Borg Warner EFR Series Turbo's V 2.0

[MaximuSmurf]

Just grabbed these off the GCG website.

EFR 6258 - 166,300 RPM

EFR 6758 - 153,900 RPM

EFR 7163 - 150,600 RPM

EFR 7670 - 139,200 RPM

EFR 8374 - 127,000 RPM

EFR 9174 - 125,000 RPM (taken from Full-Race website)

EFR 9180 - 116,000 RPM

 

[Lithium]

Those are clearly pulled from the compressor maps - unless there is info which answers what I was asking (ie, that the compressor map factors in turbine speed) however if you look at the EFR6258 and EFR6758 ratings, those speeds are clearly not to do with turbine speeds given they run the exact same turbine.   

I'm talking about something actually official and definitive, from Borg Warner and stating that it is about the *turbine*.

 

 

[usmair]

6 hours ago, Kinkstaah said:

Good way to find out whether the overspin problem is instant death or not. Garrett rate their wheels to near-similar maximum RPM too and people don't really seem to care much about spinning them way past it

Please post results

Been running 30 psi since September 2016 and no problems so far.

I don't hit 30 psi every time I drive it but at the same time I don't drive it like a grandma either (example below).

 

I know one other person with an 8374 running 33 psi..... his car is a daily driver and still going strong for over 2 years. Another friend will soon be pushing 30 psi through a 9180, which has an even lower RPM limit and the only reason it is being capped at 30 psi is due to the stock bottom end of the motor, rather than worrying about the limitations of the turbo.

I'd cram 35 psi through it if I had a forged bottom end.

IMO it is pretty pathetic of a modern tech turbo if it cannot live at this kind of boost levels, which are very common standard these days. If it does fail due to exceeding the RPM limit, I definitely will not be using another EFR as I'd like to be able to run these level of boost pressures.... and the Garretts and Precisions of the world have no problem doing so.

These RPM limits could simply be for warranty purposes.... i.e. BW told you not to exceed X RPM, you did and now the turbo failed so BW has no financial obligation to cover warranty. In my view, it would be near impossible to lodge a warranty claim anyway on car parts given how many hands they go through (e.g. seller, mechanic, tuner, user etc). Too easy to play the blame game.

My 2 cents.

 

[Lithium]

14 minutes ago, usmair said:

 

IMO it is pretty pathetic of a modern tech turbo if it cannot live at this kind of boost levels, which are very common standard these days. If it does fail due to exceeding the RPM limit, I definitely will not be using another EFR as I'd like to be able to run these level of boost pressures.... and the Garretts and Precisions of the world have no problem doing so.

These RPM

 

I don't agree at all, that is bizarre logic in itself "If it does fail due to exceeding the RPM limit" is ... uhhhh....  just read "Exceeding the RPM limit" and think about the meaning of that phrase. You've (and others) have bought a turbo which has a turbine wheel which is way lighter than the typical inconel offerings and that is why you have the epic response you'd not have with the equivalent Precision, the cost is that the fancy material is less tolerant to abuse... its nothing to be cheap or dodgy.   Its about being a numpty and expecting a precision piece of equipment to hold together being push outside it's design specifications and somehow thinking its on the components fault if it doesn't cope.  

You are right, you can probably push a 6266 harder and make more power so if that extra response is not your cuppa then you know that - so it naturally makes sense to you if you are willing to accept the alternative situation where you could run the turbo within the advised limits and it could start smoking just because it feels like it, or get a Garrett and again ... not get quite the response but know it will be reliable and perform well.  

In all reality a lot of this is why I often recommend Garrett turbos as the GTX are the simplest most reliable solution even if they aren't the pinnicle.   If you / the people you are working with know what you are doing and want the best and can afford it then the EFR is the best option but certainly not the only one.

Edited September 8, 2017 by Lithium

[usmair]

I didn't know about these RPM limitations when I purchased by BW.

Had I known it was a 'real' issue (still to be convinced that it is...) and I could not run more than 24 or so psi, I would have purchased a Precision as personally, I am not willing to give up 50/60/70kw of top end power for better response.....

A 6266 is a great turbo and while it does not have the pick up and go of the EFR, I would have been completely satisfied with the response of a 6266/3582 if it meant being able to run more boost for that top end power.

Others may (and that is fine) but I would not have if someone told me you will blow the turbo if you run 30 psi.

Speaking of running 30 psi, nothing has blown up yet and there is nothing to indicate that it will in the near future. Applies to me and others I know with EFR turbos so perhaps this concern that your EFR turbo will go kaboom if you exceed its RPM limits is not much of a concern after all.

At the moment it appears that I have my cake and I'm eating it too 

[Lithium]

As far as I know the 8374 can reach the max compressor flow without any worries of the turbine speed being exceeded - if you start overspinning it then part of the silliness is that the gains are going to not justify the risk.  When you reach that point there is nothing a GTX3582R would be doing that the 8374 isn't - in fact you could probably run it with no gate and still fall short though I am not totally sure of that but you should get the idea.  

