[Closed] Borg Warner Efr Series Turbos

[Full-Race Geoff]

thanks buddy i am not worried. and we are very excited about lots of the changes. hard to pick one that I like the most. we have been bouncing around the airwaves talking about stuff and I have a new email for you in your inbox.

OK sir - i will check the email and get back to you! Weve been working like mad to redesign many of our 4cyl manifolds for the EFR internal wastegate fitments. Lots of fixtures and tooling have been in heavy surgery for the past 2 weeks. The RB engines will fortunately not require any changes.

lith - no worries mate!

if you guys have any specific questions or need some closeup photos, post what yuou would like to see and ill do my best to get them online. I hope to get the R34s on the dyno soon, Ive got too much going on in the fab shop to break free right now

Edited November 22, 2010 by Full-Race Geoff

[Full-Race Geoff]

BUMP -- this afternoon we received the first shipment of EFR turbos (T25 and undivided T3 turbine housings only in this shipment). Anyone looking to build a Twin-T25 EFR setup OR a singlescroll T3 EFR, these are in stock for a short time

[bigmikespec]

Did the other two GTR's get tuned?

[Full-Race Geoff]

the white R34 engine is back at the machine shop (shoddy piston:wall clearances) and the blue R34 is street tuned, have not put it on the dyno yet. Holidays have been keeping us busy but will be back on this asap

[bradsm87]

Hey Geoff,

What other turbine housing options are in the works and when are their expected release dates?

I'd really like to see a divided twin scroll T3 0.8x housing for the B1 frame turbos. Also a 0.7x and 0.8x turbine housing option for the B1 frame turbos would be good. It's kinda a massive jump from the T25 .64 to the T4 divided .92.

Also can you offer these turbos at a slightly cheaper price without an actuator? I plan on cutting the outlet and wastegate off the back of the turbine housing because it's too long for my application and welding a V band flange further in and I'll use an external gate.

[Full-Race Geoff]

Hey Geoff, What other turbine housing options are in the works and when are their expected release dates? I'd really like to see a divided twin scroll T3 0.8x housing for the B1 frame turbos. Also a 0.7x and 0.8x turbine housing option for the B1 frame turbos would be good. It's kinda a massive jump from the T25 .64 to the T4 divided .92. Also can you offer these turbos at a slightly cheaper price without an actuator? I plan on cutting the outlet and wastegate off the back of the turbine housing because it's too long for my application and welding a V band flange further in and I'll use an external gate.

i do not know the final answers on which will be the next housings for release, but the current housings are the "sweet spot" for the given turbine and compressor matches. If you need more flow, go up in turbo size. BTW - The B1 turbos will not be getting the .92 a/r, even tho it was originally listed as a possibility (that will be updated shortly on our website).

In my opinion --> using the .92 twinscroll housing in a divided configuration without mixing between cyl pairs - will work GREAT. this setup with an EFR 7064 is to me the top-shelf setup for an RB25 or SR20 with fastest response possible for a <500hp application. the 7670 for RB26/25s or built SR20s that want a bit more power. Do not be scared by the T4 footprint, or the A/R sizing. this isnt a traditional turbo!!

Edited December 29, 2010 by Full-Race Geoff

[bradsm87]

i do not know the final answers on which will be the next housings for release, but the current housings are the "sweet spot" for the given turbine and compressor matches. If you need more flow, go up in turbo size. BTW - The B1 turbos will not be getting the .92 a/r, even tho it was originally listed as a possibility (that will be updated shortly on our website).

In my opinion --> using the .92 twinscroll housing in a divided configuration without mixing between cyl pairs - will work GREAT. this setup with an EFR 7064 is to me the top-shelf setup for an RB25 or SR20 with fastest response possible for a <500hp application. the 7670 for RB26/25s or built SR20s that want a bit more power. Do not be scared by the T4 footprint, or the A/R sizing. this isnt a traditional turbo!!

I know what you mean about upsizing turbo but as you know, there are more reasons to go with a bigger housing than to get more power. I'm planning on running a high compression engine and I don't want the exhaust backpressure of a T25 .64 turbine housing. Something around .75 would be ideal but I'd also be happy with a .86. I'm a strong believer in building the engine to make power by itself with lots of timing advance, high compression, cams and/or capacity increase and running low boost with a large A/R turbine housing. It just makes it have a more N/A-like power delivery which I prefer for the street.

