Guest Anonymous Posted July 11, 2001 Share Posted July 11, 2001 Ok, here is the new skinny, i took my car out today and drove it around to see if i could produce any boost, when i was getting on it hard and at about 4500 or 5000 rpm i here the turbo spool up! I thought, finally, but at that rpm and with the blowoff valve closed up i only produced 4lb of boost. i dont have any leaks in the pipes, and i have great exhaust pressure out of the tail pipe.. what is going on?! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 11, 2001 Share Posted July 11, 2001 I donno, I'll give it a stab or two. Possibilities: very small compressor, restricted exhaust flow, is the blow off valve sealed all the way (not leaking off boost prematurely?), restrictive air cleaner or carburator if its a draw thru system? (this was that bae system right?). I'm sure if it uses no wastegate that its sized pretty small to avoid overboost and detonation, but 4 lbs seems a little weak, I would have expected probably something like 6 lbs or something. Perhaps the bearings in the turbo aren't the best and requiring alot of pressure to turn them slowing down its ability to produce pressure? Or leaks in the system somewhere. Just a few thoughts, I'm no turbo expert, but those are some things I would expect might be occurring if I was'nt seeing boost. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 12, 2001 Share Posted July 12, 2001 That system produces 6 psi on my buddies car under boost. Now my question to you is this... where is your boost gauge hooked up? the intake im assuming. I have NO clue why your not seeing more boost, are you sure your turbo is getting adequate oil supply to it? Evan Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 12, 2001 Share Posted July 12, 2001 thanks guys.. yeah oil is no problem, and yeah boost gauge is right off the manifold.. i am taking the turbo to a turbo shop tomorrow, i dont think it is right.. they guy told me it was just rebuilt but.. when you spin the impeller should it spin and keep spinning and spinning, or should it stop right after you turn it? Mine stops right after i spin it, but it is smooth. so.. i am at a loss here! Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 12, 2001 Share Posted July 12, 2001 In general, the impeller won't keep spinning and spinning on it's own. If you can spin it easily with your fingertips, and it turns smoothly and doesn't wobble, then it's probably not your problem. It's quite possible that that's all the boost that system will make. Remember - that was a very early turbo setup, and they didn't do anything terribly sophisticated for additional fuel delivery. Apparently, they only relied on turbo sizing and the popoff valve to regulate boost, so with the heat that that generates, and no intercooler, I doulbt that they could safely run much more boost than 4 or 5psi. I don't remember for sure, but I don't think that is out of line with what the stock ZXTs produced, either. [ July 12, 2001: Message edited by: TimZ ] Quote Link to comment Share on other sites More sharing options...
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