4G634ME
20+ Year Contributor
- 30
- 0
- Jul 12, 2002
Hey guys. Apologize for not posting this on the 'Newbie' forum... from what I could see it does not get frequented too much by the knowledgable folks I have begun to respect in this forum. Too much focus on non-technical stuff too. No thanks.
Anyhow, here's the deal. My '91 GSX I recently purchased is a blast to drive, but I've noticed that on full throttle in first and second gear, the boost originally hits 16psi, then slowly drops down to around 13psi! In third it seems to hold 15psi just fine. Whasupwitdat?
Could it be a cracked manifold? I'm almost positive I can feel exhaust pressure leaking from behind the heat shield. In addition, it sounds like a car with a cracked muffler, but from the engine bay (rather than below the car).
I'm nearly positive it was holding the boost just fine when I bought it a week ago... could I have just cracked it with all those miles, 100+ degree weather, and hard driving? Maybe it was just it's time to go? No big deal really, planned to replace it anyway with a ported 2G manifold. In the mean time, can I hurt her by driving with the manifold cracked?
The only other thing I can think of is the intake. I 'dremmeled' the air can in accordance with instructions on numerous DSM sites, and reinstalled everything (I believe) properly. Someone mentioned an easy way to check for intake leaks... fill me in?
FWIW, I'm reasonably mechanically inclined and feel somewhat comfortable behind a wrench. With that, how difficult is it to install a manifold? I have the Haynes and Chilton's manuals, and it seems rather involved. I mean, I've done two clutches, shocks, headers, all that sort of stuff, so I imagine I am capable of installing it... just wondering if it's one of those things that is such a headache that you let 'them' do it. Hope not, I like doing my own work.
Finally, in addition to my current setup (full 3" exhaust, FPR, Fuel pump, K&N, hacked airbox and MAF, TurboXS MBC, Autometer boost gauge, GReddy turbo timer ), I plan to install the following in a few weeks:
Buschur Upper Intercooler Pipe
Undecided brand intake pipe
Test pipe
2G Manifold (ported)
Evo 02 sensor housing (p&p)
ACT 2600
Remove BS
New gauges (EGT, A/F, boost)
Pocketlogger
Apex S-AFC
Does this seem a decent upgrade path? Suggestions? Oh, I understand the importance of preventative supporting modifications and maintenance (timing belt, plugs, wires, fuel filter, compression, etc.) and luckily almost everything has been taken care of already. Plan to recheck the compression just to be on the safe side.
Well, there it is. I have spent a lot of time on VFAQ.com and a number of DSM sites, plus searched the heck out of this forum... can't seem to find the exact answers to my questions. Really hope you guys can help... makes things a LOT easier for a lot of new DSMers.
Thanks again,
Jason
P.S. Is there a good site that has 'customer cars' (or just people's own pages) that list current mods and 1/4 mi times? I want to buy the right stuff, and could use a brand based recipe that has already worked for others. Only want low 13s. For now.
Anyhow, here's the deal. My '91 GSX I recently purchased is a blast to drive, but I've noticed that on full throttle in first and second gear, the boost originally hits 16psi, then slowly drops down to around 13psi! In third it seems to hold 15psi just fine. Whasupwitdat?
Could it be a cracked manifold? I'm almost positive I can feel exhaust pressure leaking from behind the heat shield. In addition, it sounds like a car with a cracked muffler, but from the engine bay (rather than below the car).
I'm nearly positive it was holding the boost just fine when I bought it a week ago... could I have just cracked it with all those miles, 100+ degree weather, and hard driving? Maybe it was just it's time to go? No big deal really, planned to replace it anyway with a ported 2G manifold. In the mean time, can I hurt her by driving with the manifold cracked?
The only other thing I can think of is the intake. I 'dremmeled' the air can in accordance with instructions on numerous DSM sites, and reinstalled everything (I believe) properly. Someone mentioned an easy way to check for intake leaks... fill me in?
FWIW, I'm reasonably mechanically inclined and feel somewhat comfortable behind a wrench. With that, how difficult is it to install a manifold? I have the Haynes and Chilton's manuals, and it seems rather involved. I mean, I've done two clutches, shocks, headers, all that sort of stuff, so I imagine I am capable of installing it... just wondering if it's one of those things that is such a headache that you let 'them' do it. Hope not, I like doing my own work.
Finally, in addition to my current setup (full 3" exhaust, FPR, Fuel pump, K&N, hacked airbox and MAF, TurboXS MBC, Autometer boost gauge, GReddy turbo timer ), I plan to install the following in a few weeks:
Buschur Upper Intercooler Pipe
Undecided brand intake pipe
Test pipe
2G Manifold (ported)
Evo 02 sensor housing (p&p)
ACT 2600
Remove BS
New gauges (EGT, A/F, boost)
Pocketlogger
Apex S-AFC
Does this seem a decent upgrade path? Suggestions? Oh, I understand the importance of preventative supporting modifications and maintenance (timing belt, plugs, wires, fuel filter, compression, etc.) and luckily almost everything has been taken care of already. Plan to recheck the compression just to be on the safe side.
Well, there it is. I have spent a lot of time on VFAQ.com and a number of DSM sites, plus searched the heck out of this forum... can't seem to find the exact answers to my questions. Really hope you guys can help... makes things a LOT easier for a lot of new DSMers.
Thanks again,
Jason
P.S. Is there a good site that has 'customer cars' (or just people's own pages) that list current mods and 1/4 mi times? I want to buy the right stuff, and could use a brand based recipe that has already worked for others. Only want low 13s. For now.
Misread the Chilton's manual... removing and installing the manifold/turbo/o2 housing is not involved at all. Gonna do it all (including the clutch) myself.
