legacycentral bbs

We all know how it goes. Equal length kills the Boxer rumble. Unequal enhances/keeps it.

Are there performance differences? I'd think equal length would be better as exhaust velocity would be similar between each bank.

My theory correct?

Would it matter to much for the turbo cars?

What kind of power differences are we looking at?

yup equal is like better for power, like 5-10 hp or something

Same deal for the Turbo?

Hmm, I wonder if it'd be worth it... I wanna hear the differences

I don't like to quote them, but I think Cobb ran a test with the stock turbo manifold and a SS equal-length and concluded the difference in performance to be small.

I don't think it would matter much as the exhaust pulses are: right, right, left, left. If they alternated right bank, left bank, it might make more of a difference, but with the point is to keep heat and get the exhaust pulses to the turbo ASAP. I think the stock manifold already does a great job. An equal-length would only increase time for the pulses to hit the turbine. Plus, like all set-length exhaust systems changing the lengths (with all else being equal) just moves scavenging efficiency around the rpm range.

I also think the longevity of the stock manifold would be better as the parts that bolt to the heads are cast iron (the cross and up pipes SS). The cast iron would be more likely durable long term than SS depending on manufacture of the aftermarket piece. Though a one-piece wouldn't have the gaskets that could fail (although this doesn't seem a problem).

Of, course this is educated guesswork and assumptions based on something I read a while ago and can't even remember the source of.

Steve