GTX2867r vs GT3076r
 

It is my understanding that the GTX series flows better at higher pressure.
Lets say stock block

what kind of pressures will pull similar power numbers between these two turbos?

Which turbo will provide the most area under the curve at say 350, 400, 500 whp?


how high can you safely go with each on 93 pump gas?

:cheers:

I have the gtx3076r @ 7psi WG spring but it's closer to 8psi boost on 93 octain and love it. All I hear is the turbo starting to spool around 2500 rpms. Psht....

I suggest plotting points on a compressor map. Make sure that the additional flow is actually a part of the map your even going to use.

http://www.atpturbo.com/root/release...76Roverlap.jpg

Nice gains in the top right sure but do you get there?

Basically I would like to upgrade my 20g, and I know that someday I want to build the motor for a high horsepower track build. I would like to target 600 whp with a built motor (I'm hoping by then we'll have more transmission options).
I'm not a shop using this for a business expense or for product development, so I'm not tearing the motor out of my 2015 BRZ that I've just began enjoying unless something goes wrong. With that said, I am just not happy with 280 whp and fear that with my turbo I can only pull maybe 320 with E85. I would like 350 whp, but I don't want to have to buy a third turbo after the motor goes for building. I am assuming that I would need to at least slightly lower compression to pull 600.
I don't believe the GTX2867r can get me to 600whp, and I believe the GT3076r will be more efficient for the lower 350 target but still be enough to get me to 600 or at least close enough to dissuade me from spending the extra cash for the GTX3076r.

I know you have been playing with the GT30 so what do you think about this?

:cheers:

Also any updates on your next run of crash beams? I appreciate that you value doing things well over banging out projects and know you gave me a long lead time so no rush. I just have a couple of other projects to coordinate when that goes on and intend to meet with my paint guy soon to discuss that.

Also I saw you had changed the gearing to stay in boost longer. Not sure if you've been tracking before and after, but do you expect that lap times would be reduced with your gearing change and how do you expect the change to affect the durability of the transmission as in would the gearing change equate to more or less stress on 4th and 5th lol?

For ~600hp a GTX3076 is a good choice. Look at the HP rating Garret gives there turbos for a guideline on what they can do.

GTX2867, 475hp
GT3076, 525hp
GTX3076, 640hp


Your right that GT3076 is a good idea for 350

A longer gear diff is certainly a good idea for power like this. Lap times would very by track, I would have no problem changing diffs for given tracks. Longer for a fast track, short for tight track. Final drive will have minimal effect on transmission longevity, your driving style makes a bigger impact there.

I need a bigger turbo for 600-650...
 

Yeah the 3076 is good at higher boost levels.

I'm gonna need a bigger one though because first I'm getting an e-force and then I'm going compound boost once I get a built motor, so I need something that will flow 45lbs/min at between 13-15 lbs of boost to compound it to 30 with the sc...

Jaden

This I've got to see!!!!

doesn't it also matter how you'd like your power band to sit? idk how it is on the fa20, but on the ej257 i run a gtx3582r.. keep the power further to the right so i can pull all the way to redline. i'd like the same with the fa20 rather than having it die off around 6krpm or so. ..

personal preference is a massive factor that gets sticky when you ask alot of people on the internet. I thought I would enjoy the far right big turbo feel, it was fun for a little while but now Im back to a 28 and just find it a better street turbo since thats all my car is. I don't constantly take my car up to red line so having a turbo that needs that makes no sense for me.

....borg warner 7163.....


But between these two, Id go with the 28. I like response time better than top end, more streetable to me

Don't forget the new GTX2971r and GTX2976r. The 2971 is a good balance between the two. The 29 exhaust housing is a clipped 30 wheel in a bored out t25 exhaust section, which should retain pretty good spool and still outflow the t28 when matched with the bigger compressor. With these new turbos it means you can go with a t28 based turbo while you're on the stock motor, then do a direct drop in gtx29 series when building the motor.

But IMO a 30 series only has a place above 400 HP. Below that there is just no reason when the gtx2867 can cook 400+. Most people we see here stop at the low to mid 400's anyway as that's where things become very expensive.

This is absolutely correct, and there are few dyno sheets I can find with these larger turbos and similar enough setups to actually compare the actual differences at big hp numbers. What I believe is possible and am seeking confirmation of is: can you build a custom setup to minimize spool up with a twin scroll manifold, shorter intercooler piping and minimizing bends (with appropriately sized radii) everywhere you can in order to make the real world results competitive between an off the shelf GT28X vs a bigger turbo.
My end game is a big turbo FA20 that can outperform a medium turbo on a track with all other variables being equal. I'm sort of putting plans in motion to live out an adolescent dream of mine to bring some passion back to my now monotonous adult life.

Interestingly I was able to find a comparison video of Audis I think running very similar setups in a rolling start drag and the GT3076r walked the GT2x28 (I think running same boost) unless he was brake boosting. This leads me to believe that the bigger turbo should have potential to outperform the medium turbo even with the lag, but different car and that was straight line.

Thank you for adding to the discussion, I didn't see these turbos from the Garrett catalog I skimmed. I've been eyeing the hell out of your flex fuel kit lol
I'm sure we'll be in touch at some point in the future.:cheers:

Do you have any experience personally installing and tuning any GTX29 turbos? Im thinking about switching from a GT3076R for quicker spool while still maintaining top end and google doesnt give me much info as far as reviews.

I'm interested to know, are you running a 3" exhaust from the turbo back? Because I have zero spooling issue. I hear the pig all the time as i'm driving down the street. kinda reminds me of a big old turbo diesel driving around. All you hear is the damn turbo spooling. I punch it and it snaps and that's under 3000 rpms.

Most of the time I would say about 2400 rpms I see picking up boost. Kinda annoying when i'm trying to take it easy and not try to act like I want to race everyone at the stop light.