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Lithium

Current state of the game for single turbos

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Hi all, 

There have been all kinds of conversations on and off SAU about single turbo options for RBs (and other engines really) in the current state of the game and while I've not seen any evidence of compressor maps being inaccurate, different manufacturers use different ways to normalise and present the numbers, different cut off points, and different ways of estimating hp from compressor flow which can result in people expecting too much or too little from their turbos.

I've decided to semi-roughly translate it all into an even measure and shove what I consider "the most relevant" turbos for most people who would be talking about turbo choices in here, and split the compressor flow potential they have at 20psi, 25psi and 30psi - using "65% compressor efficiency" as a cut off.   Those are fairly familiar and reasonable reference points, and as you exceed 65% I view it that it's where the intercooler and hotside are starting to have to carry disproportionately more of the load to keep things happier.  This is the "you're pushing it" zone, imho - even if it's not really maxing the turbo out.    It seems to be a reasonable way of gauging them on a similar scale if you're going to being matching the turbos for real world performance.

It may not be PERFECT but I think it gives enough of an idea of how they may compare, I'm pretty sure all these turbos have hot side options which are pretty close to supporting the exhaust flow needed these days - give or take, but some of the numbers here may explain a few interesting things seen..

Hope it's vaguely interesting reading :) :)

Turbo 20psi 25psi 30psi
GTX3071R  50 52 53
GTX3071R Gen2 51 52 53
EFR7670 53 56 57
S257SX-E 54 57 60
G25 660  55 60 59
GTX3076R 59 61 62
Gen2 GTX3076R 59 61 62
GTW3476R 60 64 67
EFR8374 65 68 69
GTX3582R 70 72 74
Gen2 GTX3582R 70 75 77
EFR9180 74 79 84
GTX3584RS 75 80 84
Edited by Lithium
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And because people like this kind of thing, a loose translation of what kind of area these flow figures may convert to in dyno numbers if everything else is up to the task.  
 

Bare in mind, these numbers are not what I'd say are "on kill", but where the compressor is starting to really earn it's keep - they should have more to give, but the things start working harder to get there and you start moving more into "how optimised is this setup" territory.  These numbers aren't a guarantee of what setups WILL hit using these turbos, it's what the turbos should be able to achieve working reasonably hard - but not too hard... and of course me making a bunch of assumptions lol.  

 

Turbo 20psi 25psi 30psi
GTX3071R 339 352.6 359.3
GTX3071R Gen2 345.78 352.6 359.3
EFR7670 359.34 379.7 386.5
S257SX-E 366.12 386.5 406.8
G25 660  372.9 406.8 400
GTX3076R 400.02 413.6 420.4
Gen2 GTX3076R 400.02 413.6 420.4
GTW3476R 406.8 433.9 454.3
EFR8374 440.7 461 467.8
GTX3582R 474.6 488.2 501.7
Gen2 GTX3582R 474.6 508.5 522.1
EFR9180 501.72 535.6 569.5
GTX3584RS 508.5 542.4 569.5
Edited by Lithium
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Interesting to see how little extra power is generated by some turbos with an extra 10 psi (as low as 14kw) while other turbos gain much more ...such as the EFR9180 with an extra 68kw

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Just now, KiwiRS4T said:

Interesting to see how little extra power is generated by some turbos with an extra 10 psi (as low as 14kw) while other turbos gain much more ...such as the EFR9180 with an extra 60kw

100%.  One of the reasons I decided to break it down as often people just seem to look at the power claims or the peak airflow levels without considering the compressor efficiency.     

The EFR9180 doesn't really seem to be a turbo best suited to a setup which can flow a heap of air in it's own right, at least based off what I've done here it would indicate it'd roll over early if you treated it like a 90lb/min turbo and tried to flow that at relatively low boost.   On the flipside, you could potentially shove one on a solid RB26 and crank a heap of boost through it and potentially make more power than you would with an RB32 with big cams capable of making lots of power without heaps of boost

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https://bmw.spoolstreet.com/attachments/c92a58335a9c242d64ec466cfc9172ee_zpsniwwkwsu-jpg.13075/

 

Man I wish the 8474 was a thing.. maybe too good to be true.

20-25-30psi

77-84-91 lb/min

also, G series hopefully scales well. Med and large frames are going to be beasts. if the G25-660 is smaller in every way than a gtx3071.

 

Edited by burn4005

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4 minutes ago, burn4005 said:

Man I wish the 8474 was a thing..

20-25-30psi

77-84-91 lb/min

also, G series hopefully scales well. Med and large frames are going to be beasts.

 

Fark yeah, good call on mapping the 8474 in there - GET ON IT Borg.  That would change the game if it delivered on that :o    

Also +1 on the G-series scaling.  

This stuff is all on paper, but imho the simple job of just compiling some points into one list kind of explains some of the things we see happening in practice on some of these turbos.

The G25-660 with a .92a/r hotside could be quite a surprising beast on an RB25....

Edited by Lithium

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yea the 8374 getting close to all in at 26psi/65%, but the 84 is just getting started.

literally off the chart... might be hitting a sonic stonewall or something so they stopped mapping to the right, still fine rpm wise.

