turbo header build Q's

Im building a 545bbf with twin s400 series turbos and need to know what size tubing to use for headers and also what size the hotside pipes should be. thanks

If you are talking about the B/W s400 I think it is a 5" DP and tubes for the headers what heads are you running?

Most are 5" and they have a different taper than the Precision's and Garrett's. Stepping down to a 4" quickly after the flange is what most do.

NW outlaw can help you on tubing size. The only turbo headers for bb's that I have built were for a twin 91 car and they were 2.25" with a 4" hot side and 4" after turbo but the exhaust was only like 18" long each.

Northwest outlaw wrote:If you are talking about the B/W s400 I think it is a 5" DP and tubes for the headers what heads are you running?

yes, the exaust is 5" but what size pipe should I run from headers to the turbos? 3" or 3.5"?The heads are SCJA Kasse heads. Thanks Outlaw, was wondering if anyone could help me here.

I'm doing a single turbo 547 and decided to use 2", 14 gauge primary tubes to 2.5" collectors combining to a 3" as it goes to the turbo. I'd think that a similar setup should be fine for you too. All of that seems very small, but the exhaust gauge is under pressure.

Have a good day!
Michael