Originally posted by IL Sean:
Oh I don't have much back pressure. But I had it explained that some of those gases are unburnt, there for stay for another cycle to get burned again. That would be why people would loose milage, at least thats how I understand it.


How would unburnt fuel vapor get burned up in the exhaust system?

Even if said occurance happened how would it effect the gas mileage of the "engine"?

How would unburnt fuel stay in the cylinder to be burned again?



Needing back pressure is a myth. It is all about exhaust velocity and scavenging.
The best performing setup would have maximum velocity, no back pressure, and optimum scavenging.



Using oversized piping for a specific engine size kills exhaust velocity and therefore overall power.

2000 SVT #674 13.47 @ 102 - All Motor! It was not broke; Yet I fixed it anyway.