[Closed] Borg Warner Efr Series Turbos

[omnigear]

The single is smaller, more responsive than the twins. 6258 are capable of heaps

T4 twin scroll or just the single?

nm the bigger A/C might be a problem for my r32 and certain exhaust mani.

[cobrAA]

A single EFR7670 would however be more responsive and make more power than -9s

I alays been a die-hard fan of twin application because.. well,, thats how the rb26 came out of factory.. but the more i think, it appears things have changed and single can be as responsive as the twin but cost less and easier to deal with if something is wrong.

[Lithium]

I alays been a die-hard fan of twin application because.. well,, thats how the rb26 came out of factory.. but the more i think, it appears things have changed and single can be as responsive as the twin but cost less and easier to deal with if something is wrong.

This isn't really a specific twins versus single thing, its comparing three turbo options which aren't really comparable.

The first is the "GT2560R-9s" which are the ultimate response twins of the "last generation" of turbo tech I guess you'd call it... they flow ~30lb/min each (60lb/min peak flow combined in a perfect world).

The next is the EFR6258s which are the smallest of the EFR range and ever so slightly larger physically than the "-9s" but arguably similar in response due to design and better materials, and are rated to flow ~44lb/min each (88lb/min peak in a perfect world) - so while they are fairly close in size to the -9s, they are a newer generation and essentially targetting a way higher power level. The reason you can't get a closer flow match with twins to a -9 or even -5 setup is basically there is no EFR small enough to do it.

The last is the EFR7670 which is rated to flow around 64lb/min all by itself, so is essentially the closest match to the -9s - still capable of flowing more but is an all bells and whistles current generation turbo, nice core, twin scroll option, TiAL turbine wheel, better aerodynamics etc. so is like the equivalent of a size down in single turbo speak - but able to still outflow the -9s. If you are from the mindset that -9s are the ultimate "driving" turbo on an RB26, then an EFR7670 would probably be eye opening.... better response and moving the power potential that bit closer to -5s.

[9krpm]

I wonder what twin 7670 will be like....

[Lithium]

I wonder what twin 7670 will be like....

On an RB? Hard to fit and rather laggy - but probably not too bad for a setup capable of ridiculous hp.

[SRS13]

Here's a fun little clip (if anyone is familiar with the old High Octane DVDs the sensor of humour and style will be familiar - this is a little tongue in cheek) with an EFR7670 showing it's worth on an E85 fuelled EJ STi WRX: ("700hp" is actually ~450kw @ 4 hubs):

He did some of the best DVD's back then! Still a crack up!

[Lithium]

Agreed - looking forward to him bringing out more

[cobrAA]

This isn't really a specific twins versus single thing, its comparing three turbo options which aren't really comparable.

The first is the "GT2560R-9s" which are the ultimate response twins of the "last generation" of turbo tech I guess you'd call it... they flow ~30lb/min each (60lb/min peak flow combined in a perfect world).

The next is the EFR6258s which are the smallest of the EFR range and ever so slightly larger physically than the "-9s" but arguably similar in response due to design and better materials, and are rated to flow ~44lb/min each (88lb/min peak in a perfect world) - so while they are fairly close in size to the -9s, they are a newer generation and essentially targetting a way higher power level. The reason you can't get a closer flow match with twins to a -9 or even -5 setup is basically there is no EFR small enough to do it.

The last is the EFR7670 which is rated to flow around 64lb/min all by itself, so is essentially the closest match to the -9s - still capable of flowing more but is an all bells and whistles current generation turbo, nice core, twin scroll option, TiAL turbine wheel, better aerodynamics etc. so is like the equivalent of a size down in single turbo speak - but able to still outflow the -9s. If you are from the mindset that -9s are the ultimate "driving" turbo on an RB26, then an EFR7670 would probably be eye opening.... better response and moving the power potential that bit closer to -5s.

I went form STD to gt-ss, maxed them out and went with -5s last year ( i can tolerate the extra lag for the extra power but wouldn't really want to go any laggier) So I'm more interesting in the 2x 6258 vs 1x 8376 the 7670 is just too close to the -5.

And it appears the twin 6758 would be too laggy on a rb26 but well suited on a 2.8 or 3.0

[Lithium]

Bri73y on here had (or maybe has again?) EFR6258s on his R32 GTR, he may be able to give feed back on how they respond and flow - an EFR8374 would also be awesome, sound like sensible alternatives to -5s if you're looking for more power

[NismoSTune]

There's a guy in Canada who is running twin 6258 EFRs on a tomei 2.8L (first twin EFR in Canada) but can't find any dyno charts... Word is the kit, including oil/coolant hoses and intake pipes, cost around $8k USD. That had better kick some farken arse for more than 3x the cost of twin -5s

[bri73y]

Bri73y still has them....

Mine have made 677hp so far on a dyno I know is low reading. My car lost near on 100hp when I first went to this dyno with no changes whatsoever.

