GTX3076 or GTX2867
 

Hey guys right now i'm deciding which size turbo to go for.

the purpose of my car is to be a track/street car

i have thought about the gtx30 but i think it will lag through the corners(correct me if im wrong)

does anyone have a rough idea on when the boost kicks in on the gtx30 and gtx28?

too many variables, fuel, tuner, turbo kit design.

go to the turbo kit compilation page and go through all their dyno charts, most of them run 28s and 30s, general consensus I hear is that people who went with the 28 upgraded or want to upgrade to a 30 because the spool difference is minimal.

Not to throw you off your horse of choosing which GTX series, but the BW EFR 7163 will make the same power as the GTX3076 and spool about 400-500 rpm sooner, those can be found on the treadstone turbo kits. Just throwin in the wild card :thumbsup:

Gtx3076r is a decent turbo, but adding more flow to a (IMHO) mismatch turbo is going in the opp direction of what I would find ideal. The GTX3576r is a better option going that big. The GTX2867 is a pretty awesome turbo. Very well balanced, and will perform well on the street and track. But... the GTX3576r is much larger... and you can't really go too big, can you?

The big power nut in me wants to see the larger turbo in use, but transient response in that size will be nothing compared the GTX28 turbos. They are insanely responsive. Spool characteristics and transient response are a different subject. Both will spool really close, but the GT28 will feel more lively all around.

how far apart does gtx28 and gtx30 hit boost?

Couple hundred rpm. But there are other factors that will dictate when they hit boost. Generally the GTX28 is 2-400rpm sooner. I used a GT3076r twinscroll with an air/water intercooler and open downpipe to achieve spool very similar to the GT2860rs. Just a tiny bit slower to spool. But considering the extra work needed to get there, if you really want spool just stick to the smaller turbo. Not everyone wants to run without an exhaust, and not everyone can get away with 3' max of intercooler piping.

On the street, the GT3076r was pretty forgivable as far as lag goes. But the GT28 turbos will spool faster, and the dyno chart may not always show the true character on the street. I'm not a big advocate of the 2871r though. The gtx2867r is on a completely different level. Next to the original Disco Potato, I've not found a turbo that comes close for responsiveness/power. The 2871r has always been "meh" to me, as I've used it in many applications and none of them really wowed me. I'd stick to the GT3071r over the 2871r, but that's me.

Im at 380whp 300tq with the gtx2867 at 15 psi, part of me wants to pump up to the gtx3076 since long term i want a built bottom end and cams.

But another part says to just get a turboback and see how far the gtx28 can go for now.

GTX3076R/end of story.

I have it in my car with great results, 550 whp @ 19 psi.
@jamesm (best tuner out there in other words) is upgrading his 2867 to a 3076r as we speak.

/end thread.

Whats your fuel setup? Im thinking of getting the 485 pump and 1000cc injectors, I dont know if thats enough for e85

Exactly that. 485 pump and ID1000s

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Is there still room to do more?

I might just go your route and do a built motor later

What rpm do the boost starts kicking in for you? As I don't want to be entering a corner and getting lag while exiting

Gtx3076r will destroy cars on the street I'm prob going to do that turbo instead of the gtx28 when I go boost. I want to be in modified vette territory. I'm sure the gtx28 can too a 2800lb 450-550whp car is pretty scary

Starts at right around 3k and full boost 12 psi about 4.2k.

For higher boost like 19 psi full boost is around 4.5k


I needed to add my back housing is .82 so a .63 would spool a bit faster.

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Why wouldn't you opt for the GTX3576r instead? Better wheel matching and better flow. Spool difference is extremely minimal considering the T350 turbine is a overall better and more efficient design than the T30.

The T30 turbine does well with the vband housings.

I honestly didn't consider it.
I was between the 3076 and 3582 and between those two there is noticeable spool difference and since I didn't plan to go over 600 whp anytime soon stayed with the 30

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I have extensive experience with the GT3076r, but the GTX is a different animal. Would love do testing on a .82 vband setup with the GTX, as the .63 housing is not my preferable choice for that turbine wheel. It would be interesting to see how this turbo reacts to different cams as well. But 550whp is really cranking on that turbo for stock cams. Congrats on that power number. I've never seen a GT30r hit anything over 480whp In Utah. Turbo just runs out of steam. GTX may be a different story, as it handles higher pressure ratios much better than the regular 76mm wheel.

Would be crazy to see the power this engine would make with a 6262. Probably would only be worth it with cams/springs and a 9k redline. That would be insanity right there. Engine would need extensive work.

Look at fullblowns car that's what they ran at 25psi to hit 760whp

Perrin Performance in wrx

Pre Race brz

Revvolution brz

Ptuning brz

Dynosty brz

Interesting to see Pre Race, Revvolution, Ptuning and Dynosty All used GTX3076R in their tuning for over 350whp.

The GT3076r should perform well on lower boost levels, but I think the GT3576r will perform better all around. This is purely based on my experiences with the GT3076r and it's downsides in comparison to other turbos in that frame-size. I haven't used the GTx3576r myself, I'm just a number cruncher and theorist at this point. But if it's any consolation, I have been spot on with my predictions in the past...

I believe the hit to response from using the larger turbine would be offset by pairing the larger turbine with the 76mm compressor. The turbine with the longer moment will drive the larger compressor more easily with less backpressure in the housing. Pairing the .63 housing to the t350 turbine will help offset any loss to response while still flowing better than the T30 turbine. Also, surge would be reduced which would help low-end power. If the GTX76r compressor wheel could be had without the ported shroud housing you could gain some efficiency back by switching to a non-ported shroud.

I feel like a lot of decisions are made based on what is popular or has been used a lot in the past. It would be nice to see more data and science to determine which would be the best match for a particular setup. Of course, it probably won't matter on lower boost levels, but I like to geek out over this kind of stuff.

Now your making me want the GTX3576r, I wanted the gtx3076 originally but now I dont know

Thanks so Coheed :-)

I personally preferred the GTX2863 over the GTX2867 based on both dyno results and driving results. Had em both on the car. I have driven several and worked on several with the 30 series on them of different variants and still prefer the smaller 28 series assuming you plan to stay sub 450whp. Response is basically instant regardless of RPM and it eats up far less real-estate in the engine bay. At the end of the day there will be several good routes to go and it will come down to type of use the car will be exposed to and personal preference.

What A/R are you using on the 2863? The .64 A/R Tial? How is the spool and response compared to the 2867R? I agree both turbos are more than enough for almost everyone.