Friends GA has no torque [Archive] - GrandAmGT.com Forum

PDA

View Full Version : Friends GA has no torque


95-GT
07-31-2005, 01:28 PM
A friend of mine has a 99+ GAGT, he had some heads ported, a custom cam made, posted intakes, S&S headers, TB, stock MAF, aftermarket cat and SLP catback. He had some minor tuning done. After all the work, it ran like a champ and pulled like a raped ape. But for some reason, it seems to have lost all its torque down below, and at 3000 RPM+ it pulls hard. The transmission temp stays steady at 180*F and he is throwing no codes at all. It doesnt feel like its misfiring or the transmission is slipping at all. No backfiring also.

Anyone have any ideas on where to look or what to do?

Sprucegagt
07-31-2005, 01:51 PM
DHP Powrtuner. Tell him to get it.

Stock program and torque managment settings are killing performance.

KPimm
07-31-2005, 01:55 PM
I'm gonna guess that the cam, depending on the profile, has shifted the power band up dramatically. He may want to look into getting a higher stall torque convertor.

AMRAAM4
07-31-2005, 02:08 PM
^^ what he said.

Opened up a lot of flow thru and there isn't much down low now.

coupe
07-31-2005, 02:16 PM
Are you positive that all header bolts are tightened down. Even the smallest leak can kill performance.

95-GT
07-31-2005, 02:18 PM
DHP Powrtuner. Tell him to get it.

Stock program and torque managment settings are killing performance.

He told me that the torque managment was changed.


I'm gonna guess that the cam, depending on the profile, has shifted the power band up dramatically. He may want to look into getting a higher stall torque convertor.

That was my first guess, as it pulled hard from 3000 and up, but he could bake the tires off before this problem started. I recommended a higher stall TC, but I fell that since it worked fine before, that a higher stall wont cure it.



Coupe: I went thru the headers, crossover and downpipe to verify the tightness. They all seem good, and I hear no audible exhaust tick from a leak.

coupe
07-31-2005, 02:24 PM
In that case this is gonna be a hard one to figure out. Nothing ever seems to go right when ya mod, but man does it feel good when ya figure it out.

Sprucegagt
07-31-2005, 02:44 PM
He told me that the torque managment was changed.

More than the torque managment needs to change. Is he still running stock fuel pressure? How do the LTFT and STFT trims look? How much timing has been added? How much KR is there? What is the commanded A/F during PE mode? ANY of these being off can cause a drastic change in performance. Especially with a different cam. LTFT and STFT being off will not show up immediately, only over time since I take it the battery was disconnected during the install of his mods.

Since the car ran great before then started sucking, a torque converter will not fix this. Car would not have pulled at all if converter stall was to low.

atc3434
07-31-2005, 09:17 PM
My low end isn't what it was when the car was stock, but the top-end more than makes up for it. Still got enough to light up the tires, but not like before. Of course, once I'm turning 3000rpm plus, seeya!

KPimm
08-01-2005, 06:57 AM
More than the torque managment needs to change. Is he still running stock fuel pressure? How do the LTFT and STFT trims look? How much timing has been added? How much KR is there? What is the commanded A/F during PE mode? ANY of these being off can cause a drastic change in performance. Especially with a different cam. LTFT and STFT being off will not show up immediately, only over time since I take it the battery was disconnected during the install of his mods.

Since the car ran great before then started sucking, a torque converter will not fix this. Car would not have pulled at all if converter stall was to low.
I agree with this totally, but depending on the profile of the cam he may want the higher stall TC once the tuning is nailed down a little better.

David, how radical is the new cam? Is it one of Milzy's, a regrind, or completely custom? This info may help others to troubleshoot.