JDSfastGN
Well-Known Member
- Joined
- Jun 16, 2001
- Messages
- 3,506
I've been working on my dads old 85 GN for a while now trying to get it figured out and I'm at a loss. The car has ATR headers, 2.5" DP, retrofitted TA49, cold air intake, LT1 MAF/translator, 87 ECM and module, ported heads with bigger valves, .030 over TRWs, home ported intake, ported throttle body, 50# injectors as well as a walbro 340, hotwired. The tranny is decent and has a TCS "supposed" 2800 12". The big ? is the camshaft amd converter. He had the cam installed years ago when the motor was rebuilt and does not know the specs or manufacturer anymore. The tranny was done at the time as well and since then its never been the same, although i did switch out the D7 that was in there for the TCS 12" thats in there now about 3 years ago. The car has no balls at all. From what ive read and seen tuned right it should be a low 13 sec car on pump gas and mid to low 12s on race gas. I've come to the conclusion that the cam is just completely wrong or the stall converter is a POS. The 49 spools pretty slow barely hitting 15 psi in 1st gear. The cars RPMs seem to rise very very slowly compared to other hotairs ive been in and compared to both intercooled cars in the family. On the footbrake it stalls to around 1900-2100 rpms before the peg leg breaks loose even with the parking break applied. I know stall can be dependent on power output so im not sure which is the big hang-up on the car. Has anybody installed a cam that was just completly dogged down a motor? It has a known good module, coil, no vacuum leaks, BLMs at 125ish, 02s at WOT are low 800s, TPS is .42 and 4.45 15 psi with no knock etc... I plan on doing a compression test tommorow to see if anything is noticable there. Any other ideas? I just recently did the intake, turbo, and injectors and it was slow even before those mods. Thanks guys, i know this is long winded and a lot of fluff but im just looking for some ideas. I think ive narrowed it down to a horribe cam choice, or degreed incorrectly (the car idles and drives great BTW) or a TC thats just soaking up all the power.