What's the limit of an internal gated turbo?

[Clinical]

Just curious as to what the limit is of the average turbo on an internal gate and the overall benefits of going external.

I'm running an FP Green at 25psi internally gated currently. I intend on going 28-30psi in the spring.

Also does anyone know any good inexpensive exhaust manifold with mounts for a 38mm tial? I'd like to not bother with some stupidly expensive o2 housing.

 

[jjrock5]

I'd say grab the Slowboy Racing cast manifold. It has a provision (flange) for wastegate at the runners.

The only problem with internal gates is that at those boost levels, you will probably not hold the boost that you want.

 

[Clinical]

Surprisingly it has been holding 25psi perfectly, never fluctuates at all - I just rarely hear of people running internally gated at the 500whp+ level which is what I'm going for this winter so I figure I'd better look into upgrading.

I'll check out the manifold, thanks!