Borg Warner EFR Series Turbo's V 2.0

[iruvyouskyrine]

On 19/10/2017 at 9:46 PM, mtnickel said:

I hate to be "that guy" who posts: "how much boost do i need for 400wkw", but i have a similarly annoying/unresearched question that I'm really just doing a sanity check on...

I picked up an efr6758 in North america (I'm from Canada). it's one of the Indy Car turbos people were liquidating on subaru forums. 0.64 a/r turbine. Mint condition for a price I couldn't refuse ($675cdn=675AUD roughly). 

Anyways, i'm already externally gated on stock manifold on an RB25 and looking to run this for the ultimate "response" type turbo. 

Anyone think this is a good choice for the fastest possible spooling RB25 with hopefully around 275kw with aprox 1.2Bar?

I haven't seen anyone with an efr6758 on an RB25, but I really just look at it as a good stock replacement that will make 100hp more. Will happily post dyno results when I get them next year.

Thoughts?

PS. chassis the rb25 is in is a datsun 240z. It's light and I'd really just like response to have it a little more lively in first and second. Current turbo is td05h-18g 10cm kinuagawa billet turbo. 10cm terrible choice. shouldn't go bigger than 8cm for any td05h turbine. My other option is to sell the EFR and get a kando/mamba/kinugawa gtx3071r.

6758 with .64 A/R rear end will surely overspeed the turbine on 20ish psi wouldnt it? I have a 6758 with the .80 T4 twinscroll and thought that would be too small for an RB25.

[Piggaz]

"Whatever you think you need, go one size up"...

7163 minimum on an RB25. 7670 FTW. Forget the smaller 67 series!

[mtnickel]

6 hours ago, iruvyouskyrine said:

6758 with .64 A/R rear end will surely overspeed the turbine on 20ish psi wouldnt it? I have a 6758 with the .80 T4 twinscroll and thought that would be too small for an RB25.

I'd prefer the housing you have, but as I said, I got this turbo for dirt cheap, so the compromises are worth it. The turbine won't overspeed any more with the smaller turbine, but backpressure will be higher and more flow goes through wastegate. 

If you adjust he volumetric efficiencies in the matchbot to better reflect where the stock cam rb25 will make peak power, then it would probably go up to about 23psi without hitting the choke wall. At those pressures though backpressure may be chocking where adding more psi isn't making more power. 

3 hours ago, Piggaz said:

"Whatever you think you need, go one size up"...

7163 minimum on an RB25. 7670 FTW. Forget the smaller 67 series!

If it didn't fall in my lap for $675, I wouldn't run it. But 675 vs $2000 is a big difference. 

For moly power goals, I think it'll be great. I'm stock everything anyways. 240-270kw will be just perfect for me. 

[mtnickel]

https://forums.nasioc.com/forums/showthread.php?t=2711435

some good supporting info on the efr6758 on a 2.5L. 

Ill take the 600rpm of spool for the 5-10hp up top. That 2.5 didn't overspeed at 22psi on the sti, but on the rb it may be closer. I probably won't go over 18psi. 

Cool real world data though. We should plot that turbo on the matchbot and see how the exhaust delta pressures compare to real world. 

[Kinkstaah]

Get a 7163 - Have seen and driven it in action on a 2L.

0.8 or perhaps larger rear housing. Don't flirt with overspeed, this isn't overspeeding at 320kw, which is great for your target or 275-300.

[Mick_o]

19 hours ago, mtnickel said:

https://forums.nasioc.com/forums/showthread.php?t=2711435

some good supporting info on the efr6758 on a 2.5L. 

Ill take the 600rpm of spool for the 5-10hp up top. That 2.5 didn't overspeed at 22psi on the sti, but on the rb it may be closer. I probably won't go over 18psi. 

Cool real world data though. We should plot that turbo on the matchbot and see how the exhaust delta pressures compare to real world. 

Even though its a 2.5L i dont think thats going to give you any kinda indication on how its going to behave on an RB. 

The old EJ isn't exactly the most efficient motor with metre long headers etc... I take it you'll be throwing it on the standard manifold too? 

