jamie956

Dose a YB require exhaust back pressure to run correctly, im toying with making a side exit system for my car with no silencers, would just be down pipe 90 deg bend then out the side.

ajamesc

I don't think turbo cars need back pressure I'm sure I read that somewhere

burnzy

No exhaust is best exhaust on a turbo car, hence why hyabusa turbo's run just a short length of pipe off the turbo.

N/A require back pressure to help empty the chamber of exhaust gassed to give a cleaner burn iirc.

stevieturbo

No engine likes being strangled.

Caddyshack

David Vizards excellent book talks a lot about the testing he did on the a series engine with loads of types of normally aspirated engines and it was amazing what the exhaust does on a normally aspirated car. An open pipe on that would lose power but I believe as others have posted that it doesn't matter on a turbo car.

stevieturbo

Absolutely, but the siamese port nature of the A series is a little different, and n/a can respond very well to tuned length exhausts....which is not quite the same as simply adding backpressure.
And of course it's all very camshaft ( and rpm range ) dependent too.

Caddyshack

True, he def had a section where back pressure was needed, maybe it is to do with the a series specifically?

stevieturbo

Nope, definitely not needed. It may have perhaps performed a little better on some combinations where there was some backpressure, that isnt quite the same as saying backpressure is needed.

It just means it was a bad combination to start with. But as said there are so many variables it would be a nightmare to optimise for everything and every one


But turbo....bigger is better. Nice and simple !

Caddyshack

Read the book then and argue with David Vizard, google him, he knows his onions

Ridgey

iTrader: (5)

The turbo is the restriction and provides far more back pressure than needed, therefore as free a flowing exhaust is desired on turbo cars.

stevieturbo

I've read it many times...I guess some people interpret things differently.