I am terrible at mapping out stuff on turbo compressor maps.

Basically, I am looking for a turbo that is extremely quick spooling to make 10PSI (ish) as fast as possible at 2-3k RPM and is efficient while doing sowhile ALSO being able to flow an easy 5-6PSI at 7.5kRPM. The PSI it would be pushing out of the compressor would be a linear down curve starting at about 10PSI at 2-3k RPM to approx 5-6PSI at 7500RPM.

Large external wastegate will be involved so turbine housing choke is not a big deal since a huge majority of exhaust gases will be bypassed at high RPM. So a small quick spooling turbine housing is a must.

Pls and thanks.

(if you think there is a tuburbo that has an internal gate (ported gate obviously) that would also meet this criteria I would be open to it.

So far I'm thinking a GT2550R meets this after briefly looking at the compressor map. But which turbine housing would be best?

Am I right in thinking that if it is efficient in flowing 10PSI by 2-3k that it will have no problem with the 5-6psi at high RPM? I'm guessing here that the high rpms stuff doesn't really matter?

 

so basically you want this in red?

 

More or less. What turbo is that?

 

a t25 off an SR20, thats running around 9.5psi to redline.


basically a GT2554.

 

Yeah that's what I meant to say in my original post... 2554R. But those aren't available in v-band are they?

 

http://www.atpturbo.com/mm5/merchant...egory_Code=GTH

 

A GT2554 with a .86 turbine housing on a VVT engine would be pretty bauce.

 

I agree. Would make a really nice 225-250rwhp turbo.


also looks like if you have access to a machine shop, you could make the same happen.

need to go to GT28XX to get the cool Tial v-band housing or the one with integrated EWG.

 

I think the GT2860rs is still a viable option for daily driving, especially if you're using a tubular manipheould.
I have a GT2860rs .86 turbine housing, slight overbore, low compression, and 99 head and I'm seeing about 200wtq at 2700rpm. If I had a VVT head on that car, man it would be crazy low. I realistically feel like the car "moves" at 2250rpm even with the trailer on it. When I'm cruising on the highway, I leave it in 6th unless we go below 2500rpm because it just looks weird and it's not a Corvette, lol.

 

Yeah, looks of the milled v-band housing is not a big deal because it will be for the most part completely hidden away. I just want it for the reliability and not having to deal with turbo studs. Downpipe studs I think I can deal with.

This is just for an idea I have working in my head right now, we'll see if it ever comes to fruition.

 

well you can always bolt on a vband adapter on the outlet...

 

true... would that solve the problems that some people have had with down pipe studs backing out? I dont really see it being THAT big of a problem?

The only think that I'm somewhat concerned about is the fact that while the turbo may only be pushing 5-6psi out of the compressor, there will be exhaust gasses coming out of the motor will be equivalent to 300+whp on a flowed, cammed head. This is why I'm thinking a big 44mm tial would be a solution.

 

i dunno, just saying.

 

That's not really how it works, lol.

 

You don't know what I'm doing

Lets just say that the motor will be seeing a substantially higher amount of boost than what the turbo will be pushing out.

 

so you're using the turbo for lowend and rotrex for topend. different from how its "normally" done but I can see it working

 

As long as you don't choke out from the small turbine wheel, this plan should work just fine .

 

yay twincharged miata

 

5PSI at the turbo = 1.34 PR
feeding into something else making 12PSI or 1.81PR

1.34 x 1.81 = 2.42 - 1 = 1.42 x 14.7 = 21PSI.

 

Get 1 giant (or 2 large) ewgs to vent that ish and you should no problem with turbine choking.