6 branch manifold questions

[bullyd]

im lookin at getting an alpina 6 branch manifold for my 535, does anyone know if it would be wasted if i keep my original centre box but put a fastflow s/s rear box on? i dont really wanna fork out and get no gains, also, can i have an idea what is a fair price for one of these?, thanks, daemon

[Anthony (M5 in Calgary)]

6 branch manifold = exhaust header.

Gains? Maybe at the top end but you'll need to get more air in to make a big difference. I'd bet you'll lose bottom end torque unless the pipe diameter is quite small.

[bullyd]

some pics

[BigKriss]

some pics looking very good. I love the exhaust manifold. A whole new exhaust is your best best, but money wise, I would leave the exhaust stock. The center box is the damm large. Why not try some straight pipes from the cat to the stock rear muffler?. A fastflow s/s muffler would sound different, i'm unsure of performance gains though.

[bullyd]

looking very good. I love the exhaust manifold. A whole new exhaust is your best best, but money wise, I would leave the exhaust stock. The center box is the damm large. Why not try some straight pipes from the cat to the stock rear muffler?. A fastflow s/s muffler would sound different, i'm unsure of performance gains though.
ive already bought a s/s twin dtm rear silencer so im hoping to utilise that, i was told to expect 15-20 bhp increase with a manifold and full exhaust system i was just wondering how much of that id lose by keeping the middle box as i wanna keep the noise level down a bit but dont wanna huge dent in the power increase! anthony says ill lose some bottom end torque ?? is this right? i thought id get power increases??? :(