ChaMan

Hey guys,

Currently looking at getting at EFR 7163 for my X MR. Debating between the twin scroll and open scroll. Does anyone have any experience with the turbo?

I seem to understand the difference for the most part. But just looking for a bit more detail.

ie, would it be better just going for a 7670 T4 instead of a V-band 7163?
Hows the transient spool between the 7163 TS vs Open Scroll?

Car is used for weekend driving and sometimes my DD for a couple weeks at a time.

Thanks!

Silverton

Set your power goals. For an MR, an EFR7163 may not be cost effective. Currently, I'm only getting 363 awhp @26psi from my CBRD T-S/RBX 7163 on 92 octane; I'm planning a re-tune with AMS TMP cams hoping to get more power - maybe 400 awhp! I'd recommend at least an EFR7670; an EFR8374 should produce 450 awhp on an MR.

ChaMan

Thanks for the feedback. That's a pretty wildly low number. Been seeing different and higher numbers elsewhere. That said some do use different kits. My power goal is mid 400s on E85. Have heard around that 7670 produce almost the same power. Just wondering the difference between both the T4 and V-band kits.

LetsGetThisDone

iTrader: (1)

The MR makes about 10% less whp than a GSR. So there is that.


IMO, the EFR stuff isn't what it's cracked up to be. The 7163 pretty much makes MHI 18k numbers. I would do a vband precision 5858 setup from ETS. You'll have full boost at 4500, which is perfectly acceptable, and it will make around 450whp on pump gas, more with cams.


Here are 18k numbers (on ****ty ACN 91 pump fuel).
https://www.evolutionm.net/forums/ev...flex-fuel.html


and 5858
https://www.evolutionm.net/forums/ev...turbo-kit.html

ETS Michael

iTrader: (91)

I wouldn't bother with the 7163 personally. If your going for a turbo that small an 18k would be comparable and a lot cheaper. I would step into a 7670 T4 Twin Scroll or a PTE 5858 (the one above is my car). If your on stock block the 8374 and the 7670 will probably make around the same power on pump gas but the 7670 will spool better.

ETS T4 Twin Scroll Kits (EFR Now Added)

- Robert

ChaMan

Thanks for the info. Glad you brought up the 18k as I was originally looking at that. Everywhere I've looked though, the 7163 does seem to make more power than the 18k. Havent looked into the 5858, Ill look into that!

Thanks Robert, from what I was looking it at it seemed the 7163 made a bit more power than the 18k. I was originally set on the 18k, aha.

I have contemplated the 7670 also, wanted to see spool difference between that and 7163 especially if the 7163 was in V-band config.

Hiboost

iTrader: (9)

While a MR might be a bit more driveline losses than a GSR, I seriously doubt it's as high as 10%. That would mean if I converted to a 5 speed driveline that my car would suddenly put down 430 whp instead of 390 whp on E85 with a 20g? That's like trapping 4-5 mph higher in the 1/4 and I just don't see that happening, maybe 3-5% range is likely but most of the difference is made up with faster shifts and probably wouldn't see a noticeable difference until 5th gear and beyond.

The MHI-18k is a 54 lb/min turbo and what I ended up going with this season. On a Mustang Dyno I'm probably looking at 390-400 whp on pump gas and 450-460 whp on E85.

Compare that to an EFR7163 and it supposedly has a 60 lb/min rating for a single scroll setup, probably a little less for a twin scroll. So that puts you at 430 whp on pump gas with a twin scroll and probably closer to 450 whp on single scroll. E85 I would expect a potential 480-500 whp twin scroll and probably 500-520 whp single scroll.

EFR7670 is supposedly 64 lb/min and PTE5858 65 lb/min where you could aim for 560-600 whp on E85. Pump gas will be less but I tuned an MR recently that was about 510 whp @ 28 psi on a 5858 with a 4500-8500 rpm power band.

Pretty much the higher flow rating turbo you get the slower it will spool at lower RPM's but once you keep the RPM's above that boost threshold it's really just a matter of downshifting. Generally the EFR turbos have above average spool and response versus their flow ratings but if you are just going for drag racing or gear pulls it's not that big of an advantage.

LetsGetThisDone

iTrader: (1)

Considering a stock turbo GSR will make around 380-390 on E85, I would say yes...

deylag

iTrader: (23)

This is what I was thinking. I would like to add that comparing VD to MD is like comparing apples to oranges.

I would argue that the twinscroll T4 EFR 7163 has more potential and better transient response. If money were no option then go with the EFR 7163.

Since there is an OEM budget friendly option: MHI TF06-18K that is plug and play while producing a similar powerband. It depends on your personal preference and goals.

ddawg1130

iTrader: (1)

I love my 7163. I went open scroll because I wanted the v-band connection.

Below is the 93 and e85 flex fuel tune on Kozmic's dyno. I asked them to stay very conservative. This is at 27.5psi (engine has kelford 214bs, sleeved 2.0L with stock compression ratio).

They said with some additional fueling capacity and a less restrictive intake I could probably squeeze out some more power, but this should give a good idea of the 7163 performance capabilities. The powerband is amazing: smooth strong pull all the way through once above ~3500rpms. Above ~4k rpm it spools unbelievably fast, very very responsive.

CBRD RB-X v-band 7163. Red is e85, Black is 93

Jaraxle

With a 20g and 9 blade TD05 I have reliably made over 400whp (220whp baseline) ON 93 PUMP and my car is an MR. I ran it at that level for 20kmi with no issues. For me, to be basically at the limit of the stock block and transmission AND have super fast spool is a win across the board. I have all the logs and data to back it up in my build thread linked below. I just swapped from a 20g 11 blade GTX style compressor (71mm extended) to EFR style (7+7 blade, 73mm extended) just for the heck of it. So my points is this: unless your cracking open and upgrading your block AND the SST transmission there is no point going bigger than a 20g or 18k. There isn't really a point in going the EFR path unless your willing to go big or go home. By staying stock frame I am able to use the MAP stainless manifold and AMS widemouth downpipe which are both built out of thick walled cast stainless steel that will never crack or cause issues. Welded up manifolds WILL crack, not if, but when.
As for your question about TS or not. Twin scroll does not have any losses and only gains according to studies by Mazda (link in my "going ghetto Garrett" thread off my build thread).

moparfan

MHI 18K seems to be a safe route. If you can get them.

I always looked at the EFRs as OEM level of reliability. Not sure if that is true and it's not like there's tons of people running around with 50k plus on them. I vote for twin scroll because it's that its reason for being?

LetsGetThisDone

iTrader: (1)

If you're doing a turbo kit, spend your money for a turbo that will actually make power, a precision 5858 or gen2 5558 will approach 500 on pump, and make 600 on E85 with a stock motor. With same spool up as the 7163, low 4000rpm range (4200-4300ish). And you never have to worry about the turbine wheel falling off.

3kg

iTrader: (1)

hello, I found this simplified, but well done, illustration of the twin scroll character which explains well it's advantages in spool behavior - think exhaust pulse harmonization at the turbine...
you need to scroll - haha - to the movie/animation, called 'RENNSPORTCHARAKTER. AUCH IM KLANG.'
https://www.bmw-m.com/de/alle-modell...4/bmw-x5m.html