Lets talk aftermarket turbo manifolds.

[MaczPayne]

For a nearly turn-key turbo setup, I've heard a lot of good things about A-spec's kits.

[classicauto]

Originally Posted by RotaryResurrection

As for the manifold debate...a turbo manifold is not so much like an NA header...runner design is not as important, since there is backpressure created by the turbo behind it. This is shown by the undivided "log style" FC manifolds still being able to make power despite the common chamber they use (as opposed to divided, equal length tube manifolds).

I made over 450rwhp on an HKS cast log manifold, but the tubular copy manifold would have worked just the same. The only advantage of cast manifolds are the noise retention and longer life since the welds will not crack.

The log style manifolds sure do work, I've put down decent power on my Greddy manifold also.

BUT

Runner design can and does have a large effect on the setups effciency. Changing only my manifold out to a stainless divided A-spec unit (and I/C hot side piping, and downpipe because turbo placement was different......) I could get ~500rpm better spool up, and harder spool up with lower EGT's pre turbo. So there absolutely is benefits to be had, but yeah you can put down decent numbers on a cast baby