[Closed] Borg Warner Efr Series Turbos

[Lithium]

Yep Geoff, definitely sounds like the same guy - I was suspicious that it may have had leaks or other issues going by the things that he said, it was making poor power (a couple of my mates have made more on EFR8374s on less serious motors and far less boost) and not responding amazingly well.... but one way or another they work clearly making it work at 110+% to try and get results from it. I can't help but feel a bit like there is conspiracy there, anytime those guys get something non-Precision there are weird issues that no one else gets which come up.

[scotty nm35]

Typically the change from singlescroll to twinscroll is best described as a 10-15% improvement in turbine efficiency at low engine speeds & the twinscroll may have 3-5% less top end compared to singlescroll, due to the increased wall friction found on the divider surface. ive run EFR's singlescroll and ive run them twinscroll, on the same engine. to say that there is no difference and the Ti wheel is all that matters would be selling yourself very short

for twinscroll to work right, you need the right manifold, the right turbo and the right turbine housing. If the pieces arent there or the turbo is undersized you probably wont appreciate the benefit..

Of course it needs one of your manifolds to work. Credibility suffers when you are making a profit from the supplied information too in my eyes.

I stand by my statement, twinscroll is a farce if you compare apples to apples, eg. a .82 single to a 1.06 split. It is not cost effective in the slightest per kw from my experience.

How was I to know the shaft isn't Ti, I would prefer the wheel and shaft to be one piece not bonded. Thanks for putting me off this BW tech.

[bigmikespec]

How was I to know the shaft isn't Ti, I would prefer the wheel and shaft to be one piece not bonded. Thanks for putting me off this BW tech.

ewww... friction welded?

[discopotato03]

I'm not up on turbocharger turbine production and I though friction welding was passed over to spectron beam welding ?

On a Nissan RB I'd rather use the original equipment throttle recirc and by the looks of things the EFRs one is in the way on a typical bolt on Skyline app .

Yes with a V Band housing the overall length is vastly shorter so adapted to an RB manifold or T3 with V out and a Scotty mount external gate it's looking easier .

A .

[Full-Race Geoff]

friction welded?

every turbo you've ever seen whether Garrett, Airwerks, Turbonetics, Precision, FP, MHI or chinese-ebay-turbo, they all have a friction welded 4340 steel shaft to a steel turbine, every single one. Except EFR. it is not possible to weld steel to Ti, so BorgWarner owns (9) method patents on how to attach steel shafts to titanium turbine wheels... they use one (the strongest). This is also why you are unlikely to see a titanium turbine from Garrett- since they'd likely be paying BW a royalty here

I'm not up on turbocharger turbine production and I though friction welding was passed over to spectron beam welding ?

there is no welding of any type used on an EFR turbine shaft

Of course it needs one of your manifolds to work. Credibility suffers when you are making a profit from the supplied information too in my eyes.

I stand by my statement, twinscroll is a farce if you compare apples to apples, eg. a .82 single to a 1.06 split. It is not cost effective in the slightest per kw from my experience.

Hi scotty, what follows below in the attachment is purely fact. We presented this to Ford, it is a result of a big-budget project we did with their CFD and engine performance teams - validating twinscroll for use in their ecoboost mustang performance engine.

http://docdroid.net/c6j6

fully divided cylinder pairs allows exhaust pulses to have maximum kinetic energy. The net effect is the turbine wheel spins faster for a given exhaust pulse (higher turbine efficiency). it doesnt matter if its a FR manifold or a garrett turbo, when the shit is done right it works. If this is lost on you, let it go. If you disagree thats fine, Ill add you to my growing ignore list and you can do the same... but please stop posting bullshit misinformation here its lame and clogs this thread for anyone trying to decipher fact from fiction.

How was I to know the shaft isn't Ti, I would prefer the wheel and shaft to be one piece not bonded. Thanks for putting me off this BW tech.