[discopotato03]

I think an EJ25 is a LONG way from an RB25 and besides having fewer larger pots yep the manifolding is light years apart .

I can't speak from experience but I reckon speak to Mr Lith because he's at least had some first hand experience with a single scroll EFR on an RB25 , as in bolted to factory exhaust manifold with a non bastardized integral gate turbine housing . 

AFAIK EFR don't make a T3 flanged housing for the 7163 so you'd have to modify the T2/25/28 flanged one to suit or use an adapter plate with the T4 flanged one .

I've had one tuner say the 7064 can be a little more responsive on engines without brilliant volumetric efficiency , and lets face it the RB25 even in Neo form dates back to 1998 .

My opaque crystal ball thinks the toss up for an RB25DET , that can at least bolt to the standard manifold , is probably the 7064 or the 7670 . These are from memory the same frame size and use the same sized housings so outline interchangeable .

The thing is that the usual go to turbo for an RB25 used to be an integral waste gate Garrett GT3076R , nowdays if it was known that a 7670 (0.85 T3 integral gate) was same or better response wise than the GT3076R then it'd be a no brainer . 

Another way to look at it is that if you want up to 300 wasps at the bags 7064 looks pretty good , for up into the mid 300s + then 7670 looks better .

A .

  

[mtnickel]

Advice noted. It will be on a stock manifold yes. 

I would rather sacrifice my power goals for greater response. I know boost 'threshold' can be low on the bigger turbos, but 1st and 2nd gear pulls is where i do 95% of my acceleration, and those sometimes don't hit peak boost till much higher up the RPM band.

 It will only ever be an autocross car and daily driver. I don't rev out 3rd gear on the highway risking having my car impounded here. Nor do I take it to the track. 

To put it into perspective, I currently have an 18g td05h with a 10cm housing and it's far too laggy for me in those lower gears. Everyone said don't go 8cm as it'll choke. Well. I wish I did go smaller. I also only ever run between 10-14psi tops.

Now that the 6758 fell in my lap for a song, I'm just hoping to have great response, 16-18psi (to be safe on a completely stock block) and hopefully make another 75hp than I'm making right now which I think is very plausible. I don't even mind if it only really wants to rev out to 6k as I hardly push it past there anyways (even though it does keep pulling up there).

Maybe this was the wrong thread to suggest a small power goal turbo, as really these EFR can do so much more.

[Nismo 3.2ish]

1 hour ago, mtnickel said:

Maybe this was the wrong thread to suggest a small power goal turbo, as really these EFR can do so much more.

I was told the 9180 would be better on my car but I put the 8374 and love it.

I also want it to go as good as I can get it down low , we all want something different from our car but this is the thread for you as most of the blokes here know what they are talking about and will give you good advice.

[GTRNUR]

Pete, I think "better" is a relative and an opinionated term.  It comes down to what  you want from the car in terms of the power curve. Different people have differing opinions on what is desirable in a power curve.

For me, I think that what it comes down to now is that while I have mad low end and mid range power, I do miss that rush feeling you get above 7000 RPM from power that continues to climb. That and traction was the lure of a GTR in the first place.  

While still currently part of the Precision crowd, I do also plan to go 9180/1.45 on my 3.4.  Perhaps next year the 9180 will deliver close to both.

Edited October 24, 2017 by GTRNUR

[Nismo 3.2ish]

Yes "better" is a relative and opinionated term, in my car, my opinion is the only one that counts , LOL

A lot of blokes are happy to DD Skylines that come on later and I am sure they have a ton of fun in them and mad on the track as well.

  I think my limiter is at 8000rpm and the 8374 runs out of puff before that but it suites me. I see the Nitto 3.2 stroker going to 10,000 ish but I would rather be changing gear at 6000 to  7000 than waiting for 6000 to get the rush and motor is not being pushed to its limits .

Love to see how the 9180 would go on your car What Precision do you have , Gen 2 6466 ?

[mtnickel]

Followup question:

Everyone is pushing for bare minimum of a 7163. Now what sort of boost/power level would be the consensus to run on a completely stock S2 RB25. Stock cams, stock exhaust manifold, Greddy intake. External gate. full 3" exhaust off turbo, no cat, straight through mufflers.

