GT3037/GT3076 Wheel/Housing upgrades?

[joshg123]

Hi all, engine is out for another build. Had a few little gremlins with the previous setup clutch wise, and head wise so am changing to my spare rally head, and going to solid lifters and balancing the bottom end.

On previous tune we spun the motor to 7500rpm, 1.5 bar saw 350ahp or thereabouts on 98. Currently spinning full boost before 4200. With the cars gearing it comes on just right to punch 2nd out of corners at 60-70km/h. 400 or just over was on the cards on the race gas before i ruined the clutch. However Sean was telling me this turbo normally hits a bit of a brick wall at 400whp

Looking to step it up a notch this time the engines out, blueprinting and balancing the bottom end, with the solid lifters should see it safe enough to spin 8750 or so, and run 2.5 bar of boost where possible. Oversize valves and a flowbenched head will see me bring boost on earlier (over my stock head bar cams last build)

Currently i have a HKS 3037 pro-s, my question is are there any upgrades housing/wheels wise that can lift output by 50hp or so, without having a detrimental effect on lag.

Any advice muchly appreciated

Cheers

Josh

[PAGZ]

3076r wheels a little larger maybe good for another 20hp or so?

[joshg123]

3037 is the same as garrets 3076 hence why i put it in the title

[PAGZ]

The 3037 needs machining to fit a 3076r wheel, slightly bigger.

[180SXTCY]

pretty sure there is two spec 3076r's made by garrett.

first one specs:
Wheel: 60mm w/ 84 trim
-Housing: .63 ar, .82 ar, 1.06 ar
-Maps

Compressor
-Wheel: 76.2mm w/ 56 trim
-Housing: .60 ar

other ones specs:

Wheel: 56.5mm w/ 90 trim
-Housing: .64 or .86 a/r
-Internally Wastegated (No Actuator)


Compressor
-Wheel: 76mm w/ 52 trim
-Housing: Various a/r
-Inlet: Various

afaik it depends on if its internally gated or not. also what size rear exhaust housing you running? if its small such as .63 maybe look at going to something bigger like a .82 however you will loose some response but pick up power in the top end.

chasing more power..theres always a compromise in something whether it be response, boost levels etc..

[PAGZ]

t3 or t2 josh?

[joshg123]

i understand that, however i figured with the gains in headflow, and the increased rev limit. i can have a minimal lag increase and move the rev range a bit higher

i already have a 0.78 twinscroll/splitpulse rear housing, about the most responsive housing i can get for it

[joshg123]

T3 split, vband rear

[ossie_21]

However Sean was telling me this turbo normally hits a bit of a brick wall at 400whp

Pretty sure it's rated at about 525 engine horsepower, 400hp is about 470 so yeah it's starting to get close to full potential around there. That said, the biggest figure I've seen mentioned out of a GT3076 is 487rwhp, which should be well over the limits of the turbo....

[1JZNOSHIT]

Scradly just had one of these tuned on his Neo RB25. 0.82 rear i think, with external gate. made 430 @ 20psi at ASG.

[joshg123]

Dont forget that im 4wd, have a lot of driveline loss

[juggernaut]

I have the 3071 with the divided .78 housing and making 388rwhp on 22 psi with Tomei 260/260 hydro cams. So your 350 on a hubber seems a little low with a bigger 3037 turbo even with awd.

I was just about to upgrade to the 3076 to hopefully punch out over 400rwhp on pump fuel so it was interesting to hear Seans comments.

Are you running a divided ex manifold to suit the housing? What brand of ex manifold are you running.

PJ over in the east made over 500hp at the wheels with a 3037 with E85 and 264/272 HKS hydro cams in his s13 which now holds the national record for the quarter for an s13 which was a lowish 10 with manual box.

I'd suggest you try a bigger ex housing - you can get divided T3 ex housing from GCG in a .82 and from memory 1.06. However, the 1.06 will come at the cost of lag.

Alternatively, you could try a Borg Warner twin scroll turbo i.e. S200 which is higher flowing and far more efficient at higher boost levels than the 3037/3076 could ever hope to be. Available with .75 and .85 twinscroll ex housings from memory.

Also did you grind down the CHRA to ex housing bolts so they don't protrude into the volute of the housing on the .78 housing as this has been known to cost hp?

PJ's dyno graph:

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

[joshg123]

Thanks for your reply.

I think i need to clarify, we were mid tune when the clutch gave out. So may not even have a final figure. Im not really working off the figures i pulled, more so that most cant really make more than 400-420.

I figured while its out, if its not that dear ill get some wheels swapped and housings changed to get some more out of it. If not im not fussed, it will still tip over 400atw. I just thought if i can get 20-50whp from a common wheel or housing mod i would.

Cheers

Josh

[juggernaut]

PJ gained 50rwhp from changing to a larger ex housing. In the end he was running a HKS T2 1.12 or something up from the HKS T2 .73.

Power went from around 450 to a tad over 500rwhp with the larger housing and bit more boost.

I obviously can't vouch re the twin scroll stuff - the .82 TS housing might make another 10rwhp or so, the bigger TS 1.06 will obviously make a fair bit more. Michael at GCG quoted me around $450 or thereabouts for either of these housings from memory. But you would have to redo your dump pipes, intake pipe, and possible your oil and water lines as the housings will position the turbo in a slightly different location compared to the .78 that you currently have. There is nothing in the way of wheel options for this turbo that would help your cause either so its down to a couple of housing options.

Cheers,

Ian