[Closed] Borg Warner Efr Series Turbos

[Beer Baron]

I am interested to know why the move to ball bearings on these turbos... guys such as Full-Race have flown the flag with the Airwerks range saying the ball bearing is a myth in terms of mech. losses (friction), etc. And now the EFR has been released with ball bearing and it is no surprise that it is more expensive.

So why the change? Market driven and hype or are there actual performance benefits. You would expect it to spool quicker from the wheel design and material selection more so than the bearing type. At least this is what BW tried to sell to everyone before.

certainly in my experience wheel selection (and their comparative sizes/trims to each other) has many, many times more effect on turbo response and spool up than the type of bearing used. bush type bearings work fine. they operate on a film of oil and spin very freely when oiled properly. sure they don't have a water cooled housing but as long as you use good quality oil and keep it in good condition i've not seen any effect on turbo longevity either. if anything I think the bush type bearings seem to be more robust than some of the ball bearing cores which seem to damage easily.

as far as why did BW go to ball bearings for the EFR turbos? I would say market driven. They are marketing these products as new gen technology and aimed at high performance and motorsport applications. so to help shed the image of basic but stout turbos they added features to hammer home the high tech aspect. personally I'd be just as happy using one regardless of bearing type. as you said the big disadvantage of ball bearing cores is they cost a shitload more to buy and a shitload more to repair/replace if something goes wrong.

[Full-Race Geoff]

Great to hear the turbocharger arrived safely, thanks for keeping us posted on your progress. I am very fond of the 6258 - it's my favorite T25 flanged B1 EFR turbo based on the turbine:compressor match ratios and overall turbocharger efficiency. The R34 GTR we run (2) of them on is a lot of fun to drive and has been very solid as a Daily-Driver

I am interested to know why the move to ball bearings on these turbos... guys such as Full-Race have flown the flag with the Airwerks range saying the ball bearing is a myth in terms of mech. losses (friction), etc. And now the EFR has been released with ball bearing and it is no surprise that it is more expensive. So why the change? Market driven and hype or are there actual performance benefits. You would expect it to spool quicker from the wheel design and material selection more so than the bearing type. At least this is what BW tried to sell to everyone before.

Full-Race never said ball bearing is a myth; what we have stated is: **on the dyno and drag strip ball bearings do not matter** Combining top-notch blade aero efficiency levels with incredible durability of the Airwerks turbos allowed us to reach great performance levels from these turbos (case in point S200SX 1.22 a/r spools earlier and outperforms the twinscroll 30R at all points in a recent evo test) Quite honestly, the ball bearing makes zero difference once the turbo is already up on boost. However - on the street, road course, auto-x gymkhana, drift, etc the ball bearings' improved transient response is absolutely there. In fact on OE applications we are seeing a change to ball bearing turbos becuase it can offer a 3-4% fuel economy improvement. In a time attack application, the difference of BB vs non-BB is considerable

It took a LOT to come up with a bearing design which meets the borgwarner engineering team's requirements. The EFR bearing uses a metal bearing cage plated with silver to prevent galling. Check out this photo from MotoIQ.com comparing the EFR bearing cartridge to a Garrett GT bearing cartridge (which uses a plastic bearing cage)

Edited June 17, 2011 by Full-Race Geoff

[bigmikespec]

Did not mean to misquote but I am glad it got your attention!

I am dubious about the S200SX because of this result: http://www.gtr.co.uk/forum/121247-borg-warner-s200-bad-result.html

It might be just one that is not set up correctly...

I do not mean to nit-pick but just playing devils advocate here. So from what you said bearing type has no effect when already on boost; if you have a well set up package (diff, gearbox, engine, mapping, etc) you should not be off boost anyway in a time attack scenario. What is the considerable difference between non-BB and BB in time attack?

[TheKeeper]

Did not mean to misquote but I am glad it got your attention!

I am dubious about the S200SX because of this result: http://www.gtr.co.uk...bad-result.html

It might be just one that is not set up correctly...

