Schister66

Since a few of us have been thread-jacking to talk about this, I figured we could start a thread specifically for info regarding the EFR series Borg Warners...in order to iron out fact from bullsh*t. Unfortunately i have gotten most of my information for Subaru forums like NASIOC which are notoriously full of misinformation. That is why I would like to have a constructive discussion about that here...where people know what they're talking about.

EFR Info from Full-Race: http://www.full-race.com/articles/bo...fr-turbos.html

Prior to hearing any negative issues with these turbochargers, I had been considering the EFR 6758 which is a 53lb/min turbo which isn't directly comparable to any GTX series I could find.
http://www.full-race.com/store/efr-t...8-turbo-2.html

Other options include the EFR 7064 which flows 56lb/min (comparable to GTX3071R) and the EFR7163 at 60lb/min (comparable to GTX3076R).


Discussion
-Are these turbos really worth the hype? If so, what makes them different/more effective?
Thanks to Wantboost, I read a great article on MFT turbines vs radial turbine geometry...it seems like this is the step forward. IIRC, the EFR series runs an MFT turbine.

-What features of the turbo are worthwhile? Does the IWG and integrated BOV function properly?

-Do we have real world comparables with data/dynos?

wantboost

iTrader: (2)

the 7163 outperforms and spools faster than the 7064. the 7163 spools only 50rpm slower than the 6758.

the multi flow turbine really makes the 7163 outperform larger units and make stupid midrange power. as the 7163 has turbine housing options from t25 .85a/r (yay for me) to the typical t3 and vband offerings. also, since this turbo was built from IRL feedback it has an aluminium bearing housing which makes each turbo 2lbs lighter than a typical EFR

I'm seriously considering the 7163 in the t25 flanged turbine, that is if I ever have 2,000 laying around

wantboost

iTrader: (2)

as of now only the 7163 features the MFT. I have no idea as of yet if BW has plans to incorporate the wheel into other EFR models

Tony the Tiger

The main issue with comparing turbochargers is trying to use a dyno to illustrate the differences. Although we gotta admit that dyno results are one of the only things we can easily share on the web regarding to our turbo setups. I usually try to include both dyno and video if possible, and maybe some street runs if I don't get in trouble...lol

Every engine wants something different, and reacts differently. Some are looking for best spool and power, meanwhile some are looking for best power and engine reliability. Some are looking for best power on limited octane.

What you see on the dyno, is just a snapshot of the engine and power with no regards to engine run time, heat saturation of the turbine, transient response time or how safe that power is for the engine based on combination of parts.

On some cars, I would favor the GT-series turbine, on some I may consider an EFR. You can manipulate turbine requirements by building an engine and building the turbo setup differently, but it is much much harder to manipulate compressor requirements without resorting to extreme ways to achieve efficiency.


We have to do testing beyond of just a snap shot of the turbo. I can size a turbo with a turbine that can spool up really fast, but after about 15 mins of run time at peak temps, it becomes inefficient once fully saturated with heat. I can do the same with the compressor as well. The article on MFT should explain this better than I can, but it was something I always go with when building my setups. It's always about the time subjected to maximum stress.

On the other hand, I can have another turbine that spools later, but it maintains that efficiency up to one hour of steady state run time.

One turbo is better for a short drag racing pass or a street turbo, one is better for a 30-lap circuit session or a top speed runner.

The way I see it, I just see the 7163 working for a different type of condition, and the 7064 meant for another. It depends on how precisely you can size everything, and then combine it with the engine. Everything from intake manifold down to the tailpipe will affect the turbo's flow requirements on both sides of the wheel

TheShodan

iTrader: (14)

I would agree with this completely from every aspect. I remember when the Sierra Sierra Evolution was the first to use this turbo when the "Racing" in the name of Environmental Friendly Racing was used. I was rather impressed with the usability of the turbo in an endurance environment, but thought that the turbine wheel was really the weaker link in terms of development strategy.

In most of the applications that I've used the EFR series on, A couple of S2000s, Evolutions and even a Cobalt SS, I've noticed that the turbine wheel used in comparable applications to the GTX smaller and midframed series are either WAY too large (like in the 7670) or too small for the power level desired, (like the 7064)..

