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I have
actually done some very careful dyno testing (the before-after-before type
of comparisons - - - all in the same day) of a variety of different tuned
exhaust configurations on aircraft piston engines.
If you
are expecting 5% - - then think 2-3% - - and at WHAT RPM ?
2700? OK... but if you do that, then think MINUS (-) 2%
at some other RPM - - like 2400 RPM when you are in cruise. No free
lunch.
In
general, tuned exhausts are going to be heavier, more complicated,
and harder to maintain.
They
are not going to effect the CHTs in any way you are going to be able to reliably
measure.
Regards, George
PS. It is very easy to fail to hold the relevant variables -
- constant. Such as failing to hold the F/A ratio constant when enjoying
the small improvement in volumetric efficiency at some particular RPM.
Thanks for inquiring.
Gains hoping to see are 5%-15%
gain in HP and torque. However, I don't think we'll see the 15%.
Aircraft engines don't turn fast enough to give us the 15%. We should
see a cooler CHT temperatures since the scavenging will be improved.
I've just returned from Sun 'N Fun and hope to get the system dynode. I
will be dynode testing this new system as well as Lancair's current
system.
Chuck Brenner
CHB Aviation LLC
Go
Fast Parts
303-261-4466
chbaviation@aol.com
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