Going back on dyno before WTAC to push some more, tuner reckons there's another 50hp in it yet.

So 700+hp on a low reading dyno for a pair of twins that spool like -5's is fairly decent. Don't know of any -5's making that kind of power.

Full Race are tuning one at the moment, it's made 630hp @ 21psi. It's also tracking well over 700hp by the time the pump 30psi into it.

It's running 280deg cams and has boost all in by 4400rpm. Not too shabby.

[Lithium]

There's a guy in Canada who is running twin 6258 EFRs on a tomei 2.8L (first twin EFR in Canada) but can't find any dyno charts... Word is the kit, including oil/coolant hoses and intake pipes, cost around $8k USD. That had better kick some farken arse for more than 3x the cost of twin -5s

One of the reasons I am not sold on twins - I'd personally go an EFR8374

Mine have made 677hp so far on a dyno I know is low reading. My car lost near on 100hp when I first went to this dyno with no changes whatsoever.

Going back on dyno before WTAC to push some more, tuner reckons there's another 50hp in it yet.

So 700+hp on a low reading dyno for a pair of twins that spool like -5's is fairly decent. Don't know of any -5's making that kind of power.

Full Race are tuning one at the moment, it's made 630hp @ 21psi. It's also tracking well over 700hp by the time the pump 30psi into it.

It's running 280deg cams and has boost all in by 4400rpm. Not too shabby.

Is that a stoke stroke one? That is pretty serious spool for that power, again EFR6258s are very big for twins on a 2.6 - and it's pretty amazing they are comparable with -5s in spool. Going for a slightly smaller single equivalent would make for a hell of a ride imho

[bri73y]

I believe so. Certainly RB26 was mentioned in discussion, nothing about a stroker.

EFR also make a 6255, slightly smaller than the 6258. Now they'd be fairly responsive and still make good power!!

[Lithium]

I thought the EFR6255 never ended up being a thing?

[bri73y]

you might be right there, they don't appear on Full Race's website anymore...

My bad - sorry!

[NismoSTune]

One of the reasons I am not sold on twins - I'd personally go an EFR8374

Is that a stoke stroke one? That is pretty serious spool for that power, again EFR6258s are very big for twins on a 2.6 - and it's pretty amazing they are comparable with -5s in spool. Going for a slightly smaller single equivalent would make for a hell of a ride imho

I think he was on the waiting list for an 8374 for over a year but because 95% of GTRs running EFRs are using that exact turbo, he went a different route. Could be wrong too.

[cobrAA]

Bri73y still has them....

Mine have made 677hp so far on a dyno I know is low reading. My car lost near on 100hp when I first went to this dyno with no changes whatsoever.

Going back on dyno before WTAC to push some more, tuner reckons there's another 50hp in it yet.

So 700+hp on a low reading dyno for a pair of twins that spool like -5's is fairly decent. Don't know of any -5's making that kind of power.

Full Race are tuning one at the moment, it's made 630hp @ 21psi. It's also tracking well over 700hp by the time the pump 30psi into it.

It's running 280deg cams and has boost all in by 4400rpm. Not too shabby.

thanks for your input. I really think the decision will be 2x 62 or 1x 83 .. car still run fine on -5s and going to storage in less than 2 months so I have a solid 8 month to think or wait for more result

[NismoSTune]

Hasn't precision turbos (proven over and over) been the best choice turbo for cost/power? I often read how they are simply awesome turbos and cost much less than EFRs while being very close in response/top end.

[TheKeeper]

Hey Gents... Here is the dyno graph on the twin 6258's we are working on that John mentioned. We had to cut the dyno session short after the 28psi pull because we heard a noise coming from the CAS area and decided to investigate before another run. It's on an RB26, 280º HKS Cams and port work (standard sized valves), E85. (76% Ethanol content)

Edited September 13, 2013 by TheKeeper

[Lithium]

Hasn't precision turbos (proven over and over) been the best choice turbo for cost/power? I often read how they are simply awesome turbos and cost much less than EFRs while being very close in response/top end.

No, there are just a lot of Precision fanbois that insist that without providing any solid proof. The Precisions are proven to perform really well but their prices aren't ultra cheap, their reliability is below all their competitors. I do like them but they are in cases overrated.

The only test I know of against an EFR was against a 8374 on a Supra where the testing was biased massively towards the Precision the biggest thing I remember was the EFR was a twin scroll one put onto a car which was setup for the Precision T4 open turbo, ie open manifold. Despite it being well known that doing that will do bad things to both power and spool, the EFR out spooled the Precision and made respectable power however fell a bit short of the Precision... Not sure if it would have matched or bettered it but it was within spitting distance despite being choked, so really when peopll the declared the Precision as the moral winner for being a bit cheaper and performing ad good or better, I was impressed the EFR did so well when you know that on a proper twin entry manifold it would have been a different turbo....