Porting exhaust manifolds

[wvhylander]

I am ready to purchase a set of headers for my BB Camaro, but I'm looking into Extrude Honing the exhaust manifolds. Doing so would reduce the problems associated with headers. Anybody had this done? Did you see a noticeable improvement. I know there are those that will say it's a waste of money for minimal benefit. But the Fast(Factory Appearing Stock Tire)Racers are making huge horsepower and running 10 second times in 1/4 mile through the exhaust manifolds. Thanks

[KenMaisano]

Its really about exhaust tuning and scavenging. and you can't get that with the manifolds. You might get around 5 to7 HP from porting the manifolds. I have done testing on the dyno.. If your using the manifolds it's best to keep the duration small and Lobe center wide. 110 to 114

[Salvatore]

I never really had much problems with headers. Gotta buy a good set.

[wvhylander]

I contacted a couple companies that port exhaust manifolds. The perfomance gains didn't sound encouraging so I ordered a set of Flowmaster 1" 3/4 headers. They have the ball and socket collectors, which should eliminate collector gasket issues. I'm hoping they fit as advertised. Thanks for the reply.

[Salvatore]

I am sure you will be happy.