I'm pretty confident that 6758 could make a solid 260kw on the above with between 16-18psi. All while not over-reving. Peak power may be closer to high 5's than mid 6's. But should make for a FAT power band.

Now, the 7163 with the .80 housing will spool slower but has more potential, but what do I stand to gain on the above setup with a mainly stock build. How high can we push the boost on it while maintaining a fairly reliable setup.

I've found a reasonable deal on a 7163 with the same Indy car housings. They actually made them to swap right out for the 6758 on the indy cars when they changed the turbo spec. Maybe I need to get both and swap either one in. Would probably only take an hour or 2 for full turbo swap with all the v-bands I have.

[MaximuSmurf]

3 minutes ago, mtnickel said:

Followup question:

Everyone is pushing for bare minimum of a 7163. Now what sort of boost/power level would be the consensus to run on a completely stock S2 RB25. Stock cams, stock exhaust manifold, Greddy intake. External gate. full 3" exhaust off turbo, no cat, straight through mufflers.

I'm pretty confident that 6758 could make a solid 260kw on the above with between 16-18psi. All while not over-reving. Peak power may be closer to high 5's than mid 6's. But should make for a FAT power band.

Now, the 7163 with the .80 housing will spool slower but has more potential, but what do I stand to gain on the above setup with a mainly stock build. How high can we push the boost on it while maintaining a fairly reliable setup.

I've found a reasonable deal on a 7163 with the same Indy car housings. They actually made them to swap right out for the 6758 on the indy cars when they changed the turbo spec. Maybe I need to get both and swap either one in. Would probably only take an hour or 2 for full turbo swap with all the v-bands I have.

Well I have an EFR 7163 with 0.80 rear housing (T4 TS) on a little SR20. I'm hitting 29psi by 3800rpm. 320rwkw peak, and 250rwkw by 4000rpm. Certainly fantastic response. That's on e85 too. I imagine it would be insane on an RB25, might balance out if you're planning 98 fuel and stock mani as you'll lose response on both counts.

[mtnickel]

Well, it's done. Picked up another EFR 7163 for $760US. Not the best deal, but pretty solid. It's one of the indy car program ones. While I was originally going to just weld a T3 flange on the housing, I will now fab a T3 to V-band adapter so I can easily swap them in and out. We'll see if you guys are right on the response of the 7163.

1 hour ago, MaximuSmurf said:

Well I have an EFR 7163 with 0.80 rear housing (T4 TS) on a little SR20. I'm hitting 29psi by 3800rpm. 320rwkw peak, and 250rwkw by 4000rpm. Certainly fantastic response. That's on e85 too. I imagine it would be insane on an RB25, might balance out if you're planning 98 fuel and stock mani as you'll lose response on both counts.

You are also Twin Scroll vs my SS. I wouldn't think fuel type would affect spool much, and I thought smaller log manifolds can often spool faster than full size ones but give up power up top?

[2pee]

I probably would have seen if you could get a swap of the "big" housing on the 6758 if mostly used for autocross.

Prices you've paid seem a bit steep too! 7163 indy with the .85 v in/out picked them up for $US350 a while back, saw those .64 6758 being offered for $US450 in one ad recently too...but expect you could have bought for less.

Are you buying a 2.84" flange somewhere off-the-shelf?

[Dale FZ1]

4 hours ago, mtnickel said:

I'm pretty confident that 6758 could make a solid 260kw on the above with between 16-18psi. All while not over-reving. Peak power may be closer to high 5's than mid 6's. But should make for a FAT power band.

Now, the 7163 with the .80 housing will spool slower but has more potential, but what do I stand to gain on the above setup with a mainly stock build. How high can we push the boost on it while maintaining a fairly reliable setup.

Consensus on dynos is that Australian horses are bigger than those in the US and presumably Canada.  ie. our dyno figures are generally lower than what you might get.  So bear that in mind when interpreting comments from Aussies and Kiwis.

