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Borg Warner EFR Series Turbo's V 2.0


Piggaz

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Hello. I am in the finishing stages of a 3.2L gtr build and was settled on using g a G42-1450 but the more I read about the 9280, the more I'm starting to sway. It won't give me the same peak power but might make it a faster car due to better responce and torque while still netting a 4 digit dyno sheet. Im thinking 1.45 twin scroll rear housing. What do you guys think?

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The power target would be helpful with this discussion

Generally speaking, most people I know who have tried the EFR9280 have not been particularly blown away so far, exhaust back pressure seems to be a thing - especially on bigger engines... if you're going to do it then the 1.45a/r hotside is the only option I'd consider.  The G42 1450 is definitely going to flow better but also most definitely comes at an impact to response, in fact one of the guys I know went to a G42 1200 from an EFR9280 and that delivers power in the higher rpm better but even that turbo added reasonable lag over the EFR.

 

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7 minutes ago, Lithium said:

The power target would be helpful with this discussion

Generally speaking, most people I know who have tried the EFR9280 have not been particularly blown away so far, exhaust back pressure seems to be a thing - especially on bigger engines... if you're going to do it then the 1.45a/r hotside is the only option I'd consider.  The G42 1450 is definitely going to flow better but also most definitely comes at an impact to response, in fact one of the guys I know went to a G42 1200 from an EFR9280 and that delivers power in the higher rpm better but even that turbo added reasonable lag over the EFR.

 

Interesting that everyone is saying back pressure is a thing  - I assume that is only once you starting pressing out 900+hp?

Here is my 8474 using 1.05A/R on 3.2L Nitto.  about 750hp at hubs.     eMAP/MAP is rarely over 1.2:1  as you can see here 1.17:1 @7515rpm     

Yes circuit car, not Drag car - but I guess I this would be around 800-820hp at the engine - at what point does exahsut pressure become a problem - ?   Or do you think I already have a problem...?

 

Screenshot 2021-04-16 124204.png

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1 minute ago, R32 TT said:

Interesting that everyone is saying back pressure is a thing  - I assume that is only once you starting pressing out 900+hp?

Here is my 8474 using 1.05A/R on 3.2L Nitto.  about 750hp at hubs.     eMAP/MAP is rarely over 1.2:1  as you can see here 1.17:1 @7515rpm     

Yes circuit car, not Drag car - but I guess I this would be around 800-820hp at the engine - at what point does exahsut pressure become a problem - ?   Or do you think I already have a problem...?

 

Screenshot 2021-04-16 124204.png

Nice!  Awesome to finally see some data on the EFR8474 looks really solid in terms of what the data is saying about it - I'd be happy with that EMAP at that power.  What is odd though, and seems to be a bit of a trend...  where your IMAP is, and where your turbine speed is lines up with 90lb/min of compressor flow.   Do you reckon you're making the power you'd expect when your compressor speed and boost level suggest you are pushing at least 90lb/min of air?  This is part of what I've been told from people who have tried black series EFRs, they aren't getting the numbers they were expecting before they run out of compressor speed but perhaps the expectations need to be adjusted?

And yeah, the back pressure comment was about people looking at making use of the >100lb/min rated compressor flow of an EFR9280 - so closer to the 1000hp @ hubs territory, unfortunately I don't have first hand data so much as just going from people who I'm spoken to who have used them.  

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I haven't looked at it on the map - but even if the compressor is making 90lbs on the map - there is that 1.2:1 back pressure no?   Hence flow would be less?

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back pressure not relevant to compressor flow. (in the context of the operating point on a compressor map. yes, it affects VE)

but remember that 2.6 bar gauge inlet pressure will end up being more like 3.7 absolute PR (Possibly higher) once you factor in the inlet filter and intercooler pressure drops, which crosses closer to low 80s flow point at that wheel speed.

i'd be happy with 750hp at the hubs at this operating point. 900 at the hubs through diffs and gearbox flowing ~85lb/min is asking a bit much isn't it?

the Motec will have a logged VE calculated airflow. if your injector data is good and you lambda=target the Motec calculated airflow will be accurate if you wanted to verify.

Edited by burn4005
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Sorry what I meant was, in answer to this question - "Do you reckon you're making the power you'd expect when your compressor speed and boost level suggest you are pushing at least 90lb/min of air?"    -  I'd say 'I think so',  given the restriction to overall flow caused by eMAP.       

Would that be correct?  Or am I misunderstanding?

 

 

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13 minutes ago, R32 TT said:

Or am I misunderstanding?

Probably misunderstanding. The compressor map should be viewed as a statement of fact. If the shaft speed is Z and the PR is Y, then the flow on the X axis that corresponds to that operating point is what the turbo is flowing. That flow is happening regardless of the restriction caused by the EMAP. If the EMAP were some different value and your turbo was operating at that same point, the flow would still be the same value. Make sense?

I think the element of surprise exhibited by other posters above is that the operating point you describe sounds like you shoudl be making more power than you think you are, which starts to throw some doubt on the factiness of the compressor map (or perhaps the measurements you have to put the operating point on the map).

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Yep - following.

 Well then I guess the map has to be wrong - or I am making close to 900 engine hp.  Which I doubt.

 

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The trick is there seems to be a trend of this from the few black series EFRs I've seen results in, at least one tuner I've spoken to has decided it's a back pressure issue but this data doesn't suggest that to me.  The trick is I don't know where to go with it beyond the possibility that the compressor map or something about the data is not accurate which I'm not going to leap to concluding.

If you follow the compressor map the line where 116,000rpm sits hovers over 90lb/min until about PR3.2 which I would be surprised if it is reaching that high, but never know. 

Fwiw Gen2 GTX3582Rs fall fairly short of 90lb/min on the compressor maps and cars have made more power at the hubs than this on E85.  Not hating at all, I would prefer an 8474 over a GTX3582 but there are things I still have some question marks about

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Yes all good - the only way for me to know is swap to a GTX3582 or 6466, perhaps 6870 to compare.  A fair bit of money just to experiment though,  and then - will I miss how it drives...?     that said the 8474 is noticeably lazy compared to the 8374 for just an inducer change.  Its not the "same down low but more up top" the internet seems to suggest.  

Edited by R32 TT
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You know Elon Muskrat has won a contract with the Lebanese space agency to make a special Uranus probe lander mission using emotionaltron ECU and GTST body shell with special hiflow fitted with EFR black series internals using all the hypothesis off this forum, he was saying the key is the independent staged drive by wire and keeping the turbo on the small side cause when you do a hektik launch everyone knows that its area under the curve that is important when going to Uranus

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On 4/16/2021 at 5:28 PM, R32 TT said:

Yes all good - the only way for me to know is swap to a GTX3582 or 6466, perhaps 6870 to compare.  A fair bit of money just to experiment though,  and then - will I miss how it drives...?     that said the 8474 is noticeably lazy compared to the 8374 for just an inducer change.  Its not the "same down low but more up top" the internet seems to suggest.  

Yes, yes... Come to the dark side

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14 hours ago, R32 TT said:

6466 is tempting with the 5 Speed.

Don't wreck ya car with a precision lol.

Precision turbos are like bumholes.. Everybody has 1! 

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2 minutes ago, Dose Pipe Sutututu said:

Run an OPR and an oil filter and they will last, at least they won't shit out turbine wheels if you accidentally over speed them :)

Have been over speeding my 8374 by a few 1000 rpm since the day it was put on 2017. Was pulled off a few weeks ago in perfect condition. No shaft play, no missing turbine wheel. 🤷‍♂️

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