For ~450whp what type of exhaust housing would you guys recommend?

[Insidious Surmiser]

The goal is to achieve the best response/spool.

There is so much data on this topic that I found it hard to draw a conclusion. Especially since the measured results were from so many different types of engines.

For my power goal I was thinking of a either using a .63 A/R T3 single scroll or a T4 .91 A/R twin scroll.

Does anyone have any experience with either, or have any recommendations?

 

[scottiedawg66]

I have a .91 twin scroll on my sw360. I am hoping to make around 450 @ 16 psi on sunoco 94. On my 1j with 272s my powerband starts at over 4000 rpm. Feels like i am around there right now but i wont dyno until early 2014.

With the t3 .63 housing response would be much better but you would need race gas / meth / e85 and higher boost to make 450 most likely.

 

[Insidious Surmiser]

Ok, thanks for the input. I'll have a talk with my tuner about it. Just looking for any input though, really. My tuner already said stock cams will be good for 600whp at least, and that's over my power goal.

 

[IJ.]

.63 will likely choke long before 450...

 

[IndigoMKII]

I'm hoping for 450 rwhp on my t4 .68 at like 16-18 psi.

 

[toyotanos]

IMO, a .63 would be the best if your power ceiling is 450. I'm pushing 788 through a .81 w/cams so there's lots of room for you to upgrade if you want. You also get the added benefit of earlier spool with the smaller housing!

That said, early spool can be a detriment, I'll need to be upgrading to a .96 because I'm surging at ~4300 and that's no bueno.

 

[Insidious Surmiser]

Looks like the .91 twin scroll is where it's at. Not 100% positive from dyno results I've seen from various engines, but it looks promising...

I was planning to get a .68 A/R single scroll T4, but the turbo was discontinued...

 

[scottiedawg66]

.68 t4 is a pretty sweet deal and i think probably a good bet for your requirements. But i still would bet u would need to run race gas / alcohol to get your goal.

I will be surprised if i hit 450 with my set up on pump only @ 16 psi

 

[Insidious Surmiser]

My tuner said he did a 2jz @ 550whp on 93 oct. (pump) with a 58mm borg warner and .68 A/R. My head is actually flowing a bit better than a stock 2jz head, so I'm thinking a 60mm should pull the same numbers if not even more. I've seen really good results with the .91 twin scroll in terms of spool and flow (from looking at other builds and dyno results) It's still not possible to take into account all of the variables that would affect both aspects....

I'm kind of looking into everything ATM....

I am only shooting for 400whp. So the engine will most likely be de-tuned from what it's capable of. Or if 400whp isn't quite enough I'll have some breathing room.

 

[IndigoMKII]

Well, the good thing about it is if you try the .68 t4 and its not quite enough, there's always people selling or trading turbine housings. I'm going .68 til I can open up my head and the revs a little bit then I'll go to a .81

 

[scottiedawg66]

Not alot of people have dynoed those "new" efr borg turbos. Sounds like you are looking at the 7670? That looks like a very promising unit for sure i say go for it.

I was going to get that same turbo, but the lack of real world testing and unknown general reputation of the efr series steered me to the cheap s360 until more is known about the efr. I have never been an early adopter or new technology.

 

[MNBmk3T]

My buddy, aka GrimJack, is putting down 580 with a PT6765 .68 T4. I would think with a .63 you should be able to make 450.

 

[Insidious Surmiser]

nice^ thanks for that info. I was looking at the s360 or the s300sx fmw.

 

[scottiedawg66]

a 6765 is a 67mm inducer i believe. that is a far cry from a 58mm inducer... spool would be drastically different on the 67 vs 58 and hardly what most people would call a response turbo compared to a 58.

there is a lot more to turbo sizing than the ar ratio of the exhaust turbine housing. I would start by reading the compressor maps. Then choose the ar ratio that best suits your needs once you have decided on a compressor and turbine wheel.

the s360 is a 60mm inducer, full race makes a 61.4mm billet wheel the 84-75, and boost lab has a 62mm billet wheel known as the s362 FMW. I just spent loads of time researching turbos. I went with the standard s360 since I planned on changing my set up again before too long and the price was ridiculous.

 

[Insidious Surmiser]

67 should be the exducer. At any rate it looks like a 8375 (s300sx3-60) w/ .91 twin scroll would smash my power goal with good response.... still gotta have that talk

as far as anything with the type of flow I'm looking for... I can't really find a basic T4 from BW in production that has a smaller compressor.....

 

[scottiedawg66]

the current 6766 is a 67mm inducer i imagine the 6765 is the same with a smaller turbine wheel. http://www.precisionturbo.net/Stree...treet-and-Race-Turbocharger---PT6766-CEA®/480


to get a smaller inducer size in the BW line you would have to go down to the s200 series. the s259 is really expensive, and the s258 didn't flow enough for my goals. ~450 on pump and an easy 550+ on race gas.

that is why i "settled" for a s360 83-75 with the .91 twin scroll. For another few hundred I could have had the full race 84-75 and if i was not eying that efr 7670 I would have gone with the 84-75.

once I dyno I will share my results here, but its not really a good comparison for you since I am a 1j on 272s.

 

[Insidious Surmiser]

oh, true. I'm using stock cams, w/ a true 3.0 7mgte w/ ported head (bored over .05 on oe pistons makes it pretty close to being exactly 3.0 litres)

I'm seeing roughly $700 for the s360 or for the FMW it's $800 with no additional options... I'd probably get the flat turbine though ($15) the s360 is the same price on full-race (800)

 

[scottiedawg66]

I got my s360 with the 90* compressor housing and open .88 exhaust housing for $600 shipped and tax. then I went to boost lab for the .91 divided with the standard vband welded on for another $ 225.

Now it looks like boost lab and full race offer the 90* compressor housing option, when I was shopping they did not. I probably could have got a better deal and not ended up with the spare .88 open housing if I was ordering currently.

hopefully some of this helps!

 

[Insidious Surmiser]

Definitely food for thought, I appreciate it.

 

[atmperformance]

this has been a good read, i plan on shooting for 450-500 on a t4 turbo when I'm up to take the next step. I'm looking for response over peak power.