tail 38mm wastegate or 40mm

[BOOSTED4LIFE90]

hey fellas im about to purchase a 3'' downpipe and a 3'' o2 housing w/an external dump and a external wastegate flange.my question is how big of a wastegate do i need,some people say go with the 38mm and some say 40mm but i need more info.i will upgrade my turbo by next year in june,i will upgrade to a 50trim so what do u guys think?wheres a good place to buy wastegates for cheap. allright fellas all ur help would be greatly appriciated! thanks!

 

[DSMJim]

The 38mm is large enough for most people and is much easier to work with as most popular manifolds have that same Tial 35mm flange style on them. If you goto the 40mm you would have to deal with the flange style on a 40mm which is different. You would have to make a conversion plate or get a special manifold made etc etc.. Not worth it IMO for a non-race car on a 50trim.

 

[TwoLiterV8Eater]

I have the 35mm Tial gate(14psi spring) on my manifold with a 50 trim t3/t04e. It holds 14 psi to redline, without a boost controller hooked up. So I would say the 38mm is going to be plenty. I wish the 38mm was out when I bought mine, but the 35 works so I guess its not a big deal really.

 

[DSMJim]

Originally posted by TwoLiterV8Eater
I have the 35mm Tial gate(14psi spring) on my manifold with a 50 trim t3/t04e. It holds 14 psi to redline, without a boost controller hooked up. So I would say the 38mm is going to be plenty. I wish the 38mm was out when I bought mine, but the 35 works so I guess its not a big deal really.

Speaking of that, my 35mm only has a 10psi spring and it holds 10psi to redline as well with no spike and no boost controller so the 35mm gate really is a pretty good piece. I have a 50Trim as well.

 

[DongeR]

why are you running so less boost on an external?

 

[DSMJim]

Originally posted by DongeR
why are you running so less boost on an external?

What do you mean? I'm making 357whp on 10psi :laugh:

I'm saying my spring in my wastegate is set to 10psi meaning if I unhook my boost controller it will just goto 10psi and hold there with no creep which is hard on a larger turbo. That basically means the 35mm gate is good enough to do that then its a good gate all around. I run 22psi daily.

 

[jake98gst]

Just a question: What O2 housing are you gonna use/make/buy to where the WG bolts to it?

Thanks,
Jake

 

[92tsiawd84]

I am going to have a local buddy make an o2 housing for me for my tial 38mm external. I am also going to run a 50 trim. Ordered last monday. I bought teh wastegate through darksideracing.com. I wouldn't buy from them again though. It took over a month to get. The price was $255 shipped (I think) with 2 flanges.

 

[BOOSTED4LIFE90]

hey fellas well im going to be using an RNR 3'' o2 housing with an external dump and i will also be running a 3'' downpipe.so the 38mm wastegate will be enough right?what kind of spring should i get on the wastegate,for now i will be running the t-25 at 14psi until i get the 50trim in january.allright fellas i really appriciate all the info that u guys are providing me with.thanks!

 

[->PrOjEcTGS<-]

I just bought a 35mm off of a guy I know and was wondering if the flanges were the same for the 38mm and the 35mm? I was thinking about getting the VP o2 housing and they don't specify a flange for the 35mm but they have one for the 38mm. Thank you..

~kletke~