Something most people here are missing is that you're running this donk in an early Z car with its inherent advantanges (much lighter weight than an R chassis Skyline) and disadvantages (semi trailing arm rear end, lighter components, less potential traction).  So the car isn't going to require nearly as much hp to be fairly quick.  And depending how you drive the car, how it's setup etc you may not want really high torque to avoid breakages and make it useable.

It's not clear to me how the 6758 or 7163 is going to bolt up to the OEM manifold - flange differences?  Not that keen on adapters.

Talking Aussie hp numbers, and running on Aussie pump petrol 98.  Using conservative tuning, I'd say 6758 around 320rwhp.  7163 around 370rwhp with turbine flow efficiency, ignition timing and a touch more boost up top the difference. E85 should add around 50rwhp to both.

Feel - 6758 would be stronger up to 3000rpm, roughly equal up to 5000, and then compared to the 7163 fall off the pace after that.   Ultimately the 6758 would make the RB25 feel comparatively strangled up top and (for road use) let you pull a higher gear a bit easier, using less throttle because it's feeding boost into it at lower revs. So I wouldn't see it making much different dyno numbers than the TD05H-18G you want to get away from, but the feel would be very different (quicker to make meaningful boost and more flexible).

7163 should hit all the marks most people expect of a short stroke smallish capacity 6 cylinder in a sporty car.  It won't turn tyres at low rpm like some of those old small block sporty cars you'd see (eg Mustang) but the mid range and relative lack of "high" rpm (thinking 7000) torque drop will make it a comfortably better performance package than a comparable USDM sporty car.

The 7163 should offer a fatter torque band simply because it won't be weak down low, and the torque will hold up for another 1000rpm.  In my books, makes it the better of the two.

[mtnickel]

12 hours ago, 2pee said:

I probably would have seen if you could get a swap of the "big" housing on the 6758 if mostly used for autocross.

Prices you've paid seem a bit steep too! 7163 indy with the .85 v in/out picked them up for $US350 a while back, saw those .64 6758 being offered for $US450 in one ad recently too...but expect you could have bought for less.

Are you buying a 2.84" flange somewhere off-the-shelf?

I've seen some ancient threads where the guys initially asked that, but recently, they've been wise and we're getting between 600-1000usd. Well at least on the Subaru forums and Miata and such. Show me some recent links of such sales and places they pop up for that much. The 7163 is returnable and it yet shipped.

A user on instagram made some flanges. In contact with him. Otherwise will Machine at friends shop. 

11 hours ago, Dale FZ1 said:

Consensus on dynos is that Australian horses are bigger than those in the US and presumably Canada.  ie. our dyno figures are generally lower than what you might get.  So bear that in mind when interpreting comments from Aussies and Kiwis.

Something most people here are missing is that you're running this donk in an early Z car with its inherent advantanges (much lighter weight than an R chassis Skyline) and disadvantages (semi trailing arm rear end, lighter components, less potential traction).  So the car isn't going to require nearly as much hp to be fairly quick.  And depending how you drive the car, how it's setup etc you may not want really high torque to avoid breakages and make it useable.

It's not clear to me how the 6758 or 7163 is going to bolt up to the OEM manifold - flange differences?  Not that keen on adapters.

Talking Aussie hp numbers, and running on Aussie pump petrol 98.  Using conservative tuning, I'd say 6758 around 320rwhp.  7163 around 370rwhp with turbine flow efficiency, ignition timing and a touch more boost up top the difference. E85 should add around 50rwhp to both.

Feel - 6758 would be stronger up to 3000rpm, roughly equal up to 5000, and then compared to the 7163 fall off the pace after that.   Ultimately the 6758 would make the RB25 feel comparatively strangled up top and (for road use) let you pull a higher gear a bit easier, using less throttle because it's feeding boost into it at lower revs. So I wouldn't see it making much different dyno numbers than the TD05H-18G you want to get away from, but the feel would be very different (quicker to make meaningful boost and more flexible).

7163 should hit all the marks most people expect of a short stroke smallish capacity 6 cylinder in a sporty car.  It won't turn tyres at low rpm like some of those old small block sporty cars you'd see (eg Mustang) but the mid range and relative lack of "high" rpm (thinking 7000) torque drop will make it a comfortably better performance package than a comparable USDM sporty car.

