running series turbos
 

now its hard to say what i am thinking...so bare with me...
i have been thinking about running series turbos because it just seems like such a good idea for spool and turbo efficiency

(lets just say the big turbo = 60/62 and the small turbo = 48/42)
my problem is understanding the turbochargers physics.
-do i want to run a smaller turbo off the manifold which compresses air into the inlet of the larger turbo? or would the larger turbo over spool the smaller one because it sucks in a larger diameter of air than the smaller turbo can compress out of the outlet? as in what is the amount of lbs/min of air that the bigger turbo can suck in through the inlet vs how much air can the compressor of the smaller turbo push out throught the outlet, is it greater that the smaller turbo can produce?

-now lets just say i have the same 42/48 turbos running in series.....both wastegates are set at 7psi...will that mean i get 14psi into my manifold?

in doing that i am technically staying in both of the turbo's high efficiency range witch would just be like running 14psi on a 60/62 correct?

hope i dont sound like a noob, but i figured SOMEONE has to know a little about this. if you have a website that has some usefull info it would help me from wasteing my time searching all day through google. thanks!

Re: running series turbos
 

Ok just skimmed but No 7psi and 7psi dosn't equal 14 psi it is 7psi...and you don't run the FI into the second turbos exhaust...

The smaller turbo will provide boost at lower rpms to provide power which in turn spools up the larger turbo which will somewhat take over for the smaller turbo peaking out at lower rpms..HTH

Re: running series turbos
 

*Always* blow the smaller compressor into the larger one.

Re: running series turbos
 

but what if i ran two of the same size turbos in series....wouldn't they both spool up a lot faster because the one turbo is getting rammed COMPRESSED air into the inlet and forceing out more compressed air. so if i was running 7psi on both turbos....where does one of the 7psi go? they equal out? doesnt make sens to me

Re: running series turbos
 

7Psi equals out, each turbo is pushig 7 psi it dosn't add together you are forcing 7 pounds per square inch into the intake, its how it works...psi dosn't have to do with the amount of air being forced into the intake only the pressure read up on cfms

Re: running series turbos
 

so lets say i didnt run that smaller turbo into the inlet of the other one. and instead i ran it into the intake manifold...that wouldnt equal 14psi? 7x2?

Re: running series turbos
 

I know that RX7's they have A Cozmo Rotary engine that is a 3rotar twin turbo setup with a small turbo and big turbo combination... i know the little turbo is to help spool the bigger turbo from Lag, but from what i hear just put a little bit of spray into it to help the spooling... i heard this from people with built motors so if you have a stock motor i Dont recomend...

Re: running series turbos
 

No you keep thinking about the amount of air yes there will be more air going into the engine but no the pressure will not be increased...7psi on a T4 is the same as a tiny t3 but he amount of air being moved is different

Re: running series turbos
 

so then the only good thing about running a series turbo is to get better spool up? that sounds dumb it seems like it should do more than that

Re: running series turbos
 

Better spool up, MORE AIR, Instant boost and then all the way to redline...not worth doing on a 4 banger, more work for a not so great out come...look up whitey's TT civic and ask him he'll tell you it wasn'y worth it