Biggest 30 framed turbo without sacrificing spool

[joshg123]

Hey all,

I currently have a hks3037 that ive fitted a garret twinsrcroll .78 rear housing to, on a 6boost manifold and twin tial gates.

Im thinking of experimenting with a slightly larger turbo as im building a new motor to rev higher and my dogbox will help with dropping off boost in gear changes.

From what ive read, a 35 framed turbo is going to essentially throw spool out the window, even with the twinscroll. I base my figures off the VE of a pretty standard SR20, as a rough guide.

Is there a GT30 framed turbo, that i could run on my T3 flanged manifold that will nett me a extra 30-40whp. I could sacrifice 500rpm more spool (bringing reasonable boost to 4250, current turbo has about 18psi at 3850 or so). From all accounts this 3037 will run out of puff at about 400awhp.

Any suggestions appreciated

Josh

[Joe]

Twin Scroll GT3071R... but of course you'd have to re-do the manifold.

[cplagz]

BorgWarner S259, billet wheel, extended tip. Talk to BullseyePower...or step up to a S362

[datsqik]

Ive used the T3/60-1 combo before with a 63 housing to get 430rwhp (27psi) on an SR20. The 60-1 can flow around 7 lb/min more than the 56 trim gt30 wheel without loosing to much response. They can be ordered in with bb cartridge and split pulse 78 rears.

[magic1]

NOS

[mitchy]

Twin Scroll GT3071R... but of course you'd have to re-do the manifold.

that's smaller?

3037/3076 same same i thought

[SimonR32]

Technically a GT3082R (GT3040R in old speak) is a little bigger than your current turbo in both compressor and exhaust trim...

Also a little more laggy but not as bad as a 3582R

[180SXTCY]

Twin Scroll GT3071R... but of course you'd have to re-do the manifold.


youo'd be lucky to see over 400rwhp with a 3071r...

why not keep ur 3037 / 3076 and change the exhaust housing from .78 to say .82 to allow it to flow abit better?

[Joe]

FFFUUUUU

Don't mind me.. sleep deprived and didn't even read your original post properly! I see you already have a twin scroll manifold and a .78 rear housing, so the 3071R would be pointless.

Look here.. http://www.full-race.com/catalog/index.php?cPath=214

Try for something like a GT3076R, the ones for sale on the Full Race website are rated to a full 45HP more than the 3071R.

Spool though, I have no idea.. its one of those trial and error things I'd imagine.

[180SXTCY]

my mate has the 3076r .82 on his sr20 with cams etc and it made 418 rwhp at 22psi. making 22psi at around 4000ish rpm

[PAGZ]

gt3040r with ur .78 twin scroll would probably do the job?

[juggernaut]

You could try the T3 1.06 twin scroll housing. IMHO at around 400rwhp or thereabouts the .78 or .82 ex housing becomes the limiting factor not the compressor. Single scroll 3076's on E85 have churned out over 500rwhp and run low 10's - in an s13. The larger housing will also help with your goal to rev a little harder too and be within your additional 500rpm boost tolerance.

http://www.atpturbo.com/

I've had my .78 housing extrude honed in the US for more flow and C-Red are currently finalising the instal at the moment - but I'll be running the smaller 52 trim 3076 compressor.

Cheers,

Ian

[joshg123]

Well as im setting up to run E85 id call that a pretty fair comparison in terms of engine output (obviously bar the 200cc capacity). Taking from that, the turbo can produce the airflow for 500rwhp on a SR, you would then say it would flow enough for 430-440awhp if everything else went right. I like that idea, its inexpensive and i have an account with ATP for all my other stuff.

On the flipside, the S326 Borgwarner looked pretty awesome, but im thinking thats gonna be a lag monster even with a .55AR twin entry rear. USA people report usable boost at like 4750 on 4G's. So id be way worse than a cammed 4G. I dont really want to rev my new motor past 8500/8800 area depending on the power curve i end up with. Thoughts?

Thanks for your input Ian, has yours now been tuned?

Cheers

Josh

[juggernaut]

As far as I'm aware it was supposed to go to ASG yesterday for tune and should be finished today. C-Red organised it for me. Marc at C-Red suggested if I was going to go to E85 down the track then it was better to go to Sean for the tune in the first place.

I just go with what Marc recommends. So I should hear today unless something went pair shaped in the mean time. I'll post up the results and dyno when I hear something so this might give you some insight.

