Twin Turbo'd Supercharged STi - Page 2 - Perth-WRX.com

trainwrex · #11 15-09-2005, 10:23 AM

Quote:

The supercharger doesn't run in a compound setup to help the turbo's spool, its running on its own, and looking at the setup, has an actuator to then bypass it when it hits a certain boost point, looking at the pipework setup and the boost actuator on the super charger anyway. so its running in the traditional twin charge setup of supercharger down low, and then the turbos come in when they start to work..

Hmmm he uses the exhaust gases to spool up the turbos. Without the charger the turbos make full boost at around 6000rpm. But with the charger he told me that they make full boost around 3500-4000rpm. The S/C has piping which follow on to the turbo.

geoff · #12 15-09-2005, 10:24 AM

See the disgusting manual boost bleed valves?

Ew!

Wonder if it works ... looks like theres a lot of sorting out to do.

trainwrex · #13 15-09-2005, 10:28 AM

its still in development stage geoff... hes only just got the kit together. Itll be a few more months before everything is sorted out.

Denver · #14 15-09-2005, 10:31 AM

Quote:

Originally Posted by trainwrex

Hmmm he uses the exhaust gases to spool up the turbos. Without the charger the turbos make full boost at around 6000rpm. But with the charger he told me that they make full boost around 3500-4000rpm. The S/C has piping which follow on to the turbo.

er, where?

theres nothing going into the turbo inlets from the supercharger, they just suck straight out of the air filters, and looking at the direction of the turbo outlets, they lead towards the underside/rear of the super charger..

a true compound setup in turbo terms anyway works like so..

the larger of the turbo's is mounted to the exhaust manifold of the motor
The exhaust outlet of the large secondary turbo, is then piped into the smaller primary primary turbo exhaust housing, and then into the exhaust pipe from there..

The primary small turbo, sucks air from atmosphere, the outlet of the compresser on the smaller primary turbo, is then fed into the inlet of the secondary larger turbo, and the outlet of that goes into the motor..

that is a compound setup in the true sense..

What the setup on that rex looks like is a sequential setup.. so its not a compound, and just switches from one to the other at a certain boost/rpm point..

if done correctly can work very well, but i have a friend who's been jiggering around with a mk4 supra in this same manner using turbos, smaller turbo down low into a gt40 up top.. using actuators and boost controllers etc, hes been jiggering away for over 12 months now and still hasn't got it perfected..

so its a pain to get right

and as geoff pointed out, manual bleed vlaves for boost control, what the..

trainwrex · #15 15-09-2005, 10:42 AM

Quote:

er, where?

i dont know where it is either as i couldnt see from the pics... but i actually called him up last week, as i was considering this setup with my GT35R. He told me that the S/C is linked to the turbo, and it gets bypassed at a certain rpm/ boost.

in terms of the bleed valve this engine wont be remaining in that car. its a stock standard STI EJ25 he just wanting to get the thing running right before he builds up a 2.2ltr to replace it..