Like the GT(X)R series, these turbos from what I've noticed is that they like boost pressure. once you get to the 16psi mark and above, the fun begins.

wantboost

iTrader: (2)

and you've hit every turbo guys dilemma and described it to a tee Tony lol

the 7163 is BWs first venture into MFTs... and the IRL is a perfect test bed (think about the different operational situations a motor goes through during a race.. I know BW has gained untold amounts of valuable data about its EFR series) data that hopefully trickles into the aftermarket street/race segment like Multi Flow Turbines

if you look at the 7163 cutaway demo, when the MFT wheel comes up to the turbine volute, the wheel perfectly forms the rest of the volute. that shape is what gives it the range, as a typical turbine would just be sticking out into the volute

I have a 2871r right now. I'm going to try it with a custom billet wheel from a supplier I've been following and finally met at PRI this month. I might be happy with it for a bit (15-25% flow gains on the wheel based on application, boost level, tune)

it has the .64 t25 housing, which isn't ideal (really need the .86) but it will get the car moving for now. unless I can trade or find a cheap .86 housing. I know it'll make the torque I want but not all the power. it'll get me close.

I was going to use the 2871r as a get it going turbo anyways.

I think the 7163, with its humongous bearing housing (military grade ceramic ***** and steel races) that is literally the size of a GT-R series chra, have changed the way the turbo handles thrust loading, and it has a very broad flow range so you could run the turbo at 300-400hp and still be efficient and make power downlow, same if you were pushing it to the listed 60lb maximum. the turbo would still produce amazing midrange power and I see it (with a little more testing on various platforms) becoming one of those "staple turbos" like the gt3076r has become

plus even though they are just dynos, the 7163 comparison graphs were done at the same pressure levels as the 7064 and 6858. I can't remember back housings though, I think they were roughly similar, also I don't know if it was a bolt on and go comparison or if there was tuning involved..

but you can't argue that the 6758 responded quicker than a 2871 and made more power everywhere.

while the 7064 is a popular EFR unit, its kinda like when precision went to the CEA turbines and how some using the 6266 make over 700whp at 19psi.. that's how the MFT will be to BW but better

you can't deny that on the same chassis and motor that the 7163 spools almost like a 6758 (50rpm slower) and outspools the 7064. they showed boost vs rpm plots and when Perrin does testing they are pretty honest... same boost pressures, tune, fuel, etc. no cheating like a certain company that will have the EFR run slightly higher boost

wantboost

iTrader: (2)

also what a lot of people don't understand is that BEs Gamma-Ti (titanium aluminium) turbine wheel/shaft is actually brittle at ambient temps. the higher the exhaust gas temps, the stronger the wheel gets and the material becomes slightly more pliable

a BW rep told me that when they cast the shafts after they cool, they have to be careful transporting them and installing them, as one good impact with any solid surface can damage the wheel. once its installed though its a very happy wheel, it'll even stand up to loads of anti lag abuse

Tony the Tiger

^ Your explanations are great for comparing the turbo themselves, and yes, further improvements made on turbo technology is what pushes everything forward What Shodan was referring to, was not the wheel material, but the vague use of larger turbines in the EFR turbos. Now we know, they had to compensate.

In order to get more flow within the same space means more RPM. The phenomenon is just like our Honda 4-cyl trying to make V8 power, yet what we are chasing now is "low-end torque off idle". That's what the MFT reminds me of, but instead, MFT took a hit on the high boost regions to trade off for better low speed and transient flow regions. It's not an upgrade in turbine technology but rather a "sidegrade" and gives the turbine wheel more characteristics that we can choose from. It is surely a good design, but MFT will be something OEM's would love to use when sizing small turbos on highly strung small engines which are cammed for midrange operation; when the engine has to "breathe" before the turbo picks up speed due to lack of displacement and doesn't require much overall boost to achieve target HP.

With lighter wheels in mind, it's also a sidegrade. Back in the days when we had ceramic turbine wheels; despite the reliability problems, they did spool faster although they sucked in maintaining inertia. Again, lighter wheel is another option that we can use for better turbo matching, but it does not favor most of our racing conditions. Drag racers would simply love to keep as much inertia as possible, thus their choices on big heavy turbines and their love their PTE's.

So far, in terms of overall turbo improvement made in the last decade, only the GTX wheel has been able to get more flow in the same space, and literally almost no sacrifice in the low shaft speed regions. That's a true technology that moved everything forward from OEM, performance, racing, economy. All the other billet wheels have cheated more flow from a smaller diameter by bumping up the efficiency ranges to sky high pressure ratios and RPM's.

What I was trying to elaborate was the fine line between choosing the "best" turbo, versus choosing a "proper" turbo for the engine. The gains I get from choosing a proper turbo easily surpasses the gains I get from choosing the best turbo.