The Borg Warner stuff looks good too. However, there just isn't enough data out on these twin scroll turbos for the SR's. You could be a pioneer! :)

Cheers,

Ian

[datsqik]

There is a whole bunch of new billet compressor wheels hitting the market at the moment from various turbo manufacturers. There is basically 2 different styles of these wheels. One is basically a copy of either garrett gt style wheels or borgwarner wheels. Garrett themselves actually do some of these in larger wheels that arent so much in demand as its easier to machine these up rather than cast them up. They offer some advantages over the cast wheels with slight increaes in flow. The other type of wheel is a whole new design that uses 11 large blades rather than the normal large and small blade combination, these new wheels offer more flow and a much broader compressor map and can be run at much higher boost levels. These new 11 balde wheels will filter thru the whole range eventually i'd imagine and places like forced inductions are currently doing the same thing. Precision turbos are also doing some billet wheels but they look to be like the gt style wheel but in billet. They are claiming that they are getting more power and better spool from these compared to the same size in a cast gt wheel and have a huge range in particular t3 sizes. Not much on there web site but a bit on them on some US based forums. If you really want the most hp for the least lag then this new generation of wheel is the way to go. I have no idea when any of the smaller 11 blade wheels will hit the market but the billet gt style wheels are out there and it might be worth giving precision a call and see if they can supply something like a 600hp t3 wheel ( around 60mm inducer - 76mm exducer) billet wheel that you could fit to your turbo whit a bit of machining.

[cplagz]

7/8 blades - http://www.bullseyepower.com/news.asp?id=71

11 blade billet wheels datsqik is talking about here -http://himni-racing.com/index.php?main_page=index&cPath=25_275

[juggernaut]

Dyno results are in....will post up boost graph when received:

http://i241.photobucket.com/albums/ff132/juggernaut000/3076Dyno.jpg

[c.rusli]

what a monsteer........

[joshg123]

Whats your car Ian? and supporting mods?

[juggernaut]

Josh,

Car is S15 ADM

Mods include:

Full-Race Motosport Twin Scroll mani with twin tial MVR 44mm gates
3076 52 trim with extrude honed .78 divided ex housing
Hypertune Intake manifold and t/b
1000 cc Sards
Autronic
Forged and Darton Sleeved Bottom End
JHH Engineering Head with larger Super Tech inconel ex valves
Tomie 260/260 12mm lift pro cams
3.5 inch dump and exhaust
100cpi cat
gate dumps merged back into exhaust

This is a pic when it had the 3071 on it.

http://i241.photobucket.com/albums/ff132/juggernaut000/SR20Build019.jpg

[Passage GT]

shit that's an awesome engine there, great torque and fuck all lag for near 400rwhp
nice work dude, engine bay looks sweet too

[juggernaut]

Thanks.

Josh,

Here's a link to a thread with a 3076 with a .78 twin scroll ex hsg....but running big 280/280 tomei cams to make 472rwhp at 24psi. Not ridiculas rpm either. This is motor is in a circuit/timeattack car.

I think he is also using race fuel to make this hp. In summary, you can make big hp with the 3076 if you run a big ex hsg or big cams (and race fuel/E85). So it seems the .78 twin scroll ex hsg can support big hp with big cams and decent fuel.

http://www.freshalloy.com/forums/showthread.php?t=171645&page=2

[joshg123]

Hi Ian,

Thanks for that link. Very interesting.

Just to make sure all info is on board, ive sent a email to bill at bullseye to see what he thinks.

[juggernaut]

this is the car in action

http://www.youtube.com/watch?v=N5hmiql_h3E

[cplagz]

josh - let me know what bill says, I also know TurboLogic in woolongong do BWs a mate just picked up a s256 for 1600 delivered.

[Friar]

I'm running a hks3037 44 mil gate 272 cams on a stock bottom end and when initially tuned made 450 hp at the hubs and was detuned to a high boost of 23psi makes full boost by 4200 and doesn't drop off till 8k rpm

[masTers]

Was looking at those BW twin scrolls to run on my FJ20. Those fullrace guys seem to know what they are talking about.

[joshg123]

Marc, Bill reccomended the S259B extended tip with a .55 stainless housing.... For the price its well worth a try considering i only have to change my dump pipe to suit a borgwarner. Compressor maps shows it will reach 60lb/min wheras the GT3037 runs out at 55lb/min

Sunshine - thats when i expect mine to run out, i would expect a bit more drivetrain loss being 4wd over a rwd that i assume you have?

[cplagz]

Do it! And then I can have it if you don't like it :D What price is Bill quoting? I got a mate building another turbo BMW who needs a snail.

[joshg123]

Marc,

Bill said 1590USD for the Billet 259 wearing the .55 stainless housing. He said he would discount it a bit more to help with shipping also, however dont know what he will take off.

Expensive for a journal bearing turbo, but from what i read worth it with the billet wheel on the front

[Friar]

sorry i have an evo 7 so its awd that was on a hub dyno sean at all star said there is still a fair bit to go with my turbo isnt fully efficient until 2 bar :)

[joshg123]

Interesting, thanks for that.

You still a 2L?

[Friar]

Yep still a 2 ltr does your turbo have the 4 inch inlet with anti surge housing just want to see if it's the same turbo if your keen to run a bit more boost I'm sure you would easily get another 30 or 40 hp out of it

[joshg123]

4 inch inlet and anti surge yes, its one of the last ones with HKS GTPRO written on it before they went to the garrett front covers