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hi guys on with parts for my rb30/26 rebuild using a gt35r 1.06 rear..

two questions. is 3" big enough bore for downpipe, and what bore of pipe would i make the wastgate pipe? 1.5" ok?. looking for arond 600-700 bhp @ the fly..bernie

Edited by rockabilly
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Hey Bud,

I'm running the same turbo. I would match the gate dump, to the gate valve? ie, 45mm = 1.8" (so 2")

I haven't found the turbine outlet diam, but figure ill expand it out to around 4" for connection to a metal'cat, then Trust PEII... so i can upgrade later on.

Hope this helps

Michael

cheers cubes your rb30 guide comes in handy..

here,s the spec.

rb30/26

extreme manifold, gt35r 1.06 turbo, 720 inj, d-jetro, jun 264/272 cams 9.7mm lift, cp forgies spool rods, acl bearings, n1 oil/water pumps, tomei 1.0 mm headgasket?. tomei sump baffle plus bits. hoping for 500 +ilbs torque and spooling from 3500rpm,s....

this is the old engine bay as is but soon to be replaced..25/30,s etc. 600 bhp/445 ilbs.

post-13735-1168528523.jpg

  • 1 month later...

I've got a 45 turbonetics gate with a GT3040, and on 10psi, a 40mm pipe was too small. the boost kept on climbing! it now has a 50mm pipe and that solved that. if i were to do it again, i would fit a 55 just to be sure.

Dump pipe. No brainer, At least a 4inch! 4.5 if u can fit it!

:happy:

Was that manifold made in UK or here in AUS?

Looks like a direct copy of Kyles manifold.

Also rule of thumb for wastegate pipe length is min 18"(450mm) before it rejoins the exhaust system, typically at the arse of a bend so the flow is heading in the same direction as the exhausts.

yeh thats the bloke who copied kyles manifold and started undercutting him in price. Cant say much for blokes like that, but every area has these types of people.

Look for 6boost on calaisturbo also and you will see manifolds that are identical.

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