A friend of mine is interested in a sebring style exhaust for a type I engine in a bus. Ive searched around and found that A1 makes a type 1 version without the longer primaries on the #2 and #4 like the originals.
Im wondering if there is really any advantage since the pairing is not optimum and the primaries are far from equal length. Does the "collector" make up for it and provide actual scavenging? Is it more of a look/sound/ground clearance thing over actual performance?
I don't believe this exhaust -- which is very close to the Porsche factory design for the 904 -- would be as efficient as a real 4-into-1. The 904 system used (almost) equal length tubes from the cylinders on back, into a 2-into-1 per side, then the dual 1-into-1 collectors merged. Exactly as the A1 photo shows.
Being midengined, the long runners to the aft collector made the system work. There was no stinger for fear some tail-gating Ferrari might knock it off.
But this A1 exhaust does not have long runners. My educated guess is it's better than stock, probably sounds great, and certainly looks good.
I do not believe it would rob torque, but I' would't expect it to boost power more than any slightly less restrictive street exhaust.
A1 makes other headers that work as good as they look for much less.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
