ok then, I'll give you an example then and I'd love to hear your opinions
Sorry to keep insisting but I really want to get to the bottom of this as its confusing for me
Alfa 33 - 1.8ltr , 11.5:1 compression ratio ( JE pistons ) , c&b cams - (fast road medium) with hydraulic tappets.
Polished ports, racing fuel pump, omex ecu.
This car currently has , standard exhaust manifolds 4 to 2 to 1 , then 55mm pipe to the mid box which is straight through, then 55mm pipe that goes over the rear axle to the rear box which is 63mm and the "S" at the end with the exhaust tip again at 63mm's.
The exhaust now in my opinion is too small for it - you can hear the fumes whistling on their way out. ( when idling )
Although I'd hate to change it as I managed to get a fantastic sweet sound from it, this is the fourth exhaust system I changed on my 33 and I've spent more than 400 pounds on exhausts and boxes up to now !
Some people have suggested that I remove the middle box and put a 63mm pipe directly from the end of the manifolds to the rear box.
My previous setup was with a 63mm to a 63mm mid box and straight to the back under the axle with back box coming out from the middle of the rear bumper. That was too loud and I lost power as well
in other words.... HELP !!!!