I do not mean to nit-pick but just playing devils advocate here. So from what you said bearing type has no effect when already on boost; if you have a well set up package (diff, gearbox, engine, mapping, etc) you should not be off boost anyway in a time attack scenario. What is the considerable difference between non-BB and BB in time attack?

Actually BigMike there is a BIG difference between dyno/drag racing and road racing. If you have a sequential gear box the gap between the two diminishes significantly, but most people do not. Good road race drivers are very methodical with their shifts, and there is a longer time from throttle off to boost again than in drag racing. As we all know this is to keep from upsetting the balance of the car. (and increase longevity...to finish first you first have to finish)

Also, blipping the throttle (does not happen in drag racing or the dyno) is to keep the revs in "the quick boost zone", but not actually IN BOOST. These turbos (and most other ball bearing turbos) recover faster than journal bearing turbos during these transitions. So there is a significant difference over an entire lap, session or race.

[bigmikespec]

Also, blipping the throttle (does not happen in drag racing or the dyno) is to keep the revs in "the quick boost zone", but not actually IN BOOST. These turbos (and most other ball bearing turbos) recover faster than journal bearing turbos during these transitions. So there is a significant difference over an entire lap, session or race.

But do they really? And if so... by how much a lap? A long race is a different story (i.e. multiple laps) and is not really applicable to a lot of people on here.

I guess I am probing as to why the move to ball bearing. Market driven or significant performance improvement (for the weekend warrier) that justifies the extra $1k price tag, which let's not forget is the price of an Airwerks in itself.

[TheKeeper]

But do they really? And if so... by how much a lap? A long race is a different story (i.e. multiple laps) and is not really applicable to a lot of people on here.

I guess I am probing as to why the move to ball bearing. Market driven or significant performance improvement (for the weekend warrier) that justifies the extra $1k price tag, which let's not forget is the price of an Airwerks in itself.

BigMike, I can help with that. I don't think anybody will argue with the fact there ARE some advantages to ball bearing turbos. Let's just forget price for a moment. If you, BigMike, were to set out to build the top of the line turbocharger that would be unrivaled by any other turbocharger with a lot of UNIQUE FEATURES you would not leave ball bearings out of the equation. Simple as that. Now, if they kept all the other features and only added ball bearings I could see your point, but that's far from the truth. Is it worth that extra cost? well... that's up to you. And me. And everybody else that decides to open their wallet for their next turbocharger.

And to answer your question, yes it does add up even over a lap when you are talking thousandths of a second difference between first and second. But then again it's your choice as to whether you want to play at that level, and if you do... you need the best equipment available. Seems simple to me.

[scandyflick]

Mike, give this a read.

All the reasons for going BB core (among other things) are listed in there. The bigger reasons seem to be transitional response, and perhaps more importantly, the future of OE turbo development.

[bigmikespec]

Mike, give this a read.

All the reasons for going BB core (among other things) are listed in there. The bigger reasons seem to be transitional response, and perhaps more importantly, the future of OE turbo development.

I skimmed over the first paragraph then disregarded it considering it was written by Borg Warner. Show me a study undertaken by an expert not a sales pitch.

@TheKeeper. I agree that you would not leave it out if there was a no expense spared build... but I want to talk about cost because I brought it up For the weekend warrier (not the hard core endurance racer) the extra $$$ might be better spent elsewhere; if I was chasing tenths of a second I would think of everything else I could that would cost a lot less instead of a turbo change.

Bringing it back to the EFR range some what. Can you run antilag with these turbos; will they take a bit more punishment in that regard? What happens with warranty if you do?

[TheKeeper]

I skimmed over the first paragraph then disregarded it considering it was written by Borg Warner. Show me a study undertaken by an expert not a sales pitch.

@TheKeeper. I agree that you would not leave it out if there was a no expense spared build... but I want to talk about cost because I brought it up For the weekend warrier (not the hard core endurance racer) the extra $$ might be better spent elsewhere; if I was chasing tenths of a second I would think of everything else I could that would cost a lot less instead of a turbo change.

