Loss of power

[thr]

Hello,
I have a 2006 Panoz GTS LS-1
I am having trouble keeping the car running on the grid and coming off the track. It seems that when the clutch is depressed the car shuts off in idle or slowing down.
Any ideas?
Thanks, Todd

[P_Mac]

I'm sure others more knowledgeable than I will chime in, but my first thought is the flywheel. If you have a lighter flywheel, it spins down more quickly than the ECU might expect it to, and you don't get enough fuel to maintain idle.

Is this behavior new? Have you changed anything else recently?

[panozracing]

My brother had stalling problems in his corvette and went to a heavier clutch and that solved the problem.

[NZGTRA17]

Originally Posted by thr

Hello,
I have a 2006 Panoz GTS LS-1
I am having trouble keeping the car running on the grid and coming off the track. It seems that when the clutch is depressed the car shuts off in idle or slowing down.
Any ideas?
Thanks, Todd

Todd, what happens if you apply some throttle when the clutch is depressed? Will the engine keep running or does it still shut down? Has this fault just appeared or have you made some changes to the engine/trans?

I had a similar'ish problem with my carb'ed car but this was due to fuel slosh under brakes. In a carb'ed car I would be looking for a mixture or timing issue. Another thing to look (longshot) at is that the clutch is not "over stroking" and trying to turn the pressure plate diaphragm inside out. This would put some drag on the engine and could possibly stall it.

Kel.

[thr]

The problem has been present since I purchased the car earlier this year.
The car has no problem starting right back up, and if enough gas is applied has no problems remaining on. I have been heel/toeing coming off the track and have been able to keep the car on without depressing the clutch. The Weekend is probably a bust for RA. Now obligated for my Mom's Birthday dinner in Buckhead. Will plan on March BMWCCA at RA.
Todd

[eric1h]

Can you just bump up the idle screw to keep it running?

[thr]

Possibly, worth a try anyway.

[NZGTRA17]

Originally Posted by eric1h

Can you just bump up the idle screw to keep it running?

Possibly a good tip and simple fix. One thing to watch for with this though may be "running on". Certainly happens with carb race cars if idle bumped higher.

Kel.

[Cobra4B]

That's all just in the tuning.... it's probably not getting enough air via the IAC valve to keep running. Does the car have a light-weight clutch setup?

The Corvettes are drive-by-wire and you have to adjust the throttle decay rates when you put in a bigger cam or lighten up the rotating mass a bunch.

Not sure how the LS1 Panoz cars are tuned though.... I think they use some sort of MSD computer setup.

[thr]

Honestly, that sounds right about the valve. I dont know about the clutchj. Great time at RA BTW

[Cobra4B]

Originally Posted by thr

Honestly, that sounds right about the valve. I dont know about the clutchj. Great time at RA BTW

Thanks.... was pretty happy for having not been there in over 7 years and never in anything with any power. Finished just out of the "money" both days in 4th place.

See if you can figure out what engine mangement system is used for the LS1 in the Panoz, how to tune it, and then find someone who can tune it.

When I put a big cam in my old yellow Z06 it needed quite a bit of massaging to operate similar to a stock car in traffic, hot start, run with the AC on and catch idle when reving down. The Fidanza aluminum flywheel didn't help.

Before I had the cam and just had the lighter flywheel it'd dip to 500 rpms when coming to a light, then jump up to like 1200 and then catch idle. Once the cam was introduced it was all kinds of messed up, but a good tuner took care of all of it. But I don't think HPTuners will work on the system in the Panoz.

Best of luck. Maybe try calling Penske or Wirewheel? I assume the cars ran properly when they had them... wonder what could have changed? Maybe a sensor is messing up? Does it still use a throttle position sensor?

[thr]

My family is from Franklin, Va.
Anyway, would love to try VIR someday. Thanks for the advice. I have a pretty good mechanic. I will give him the recommendations. BTW, I talked to another person who has the same car and he has the same problem.
Todd