I have been told that the Tial 38mm and older Tial 35mm wastegates can be used interchangeably. Does anyone know for a fact whether or not this is true. The reason I ask is because I do not know which my turbo is flanged for. I know it is one of the two. Is the size (38mm or 35mm) the actual diameter of the hole through which the exhaust gas passes, or is it more complicated than that. If it is just simply the size of the opening I can obviously just measure that. If the wastegates can be used interchangeably then it doesn't really matter, but if they cannot be used interchangeably I don't want to order a 35mm wastegate only to find out I needed a 38mm, or vice versa.

 

Tial 35, 38 and turbonetics deltagate all share the same flange

Any larger than a 38 and they change flanges. HKS uses dif flange, etc.

 

thanks hal. that makes things easier.

 

Neal, saw this on e-bay:
Brand New 35MM Tial Wategate---NR
http://cgi.ebay.com/ebaymotors/ws/eB...922935527&rd=1

 

I have a question regarding size.....how much difference will it make btwn 45 - 48mm wastegate? Obviously the answer is 3mm, but is 48 too big for under 10psi?

What size do you guys have and what made yall choose that size?

 

bijan, for a low boost setup, the larger the wastegate the better (in most cases)

this is because you need to get rid of the exhaust gases efficiently on the low boost setup so boost creep doesnt set in.

 

Lower boost= Larger wastegate, smaller turbine.
Higher boost= Smaller wastegate, larger turbine.

X amount of exhaust needs to go through both, so both can't be too small or large. But better to go a little bigger on the WG for safety.

 

Thanks.

 

38mm Tial for me.

It is true about larger wastegates being better for lower boost, but in reality, only high hp high boost setup guys run them because they are so expensive. The benefits of a larger wastegate on a high boost setup are simply more stability, it's a lot less likely that you'll outflow the capabilities of your wastegate and have boost creep with a larger wastegate at high boost.

 

agreed. I've seen many 450-500+hp 16-20psi+/- cars with Tial 38mms....you shouldn't need more than that.

oh and deltagate = the suxor I don't trust the infamous "diaphragm blowers"

 

38mm seems to be the popular size.

shameless plug - i have 2 Tial 38mm gaskets FS if anyone needs some.

 

I already got a Tial 38mm wastegate so I need to decide on the turbine size. I will be getting a GT40 82mm compressor turbo with a choice of .68 or .81 for turbine a/r. Im not sure which one I should go with, I would prefer the .68 for the faster spool but I will also be spraying a small shot of nitrous, will this outflow the 38mm wastegate with a .68 a/r turbine?

 

It should be fine. I've seen 38mm wastegates on some very high hp cars with pretty big turbos. How much boost do you plan to run on a GT40? That's a fairly large turbo.

 

I plan to run around 14psi and maybe up to 16psi. On the compressor map it seems like it will do good, ill just have to wait and see. When you say there are high hp cars running 38mm wastegates, it might be because they are running a lot of boost so a small wastegate can be used. In my situation, im not running a huge amount of boost for the GT40 plus I will be spraying nitrous and the 38mm might not be able to flow the exhaust and I might start getting boost creep if it turns out to be too small.

 

I still don't think you'll have too much of a problem. I've seen cars in your boost range and 400+whp run 35mm Tial's without creep. If you're worried, just get the 44mm now. I just don't like the price, but if you've got a GT40, then the price isn't too big of an issue.

 

Dang I remember this thread from back when I was a turbo n00b.

Anyways I've got a Tial 38mm and run more power than most and I don't creep.

 

Sounds good enough for me, a 38mm should be fine then. Thanks for all the replies everyone.