914-6 Exhaust Questions Options

[PeeGreen 914]

I have seen my share of different exhausts on 6's and am curious as to what you guys feel is the best by way of performance. I see cars that have stingers, Triads, stock, and others.

I guess I am confussed as to why people say you need to bring all pipes together for balance and such. I don't understand this all that well. So do the exhausts that go straight back with out connecting each side not do as well? (IMG:style_emoticons/default/confused24.gif)

[ArtechnikA]

I guess I am confussed as to why people say you need to bring all pipes together for balance...

You have to look at the firing order.

on a 911 it's 1-6-2-4-3-5 which means exactly the same timing between firing events on each bank. it's basically two 3-cylinder engines 180º out of phase. 911 engines actually run pretty well on only one bank...

a VW Boxer engine, however, has consecutive firing events on adjacent cylinders. so on each bank, it's bang-bang-(nothing)-(nothing).

Scavenging exhausts work best when the pulses -leave- with equal interval.

I read an interview with Jim Busby who ran a crossover on his 911RSR's and he said it was in large part so if he backed into something or got hit in the back and it closed up one side, he could still carry on -- and mentioned twice when that exact thing happened. So there's that, which may be not as good a reason to have them on the street.

Once upon a time, the general rule of thumb was that they were unnecessary below 2,7 and of marginal utility up to 3,0. You get to factor in the weight, cost, and complexity, plus the reliability issue of Porsche's 8mm exhaust studs.

This is one thing Subaru learned - their exhaust studs are 10mm...