Originally Posted by
T Brooks
Hello everyone
In some distant thread I read the poster was talking about how they assess the length on the tuned pipe in flight. I now cant find the info or the thread. Can anyone share their tuning tips?
I am familiar with running the engine open face and getting an RPM then successively cutting the header to get the RPM above the open face reading until it then drops off again. Most website info then tells you to go and fly it and make small changes from there. What they dont say is what I should be looking for to know if the pipe is long, short, or just right.
At full throttle should I see increase in RPM when I climb or dive, should it be completely constant? The obvious clue that the pipe is too short is sensitive needle and blown plugs.
Cheers
Tarquin
P.s. for those interested I am slowly getting stuff done on the Beetle. I now hate sanding filler/primer!
Hi,
For calculating of tune pipe lengths try this formulae Lenghts (mm) = Exhaust duration X 42545 / rpm
L = Tuned Lenght in mm (edge of piston to first baffle)
ED= Exhaust duration in degrees
42545= a constant
Rpm = revolutions
pr minute
Advice, add a few centimeters on the length and check the needle on the engine. If more than 1-2 rounds between rich and/or lean, then cut a centimeter of the length of pipe. do not cut too much at each time.
Regards