High HP guys... Rev limiter?

[sir-blah]

Have any of you guys with higher HP, or maybe not, hit the rev limiter before your tach hit high RPMs? Here is what happened to me.
I was rolling in first gear at only about 10 mph. I punched it and accelerated* like a bat outa hell. Very(very) soon it felt like I hit the rev limiter but the RPM's were at only about 4-4.5. It scared the crap out of me at first I got on the clutch and rolled for a sec and noticed that I was at about 40-45 or so. I took it up slow in first to red line and had the same thing happen. I tried hard again with the same results.

I am guessing it was wheel spin that got RPMs up faster than the gauge could keep up with because after spinning the tires on purpose a couple of times it didn't do it but accelerated faster*.

* Acceleration statement based on feel of acceleration, no actual speed devices except speedometer were used... (E.G. No cops present during tests. Thank god ;-) )

 

[fatcobra]

what fuel mods do you have done on your car? it could be that you are overrunning your injectors and just aren't supplying enough fuel so you get a cut. 500+ hp is alot of power, sounds like you got one mean stang.

 

[Shadowgray03]

Fouled plugs(even 1 or 2) will cause the car to fall on its face at higher RPM.

 

[sir-blah]

Originally posted by Shadowgray03
Fouled plugs(even 1 or 2) will cause the car to fall on its face at higher RPM.

The thing is, it has no problem in say, second gear at any RPM. Floored it all the way to red line in second from about 2000 RPMs with no problem.

No fuel mods until next week, getting 55 lb injectors and a pump amp. I have a good a/f on this tune, it is actually pretty conservative.

Also, EGT, Fuel pressure, and air/fuel gauges all looked fine.

EDIT: Plus I only have about 1000 miles on these plugs.

 

[Shadowgray03]

Originally posted by sir-blah
The thing is, it has no problem in say, second gear at any RPM. Floored it all the way to red line in second from about 2000 RPMs with no problem.

No fuel mods until next week, getting 55 lb injectors and a pump amp. I have a good a/f on this tune, it is actually pretty conservative.

Also, EGT, Fuel pressure, and air/fuel gauges all looked fine.

EDIT: Plus I only have about 1000 miles on these plugs.

There could be corrupt data in the tune where it references load etc and in the lower gears where load is real light the tables could be messed up.

As for how many miles you have on your plugs, its irrelevent. You can foul a plug in a few miles.

 

[Vrrooom]

It is possible if it revs too fast that the tach cannot keep up to what the true RPM is. However, I've never had this problem in a Mustang. I have however, seen it in an Fbody many times.

Punched it in a friends Camaro and the wheels spun and it hit the rev limiter a couple times, but I was looking at the tach the whole time. And when it started to bounce, it was only at 4k rpm. After I let off the gas, the RPMs still climbed til the rev limiter (6k) and then dropped back down. You could definitely see the lag.

 

[Shadowgray03]

Ok, maybe this is too simple an explanation but sometimes the simple things get overlooked. If its only happening in 1st gear, it could be your traction control kicking in if you dont have it turned off or disabled in your tune.

 

[Boosted 03]

Originally posted by Shadowgray03
Ok, maybe this is too simple an explanation but sometimes the simple things get overlooked. If its only happening in 1st gear, it could be your traction control kicking in if you dont have it turned off or disabled in your tune.

I was thinking the same thing, but I assumed you would have thought of this. Could be in the tune, or MAF Reacing it's limit. With such fast acceleration in first gear it's hard to guess.:shrug: