Headers or manifolds for turbo??

[406ben]

I'm building a turbo 4.3 for an '83 cheVette Pro-Touring project (see the Welcome to the message board section for photos). Exhaust on the 4.3's is a big issue when swapping in a Chevette. I have the factory manifolds that I can simply swap sides to point forward, but considered modifying some ebay S10 headers instead. A local custom exhaust guy said on turbo cars, inlet exhaust flow isn't nearly as critical as outlet flow. He said a turbo converted muscle car he worked on made more power when the guy took off the headers and put factory manifolds back on. Any thoughts?? Thanks for any input.

[myclone]

You might check to see if the factory Syclone/Typhoon 4.3 manifolds will fit. They are pretty compact and I know of two or three trucks that have went LOW tens with them.

[427]

Ex manifolds will get very good results on the cheap. I have been over 1500hp on vette manifolds on a gen3 chevy.

Kurt

[JLM]

Are you goign with twins or a bigger single? If you are going with twins I would check out www.bankspower.com and navigate to their twin turbo kit. Take a look at how they have their manifolds setup. This can easily be replicated using headers and some wleding know-how. On my 455 turbo setup this is exactly what I am doing. I have the headers that are currently attached to my heads that will be hacked off with about 1" remaining of the primaries. From there I'm welding on some 2" pipe directly to the primaries with T4 flanges off the front as well as the ports for the wastegate. As said earlier inlet flow to turbos isn't as large of a deal as outlet flow, because of this even with the relatively crude way in which the manifold will be setup I should still get good power from the setup. This also places the turbos in a compact area next to the engine and makes it easy to run your intake tubing (unless intercooled in which case it's still a PITA)