Finding out facts before posting misinformation is a good practice to get into... Are you also concerned that your turbo's compressor wheel is held on the shaft with a nut? not one piece... lol

Yep Geoff, definitely sounds like the same guy - I was suspicious that it may have had leaks or other issues going by the things that he said, it was making poor power (a couple of my mates have made more on EFR8374s on less serious motors and far less boost) and not responding amazingly well.... but one way or another they work clearly making it work at 110+% to try and get results from it. I can't help but feel a bit like there is conspiracy there, anytime those guys get something non-Precision there are weird issues that no one else gets which come up.

you and me both... oh well!! i honestly couldnt care less at this point, since they are the one and only failure we've seen

Edited May 14, 2014 by Full-Race Geoff

[Full-Race Geoff]

gave up on attachments, link for PDF study: http://docdroid.net/c6j6

Edited May 14, 2014 by Full-Race Geoff

[Lithium]

I stand by my statement, twinscroll is a farce if you compare apples to apples, eg. a .82 single to a 1.06 split. It is not cost effective in the slightest per kw from my experience.

http://forums.toyspeed.org.nz/viewtopic.php?f=2&t=71870&p=709174

[scotty nm35]

Hi scotty, I try not to debate with ignorant/argumentative folks online so this will be my last response to you. What follows below in the attachment is purely fact. We presented this to Ford, it is a result of a big-budget project we did with their CFD and engine performance teams - validating twinscroll for use in their ecoboost mustang performance engine. If this is lost on you, let it go. If you disagree thats fine, Ill add you to my growing ignore list and you can do the same... but for the love of rajab, please stop posting bullshit misinformation here its lame. You dont have to click "post"

No need for the personal attacks, they are only my educated and tested views as I stated. I have never even seen an EFR, like most of the other guys on here. I welcome the debate, and happy you have set us straight on the shaft construction to some extent. Glad you edited your post anyway.

It doesn't change the fact your view is only that, everyone is allowed to have their own opinion. If it conflicts with your ideas or testing, it doesn't mean it's proven wrong, and doesn't give you an excuse to call me ignorant. There are after all many ways to extract more airflow, or gain response. I have seen some great results from a myriad of turbo setups, and even the use of exhaust pulse energy seems much less important to me than manifold velocity. In your opinion, how would a rear mount turbo setup work at all?

That aside Geoff, I just noticed your wastegate runners exit the manifold on a 90 degree or worse. You should trial facing them in the direction of gas flow to allow better breathing in the top end. They aren't just bleeding manifold pressure after all...

Are my ideas out of the box? Yes, but I have proven them to work many times. Your choice if you chose to ignore me, I won't be losing sleep over it.

Back to EFR discussion please, lets keep the split pulse discussion for the other dedicated thread.

[Lithium]

Back to EFR discussion please, lets keep the split pulse discussion for the other dedicated thread.

It is EFR discussion - doing twin scroll and doing it well is one of the bigger advantages EFR turbos have over the likes of the GTX range.

[Tonba]

gave up on attachments, link for PDF study: http://docdroid.net/c6j6

Interesting article Geoff. Thanks!

[bigmikespec]

every turbo you've ever seen whether Garrett, Airwerks, Turbonetics, Precision, FP, MHI or chinese-ebay-turbo, they all have a friction welded 4340 steel shaft to a steel turbine, every single one. Except EFR. it is not possible to weld steel to Ti, so BorgWarner owns (9) method patents on how to attach steel shafts to titanium turbine wheels... they use one (the strongest). This is also why you are unlikely to see a titanium turbine from Garrett- since they'd likely be paying BW a royalty here

Yes, I didn't realise that was how they mated wheel to shaft.

If they are patented then that information should be published, do you have any refence of the patent numbers? Would be an interesting read waht they do different.

[discopotato03]

Well my take is that if you're going to twin scroll a system it has to have suitably sized components like housings .

Something I'm guess get lost in TS translation is that sometimes larger AR housings are needed because convincing the exhaust "putts" to funnel down a passage easily needs a larger passage because the thermally (expansion) driven gasses may not not have a lot of velocity and any slower moving gas hates restriction to flow . Generally make flow happen easily - and it will .