The 7163 should offer a fatter torque band simply because it won't be weak down low, and the torque will hold up for another 1000rpm.  In my books, makes it the better of the two.

Really appreciate this feedback.

Dynos must be different. If the Subaru guys are making mid 330-350whp at all wheels on the 6758, then with a rear drive car should be upper 300s. 

Will be bolted up by welding a t3 flange to the turbine housing, but now so that I can swap, I'll probably make a t3 to v-band adapter. Either that or make a jig and weld t3 flanges to both turbine housings. May have better resale so people don't need to mess with the unavailable flange. 

The 6758 should have a fair advantage on an 18g. Bigger better flowing turbine 51 vs 49mm exducer. And a massive compressor size difference (50mm vs 54mm)  

see dyno of a Subaru with just the turbo swapped between 18g and 6758. Big change in power band.

but you raise a good point regarding the torque band and feel of the turbo above 5000. one other users comment resonated with me regarding traction: if I have too quick of spool and low end, it could be unusable power and hard to hook up. The somewhat slow response of the 10cm 18g I have now helps with putting power down in 1st  

 

 

[2pee]

4 hours ago, mtnickel said:

I've seen some ancient threads where the guys initially asked that, but recently, they've been wise and we're getting between 600-1000usd. Well at least on the Subaru forums and Miata and such. Show me some recent links of such sales and places they pop up for that much. The 7163 is returnable and it yet shipped.

A user on instagram made some flanges. In contact with him. Otherwise will Machine at friends shop. 

They come and go a bit, so you have to keep your eyes open. Nothing I know of currently, other than possibly the 6758 in .64 @450 from someone in Indianapolis. Would have thought that turbo with the .85 indy housing would be pretty good for your application minimizing  the EBP penalty.

Wasn't looking for one and I didn't watch the end result, but there was a 7163 on ebay last week mid 300s with speed sensor, not listed under borg warner or EFR but indycar. That guy, I've bought several items in the past from,  is mshindy, if it's listed in his feedback yet. He's had the Honda, cheater spec 9180 T4 welded to the manifold in the past too!

The 7163s I got were earlier this year via Roush, were ex Penske...and I like to think, ex Will Power. 

Flanges are a bit of a pain - and hate machining stainless unless it's 303.

[mtnickel]

2 hours ago, 2pee said:

They come and go a bit, so you have to keep your eyes open. Nothing I know of currently, other than possibly the 6758 in .64 @450 from someone in Indianapolis. Would have thought that turbo with the .85 indy housing would be pretty good for your application minimizing  the EBP penalty.

Wasn't looking for one and I didn't watch the end result, but there was a 7163 on ebay last week mid 300s with speed sensor, not listed under borg warner or EFR but indycar. That guy, I've bought several items in the past from,  is mshindy, if it's listed in his feedback yet. He's had the Honda, cheater spec 9180 T4 welded to the manifold in the past too!

The 7163s I got were earlier this year via Roush, were ex Penske...and I like to think, ex Will Power. 

Flanges are a bit of a pain - and hate machining stainless unless it's 303.

I guess I wasn't looking hard enough. From the searches I did all over the forums, in the last year they wanted often $900+ for the 7163.

You're right though, he did list a few under: "

INDY RACE CAR DALLARA DW12 TURBO CHARGER BORG WARNER SVRA DRIFT OPEN WHEEL

"

Only 3 sold since July. went for $610, 715, and $695 US. So @ $760, I overpaid by $60-70 on average? Not all of use have the hookups you do.

Where is the link to the 6758? @450 is that AUD? or USD? I'd be interested in picking another up for that price for a friend of mine.

[2pee]

Stu Kelly was the guy - wrote the name down for someone the other week who was sick of flange turbo issues on a circuit car, but he didn't want to go 2nd hand.  Of course, can't find the link where I saw it now!

These were the Roush ones, you might see if there's more coming into stock with the end of the season   -

http://www.ebay.com.au/itm/272367099100?rmvSB=true