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Borg Warner EFR Series Turbo's V 2.0


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7 hours ago, Full-Race Geoff said:

keep in mind the 9274 has a considerably smaller compressor inducer trim, so it plots out really well!

I thought the new turbos had larger inducer diameters to increase flow (92 compressor is 73.7/91 instead of 67.8/91 for the 91.

wouldn't that increase the trim from 55 to 65 and push the map to the right? or is the 9274 a different compressor again? because otherwise that is going to be more likely to surge not less. will hold judgement until I see a final product catalog with the comp maps and specs on it.

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I'm a bit disappointed with the 8474 to be honest. The loss of compressor efficiency to increase the flow potential at the same exducer size seems to be a poor trade-off. It'll be more responsive than the 9174 with a more forgiving surge margin but worse at everything else. I think I would have rather have seen an 87mm compressor sized between the 83 and 91 that was better optimised to fill the 850-900hp power target, but there is no denying the 8474 will have a pretty crazy to end its still pulling like a train when the 83 compressor has fallen o. It's face.. The switch over in efficiency vs the 8374 happens at about 60lb/min at 2bar. I guess we'll see when they start getting into the wild. 

Here is the link to the new catalog. 

https://cdn.borgwarner.com/docs/default-source/default-document-library/bwts_performanceturbosgeneral_1892_2130.pdf?sfvrsn=3098b63c_2

 

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49 minutes ago, burn4005 said:

I'm a bit disappointed with the 8474 to be honest. The switch over in efficiency vs the 8374 happens at about 60lb/min at 2bar. I guess we'll see when they start getting into the wild. 

Here is the link to the new catalog. 

 

 

I'm not quite sure what you are looking at tbh, I suspect one of us is missing something.   At ~PR2.6 (where most people start running to the top end of the EFR8374's efficiency on RBs) the EFR8474 is at 60% efficiency at nearly 90lb/min, which is more than the EFR9180 manages - let alone the EFR8374.   The testing done earlier in the piece (pretty sure it was posted in here) on a built Evo 9 showed not meaningful loss in spool between the EFR8374 and the EFR8474 and a good 100whp more power.

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if you're only chasing 550awkw, on paper the 9174 looks to be a better fit, but you do buy a bit of surge margin with the 8474 over it. How the rotational inertia of the ligher compressor of the 8474 helps for transient response vs the 9174 we'll see i guess.

 

the new releases are really top-end power turbos but the midrange performance will suffer a bit.

Edited by burn4005
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4 hours ago, Lithium said:

Updated my little compressor flow list with a bunch to include the "Black series" EFR additions

image.thumb.png.ad76c4763bce06b56642f88fc8b1a651.png

That's a cool table... O to be able to compare with that silly company that doesn't have compressor maps...

If that 8474 spools similar to a 8374 with that power potential it'd have to be a no brainer, I just can't see an extra 100-200hp coming for free?!?

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14 hours ago, Lithium said:

Updated my little compressor flow list with a bunch to include the "Black series" EFR additions

image.thumb.png.ad76c4763bce06b56642f88fc8b1a651.png

What are the units, please? 

 

14 hours ago, Lithium said:

Updated my little compressor flow list with a bunch to include the "Black series

 

Edited by afb312
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14 hours ago, SimonR32 said:

That's a cool table... O to be able to compare with that silly company that doesn't have compressor maps...

If that 8474 spools similar to a 8374 with that power potential it'd have to be a no brainer, I just can't see an extra 100-200hp coming for free?!?

They're not introducing more new tech with these combinations.  Nothing comes for nothing - of course they will behave differently to achieve the flow.

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14 hours ago, burn4005 said:

as promised, here are the efficiency curves at pressure ratios of 3.0 (29psi)

bpf1CJU.png

That's quite a cool way of looking at it, it puts across a reasonable amount of what you were implying.   It also goes some way to show that "nothing is for free" - there usually is some compromise in the mission for getting better, or at least more targeted performance.   I do think your graph scale exaggerates the higher peak efficiency effect the old gen EFRs have versus the "Black series" - especially when you factor in when they occur.   The absolute maximum efficiency difference the EFR8374 offers over the EFR8474 is 10%, at 40lb/min.....  where inefficiencies are not going to be anywhere near as costly, imho.  It will be interesting to see if that few % in efficiency reduction at lower flow levels will really have any meaningful loss in response, I doubt it will be anywhere near enough to make up for the increase in MOI with the 91mm compressor.  

On the flipside, the EFR8474 is 10% more efficient than the EFR8374 at ~75lb/min and the difference keeps stretching up from there (as the EFR8374 is quickly reaching stonewall from here) and is flowing >90lb/min by the time it reaches the same compressor flow the EFR8374 was at when that 10% greater efficiency is hit.   There is a HUGE amount of improved flow area and efficiency, all things considered.  

PS, Is there a reason you missed out the EFR9280?  It's not got the same compressor map as the 9274.

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5 hours ago, afb312 said:

What are the units, please? 

The units are lb/min, and I've selected the spots where compressor efficiency drops below 65% - which is where I tend to use as a line to draw to indicate where the lower compressor efficiency can start taking it's toll in terms of the intercooler and exhaust side having to work harder than you'd hope in order to keep the airflow increases coming.    

14 hours ago, SimonR32 said:

That's a cool table... O to be able to compare with that silly company that doesn't have compressor maps...

If that 8474 spools similar to a 8374 with that power potential it'd have to be a no brainer, I just can't see an extra 100-200hp coming for free?!?

There is very rarely something for free, and I don't doubt that this is no exception - however smart designs and making the compromises in the right places to target the best end result can make it seem like it's almost for free.  It remains to be seen with this, however I've long thought the compressor side on the EFR range is letting the side down a bit.

I'm not 100% sure if I'd have preferred them to do it how they have gone about it, I would have liked to have seen an option of an upgraded EFR8374 with a smaller trim for those ultimately happy with around the high 70/low 80lb/min flow and then the additional option of the full fledge EFR8474 we now see before us.  If Borg Warner used Precision naming then the EFR6264 would now be called an EFR6764, which probably tells more of the story.  

A few years ago Borg Warner did release the EFR7163 as a BIG trim wheel, like 57mm inducer with 71mm exducer and that also stretched the compressor efficiency down and across and I remember from those point being a bit concerned from the playing down of the size with their naming that it'd be a lot laggier than people expected - but in real life it actually spools better than the EFR7064 but pumps not far off 60lb/min of air, so there does seem to be a bit of method to their big trim madness.  Granted, they did the MF turbine with that turbo as well - but lb for lb I think it's arguably the best proven spooling/responding turbo for it's airflow.

Edited by Lithium
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On 11/1/2018 at 7:55 AM, Lithium said:

 missed out the EFR9280?  It's not got the same compressor map as the 9274.

That's strange. The catelog quotes the same inducer/exducer measurements so I'd be very interested in why the map is different and off the wheel or housing is different. I had assume it was the same for 9274 and 9280 without checking. 

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