advantages of equal length runners??

I just won a turbo manifold off Ebay for my engine, I have seen allot of log style mani's before but I know that equal length runners help with power I just wasn’t sure of the reasons why.
Anyone know the theory behind this to explain it?


here is the mani i got.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1863147448&rd=1

My brother has a welder so I don’t expect any problems with finishing it.

As far as I know, it's a simple matter of cylinder balance. Even with a turbo there is some amount of exhaust "tuning effect" that takes place, and having equal-length runners makes it easier to get the same level of performance from each cylinder. This is especially true for a 4-cyl engine, since the exhaust pulses will be evenly spaced.

[The downside of making more power with one cylinder than with the next is that you're usually stuck tuning the engine to get the most out of the highest-performing cylinder (knock limits, etc), and the other cylinders end up less-than-optimal.]