sbc exhaust

[bones]

hi all, does a sbc need a balancing pipe, as the exhaust is going to be done just wondered if an x-pipe would be better, at the moment there isnt a balancing pipe on it, any advice welcome, rich

[katanaman]

Any V8 will benefit from a balance pipe unless its a flat plane crank but their exotic engines generally.

[bones]

ok thanks, looks like an x-pipe it is, thanks again rich

[bones]

the engine eventually will be about 400 bhp so a 2 1/2" or 3" x-pipe, rich

[kiwicar]

I would go twin 3" on an SBC, some say over kill but it is less of a restriction due to the pipes so you can compromise on the silencers.
Mike

[bones]

thanks Mike, we are going to change the full exhaust system, and another question, on race day is it best to have open headers ,or does it depend on the silencers used, rich

[kiwicar]

Hi
if racing you normally need some silencing (I presume some form of curcuit racing) these days as they tracks have noise limits. There are many true straight through boxes and one of these about 18" long and the same bore as your system should give enough silencing and not give any restriction and therefore no loss of power. If you can run without noise limits then a well designed megaphone system that opened to about twice the area over a distance of about 3.5 to 4 feet would give you a few BHP, however I think there are simpler ways of getting more bhp from a small block chevy.
Mike

[bones]

he only does the drag racing in it, but he uses it on the road at weekends, maybe just the x-pipe and some good silencers will be ok , thanks for the reply, all the best rich

[kiwicar]

Summit and others do exhaust "valves" that let you open up to straight through pipe for drag racing, you can get ones that let you unblock to a megaphone if you want, either manual or switch on the dash like http://store.summitracing.com/partdetai ... toview=sku
Mike

[bones]

thanks Mike, much appreciated, looks like ive got more to do on it, all the best rich