<< Finn Lassen wrote:

Paul wrote:

The big question is, in addition to length, if you join the two

exhausts do you get

a scavenging effect? The flow from one rotor's exhaust pulse helping to

suck out the

exhaust from the other rotor. If so, how long do the headers need to be

(before

joining at the Y) at say 6000 - 6500 RPM?

31 inches. If it gives you 15 more HP is is worth 5 pounds? That is three

HP per

pound which is a way better ratio than your engine provides. That is the

10%

difference between a properly tuned pipe and a poorly tuned pipe based on

150 HP

to start. Probably with better BSFC in the bargain which will easily pay

for itself

in short order at today's gas prices. PL

Ok, do we know for sure that it's 31" for the 13B ?

Finn

Ask Paul Yaw about the correct length to the collector. He is developing a
street header for 13Bs on his dynomometer. Lynn E Hanover.

Paul Yaw is concerned mostly with stock RPM ranges (up to 8000) RPM. Since we 
are limited to 6000 to 6500 RPM the optimum tuning will be different.

Paul Lamar
 
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