Engine RPM hovers at Torque Peak
Thread Starter
TECH Enthusiast
Joined: Nov 2001
Posts: 585
Likes: 0
From: Green Oak, MI
Engine RPM hovers at Torque Peak I posted on here before about possible clutch slipping, well after some more work I doubt that is the problem now.
Every once and a while I'd feel the car do this. Right around torque peak the engine RPM would stop moving and you'd feel the car maintain a constent speed, then it would pull up through redline.
This happens around 4500-5000rpm or so. A buddy of mine took it to the track on Friday.
Last year on a good day at 14.5 lbs of boost it went 127mph, but it averaged 125 on a warmer day. Friday was humid and the car was running 12lbs of boost, we turned it down until the new actuators came in.
At a race weight of nearly 4000lbs it went 11.30 @ 124.8mph. The driver is 60-70 lbs heavier than me and we're at 2.5 lbs less boost and still went 124, this was after LS1 Edit so the tuning helped.
He granny shifted the car, 1.77 60'.
He said no problems launching, no clutch slip. I picked up the car and drove it, when its not really warmed up it pulls all the way to redline without missing a beat, but after a while it will pause at that RPM range. If it was tire or clutch slip the RPM's would increase.
Doesn't do it all the time, but some of the time. Just changed the plugs and all that, had it retuned.
.2 knock is the highest I've ever gotten, not dependant on the weather...
Can't figuire it out, car pulls nice and strong except for that little hiccup.
Any idea's at all?
Every once and a while I'd feel the car do this. Right around torque peak the engine RPM would stop moving and you'd feel the car maintain a constent speed, then it would pull up through redline.
This happens around 4500-5000rpm or so. A buddy of mine took it to the track on Friday.
Last year on a good day at 14.5 lbs of boost it went 127mph, but it averaged 125 on a warmer day. Friday was humid and the car was running 12lbs of boost, we turned it down until the new actuators came in.
At a race weight of nearly 4000lbs it went 11.30 @ 124.8mph. The driver is 60-70 lbs heavier than me and we're at 2.5 lbs less boost and still went 124, this was after LS1 Edit so the tuning helped.
He granny shifted the car, 1.77 60'.
He said no problems launching, no clutch slip. I picked up the car and drove it, when its not really warmed up it pulls all the way to redline without missing a beat, but after a while it will pause at that RPM range. If it was tire or clutch slip the RPM's would increase.
Doesn't do it all the time, but some of the time. Just changed the plugs and all that, had it retuned.
.2 knock is the highest I've ever gotten, not dependant on the weather...
Can't figuire it out, car pulls nice and strong except for that little hiccup.
Any idea's at all?
On The Tree
Joined: May 2002
Posts: 191
Likes: 0
From: Phoenix, Az
Re: Engine RPM hovers at Torque Peak This may be a long shot, but it you are not intercooled, you may be out of the turbo map. By decreasing the boost, you are not heating up the air charge as much. When the car is warmed up, you will make more boost, but also hotter air temperature going to the motor. Just a thought.
I've heard of several guy going slower with higher boost pressure.
I've heard of several guy going slower with higher boost pressure.
