I'm starting a turbo project. Few questions.
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Joined: Oct 1999
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From: W. Kentucky
Car: 83 Z-28
Engine: 406
Transmission: TH350
Axle/Gears: 3.70
I'm starting a turbo project. Few questions.
On my turbo project I have decided on a turbonetics T70 with a P-trim exhaust. Should I use anything other than 9.5:1 compression with 15-18 psi on 93 octane? One last question. Is the ball bearing turbo that much better than the non ball bearing one? Pros? Cons? Thanks
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From: Lubbock, TX
Car: 1989 GTA
Engine: Future: LSX Turbo
Transmission: built T-56
i dont know much about ball bearing turbos i want to know more but i do know with 15-18 psi you want like 8.5 to 1 on the CR 9.5 is WAY to high
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Joined: Jul 1999
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From: College Park, MD
Yes, that CR should be much lower for 93 octane unless you're running alky injection with aluminum heads too, or you could switch to E85 fuel if it's in your area.
A BB turbo will spool up a little quicker than a non-BB, especially the higher rpm transient response (the time it takes to go from 0 psi to your 15-18 psi from low throttle to WOT, at an RPM where the turbo would already be at full boost with a full WOT run, say a 4500 rpm punch). Hopefully that made sense.
They also theoretically last longer, but I don't know of any properly maintained non-BB turbos that haven't lasted less than 100k miles on a street car anyway.
They are more efficient as well (even under full boost), but I don't know if that makes much of a difference.
In short... If you have the money, go for the BB option. If you don't, save your money.
$.02
A BB turbo will spool up a little quicker than a non-BB, especially the higher rpm transient response (the time it takes to go from 0 psi to your 15-18 psi from low throttle to WOT, at an RPM where the turbo would already be at full boost with a full WOT run, say a 4500 rpm punch). Hopefully that made sense.
They also theoretically last longer, but I don't know of any properly maintained non-BB turbos that haven't lasted less than 100k miles on a street car anyway.
They are more efficient as well (even under full boost), but I don't know if that makes much of a difference.
In short... If you have the money, go for the BB option. If you don't, save your money.
$.02
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