get, theoretically, because nobody could make a bottom-end for that engine that would hold up that high.

Float occurs when the mass of the valve train overcomes the spring that is holding it all together and the pieces separate, lifters leave the camshaft lobes, pushrods come off the rocker arms, etc. SOHC engines eliminate the pushrods, therefore the mass of the assembly is lowered by that much, not to mention the lighter followers (lifters) and I do believe our DOHC engine eliminates the rocker arms so more mass is eliminated. 4 valves per cylinder further eliminates mass by making the valves smaller. Properly set up 427's could hit 7500, the cammers, 10,000, so DOHC possibly 11,250(?) and then 32V's = 12,500(?)! I seriously wouldn't doubt it.

I imagine the engineers took advantage of this and used springs of a much lighter tension reducing the need for higher quality valves, springs, etcetera and reducing wear on the whole valvetrain.

I've been air-castleing with the idea of a super-high rpm engine based on this DOHC 32V design. This type of engine has been used on Formula 1 cars for quite a while, and if they can wind over 10,000 rpms for 500 miles I don't see what's holding this engine back from that. Perhaps a de-stroked billet steel crankshaft down to, say 3.25" or less and I think a good bottom end could be built for less than $3000 that could hit 10,000 rpms no problem.

The valvetrain could handle that easy.

Oh, man. NOW I'm not going to sleep. You guys! :lol:

[studio460]

Shooter, i wouldn't mess around w/anything like timing curves nor air/fuel ratios since I have a S/ced engine . . .No, I wouldn't touch ANY of those parameters on an S/C'd car either. I heard that Lidio was starting to use the SCT tuner software as well--I wouldn't trust anyone but Lidio to tune my Trilogy-equipped Marauder!


Furthermore your car cannot spin the tires like mine could even when my car was N/A unless you had the 4.56's in the rear and all the other mods that I have besides the S/Cer . . . Yeah, I know . . . I just meant that info as an FYI . . . In fact, my whole post was kind of an "open letter" FYI since there's been so much confusion over the SCT and Superchips tuners over the last year here. I know that your Marauder's significantly more modded than mine!!!

[studio460]

. . . I'd definitely throw you a big thumbs up for that description.Thanks, Triple-T!!! Coming from you, that's quite a compliment for all the hundreds of helpful, descriptive posts you've contributed to this board!

[Smokie]

In regards to the 1-2 shift with no traction, it has happened to me twice, however it was at the totally wrong time. My car shifts at 5900 rpms; which those that saw my ride along video can attest to. The car went from 1st to 2nd without moving ( except toward the wall ) and at the shift it continued to spin the tires with barely a forward motion and rpm's were headed toward 5900 again, and the wall toward me so I pulled out of the run, hit the brakes and ran about 16.5 at 95 mph.

The rev limiter never came into play, my guess is because the tranny had sufficient time to shift, when it happened it seemed to happen all in less than 3 seconds, so to me it seemed pretty fast. I am not trying to disprove any theories, just like to tell my story, it seems more funny now than it did at the time....:eek:

[BillyGman]

Thanks for everyone's input here. Like Shooter said, it will srve to inform all who read this. As far as my car, and the way it reacts during a burnout from a dead punch, even w/the drag radials in the back (if I have them inflated to 30 PSI) when I hammer down the gas pedal all at once in first gear from a stand still, it takes merely one full second if even that for the engine to hit redline. It's that quick. And that's why there's simply no way to avoid hitting the rev limiter before the transmission hits second gear. The Kenny brown cars are the same way. There was a video of the KB Marauder performing a burnout that someone provided a link to on here once, and I heard the engine bouncing off that rev limiter before it hit second gear. that's just the way it is. The KB Crown Vic didn't do that, but the KB Marauder did. And it's the same way w/my car, and it has been even before I s/ced it. It was like that as soon as I installed the 4.56's and the stallion w/the 3,000 RPM stall speed.