 

You sound like you don't know enough about turbos to bag them and rslg should be talking to someone who does before making expensive decisions - if you are out of compressor then trying to push harder is just being silly.  You can't just keep trying to turn the boost up and hope some how you will make more power if you have the wrong sized turbo...  You probably should have got a bigger EFR if you needed more power and were willing to spend that money 

[Mick_o]

24 minutes ago, usmair said:

Been running 30 psi since September 2016 and no problems so far.

I don't hit 30 psi every time I drive it but at the same time I don't drive it like a grandma either (example below).

 

I know one other person with an 8374 running 33 psi..... his car is a daily driver and still going strong for over 2 years. Another friend will soon be pushing 30 psi through a 9180, which has an even lower RPM limit and the only reason it is being capped at 30 psi is due to the stock bottom end of the motor, rather than worrying about the limitations of the turbo.

I'd cram 35 psi through it if I had a forged bottom end.

IMO it is pretty pathetic of a modern tech turbo if it cannot live at this kind of boost levels, which are very common standard these days. If it does fail due to exceeding the RPM limit, I definitely will not be using another EFR as I'd like to be able to run these level of boost pressures.... and the Garretts and Precisions of the world have no problem doing so.

These RPM limits could simply be for warranty purposes.... i.e. BW told you not to exceed X RPM, you did and now the turbo failed so BW has no financial obligation to cover warranty. In my view, it would be near impossible to lodge a warranty claim anyway on car parts given how many hands they go through (e.g. seller, mechanic, tuner, user etc). Too easy to play the blame game.

My 2 cents.

 

That has gotta be the dumbest shit I've read on SAU in quite a while and it didn't come from the skidmark sadly.... 

A few questions...

A) Why are you getting caught up in "boost pressures"? Who gives a f**k about boost pressures! Would you wanna make 500kw at 30psi or 500kw at 35psi? Boost pressures DO NOT mean more power.

A more efficient motor/setup will make the same power on less boost so that is absolutely meaningless!

B) Does the turbo you chose make the power you aimed for?

If not guess what?

Its time for a BIGGER TURBO!

C) Does it not drive better than anything you've driven before and any mates or family members non EFR cars? 

IF you answer yes. THAT IS what these turbos are all about. 

 Even if you use a smokey old precision or a GTX and "overspin it" its gunna drop its guts out the dump pipe just like any other turbo will if being used outside of its efficiency range. Just so happens the EFR is more sensitive to this fact! 

Instead of wasting your time on silly posts like that & wanting to throw endless amounts of boost into your stock motor, chuck a $200 speed sensor in your compressor cover and see where your speed is at and see IF you can turn the wick up some more SAFELY! 

If not throw a shitty PTE on your car and enjoy topping your oil up regularly!

[R_34]

Please let's try to not close this thread...again.

[usmair]

Rightyo... cheers for the hospitality guys....

I'm not going to bother arguing about turbos with randoms over the internet. 

Last time i contribute any actual data to this thread.

Peace.

[Mick_o]

What data? You told us you wouldn't use 1 again because you can't run 35psi? I kind of find it hard to believe you didn't know about the speed limitations these turbos have as it is WELL documented and i have a feeling you would have done Some research in making your turbo choice?

 You will be the 1st 1 to call these turbos rubbish when you blow it up because you overspun it as you couldn't spend an extra few bucks on a sensor mindlessly winding up the boost when you know these turbos limitations. 

[Dose Pipe Sutututu]

They might have RPM limits due to the design and material used, but you need to remember these are the best turbos you can get for the money.

Good example, look at all the WTAC cars.. they are all very competitive and majority of teams are using them, must mean something. Yes, Garrett & Precision turbos might be a bit more resilient with overspun wheels however they don't offer the performance close to a BW.

Also, more boost doesn't mean more power once you've gone past the turbo's efficiency. Pretty simple really @usmair, you seem like a pretty smart guy don't be making comments that put you down.

[burn4005]

oh a product with clearly stated design constraints,  lets operate it outside those parameters and complain when it fails.

 

its like buying an engine built for 8500rpm and running it at 11,000 then going off at the engine builder when it throws a leg out of bed.

 

people are so used to the american performance market way of doing things, no tech specs, just an arbitrary power rating and do what you want.

Edited September 10, 2017 by burn4005

[Kinkstaah]

But he never said that though, he is saying that he was under the impression he could rev it to 11,000 RPM, and being told afterwards that the limit is 8500. If he knew it was 8500, he would not have selected it.

Yes boost and flow aren't the same thing but they can be closely correlated on the same motor. Usmair is saying "more boost" but he really means more power and he's basically saying the 8374 may not provide enough grunt for what he needs. Maybe he wants 750awkw and that is 52psi given the rest of his current setup and a 8374 is not going to get there.

I found it interesting that the numbers you can see from Garrett and BW are the same/really similar. If Garret think the Garrett wheel is stronger, why is the "limit" not higher than the BW item?

For what its worth, I have overspun a garrett compressor wheel, as it's on my desk at work! As to the RPM of that at the time, I have no idea. I just knew the gate wouldn't open.... ever.... at 28.9psi.

 

[burn4005]

Maybe so, but you can only do so much with 78lb/min of air, its written right there on the freely available compressor map. and if your target was more than around ~575 flywheel kw you bought the wrong turbo.

