rb25det turbo manifold... should i resort to stock rather than OBX?

[opponheimer]

I know most people would say Neither, go full race!

But i have an obx turbo manifold coming in, and an GT3582r turbo. Was curious if some of you would rather run the turbo on the stock manifold as opposed to the obx manifold. I am not sure whether it will crack, but many people seem to think those stainless manifolds are made to crack. The manifold also has a 40mm wastegate flange (which is rather small).

So run the stock one (and weld on a 50mm wastegate flange) or run the obx and gain top end at a risk of it cracking?

If i do run the obx manifold i plan on beefing it up a bit... was curious what types of things i should do; ie: slot the runners on the flange, reweld seams, add bracing, etc..

Thanks

[sillyvia13]

run it if it breaks weld it.

[SuperiorS14]

re-enforce it before using it. get some braces welded onto the exhaust flange to support the weight of the turbo.
thats what all the supra guys do with the ebay manifolds for 2j's

[Yellow4g63]

Save some coin and get the 6boost manifold. I think it's like 800-900 AUD. Full merged collector or twin scroll. Or just mod the stock manifold for a external gate and bolt on a bigger turbo.

[g6civcx]

Anything other than cast iron will eventually break. So run what you want and prepare to replace/repair later, or port out your stock cast iron however you want. Your choice.

[smelly240]

LOL - cast iron is less likely to crack but it can

Because its cast doesn't mean it wont break. They cast ones crack when u beat on them with a heavy turbo. hell - stock manifolds crack on NA cars where theres less pressure/heat.

I am not saying its not better than a obx. obx is whack. But the stock one with a 35r? wtf - dont do that.

[g6civcx]

Originally Posted by smelly240

LOL - cast iron is less likely to crack but it can

Because its cast doesn't mean it wont break. They cast ones crack when u beat on them with a heavy turbo. hell - stock manifolds crack on NA cars where theres less pressure/heat.

I thought it was clear that anything can break. Cast iron is stronger than aftermarket material.

With improper use or inadequate bracing though, anything can break.

[ANVIL]

Originally Posted by Yellow4g63

Save some coin and get the 6boost manifold. I think it's like 800-900 AUD. Full merged collector or twin scroll. Or just mod the stock manifold for a external gate and bolt on a bigger turbo.

do this. if u spend the money to get the obx, and then modify to to make it "better" ur probablly halfway to the 6boost one which is one of the if not the best manifold out there from what ive seen. they are also VERY knowledable and can also make custom to your setup to benefit you the most.

[Yellow4g63]

There merge collector is the best I have seen. Everyone else just puts them 3 in a row. His is circle which is hard to do for a Inline 6.