Rocketman442
New Member
- Joined
- Jun 11, 2003
I'm having a few '87 GN issues and am in need of some suggestions. Specs are listed below.
First, when I stab the gas from a roll I'm experiencing a substantial bog. It is most noticable from ~ 3000rpm roll like 30 mph in first or 50 mph in second when manually held in 1 or 2. It appears to be going lean in the instant it sees WOT. When quickly but gradually rolling in to WOT it doesn't occur. T-link is consistently spot on so I've ruled out the tune. During bog fuel press drops a couple of #s from static. I haven't had the gumption to stay in it, but, at its worst it seems that once it starts bogging it won't stop until I get out of it. It varies in severity, sometimes only like a stumble. I recently reset the base idle to no avail. It is fine when left to d/shift on its own or when launched from a 5-7 psi dig. All other driveability aspects are great. The car is currently running stock t/c but a Vigilante is going in in a few weeks.
Second, the 1-2 shift seems to be delayed, or, it's going flat in the top of first. Again, T-link isn't pointing out anything abnormal. Maybe tranny? It'll wind up to ~5300, leave you hanging and upon hitting 2nd it goes like hell.
Third, I've thus far kept the tune pretty conservative. Even with 21 psi I'm only seeing O2 v around .800-.830 and no KR to speak of. I'd like some input as to increasing boost and/or timing. If I don't see low O2 v or more than a couple of deg of KR, will the head gskts live on pump gas?
Thank you all in advance and my compliments on a great site!
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PT51(21 psi), stk type adj. w/g, ATR d/p, ATR 3" duals, 42.5 #, LT1 MAF, Trans +, Hot wired Walbro 307, Jay Carter chip, FP=38 static, 55 @ WOT.
T-link data: TPS=.43-4.75, O2=.800-.830, ESC=0-2, BLM=128, INT=128, LV8=255, MAF=508 g/s, KR=0-2(only saw KR of 2 on two of ten runs and only during shift).
First, when I stab the gas from a roll I'm experiencing a substantial bog. It is most noticable from ~ 3000rpm roll like 30 mph in first or 50 mph in second when manually held in 1 or 2. It appears to be going lean in the instant it sees WOT. When quickly but gradually rolling in to WOT it doesn't occur. T-link is consistently spot on so I've ruled out the tune. During bog fuel press drops a couple of #s from static. I haven't had the gumption to stay in it, but, at its worst it seems that once it starts bogging it won't stop until I get out of it. It varies in severity, sometimes only like a stumble. I recently reset the base idle to no avail. It is fine when left to d/shift on its own or when launched from a 5-7 psi dig. All other driveability aspects are great. The car is currently running stock t/c but a Vigilante is going in in a few weeks.
Second, the 1-2 shift seems to be delayed, or, it's going flat in the top of first. Again, T-link isn't pointing out anything abnormal. Maybe tranny? It'll wind up to ~5300, leave you hanging and upon hitting 2nd it goes like hell.
Third, I've thus far kept the tune pretty conservative. Even with 21 psi I'm only seeing O2 v around .800-.830 and no KR to speak of. I'd like some input as to increasing boost and/or timing. If I don't see low O2 v or more than a couple of deg of KR, will the head gskts live on pump gas?
Thank you all in advance and my compliments on a great site!
---------------------------------------------------------------
PT51(21 psi), stk type adj. w/g, ATR d/p, ATR 3" duals, 42.5 #, LT1 MAF, Trans +, Hot wired Walbro 307, Jay Carter chip, FP=38 static, 55 @ WOT.
T-link data: TPS=.43-4.75, O2=.800-.830, ESC=0-2, BLM=128, INT=128, LV8=255, MAF=508 g/s, KR=0-2(only saw KR of 2 on two of ten runs and only during shift).