Borg Warner EFR7670

[Mad]

I was doing some research on turbo's and found the following link -

http://forums.nasioc.com/forums/showthread.php?t=2135597

Although a very long thread, it is some really interesting reading about the Borg Warner EFR 7670 vs GT3076R / GTX3076R / GT3582R and others.

The Borg is just over 3" longer in body than the GTX3076R

Article conculsions below -

On the Dyno Conclusions

The EFR7670 is a turbo that I personally feel compares more like A GT3582R, but spools faster on
the dyno (like a GT or GTX3582R w/.63Ar). Comparing the EFR7670 to a GTX3076,
its slightly laggier, but that lag is a trade off for more power. Since the
GTX3076R and EFR7670 have very similar compressor maps, the HP gained is do to
the higher flowing turbine housing/wheel. Since the dyno is very controlled, and
a high loaded run, in all these tests the super light Titanium Aluminide turbine
wheel doesn't come into play at all. What this does show is the turbine wheel
and compressor wheel design is a notch up over the Garrett GTX stuff. From what
I have seen Borg Warner has designed a turbo that does what they say it should.
It makes more power and spools faster than the GT3582R.

On the Road Conclusions

My conclusions are this. The
dyno conclusions do not match what I "feel" on the road. On the road, I feel
like this is much more lively than the GT or GTX3076R. Its interesting as in
some road tests the EFR7670 shows the same spool up RPM as the GTX3076 w.82ar,
but it feels so much snappier between shifts light load low RPM shifts. Meaning
the normal day to day 2000-4000RPM shifting is about 50% better than it was
before. In some logs I notice that the GTX would show say 2-3psi of boost at
these really low RPM's, where the EFR is showing about 5psi. Its only a couple
PSI but that makes huge difference in how it feels. You can see this on the dyno
graphs where the EFR is making more TQ at 2000-2500.

Under full throttle high RPM acceleration, again the car feels a bit faster. It feels like Its right
back on the power. When comparing this to the GTX3582R graphs I have, it blows
it out of the water. When comparing it to the GTX3076, its very close in respool
time, but there is this thing that just "feels" better.


Final Conclusions

I used to think that there are lots of turbos out there, depending on the size of the
turbine, its going to spool at a particular RPM, depending on the compressor
wheel used, your redline and boost, its going to make a given HP. So then it was
a matter of what size wheels Garrett and others used to create a given turbo and
it was a balancing act of spool and HP. But Borg Warner has proven that there is
some magic left in its turbos in that it actually spools faster than its
comparable GTX/GT3582R turbo and makes almost the same power, if not more on the
GT3582R.

So it looks like there is a decent solution between the GT30 and GT35.

Any takers???

 

[vss irvine]

Not much of a solution when you tally up the work involved to get it fitted into the front of the car.

 

[Mad]

No, agreed. If your starting from scratch then it might be worthwhile but if it is something you want to add to your current spec it could be a real mission.

Im still of the opnion that the GTX3076R is probably the best all round turbo out there for running 500 - 550bhp even though the Borg's performance is slightly better.

 

[Tim!]

I know someone who is running a Borg on a S14 running in the BDC at 500bhp he recons he hits full boost by about 4k

They seem to be solid turbos and hold good power/pressure

 

[Makaveli_se7en]

Only worth considering if starting from scratch imo. Too much hassle to fit to a Garrett orientated set up. Also been told that they've been a lot of early life failures.

However the technology is pretty cool. Its a much better turbine side than a Garrett, really needs some one like HTA to stick a better impeller in the comp side.

 

[MarkTurbo]

From what i've read on the first ones that failed it was a problem with the turbine wheels.

I've seen a 7670 make 2.5 bar at 3600rpm and 580 bhp with the same torque on a 2 litre engine :shock: I'm looking at one of the smaller models which should hopefully make close to 500 bhp and have full boost around 3000 rpm on my engine :twisted:

Its a few months away yet though so just need to sell a kidney or something now to pay for it :doh:

 

[red reading]

Owens turbo I use mark is rated the same, I made 500lbft on pump fuel but exhaust restrictions held it back. And we are starting to wonder when standard rods will give at.

Sr20 hate exhaust restrictions, evo and Subaru don't seem to be as fussy.

 

[vss irvine]

I had sprouts tonight so no exhaust restrictions here ...

 

[Makaveli_se7en]

Owens turbo I use mark is rated the same, I made 500lbft on pump fuel but exhaust restrictions held it back.

and that's with a heavy ass 15 year old mis-matched Garrett turbine wheel, think how good it would be with a turbine wheel the right size (i.e 4% pts more efficient) and 40% lighter.

 

[red reading]

May have to see then, trouble is finding no bullshit (ie not American) dyno curves to compare on sr 20 .

 

[Makaveli_se7en]

Know what you mean. American horse are like their gallons; smaller so they can squeeze a few more in.

 

[red reading]

And all I have managed to find bar 1 dyno plot on a evo is people using e85,which brings turbos on sooner and gives more power anyway, can't argue with the ti-al wheels just need more info to see weather it would be worth the ag of fitting one.

 

[MarkTurbo]

This is the car i'd seen the results for, the graph is at the bottom of this page, can't find anything on an Sr20Det either.

http://www.lancerregister.com/showthread.php?t=373326&page=21

I've just been reading this though on the latest problems with them, glad i'm in no hurry for a turbo at the moment :lol:

http://forums.bimmerforums.com/forum/showthread.php?t=1919765

Looks to me like they might have been rushed out onto the market without the production techniques being fully tested!

 

[red reading]

Raj lives up the road from me, that turbo is running @2.5 bar. I think you will find the hta job I use spools quicker and produces the same power, the turbine side of the bw is impressive, the comp side is a bit of a let down.

Mark just look up forced performance gt3076hta vs bw7670 and you will see that the turbos are pretty much equal.

 

[Makaveli_se7en]

I've just been reading this though on the latest problems with them, glad i'm in no hurry for a turbo at the moment :lol:

http://forums.bimmerforums.com/forum/showthread.php?t=1919765

Looks to me like they might have been rushed out onto the market without the production techniques being fully tested!

I pretty sure that's not an investment cast housing. Looks like a snad cast stainless housing to me. Looks like they've tried to take some cost out of the product on the quiet. Either that or they have some major inssues with the slurry in casting process.

Edit: Just read on the 2nd page that they switched to green sand, this is the cheapest nastiest sand casting process. Shell moulded sand casting would be a much better option. The offest of the holes in the flange is a common issue due to a mixture of core shift and set up for machining.

 

[MarkTurbo]

Think i just need to get out on my mountain bike more and forget about the car and turbo's for a couple of months and see what happens with the borg warners :doh:

2 wheels and pedal power is much less confusing

 

[red reading]

Just get a hta with bronze cage bearings and a billet stainless heat shield. They do a 73hta which will do about 500 but spool faster than a 3071.

 

[dencon]

Mark. Just fit on my gt35/42 and try. With your cams and larger capacity, I think it would fly. It easily pushed out 515bhp on mine, but Martyn said cams and high lift was too great. Try it free and if you do a 43 second run at wiscombe you can by it. It has only done a number of mappings. Den.