1UZ GT35R and wastegate size

[lowfat_hg]

Hi all, after my last turbo was stolen i have bought another, this time a gt35r. it has the smaller 0.63 turbing housing and i want to know what size wastgate will be best suited.
i plan to use 15psi and want about 500rwhp.
I have a shot of Nos planned too, and i am worried that i will suffer boost creep if i go too small.
I think that i need a 40-44mm unit.
I can get them on ebay from america way cheaper than locally.
give us your thoughts,
thanks guys!

 

[XR8tt]

Yep 40mm .. I think the rear housing maybe too small?? I'd be looking for 1.06 housing.. I have twin's on my 5.4 ltr Windsor and they are .63 Presicion.. Import a S400SX from U.S...There extended tip makes them big turbo's spool nice... Dave at http://www.majesticturbodallas.com/index.html
will help you there...
I just bought a 46mm Tial, way cheaper than here...Our $$ is o/k too...
From here http://www.speedclinic.net/shop/index.php?p=product&make=any&model=any&cid=8&scid=17&mid=6&pid=33

 

[stevechumo]

You're making some monster hp so I think 44mm is the better deal. I think 50mm is even better.

 

[XR8tt]

You're making some monster hp so I think 44mm is the better deal. I think 50mm is even better.

YEA strange as it may seem the more boost you run the more efficiant wastegates are... One too big can be pita too...

 

[stevechumo]

YEA strange as it may seem the more boost you run the more efficiant wastegates are... One too big can be pita too...

I'm currently using the HKS 50mm wastegate on my 1UZ and the boost is very responsive and consistent at 6 psi. I think the hp rated on the wastegate also has to be matched with the engine displacement.

 

[XR8tt]

I'm currently using the HKS 50mm wastegate on my 1UZ and the boost is very responsive and consistent at 6 psi. I think the hp rated on the wastegate also has to be matched with the engine displacement.

YEP !! At 6Lb alot of exhaust is going through wastegate..
At 12Lb or so its much less precentage wise, plus there is more pressure to make it efficiant..Keeping to the theory that exhaust is approx twice boost pressure ...
The same turbo with internal [intergated ] has quite small gate, from memory around 30mm...

 

[stevechumo]

YEP !! At 6Lb alot of exhaust is going through wastegate..
At 12Lb or so its much less precentage wise, plus there is more pressure to make it efficiant..Keeping to the theory that exhaust is approx twice boost pressure ...
The same turbo with internal [intergated ] has quite small gate, from memory around 30mm...

You're right. I see the internal wastegate has very small outlet hole. That's why I'm kind of hesistating to go for internal wastegate if I aim for more than 300 rwhp. However, I think the internal wastegate has its advantage due to its close distance for venting the boost.

 

[XR8tt]

External 44mm would be fine, they jump up in price [Tial] from this size...
99% of w/g efficiancy is the merging of w/ gate pipe design...Try to avoid 90* merging ... Yes we have had to port intergated 3540's and fit bigger flapper...Some porting on inlet turbine side helps as there seems to be turbulance that prevents good flow....
A mod tike this helps w/gate flow on intergated turbo's.. This is not a GT3540...

Tune !!! Too rich and too retarded can cause over boost due to extra fuel in turbine being burnt...Vertually anti lag... Heats cra big time, maybe safe engine tune but bad news for turbo !!!

 

[stevechumo]

That looks like a modded T3. Look at all the carbon build-up due to unburnt fuel...I'm sure it smells great...LOL.

 

[XR8tt]

That looks like a modded T3. Look at all the carbon build-up due to unburnt fuel...I'm sure it smells great...LOL.

Black ceramic coating ... GT53R is a T3 housing.http://www.gcg.com.au/Catalogue_Menus/Garrett Ball Bearing Turbochargers/garrettbb_gt3540_iw.htm
. 11.7 fuel ratio..