1 psi=1 psi no matter where it came from. Turbos can make huge amount of boost
because they run off of what they produce: more boost produces more exhaust
which makes more boost which makes more exhaust and on and on until something
blows up. That's why they have wastegates(like a relief valve).
----------
>From: Jon Steiger <stei0302@cs.fredonia.edu>
>To: dakota-truck@buffnet.net
> Is PSI from a turbo the same as PSI from a blower? Seems to me that
>a lot of those imports are running large amounts of boost with turbos
>whereas blowers run a lot less. Just wondering if there was something
>about turbo boost that made it safer to run more pressure than a blower?
>>>When I talked to the guy today , he was talking about running a single
>>turbo with a wastegate . He said that twins wouldn't do much more than a
>>single and that I shouldn't run more than 5 or 6 PSI on the stock motor
>>unless I planned on doing some major internal mods .
>
Not exactly, first of all, whether using 1,2 or 4 turbos, the psi output
should be the same. When you add turbos output in parallel, output pressure
remains the same. In series(like new supra turbo and rx7 3rd gen) the boost
doubles but that is not practical or necessary. Pretend that TURBO LAG IS
DEAD! Think more in terms of "motor lag". If you start out with a 2-liter,125
hp 4 banger and turbo the hell out of it, you can double it's PEAK output(250
hp) But at low rpm it's still a gutless wonder. It's not that there is turbo
lag, it's lack of beans in the original motor.
A V8 on the other hand, got some beans to begin with. By the time you hookup
your tires your turbo will be right there with you kicking butt. Two turbos
offer No advantage over "only" one. Turbos have come a long way. Think about
it...3.8 liter 6banger,family car,1-turbo=7-second 1/4 mi. If that is turbo
lag give me some of that.
> Don't be too sure... :-) The reason for running twin (or more)
>turbos isn't to increase pressure, but to reduce turbo lag. The
>smaller the turbo, the less time it takes to spool up. Using 2 5psi
>turbos will give you the same output as a single 10psi turbo, but due to
>the reduced spool-up time, that power will come on a lot faster
>off the line.
>
> Plus, it seems to me that 2 turbos running at low pressure would
>outlive a single turbo running at twice the psi. If I were going
>to turbocharge my Dak I think a twin setup would almost be a
>must... There is the initial additional cost and the system
>complexity goes up a little, but lag reduction and turbo longevity
>are big plusses.
>
Longevity? No difference, give them cool, clean oil and forget about it.
Dr. Pat
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:12:10 EDT