A great real world example is direct injection. We have personally witnessed the extreme improvements of spool time, power and response with just direct injection alone and literally on the same turbo (MS3's, 2.0 FSI), and DI is a form of chemical/combustion efficiency adder. It doesn't gain VE much, but only gains power due to better combustion process and able to run leaner AFR's. You can tell by their airflow values which hugs within non-DI ranges, thus, this was how better fuel economy was achieved (less air, means it needs lesser fuel for the same power). We are talking about huge improvements that surpasses any comparisons between non-GT/GT/EFR/Billet/Cast/etc.. by improving the engine itself only. The engine had successfully manipulated itself to use less air and put out less exhaust, so it can make more power out of a smaller turbo and be totally safe at the same time.

Due to this proper turbo matching, for now, it is still the the most significant thing to do to satisfy all our goals. Best spool and power, best power on limited octane, widest torque curve, and safest sustained operation for its specific purpose. Whenever I choose my turbos. I would look at the engine, make certain changes and choose certain manifolds, downpipe size, intake manifold, etc.. if it falls within budget, and then choose the most versatile compressor wheel. So far this seems to give me the most control over my build.

wantboost

iTrader: (2)

and I couldn't agree more.

what I've noticed is the 9-11 blade gtx wheel really improves low end airflow below a certain pressure range. above 20 psi I've noticed the 6+6 and 7+7 bladed wheels really shine above that point as their normally aggressive profile helps with air ingestion.

I've noticed some of the EFR models had goofy turbine wheels for a given compressor size, leaving you to play with the turbine housing to get what you want. I feel the MFT wheel is a step in the right direction in wheel design, not only for the OEM segment (think EcoBoost, with their tiny (25mm) billet compressor wheels and similarly small turbine wheels) but with street cars and circuit/road course vehicles.

I know the IRL series loves the EFR and I think the 7163 is BWs first venture into a properly matched compressor/turbine mating. hence why it performs so well (i have videos of the 7163 on mild street cars and it will blow your mind)

I think for us street guys and road course/autox/hpde/time attack guys that this represents the start of a truly great turbo line.

mostly because the turbine wheel has been totally reprofiled and is very aero efficient. the old EFR turbine wheels reminded me of BWs early wheels and Holsets hx series turbine wheels (am I wrong, I mean they looked the same down to exducer.design)

Tony the Tiger

There's nothing wrong to check up on newer turbo technologies, but I think you've missed the point of my post though

Having an awesome turbo means it can cope with a wide range of engines. The versatility is what makes these newer turbos do better everyday.

There is no such thing as perfect compressor/turbine mating by looking at the turbo by itself, because this combination solely depends on what engine you use it on. A perfect turbo, is like a perfect tool... Use it wrong and it becomes the most imperfect tool, like using the world's best vise-grip to tighten machine bolts.

So whenever you look at the technology itself, you look at its ability adapt and work well in the widest ranges. The MFT, by its design, has a compromise. If you understand its design, then you will know its limitations. The small scale testing already revealed it, and that's without a compressor wheel attached on the test runs in the article. It goes against our import performance sector wanting high boost and big power at high engine speeds.

Basically, what I am saying is, don't hope for too much on the newer turbine wheels. As I said earlier, it is much easier to manipulate exhaust output requirements on an engine rather than compressor requirements, so you can always "negate" the less efficient turbine wheel as long as you have a super efficient compressor wheel to make up for it.

Engine changes like different compression ratios, cam timing and exhaust manifold type is already enough to bump me up or down a whole turbine wheel class on the same compressor wheel.

The trend of turbo choices illustrates this... We always have multiple turbine wheels and housing A/R's for one class of compressor wheel. It is never the other way around. Seems like EFR should really be focusing on the compressor, not turbine. But it's marketing, and GTX is just superior in the compressor side (where it matters most now).

wantboost

iTrader: (2)

I had a great reply all typed out and looking nice... my phone is a *****

I'll try and type it out when I can get a computer working (broke my laptop at PRI)

TheShodan

iTrader: (14)

I've noticed this with the EFR series and the exhaust wheel profiles. Although Garrett hasn't changed too many of their profiles either, it just seems that for the 2.5 litre and lower applications, The Garrett turbine wheel profiles match more in-sync than with the EFRs, which do exactly as Tony says, concentrate on material of exhaust and not proper compressor /turbine matching.

An example is the turbine wheel of the 7670 as compared to the older S366

wantboost

iTrader: (2)

that's what one of my replies said before my phone went ape.

it seems like the early EFR turbine profiles looked no different than wheels they've made for older models, hell they even remind me of Holsets hx/he series turbine wheels. the 7163s turbine wheel is BWs first venture into changing the turbine wheel profile on an EFR model and it "seems" like they are having good results with it... so far