[Super_Dude]

I'm having a hard time deciding between the .92 and 1.05 8374. Im running an 26/30 with 270 10.8 cams and lots of headwork. The car is mostly a track car.

The obvious choice is the 1.05 but the .92 will respond a little quicker and make a broader power band. .92 would be easier to work with and I could sell my tial 60mm.

Decisions, decisions...

[Full-Race Geoff]

I'm having a hard time deciding between the .92 and 1.05 8374. Im running an 26/30 with 270 10.8 cams and lots of headwork. The car is mostly a track car. The obvious choice is the 1.05 but the .92 will respond a little quicker and make a broader power band. .92 would be easier to work with and I could sell my tial 60mm.Decisions, decisions...

for my track car (RB26) ive chosen the EFR 8374 .92 a/r - with 42mm dual internal wastegate. I can make PLENTY of power with this and I want the simplicity + light weight of the internal gate. there are many things i need to work on improving - with the chassis, suspension, brakes, etc. For now, i want less things on the car to think about (turbo system included) and focus on chassis settings and driving; thats what will make us go faster on the track. maybe if I got the car truly dialed running full-tilt and high boost with a proper close ratio gearbox then i might consider the 1.05 a/r with external gates,

I know what you mean about upsizing turbo but as you know, there are more reasons to go with a bigger housing than to get more power. I'm planning on running a high compression engine and I don't want the exhaust backpressure of a T25 .64 turbine housing. Something around .75 would be ideal but I'd also be happy with a .86. I'm a strong believer in building the engine to make power by itself with lots of timing advance, high compression, cams and/or capacity increase and running low boost with a large A/R turbine housing. It just makes it have a more N/A-like power delivery which I prefer for the street.

I do understand your concerns about backpressure. I also much prefer the larger turbine housings when that is an option - particularly with divided manifolds and turbine housings. When i said ONLY the "sweet spot" turbine housings are sold - this means that the intake pressure : backpressure ratio should be under or about 1:1. We have seen in depth testing of this at borgwarner and (2) major OE's which verified this.

Also - do not get caught up in the "#" of the a/r. It is measured differently by everyone from each turbo mfg, and there is no such number you can say you want to use that will be ideal. Trust me when i say the .92 is optimal for low-mid-high- boost. for high+ boost the 1.05 will not be beat, these housings are designed for these wheels, and these wheels for the housings.

Lastly - here is the "paradox" of turbine housing design: a smaller a/r will have less efficiency at low flow and higher efficiency at high flow. Conversely, a larger a/r will have more efficiency at low flow and less efficiency at high flow. This is counter-intuitive to what you might think, but it is why you can not get unlimited airflows from a given wheel size.

happy new year!!

Edited January 1, 2011 by Full-Race Geoff

[Sidwysracr]

Hello Geoff,

I noticed that there are 7 turbos, but you only sell 6. I would assume you buy the 6258 and request the 55 turbine wheel?

http://www.full-race...efr-turbos.html

Also, does these have better boost climb than the GT2680R-5? I am seeking a twin low mount set. And with the single scroll 0.64, if I am reving up high what BP ratio should I be getting if I am rolling with 18 to 22 psi?

From what I know the GT2680R-5 can hold it's power to 9k rpm with ar 0.64, so I would expect same with the EFRs.

And finally, any recommendations of set up, such as sticking with 58 wheel, etc etc.

Thanks.

Edited January 1, 2011 by Sidwysracr

[Full-Race Geoff]

I noticed that there are 7 turbos, but you only sell 6. I would assume you buy the 6258 and request the 55 turbine wheel? Also, does these have better boost climb than the GT2680R-5? I am seeking a twin low mount set. And with the single scroll 0.64, if I am reving up high what BP ratio should I be getting if I am rolling with 18 to 22 psi? From what I know the GT2680R-5 can hold it's power to 9k rpm with ar 0.64, so I would expect same with the EFRs.

