GTX2863R vs GTX2867R vs GTX3071R

[xwd]

I doubt it. People have been running E85 through EJ engines for years with no ill effects. By the time I go FI hopefully others will have figured out the effects on the FA20.

On my old 2.5L WRX I went TMIC to FMIC and it didn't make much difference with a smaller FMIC. I later switched to a top mount AWIC IC to improve the response and it was totally not worth it.

[jamesm]

i can confirm that the 2867r spool is in fact ridiculous. it's essentially instant above the boost threshold, and comes on very, very quick from down low. the high compression really helps a lot.

[mrk1]

OP what's pump gas for you? Nice read by the way

[diss7]

Originally Posted by mrk1

OP what's pump gas for you? Nice read by the way

Pump for me is 98RON, which I believe is equivilent to US 93-94. But I didn't use that in my calcs, just chose the pump gas setting the boost advisor app.

Ethanol isnt availabe in NZ at the pump (not in the South Island anyway) But we can buy it buy the drum - its about $4/L though.

I'd be more likely to use av gas. At least I can go down to the airport and pump it in. And its only costs 10% more than the 98 anyway.

Might be a good race tune option. Airport and race track are super close, and I think they sell avgas at the track anyway. (I haven't bought it in years, so not 100%)

[mrk1]

Originally Posted by diss7

Pump for me is 98RON, which I believe is equivilent to US 93-94. But I didn't use that in my calcs, just chose the pump gas setting the boost advisor app.

Ethanol isnt availabe in NZ at the pump (not in the South Island anyway) But we can buy it buy the drum - its about $4/L though.

I'd be more likely to use av gas. At least I can go down to the airport and pump it in. And its only costs 10% more than the 98 anyway.

Might be a good race tune option. Airport and race track are super close, and I think they sell avgas at the track anyway. (I haven't bought it in years, so not 100%)

Nice, I've spent lots of time crunching numbers on turbos and its all great to see it on paper but nothing replaces actual trying it out. Its to bad the cost prohibits most people, including myself, from trying on a few sizes before settling. And no equation factors in preferences.

[Sithspawn]

I've done similar analysis on the turbo options you mentioned and it looks like the GTX2867R would be excellent for this car. Combine it with a twin scroll T3 turbine housing and you would have a very responsive setup with great top end power: http://www.atpturbo.com/mm5/merchant...egory_Code=GTH

At least, that's what I'd do if I were going for a turbo setup on this car.

[diss7]

Originally Posted by mrk1

Nice, I've spent lots of time crunching numbers on turbos and its all great to see it on paper but nothing replaces actual trying it out. Its to bad the cost prohibits most people, including myself, from trying on a few sizes before settling. And no equation factors in preferences.

Yea for sure. You can analyse and over analyse it all you like. Real results are much better.

Best thing for anyone is to go for a ride or drive in others cars, you may find that you really prefer how one setup performs, and want the same thing etc.

[SmsAlSuwaidi]

Originally Posted by jamesm

you'd think it'd spool slow... but it really doesn't at all. it's hardly noticeable compared to my 2867r, and the advantage in overhead is just immense.

i'll be swapping soon.

I remember when i asked you if youd change a while ago and you said no

I happy that i went with a 3076 .63

[jamesm]

Originally Posted by SmsAlSuwaidi

I remember when i asked you if youd change a while ago and you said no

I happy that i went with a 3076 .63

Everyone is going big these days making me jealous. The sound alone is worth the upgrade cost. I thought I'd be happy with my 2867 forever lol.

[Mrc@ptuning]

Originally Posted by jamesm

Everyone is going big these days making me jealous. The sound alone is worth the upgrade cost. I thought I'd be happy with my 2867 forever lol.

Stick with the GT3076 .63 and you'll be happy for a while even with upping the boost down the road. We did not see any gains in power or spoolup on the GTX3071R vs the GT3076R both .63 A/R at around 310-320whp on the dyno. On paper you would expect the transient response to be slightly better with the 71 but it's not enough to tell with the butt dyno. The 30R really shine when you get into the 400whp range, where as the 28s will start to run out of steam.


I'm currently running the GTX3076R with my setup and the spoolup is a tad slower than the GT3076 but again transient response and spoolup seems the same on the road. The GT30R works great on this motor and gives you a lot of room to grow when you get that itch for more power. There's no one magic turbo to fit everyone's need. You just have to pick and choose your weapon based on the type of driving/racing you plan for your car.


You can't really choose a turbo based on how it performed on another motor/vehicle. For example, a GT30R on an Evo 8 4G63, is mediocre, where as that same turbo on a S2000 make awesome power--with the right turbo system setup of course. So I don't know if it makes sense to expect the same result from the same turbo on say an EJ25 vs FA20.

[jamesm]

with the fa20, i'm quickly learning to pretty much throw out everything i thought i knew about this stuff lol. i never would've expected the spool that we got out of the 3076 on @Sportsguy83's car.

[OrbitalEllipses]

Originally Posted by Mrc@ptuning

So I don't know if it makes sense to expect the same result from the same turbo on say an EJ25 vs FA20.

With the 50% difference in CR it doesn't make sense to, either. This engine when boosted, will be much stronger off-boost than an EJ25 with a big turbo, even if the EJ has .5L more displacement. I'm a fan of the GT28, but having been in a GTX3076R equipped car, the difference is really minimal.

[diss7]

I just can't see how a gtx3076 is feeling just the same as a gtx2863/7r

The 76r graphs I've seen don't hit peak torque until 5500rpm or later. The 67r is closer to 4000rpm

That's basing my understanding that the point where a turbo has reach max psi (in other words, fully spooled" is where max torque is. Or at least where it stops significantly ramping up.

Happy to be proven wrong.

But at this point I can't swallow that stepping up to a 3076r from a 2867r is "not all that different"

[Sportsguy83]

Originally Posted by diss7

I just can't see how a gtx3076 is feeling just the same as a gtx2863/7r

The 76r graphs I've seen don't hit peak torque until 5500rpm or later. The 67r is closer to 4000rpm

That's basing my understanding that the point where a turbo has reach max psi (in other words, fully spooled" is where max torque is. Or at least where it stops significantly ramping up.

Happy to be proven wrong.

But at this point I can't swallow that stepping up to a 3076r from a 2867r is "not all that different"

My car is hitting full boost at 4300 RPMs (10.5 psi)