Performance/Speed mods

[1739T]

Anybody have any experince with Powerflow Systems and thier exhaust system mods?

I have a pa28-140 and am looking to squeeze a bit more climb out of it to handle those short soft fields.

[skid]

I have some experience with an 0360 and fixed prop in my Pitts. I found that intake and exhaust both can be improved upon greatly. After a good exhaust and replumbing the induction hoses, better airbox,and relocating airscoop, it picked up about 150 rpm in same speed climb. I know a lot of other aerobatic builders that have done same or better. I have a 180 hp Cardinal and have been curious how much the exhaust alone would do. The intake plumbing and airbox is a real joke on most factory airplanes,at least for flow, and I am skeptical that exhaust alone would be enough of an increase to be worth the stiff price tag of powerflow($3500,I believe). On the Pitts, a $900 4 into 1 was worth its weight in gold( 150 to 200 more vertical penetration, another 1/4 roll on an up line). The same hp increase would not change power/weight ratio near as much in the cherokee as it did in my Pitts. Powerflow's 23 horspower claim seems a little optomistic to me, but the Pitts already had a better exhaust than a factory airplane anyway. I do know that once an airplane is already moving an extra 100 rpm can really change an airplane. It gave me enough extra power to repitch prop and end up with same climb and more speed. It is a shame to me that factories waste 10 to 20 hp by building induction and exhaust systems like they were plumbing a sink.