G25-660 VS GTX3071 VS GTX3571 gen2

[A80Avant]

I have been having a discussion with a couple of friends with regards the above turbos

Given that the 3071 and 3576 would be on their 0.63ar hotside for best spool at a sacrifice of top end power, while the g25-660 being a smaller turbo would be on the 0.92ar what do you think the best option would be for our engines for achieving above 500hp crank with the best possible spool?

Real life evidence.

On my car, 2.2 and cams I have the 3071gen2 0.63 with 2.1bar at 3900rpm on 3d gear and 3500 on 4th, making 400whp.

I have been told the 3576 on 0.63 would shift spool about 300rpm to potentially give another 50hp(25whp)

The 660 recently on a 2.5 Subaru I was told it started spoiling from 2600rpm and had full boost at 3600 with the 0.92ar.

I may be seeing and dyno/measuring this car this week...

[rxl]

if your going to buy a new turbo why dont you go whats the fastest spooling on the market. that would be efr borg warner.

[AndyP]

This will all become irrelevant when you go 2.5, you'll have more torque than you know what to do with

[A80Avant]

if your going to buy a new turbo why dont you go whats the fastest spooling on the market. that would be efr borg warner.

A few reasons, my car is already setup for Garrett turbos. Having said that what's the fastest spool on the efr turbo range that can meet the above requirements?

[s2dk]

there is a company in germany building a 2.2 with the new g25.660. you could look them up maybe. they are on facebook ofc i cant remember their name atm.. but i think it was BS CarPerformance

[Marten]

This is GTX3076R gen2 with 0.83 hotside. Full boost (2,7 bar) is at about 3700-3800 rpms.

[prj]

3700-3800 when dyno clearly shows 4200.
3076 with 0.82 has always spooled at 4200 RPM on a 2.2 liter. It did that 10 years ago and it does that now.

EFR7163 is better in every way though.

[Marten]

3700-3800 when dyno clearly shows 4200.
3076 with 0.82 has always spooled at 4200 RPM on a 2.2 liter. It did that 10 years ago and it does that now.

EFR7163 is better in every way though.

Just to clarify. The dynochart is not for 2.2L, more like 2.5L or so. Also I'd imagine newer ball bearing turbos spool and flow little bit better than 10 years ago.

I didn't post to argue which is better... carry on.

[prj]

Just to clarify. The dynochart is not for 2.2L, more like 2.5L or so. Also I'd imagine newer ball bearing turbos spool and flow little bit better than 10 years ago.

I didn't post to argue which is better... carry on.

I think you need a small history lesson, because the 3076 has always been ball bearing, now and 10 years ago.
And no, GTX3076 does not spool better than the 10 year old GT3076. The GTX3071R does.

[Rikki Kitto]

[A80Avant]

Though I have always hated dyno charts when done just to show power rather than tuning one thing is always crucial. The torque curve is not where the highest boost is, but always a couple of 1xx rpm later. In real life I always have boost earlier to where my highest torque is due to timing and cams etc.

So 3700 to 3800 on 2.5 and 3076 0.82 sounds about right. But I agree that on a 2.2 it's never before 4000rpm, at least not in my experience

[rxl]

i found this s6 running efr 7163 comented by the user: 420whp on E85 and 360whp on pump, 26psi and 24 psi, respectively. In 2 weeks Marc is remote tuning it up to 35psi! I'll eventually get to a dyno downstate but am in no hurry. Not sure why the boost says it comes on so late on the dyno, but on the street it is around 3500.

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[A80Avant]

I'm it sure how to compare these numbers really. On my mustang road dyno which is pretty accurate I get around 398whp on the gtx3071r gen2. On the 0.63ar. And that is on a 2.2 lit.

[prj]

Though I have always hated dyno charts when done just to show power rather than tuning one thing is always crucial. The torque curve is not where the highest boost is, but always a couple of 1xx rpm later. In real life I always have boost earlier to where my highest torque is due to timing and cams etc.

So 3700 to 3800 on 2.5 and 3076 0.82 sounds about right. But I agree that on a 2.2 it's never before 4000rpm, at least not in my experience

This is only true when the dynos are crappy, have no proper loading or a bad load cell PID.
On my dyno the boost is about the same as in 5th or 6th gear on the road with a slow ramp rate. In fact I can put it anywhere 1000 rpm before and after depending on ramp rate.

[A80Avant]

If you can do that then most Greek dyno operators are as you say crap!