<VV> Re: Turbo Setup

Frank F Parker fparker@umich.edu
Wed, 17 Nov 2004 20:45:32 -0500 (EST)


> turbos.  As far as waste gates, it is my understanding that they are not
> practical on the existing Corvair setup because the carb is upstream in the flow.  As
> I understand it, a waste gate needs to be between the compressor and the point
> where fuel enters the system otherwise, you will be venting air/fuel mixture.

No, wastegate is teed into the exhaust tubing before the turbine inlet and
bleeds off any excess exhaust that would cause overboost. It is critical
to modern turbo performance. Virtually ALL turbos in the last 20 yrs use
either an internal ot external wastegate. You need the proper turbine
section to work well. That why , if u are going to use the old vair
turbos, I suggest you ask Warren since he has done it and can tell use the
best combination of stock turbine and compressor and carb to use.
With a wastegate, u can have good boost in 1st gear. Without a wg, on a
stock system, if u bought a Rajay turbine section of smaller a/r cross
section to give u 1st gear boost, it would overboost in the higher
gears-possibly 15-20 psi busting parts. The wg vents this excess exhaust
using a bypass back into muffler. Sounds like a free lunch, but it is not
cause there will be more turbine backpressure. It is a serious task to
figure out the best turbine to use or one has to try one, test results and
pick the best a/r.

regards,

frank