Bringing it back to the EFR range some what. Can you run antilag with these turbos; will they take a bit more punishment in that regard? What happens with warranty if you do?

BigMike, maybe you should change your screen name to BigSkeptic. Honestly? Just because BorgWarner wrote that you assume it's just sales pitch hype? One of the most trusted names in the automotive business and you're going to "skim over it", there may be good information in there.

That being said, I believe that if you are looking for the best bang for the buck you are not looking at the EFR turbo line. Period. You can buy a Neon SRT4 instead of a Viper, a Chevy Cobalt instead of a ZR1, a 370Z instead of a GTR and yes... a journal bearing turbo instead of an EFR.

[TheKeeper]

Here's an EFR taking a beating and has taken quite a few of these and seems to running perfectly fine.

[bigmikespec]

Come on don't be so naive, you believe everything a salesmen tells you? Nothing wrong with doing research and being a bit of a skeptic before you choose a product, especially something that will define your car.

That does sound pretty good. Which EFR is it using? Any more results?

[TheKeeper]

I've been called a lot of things, but naive has never been one of them.

That car is running the 8374 with the .92a/r housing on it. The car was suspected to have a boost leak when it was first dyno'd, which was found to be the case and has not been dyno'd since...and probably won't be for a few months. That car resides in AZ and it's about 110ºF (43ºC) there, and dyno season is over until September. Ha!

Edited June 17, 2011 by TheKeeper

[zebra]

Come on don't be so naive, you believe everything a salesmen tells you? Nothing wrong with doing research and being a bit of a skeptic before you choose a product, especially something that will define your car.

That does sound pretty good. Which EFR is it using? Any more results?

I have to agree there.

I highly doubt BB chra's will make any difference to lap times....i mean the slightest atmospheric difference, whether temp or density will affect lap times more than .002 secs of a difference in reaching peak boost on a gear change.

[TheKeeper]

I have to agree there.I highly doubt BB chra's will make any difference to lap times....i mean the slightest atmospheric difference, whether temp or density will affect lap times more than .002 secs of a difference in reaching peak boost on a gear change.

Just a simple track like our ButtonWillow Raceway Park track where a lot of time attack events are held has over 15 (on boost) shifts and between 22-25 transitions from off boost to on boost. (Evo) The Sierra Sierra team noticed a decrease in "on boost" transition time from one ball bearing turbo to the EFR, so I'm sure you'd see more when changing from journal to BB. Whether or not it's measurable enough for you make the jump is one thing, but it's there.

To be fair, much of that could be contributed to the internal blow off valve.

Edited June 18, 2011 by TheKeeper

[bigmikespec]

To be fair, much of that could be contributed to the internal blow off valve.

Can you explain this please?

[TheKeeper]

Can you explain this please?

I think Eric explains it in this article he wrote. Eric works for Cosworth and is a very reputable tuner. I'm heading out the door, but if the info is not in there it's a good read anyway...

http://www.motoiq.com/magazine_articles/articletype/articleview/articleid/1750/borgwarner-efr-turbo-feature-set.aspx

[bigmikespec]

It does not explain it. It seems like just an extra feature and personally I think it makes the turbocharger look ugly... I know that should not matter and it generally does not with me; but it is ugly! There cannot be much of a performance gain (if any) besides the position of the port on the compressor housing is situated 90° to the flow which is not a good place to have it.

The best thing I like about these turbos is the wheels and the housings. I do not see the upgrade to ball bearings and the BOV adding much value at all other than cost. If they were available with the older journal bearing type with the new wheels and housings and no poofy BOV on the comp. housing it would be a nice "in-between".

[scandyflick]

Inlet for a BOV is always going to be at 90° to the flow. All the examples I can think of are. So where exactly would you prefer it to be?

[bigmikespec]

Inlet for a BOV is always going to be at 90° to the flow. All the examples I can think of are. So where exactly would you prefer it to be?

No it is not... you are not thinking hard enough.

[scandyflick]

Clearly. Feel free to enlighten me.