Hello,

I am in the process of finishing up my T04B kit and need a wastegate. The Turbo is a Garret 60/100 and is in excellent shape. I also picked up a HKS copy manifold with the unibolt wastegate setup (Fits HKS/Tial/Deltagate). The car is a non ported TII (1989) with a SAFCII, larger injectors full RB exhaust, Fuel cut def/ aftermarket TID. I am only hoping for about 350 @ the wheels. I can get a NEW Tial 35mm for about 200.00, a used deltagate for about 150.00 or an older HKS for 200 - 225. Ideas??

The Turbo description:
The comp. has a 3 inch inlet and 2 inch comp. outlet with A/R of 60. The turbine is A/R of 1.00

 

A good rule. Wastegates are hard to buy "too big". It's basically a safe guard garanteeing no boost creep. When ya want 10psi...ya get 10psi..no more. I would recommend a 40mm.

With your setup I would definatly consider a Stand-alone ECU. The AFC is okay to a point, but with such a setup you will definatly be reaching the limits of what the stock ECU can do with an AFC.

What size injectors do you have, Primary and Seconday? Aftermarket fuel pump? Again, your definatly topping out the stock fuel system. I would recomend:

Walbro 255lph
1600cc secondarys
Haltech E6X
FMIC

Good luck

 

I have 720's in my secondary positions and a Walbro 255 in the tank.

I have a huge Hybrid intercooler that I need to get installed (Will require custome piping). I just haven't had time to start the fab work..

 

go 45mm or bigger then you know you wont have any problems

 

Good luck with your set-up.
It's going to blow-up soon.


-Ted

 

You don't need something that big! Trust me man a Tial 38mm will be more than just fine. My HKS Standard 40mm holds more than 400 rwhp perfect, now I'm gonna be going for a lot more power, so I will either buy a new bigger WG or get a new spring and port my current one. Tial and HKS are the only two companies you should really consider when it comes to WG IMO. If you can't afford those two, then maybe turbonetics. Make sure you have a good exhaust manifold. Some have leaks or the flanges don't run from both exhaust pipes.

Alex

 

you guys do realize that the LESS boost you run, the bigger WG you need, right?

 

What constitutes proper wastegate sizing?

 

Yes, but it only makes a significant change when you have a large turbo and are boosting low. Incase you're questioning me as to why, well because the WG at lower boost has to control much of the exhaust air, while under high boost the WG dumps most of it.

Alex

 

Can you explain why?


-Ted

 

Supposed flow, your trying to control flow to the turbo, the lower the boost setting the more you have to divert to avoid creep issues,spiking or fluctuation, the more boost you will be running the more flow needs to go to the turbine (less diverted). At least that's the idea he is trying to convey 45mm should be fine for most any of your needs.

 

Although you would think this would be the case, I think otherwise.
A turbo making more boost is, in essense, creating more of a differential between turbine and compressor load / pressure.
More boost means more load, and this more exhaust pressure / load.
The turbos making less boost has less exhaust pressure / load, and thus the wastegate control is pretty mild.
And higher boost, you have to deal with more exhaust pressure / load, and this better wastegate control.

If we needed to worry about wastegate sizing at lower boost, why doesn't the boost spike at lower boost levels (assuming too small a wastegate)?
Doesn't boost spiking happen more significantly at higher boost pressures (over lower boost pressures)?


-Ted

 

I tend to disagree with you for different reasons than those above,(I think). I think when going too big it is harder for boost to be modulated at lower boost levels due to too much air being diverted, the BC has a harder time maintaining boost solidly, Ive seen this a couple times, theory only here not fact when we did raise the boost though it went away.

 

GT3540 with an HKS GT 60mm wastegate
I would think this would be as extreme a condition as you can imagine.
We had no trouble punching over 18psi of boost at 3,000RPM messing with the boost control.
I would think it would've gone higher if we wanted to.


-Ted

 

Again, I urge you to go with a Stand-Alone ECU.....Have you seen anyone running a Upgraded Single on the stock computer? Your playing with fire....well,... detonation.

 

Ted how was it at 7psi? what you just desribed is the opposite of what I just described above.