BorgWarner EFR Discussion

[PRY4SNO]

A couple years ago I bought a v-banded, externally wastegated efr7163 0.85a/r.

With my stroker build almost complete, I'm eagerly anticipating driving this beast.

Who else is running one of these?

I'd love to see some data/videos/dyno graphs and general impressions of how they respond.

[diesel des]

I'm on the 6758. I haven't heard of any other efr guys other than you and me here.

[mle]

I have 6758. But then again, I'm running 2.0 stroker AEB.

[jsol]

I've decided to go the EFR route. 2.5 stroker on E85. Looking at using a 8374 and was wondering whether to bother with the twin scroll?
I am waiting on a sportquattro manifold and want to avoid using a t3 single to t4 twin scroll adapter.

[PRY4SNO]

Good choice. I'm biased, but it doesn't mean I'm not right.

Ditch the twinscroll. Unequal number of runners = unequal exhaust pulse phases = no benefit from TS.

Go with a quick spool valve to enhance the spool and offset such a big turbo's low-rpm lag.

Almost positive a standard QSV will bolt right up to your exhaust manifold. And, once calibrated, you'll gain you an easy 500 rpm in spool; similar (or better) to the stroker vs. stock displacement gain.

If you want to see more empirical results vs. my word for it, check out Jim Green's Vomit Comet and the Chaloux UrS4. Both threads are well documented on The Project Pad.

[PRY4SNO]

PS

You should see 600whp for sure, and a huge powerband with the above set up.

Think, boost from 3k rpm to 8k rpm. Full boost from around 3.8k rpm.

[jsol]

I agree with you regarding the uneven exhaust pulse but my understanding was QSV's only work in conjunction with twin scroll housings.

[jsol]

I should also add that I am running 7A cams and 10:1 comp. EFR 8374 might be a tad too large as the CR will limit boost a little.

[diesel des]

PS

You should see 600whp for sure, and a huge powerband with the above set up.

Think, boost from 3k rpm to 8k rpm. Full boost from around 3.8k rpm.

Is that 600 whp on e85 or petrol/gas? Looks tempting. Does hank sell a suitable manifold with built in quick spool valve or at least room for it?

Sent from my LG-H955 using Tapatalk

[diesel des]

I should also add that I am running 7A cams and 10:1 comp. EFR 8374 might be a tad too large as the CR will limit boost a little.

You will need a bigger turbo with high Cr to reduce ping and det. The guys in the US seem to get good response from this big efr relative to its size. What turbo were you thinking off?

Sent from my LG-H955 using Tapatalk

[jsol]

I was thinking EFR 8374. There is only one larger, the 9180 which I think is too big!

[quattrito]

My friend is using exact same turbo EFR 8374 with twin scroll on his 2Jz Supra engine. At the moment it is at 600whp on e85. The turbo spools great and is joy to hear and drive.

[jsol]

Yeah, I'm pretty sold on a 8374. Just trying to figure out if I need to run a twin scroll/QSV. Running 10:1 comp and E85 might negate the need

[andy10v]

Good choice. I'm biased, but it doesn't mean I'm not right.

Ditch the twinscroll. Unequal number of runners = unequal exhaust pulse phases = no benefit from TS.

Go with a quick spool valve to enhance the spool and offset such a big turbo's low-rpm lag.

I thought a quick spool valve worked with a divided housing and an undivided manifold?

[PRY4SNO]

Yeah you're right, I wasn't thinking totally clearly lol.

The qsv needs the divided housing to work right. But if he didn't use one there would be no benefit from a twin scroll housing.

Sent from my SM-G900W8 using Tapatalk