Although its really easy to find lots of info on this forum about 13b single turbos, 20b setups are a bit more few and far between. So here goes (and hopefully this will be a good thread for people who are searching)

What would people say about these turbos for a street ported (racing beat style) 20b engine? Here are the goals:

Run on 91 octane fuel (so maybe 15 psi limit)
No less that 475 hp to the wheels
Fat power curve (full boost no later than 3500 rpm)

Now, here are some of the turbos i was thinking about:

GT40R
GT42R
Turbonetics T66
Turbonetics T72
Turbonetics T76
Greddy T78

What do you think about these choices? Since its a 20B, there is no divided manifold obviously. Lets hear what you have to say or if you have personal experience or other turbo suggestions. A good thread for those who actually use the search function would be great ;-)

Graham

 

One of the best turbo's on a street ported 20B is a GT42R, I can get them pretty quick If wanted, I would say the 40R is going to be slightly on the small side depending on the port. It's not that the turbo is to small, it's that the exhaust housing will only go up to a 1.06 in the 40R which is on the small side for a streetport 20B. I would say if it were my car it would be a GT42R with upgraded comp wheel. This would produce big numbers.
With spool being very close to what you are asking, full boost is a relative term by the way.However this would not be a 15psi setup either, if your only going to run 15psi on 91, than a GT40R. would be really nice with a wide powerband.

-Sean

 

Graham, is this for that lovely 20B Chris just put together for that saidrail in the Midwest?

Beast

 

Thats what I'm considering for my 20b as well. Just trying to find the best deal on this particular turbo.

 

you can make 475 on a 2 rotor, why dont you set your goal a little higher man. seems like a waste of money if you dont get some serious results. Some people are making around 550 rwhp on the stock twins at 15 psi

 

550RWHP on the stock twins??? What are the names of these members?

 

I can pretty much match anyones deal on the turbo.

-Sean

 

a couple of months ago i was down at kdr and there was silver 3rd gen with red interior and a 20b with stock twins. He made 550 rwhp at 15 psi. Dave at kdr was telling me that wasnt uncommon.

 

Yep they are making 550RWHP @15psi with the stock 20B turbos in sequential mode too.

 

Is that with stock ECU or a stand alone?

 

Were these 20b's with stock ports? I've never heard of Pettit Banzai getting that much power to the ground on stock twins. It must be that Anti-Det device they have giving them a tuning advantage.

 

That is a mighty big claim. Also, are you sure they are running sequentially? I didn't think anyone was. Ithought everyone was running them in parrallel.

 

Heheheh, no beast. But that person WILL want a turbo upgrade in a little while, only staying with the stock twins because of time constraints.....

This thread/question is for my new evil project that ive been conjuring my head for the last month.....
Planning on selling my FC soon and getting a daily driver car then using the rest of the money to start my project.

Good point, but the goal is a MINIMUM of 475 on 91 pump gas. More than that is great, but i set that as a minimum. I like the 3 rotor because i can get more hp out of it without wringing the **** out of it with high boost like a 2 rotor. 91 octane means lower boost levels so displacement takes care of the power issue. Plus a 3 rotor has more low end power which is good for a street car.

So does anyone have any more suggestions for a single turbo setup that meets my requirements? ZeroR had some great input, lets hear some more!

Graham