These are great questions to ask. my answers-

1) you are correct there are (7) EFR turbos - and (6) EFR compressor wheels. Our website lists by compressor wheel, per the EFR matrix. For the 62mm compressor, you can use the 58mm turbine OR the 55mm turbine. I strongly encourage the 58mm

2) I cannot quantify "better boost climb" without back to back on-engine results -- but i can say this: the EFR turbochargers are unrivaled for their turbine wheel and bearing design. When EFR turbos were being developed, other mfg's performance turbos were purchased, tested and benchmarked for comparison... BW made sure the EFR series would outperform the competitors.

3) Due to the high-flow wastegate design, these turbos are physically long and a bit difficult to fit in a bottom mount configuration, especially if you plan to keep A/C. I strongly encourage you to consider top-mount in an RB26!

4) The BP ratio should be intake pressure higher than exh pressure, until approx 5500rpm. from that point to redline, it should be 1:1

5) The 6258 .64 is bar-none my favorite turbo from any mfg for twin turbo setups

edit: if anyone wants to build a twin setup, we have (6) of the 6258's left, and once they sell will not have anymore for a bit longer

Edited January 3, 2011 by Full-Race Geoff

[Sidwysracr]

These are great questions to ask. my answers-

3) Due to the high-flow wastegate design, these turbos are physically long and a bit difficult to fit in a bottom mount configuration, especially if you plan to keep A/C. I strongly encourage you to consider top-mount in an RB26!

I do not plan to keep the A/C, since I am building a track car. I am trying to pursuit response, with 500 to 600 mid to high rpm power. I see on the website recommends the 58 as well. As before mentioned goal, knowing that the smaller turbine will spin quicker at cost of higher back pressure and more waste-gated at max boost. What would be the benefit of the 58 over 55?

From just looking at the compressor charts alone, I can meter about 400 rpm for the 6255/6258 62 mm compressor wheel can achieve maximum boost sooner than the GT2860R-5's.

And as far as fitment issues, is it possible to use stock fitment for a pair? I am seeking low-mounted as I am trying to keep the center of gravity as low as possible; it's a track car. I know that the dump-pipes will need to be V-band, if I can get away with stock manifold fitment then it can effectively reduce my costs by saving me the design/custom work and it allows quicker replacement as well.

Edited January 3, 2011 by Sidwysracr

[bigmikespec]

http://www.gtr.co.uk/forum/146447-borgwarner-efr-8374-vs-garrett-t04z-3.html

Just to give this thread a kick up the backside...

[Lithium]

Nice, I was meaning to get to this but CBF searching for the thread - was hoping it would get bumped by someone haha. I can see my car ending up with a built RB25 and a twin scroll EFR7670...

[bigmikespec]

Nice, I was meaning to get to this but CBF searching for the thread - was hoping it would get bumped by someone haha. I can see my car ending up with a built RB25 and a twin scroll EFR7670...

Can you see it happening soon?

[Lithium]

Lets put it his way... my car has 190,000km on the clock now (GT3076R went on at ~100,000km) - at 200,000km the car will be due for a new cambelt/waterpump etc etc for preventative maintanence. I had been planning to wait for the motor to start showing signs of getting sad before looking for the next stage of build but it seems that its not going to happen of its own accord.

If the motor is still going strong at 200,000km then I've decided it deserves a reward for going so well for so long having never been opened and will probably have a bit of a holiday and rejuvination process

[--Redwork--]

Some EFR results.

http://forums.clubrsx.com/showthread.php?t=755332

[Lithium]

Another result from someone with an Integra running a built K20A on race gas who went from a .82a/r GT3582R (around 650hp @ hubs) to an internally gated EFR8374:

If I read it right, the owner believes that with a stiffer wastegate actuator so can holds 30psi to redline could yield some substantial gains - he is pretty confident there is a fair bit left in the turbo. Very impressive gains over the GT3582R with no more lag!

[Fat_Tony]

Another result from someone with an Integra running a built K20A on race gas who went from a .82a/r GT3582R (around 650hp @ hubs) to an internally gated EFR8374:

If I read it right, the owner believes that with a stiffer wastegate actuator so can holds 30psi to redline could yield some substantial gains - he is pretty confident there is a fair bit left in the turbo. Very impressive gains over the GT3582R with no more lag!

I bet Garrett are shitting themselves.

[SimonR32]

Would be interested to see the boost graph on the GT3582R?!?

Edited February 9, 2011 by SimonR32