throttle body before turbo?

[MWP]

So its pretty well agreed that its old technology, and not viable with turbos that have pressure sealed bearings. Maybe ok with ball bearing turbos?? Still the issue of rough idle though. And as I stated MWP (not havin a go at ya), murphy sez that itll be brett that cops the freak broken fins.

No problem.
Well any twin charge setup is quite unique, so i guess even old tech should be considered if new tech wont do the job.

[Norbie]

At the risk of adding more complexity to an already complex system, have you considered using two throttles? One before the blower (I assume you want it here because you're using a PD blower) and one in the normal location. So something like this:

TB --> SC -----------------> turbo --> IC --> TB --> engine
Bypass --> 1-way valve --^

Just an idea anyway. I was seriously considering a twincharge setup on my 18R-G recently so I gave this a fair bit of thought. The only problem I can see with the above scenario is finding a suitably large and free-flowing one-way valve.

EDIT: how come the CODE tags don't use a fixed-width font? That's the whole point of having it!

[oldcorollas]

and then you could run quads and have a third TB/BOV/pressure control valve to atmosphere so it runs nicely off boost too

methinks rasing the pressure differential across a turbo as a way of reducing the boost is not the best way to go (as discussed in the turbo restrictor thread before)
kind of the point with turbo is that the wastgate controls the manifold pressure, and a normal TB controls the engine food..
why not have turbo blowing into the SC, with a single TB between turbo and SC?

[brett_celicacoupe]

well it sounds like this isnt the best way to go. doesnt matter though, it isnt the end of the world.


i dont really like the idea of having a one way valve....the way i see it (correct me if im wrong) is that they have a spring mechanism that requires the pressure on the inlet side to be higher than the outlet side. and then the more air that is required to go through, the more of a restriction the valve will impose on the engine.....im sure it wouldnt be good for performance!


the route im looking at having for now is as follows;




as a bypass valve, a 1jz TRC TB will used......heaps big enough and can be controlled electronically . i wont claim all the credit for ti though...idea actually came from wilbo666


anyway.....the thread has pretty much served its purpose so we can leave the twincharge discussion for another time

[Billzilla]

Did they have any failures with this setup?? because if they had to put in several man-hours of R&D to overcome any problems, chances are they wont make the documentation for this available to the public, in which case failure is likely to be experienced if performing this.

Cheers, Owen

Nah dude, no chance! Not a huge amount of fine detail is publically known about the engine sorry. And yeah, they blew up a couple getting it right ... !