what are your thoughts 20b turbo manifold

[vex]

There's benefits and drawbacks to both manifold designs. Log style manifolds (if constructed correctly) will hold more heat which translates into more consistent temperature differentials across the turbo resulting in faster spool up times. This comes at the price of horrible exhaust flow which will limit the amount of horse power and torque when not under pressure.

Mandrel bent type manifolds flow much better but do not retain as much heat as the log style. This means, in short, that you will have slightly longer spool up times but less back pressure on the engine when not in pressure.

There are ways of getting the best of both worlds however. Taking the flow characteristics of the mandrel type manifold with a heavy steel wall for the runners and combining it with either ceramic or heat wrap causes the temperature to be retained within the manifold resulting in more uniform exhaust gas temperatures while not impeding flow.

Additionally with mandrel bent type manifolds you can adjust the various runner lengths for a specific pulse pattern to better effect the turbo--but that might be outside the scope of your build.