I also think some optimists would like you to believe you can bolt a BIG TS turbo on a modest engine and have it spool like a production car - optimistic . Example may be a GT40 or 42 on an SR20 . I don't believe TS is black magic but sized properly it does work . Mitsubishi and Subaru has it as OE .

It is a challenge in the aftermarket particularly with integral wastegates I reckon because its more difficult to package than the original turbo system .

Probably the one thing that's muddied the water in recent times is E85 fuel , it's enabled people to get away with heat and detonation issues and run stuff that would be impossible on pump fuel - minus WI/WMI .

My logic is that if forced to make a good spread of power without exotic fuel and anti detonants TS done properly is a step in the right direction .

Geoff I think the GDI and twin exhaust ports per cylinder takes engines to another level but ones that takes advantage of TS turbo systems .

Obviously we don't know the future directions of BWs aftermarket competitors ie Garrett , they could gain substantially just from using lighter turbine wheel materials and still have good market share .

My opinion is that BW has done marvellous things with the EFR range but the desire to be uncompromising can be a double edged sword , great from a design point of view - and I'll leave it at that .

Last point is that the market really does want a plain compressor housing option .

Cheers Adrian .

Edited May 15, 2014 by discopotato03

[abr33]

I got my car retuned again today, with 3.5 exhaust, although not that good, because I didnt end up with the right gate spring.

So the 7670 on 25 with 256 cams and appropriate bottom end made 380kw @ 6750 rpm. And about 560nm torque at 4500ish.

I fixed a few air leaks and boost is better but still takes 4600 revs to make 24. The boost was falling over to 20psi from 24, so it should shit 420 if it had held it. All this is on 98 vortex and 600cc/min WMI. So we still wait to lean on it hard.

Just as a slight update.

[KiwiRS4T]

I got my car retuned again today, with 3.5 exhaust, although not that good, because I didnt end up with the right gate spring.

So the 7670 on 25 with 256 cams and appropriate bottom end made 380kw @ 6750 rpm. And about 560nm torque at 4500ish.

I fixed a few air leaks and boost is better but still takes 4600 revs to make 24. The boost was falling over to 20psi from 24, so it should shit 420 if it had held it. All this is on 98 vortex and 600cc/min WMI. So we still wait to lean on it hard.

Just as a slight update.

380kw is not to be sneezed at! Do you have a chart of the boost curve?

[abr33]

No I didnt get that printed off unfortunately. 24 at 4600, about 22 at 5500 and by 6500 under 20.

It was making great power. Low boost is 16, makes 330kw, 4 psi more for 380. About 15kw/psi.

24 would have to be at the 420. Im not really after more. 380 is a lot. Lights p-zero's at 120 in 3rd

[Lithium]

How long does it take to reach 14psi? That seems astoundingly laggy considering their reputation, bit very solid power! What is it like to drive response wise?

Sent from my GT-I9505 using Tapatalk

[Mick_o]

I agree with Lith must have a restriction somewhere still or maybe boost leaks?Wouldn't think at that kinda boost would be falling off like that up top

[abr33]

14 would be at about 3500 ish. 3000 makes 10.

There is no boost leaks, and the exhaust is 3.5 inch. Its the gate spring being 12 pound. Cant take it.

To drive? its a bloody animal. You can pump the throttle it goes from vacuum to 24psi in about half a second!

When I had the t04z, I could hold it spinning in whatever gear and just constant throttle, with the efr it just wants limiter all the time with any throttle.

I need to put a heavier spring in, and wire ebc to the rpm output so I can have varied gain. Cant have it too harsh coming on boost or we have to pull too much timing. But more up top where it needs to hold harder.

The ramp is awesome, by that, at 4k there is 135kw, and at 4700 there is over 280.

[Lithium]

Ah ok, as you say... Sounds like a boost control issue, not actually the turbo being unable to spool that well - sounds like it would be a complete animal with everything dialled in right to get the best from it :-)

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[dr phil]

Turbine housing question, EFR7670 - what difference in response and outright power would people expect between T3 housing vs T4 housing, both internally gated. On a stock RB25DET Neo, with stock exhaust manifold, would there be much in it?