Moving the turbo down the exhaust...

[Canty]

Why is there not STS type system for our cars? I talked to a good friend of mine and he said that the exhaust velocity at the end of equal length headers would not spool a bigger turbo until the upper RPM range. I don't understand that. Why would the velocity be different at then end of a header than it is at the end of our log manifold? I am planning on doing some mock up and try moving the turbo but he said unless I compound the turbo, my 50 trim will never spool? What do you guys think about it?

[detobias]

you are correct in deducing that the exhaust flow rate (mass flow) will not decrease...

EXCEPT the energy lost as heat as the gas travels will manifest itself as slower & denser flow.

using SS instead of mild steel and / or thermal coating the exhaust manifold will help hold the heat in,
keeping velocity up ...

TDers have put together 'equal length' headers..
and a converted TBI exhaust mani flows well too, superior to the 'log' ..

[GLHNSLHT2]

I think your friend should go take a flying leap off a bridge.

[Canty]

that last comment made me laugh!

[The Pope]

Quote:

Originally Posted by Canty that last comment made me laugh!

Though I agree with that state ment about the bridge I think he could have gone into more detail

First you are building more pressure on the exhaust side than the boost side. It takes longer to fill not only a ton more exhaust volume but a ton more boost volume. Small engines need all the response they can get to spool the largest turbo they can. Many of these V8 cars really don't need boost and boost done badly still makes a ton of power. Also people add them there because of fitment. It is a major PITA to put a turbo there. Oil return is another wonderful down side.

The best way to do a header is equal length and pulsed. Then run a divided turbine housing feed by the header. Each pulse is then managed to the turbine wheel the most effective way with the least amount of reversion. Basically using the best of everything.