[torontocrx]

Hi guys, I'm looking for some help regarding a couple of wastegates.My turbo set up is going to consist of b18c with cast iron log manifold, gt3076r,and a few other goodies.I've been told by a respectable performance shop in my area that the 38mm turbosmart wastegate(ultragate) that I've already purchased, is too small for my application and will cause boost creep at high rpm(motor will be reving to9500 rpm).Boost is going to be kept to 8-10 psi for now. Turbosmart says this wastegate is capable of dealing with 400-500 horsepower. I'm sort of confused and not sure what to do at this point. I already have the turbosmart wastegate and don't want to have buy another one. Any feedback would be greatly appreciated, thanks.... :?:

 

[BlackCRX]

lower boost requires larger wastegate size
it sounds weird but its true, if your wastegate is currently set for 10psi then more flow will be required to maintain that 10psi without creep b/c you will need to bleed off all extra pressure. if you were set for 20psi then less flow is required since most of the exh gases are being used.

with that being said, what are your boost/hp goals for your setup?

 

[torontocrx]

Black crx,I appreciate the response.My horsepower goals are 250-270 whp at 10 psi. What you said about the exhaust gas flow actually makes sense. I hadn't thought about it that way. I've heard the tial 38mm wastegate causes boost creep at high rpm but the turbosmart 38mm doesn't.Is this true? I really don't want to have to buy another wastegate?

 

[BlackCRX]

havent really heard of that myself
i would have thought tial would have been the better one of the two
but when you think about it, 38mm is 38mm

 

[torontocrx]

I agree, 38mm is 38mm. What I'm wondering is if their is a design feature in either wastegate that makes one superior to the other.For example valve lift ,spring quality.Has anyone ever done an article,write up on this sort of thing, because I've been searching and can't find anything. thanks again guys

 

[BlackCRX]

no article/write up that i know of

but all the turbo guys i know with built motors run tial everything pretty much