ChurchAutoTest
March 16th, 2011, 05:23 PM
Working on an 09 CTS-V manual. This is a customer we've been working with for a couple of years now. Started with basic bolt ons and has progressed now to a bigger blower, cam, heads, headers, meth injection - pretty much the works.
The car is now producing about 750 hp/750 lbs-ft at the wheels. Drivability is good, but on the dyno and on the road, at about 4000 rpm the Stabilitrak reactivates, brake torque management clamps down hard (at least on the dyno - not so bad on the road where wheelspeeds are close front to rear) and the "Service Stabilitrak" message pops up. The only way we could get it to dyno to test the fuel and timing was to pull an ABS sensor.
We've done some other CTS-Vs producing similar power, but they were all automatics which I thought would have more issues with trans management. This is the first manual car we've reached this level with. I've maxxed out all the ETC limit tables. I've even moved the test activation parameters to ranges they shouldn't reach in regular operation. I've also disabled misfire checking and pretty much any code I can think of that would cause this issue. No codes pop up, but the problem is pretty consistent.
All I can think of at this point is that we're hitting about 500g/s of airflow around 4000 rpm. This is right near the 512 g/s limit allowed in the ETC tables and if we're touching that, maybe that's the problem and might require some serious rescaling of injector, MAF and VE tables. We've had this car for way too long and I'm running out of things to try. Customer is being patient, but that can't last forever.
Does anyone have any similar experiences? I've read about lots of issues on the Trailblazer SS, but nothing like this on a CTS-V.
Thanks
The car is now producing about 750 hp/750 lbs-ft at the wheels. Drivability is good, but on the dyno and on the road, at about 4000 rpm the Stabilitrak reactivates, brake torque management clamps down hard (at least on the dyno - not so bad on the road where wheelspeeds are close front to rear) and the "Service Stabilitrak" message pops up. The only way we could get it to dyno to test the fuel and timing was to pull an ABS sensor.
We've done some other CTS-Vs producing similar power, but they were all automatics which I thought would have more issues with trans management. This is the first manual car we've reached this level with. I've maxxed out all the ETC limit tables. I've even moved the test activation parameters to ranges they shouldn't reach in regular operation. I've also disabled misfire checking and pretty much any code I can think of that would cause this issue. No codes pop up, but the problem is pretty consistent.
All I can think of at this point is that we're hitting about 500g/s of airflow around 4000 rpm. This is right near the 512 g/s limit allowed in the ETC tables and if we're touching that, maybe that's the problem and might require some serious rescaling of injector, MAF and VE tables. We've had this car for way too long and I'm running out of things to try. Customer is being patient, but that can't last forever.
Does anyone have any similar experiences? I've read about lots of issues on the Trailblazer SS, but nothing like this on a CTS-V.
Thanks