So 500awkw means a very slippery gearbox/tcase/diff

Edited September 11, 2017 by burn4005

[burn4005]

compressor stonewall is a mechanical phenomenon that cannot be avoided. In turbo land garret just shows the choke line, whereas Borg Warner actually show the RPM stonewall where each constant velocity line goes vertical. once the constant velocity line goes vertical the compressor is done and something is running at unity (sonic) in the compressor so she won't push any further as it's choked.

you'll notice most turbos with the same inlet size are rated to similar flows. this is because the inlet cross section defines the maximum flow of the compressor. clever forged/cnc compressor wheels with the same inlet diameter but smaller centre shaft areas have a bit more because the cross sectional area available for flow is higher.

Edited September 12, 2017 by burn4005

[Lithium]

21 hours ago, burn4005 said:

compressor stonewall is a mechanical phenomenon that cannot be avoided. In turbo land garret just shows the choke line, whereas Borg Warner actually show the RPM stonewall where each constant velocity line goes vertical. once the constant velocity line goes vertical the compressor is done and something is running at unity (sonic) in the compressor so she won't push any further as it's choked.

you'll notice most turbos with the same inlet size are rated to similar flows. this is because the inlet cross section defines the maximum flow of the compressor. clever forged/cnc compressor wheels with the same inlet diameter but smaller centre shaft areas have a bit more because the cross sectional area available for flow is higher.

Yeah, without getting so specific - this is what I was getting at earlier.  The compressor maps from Borg Warner for all I can tell are very much based on rpm stonewall as you say - which has nothing to do with the turbine side, yet the rpm limits thrown around are painted to be max turbine speed.  What worries me about this is there have be comments about the 9174 being "safer" to push hard than the 9180, and that the new EFR range will be lower rpm to save the turbines... this could make one hypothesize that the turbine speed on some of these turbos (ie, the 9180 particularly) should be kept below the rpm stonewall for the compressor, but there is nothing to give any confidence one way or the other.

Does that make sense, or do you think I'm missing something?

[burn4005]

you're right, I haven't found anything that explicitly states the 80mm turbine rpm limit is what stops you spinning the 91mm compressor wheel any harder, but Borg Warner saying the 9174 has a higher HP capacity and rpm limit relative to the 9180 shows this is the case.

what confuses this is all of borg warner compressors are limited to 560m/s tip speed, and it is definitely the compressor tip speed they're talking about,  so why the 91mm compressor is an exception to this is anyone's guess.

it appears they have clipped their compressor map at this speed, so the 9180 map stops at the 116krpm line, but it's actually still operating at 70+% efficiency, so if spun harder you could extrapolate that map up and to the right a fair bit further if the compressor can hold itself together. you'll need quite a high pressure ratio to keep it happy though (anything under 4:1 is basically stonewalled).

Edited September 13, 2017 by burn4005

[Lithium]

9 minutes ago, burn4005 said:

I understand what you're saying but I think the speed limit is a function of rotating diameter of the turbine, and borg warner stopped mapping the compressor above this rpm line.

it appears borg warner have clipped their compressor map at the maximum rpm for the coupled turbine wheel, so the 9180 map stops at the 116krpm line, when it's actually still operating at 70+% efficiency, so if spun harder you could extrapolate that map up and to the right a fair bit further if the compressor can hold itself together. you'll need quite a high pressure ratio to keep it happy though (anything under 4:1 is basically stonewalled). the reason they didn't bother was the 80mm turbine it was designed for meant that was impossible. now they've jammed a turbine that is happy at 128k rpm on the back, it could go harder.

but you're right, I haven't found anything that explicitly states the 80mm turbine rpm limit is what stops you spinning the 91mm compressor wheel any harder, but Borg Warner saying the 9174 has a higher HP capacity and rpm limit relative to the 9180 shows this is the case.

That was exactly what I was asking Geoff... if they had picked a max line based off the suggested max turbine speed, or if it was just the stonewall for the compressor.  I don't agree that the 116krpm mark is at 70+% efficiency at all.  Look at this map and extrapolate what compressor efficiency you'd be at if you were running PR 3.1 (~31psi) and running at 90lb/min - it's going to be <60% compressor efficiency which is beyond what Garrett would normally show on their compressor maps at all.

[burn4005]

you're right, i was looking at this on my phone on the bus, now I've got it on my monitor to extrapolate, it's all done at 94lb/min no matter how hard you drive it.

[sneakey pete]

Finally got some more tuning done, switched tuners again, long story. Have got more ignition advance in now and it doesn't run at AFR's of 10.5:1.....

I've got 14psi of springs in the IWG-75 now. very impressive. boost seems to be holding at 14.5psi without any boost control enganged, still playing around with that one trying to sort out some issues. Still manages to hit full boost by 4000-4200ish rpm even with 50-60% throttle though (not sure any more would make it any faster). Car is very driveable around town, builds speed very quick above 3000rpm and over 4000 it hammers. Downchanged to second at 70k's an hour and stood on it and got a pleasant surprise, its just instant bulk power!