Edited by burn4005

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4 minutes ago, burn4005 said:

put up the precision turbo data Lith.

Got some compressor maps for me? :/

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I agree Garrett has the potential to do great things with the G series . I'm thinking the compressors and turbines wouldn't have to be a whole lot bigger to put them in the power range that the fast road market is really interested in .

If they keep the same frame size and have housings similar to the G25s , in for example a G28/G30 series , then we can have efficient responsive turbos . Keeping them compact and having reliable hot sides is where they could have it over the EFRs .  

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24 minutes ago, discopotato03 said:

I agree Garrett has the potential to do great things with the G series . I'm thinking the compressors and turbines wouldn't have to be a whole lot bigger to put them in the power range that the fast road market is really interested in .

If they keep the same frame size and have housings similar to the G25s , in for example a G28/G30 series , then we can have efficient responsive turbos . Keeping them compact and having reliable hot sides is where they could have it over the EFRs .  

The funny thing is that G25-660 already has a hotside which is comparable to the biggest hotside available for the EFR7670, and compressor wise flows slightly better at all the points one would be likely to use on an RB25/26 if they were looking for a fast road car.  Need more real world results to get a gauge of what spool is actually like, but I can't see any reason why despite seeming so small - a G25-660 is actually big enough to cover the needs of your typical punter building a quick road car

Edited by Lithium
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And because people like this kind of thing, a loose translation of what kind of area these flow figures may convert to in dyno numbers if everything else is up to the task.  
 
Bare in mind, these numbers are not what I'd say are "on kill", but where the compressor is starting to really earn it's keep - they should have more to give, but the things start working harder to get there and you start moving more into "how optimised is this setup" territory.  These numbers aren't a guarantee of what setups WILL hit using these turbos, it's what the turbos should be able to achieve working reasonably hard - but not too hard... and of course me making a bunch of assumptions lol.  
 
Turbo 20psi 25psi 30psi
GTX3071R 339 352.6 359.3
GTX3071R Gen2 345.78 352.6 359.3
EFR7670 359.34 379.7 386.5
S257SX-E 366.12 386.5 406.8
G25 660  372.9 406.8 400
GTX3076R 400.02 413.6 420.4
Gen2 GTX3076R 400.02 413.6 420.4
GTW3476R 406.8 433.9 454.3
EFR8374 440.7 461 467.8
GTX3582R 474.6 488.2 501.7
Gen2 GTX3582R 474.6 508.5 522.1
EFR9180 501.72 535.6 569.5
GTX3584RS 508.5 542.4 569.5
My real world result is quite close to your theoretical numbers, Lith.
The GTX3584RS with 542 at 25psi and 569 at 30psi vs mine with 550 at 29psi.

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2 hours ago, K_arlstrom said:

I actually updated my list with a bunch more turbos (including the black series EFRs) months ago but this thread had very little interest so didn't think to put the updated version in here.

No photo description available.

 

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7 hours ago, whatsisname said:

My real world result is quite close to your theoretical numbers, Lith.
The GTX3584RS with 542 at 25psi and 569 at 30psi vs mine with 550 at 29psi.

They were very much thumb sucks so that's nice :) What did yours make at lower boost levels?  

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2 hours ago, Lithium said:

I actually updated my list with a bunch more turbos (including the black series EFRs) months ago but this thread had very little interest so didn't think to put the updated version in here.

Thats what we get for just reading and not typing anything :whistling: 8374 might still be the better "scary fast street RB"-turbo

Edited by K_arlstrom

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They were very much thumb sucks so that's nice What did yours make at lower boost levels?  

Well they were quality thumb sucks

 

It made 533kW at 26-25psi. Not sure what it makes at 20psi. I remember it making 421rwkw at 19psi during early tuning a year or so back (posted info in the RB30 results thread) but it was far from optimal and it was prior to properly setting up the boost control.

 

Shaun's Dynotech DD dyno is a bit stingy too, having ran both my 33 (345rwkw at the time) and Stage 2+ Golf Pirelli GTI (193fwkw) on Shaun's and then a Mainline roller dyno across town, where they both picked up 21rwkw (366rwkw) and 19fwkw (212fwkw) respectively.

 

I think another 1psi and a slightly more optimistic roller dyno would put my 33 right in line with your theoretical 569 figure.

 

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22 minutes ago, whatsisname said:

Well they were quality thumb sucks emoji4.pngemoji106.png

 

It made 533kW at 26-25psi. Not sure what it makes at 20psi. I remember it making 421rwkw at 19psi during early tuning a year or so back (posted info in the RB30 results thread) but it was far from optimal and it was prior to properly setting up the boost control.

 

Shaun's Dynotech DD dyno is a bit stingy too, having ran both my 33 (345rwkw at the time) and Stage 2+ Golf Pirelli GTI (193fwkw) on Shaun's and then a Mainline roller dyno across town, where they both picked up 21rwkw (366rwkw) and 19fwkw (212fwkw) respectively.

 

I think another 1psi and a slightly more optimistic roller dyno would put my 33 right in line with your theoretical 569 figure.

 

What tyres are on the back? it does sound noisy (implies they are sticky tyres)

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