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Discussion Starter #1

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wow this kit looks amazing! Time to have these new turbo kit kick those old school japanese ones asses...

I would like to know are all piping in equal lengths?
 

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it's the best turbo kit we've ever made, for any car. On a 2.8L or larger twin 7163 are untouchable spool/response for the 1000hp+ level

Thoughts on twin 6258 and 2.8?

Looking for hks 2530 response with 10-20% more top end.
 

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Thoughts on twin 6258 and 2.8? Looking for hks 2530 response with 10-20% more top end.
twin 6258 is perfect for that - will give 2530 response, no surge "shuffle" at low rpm/high load and significant gains on the top end. the Dsport article R34 linked above, used the HKS 2530 kit previously
 

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twin 6258 is perfect for that - will give 2530 response, no surge "shuffle" at low rpm/high load and significant gains on the top end. the Dsport article R34 linked above, used the HKS 2530 kit previously

Hey Geoff, I've spoken to Mike. Seriously considering this full kit.

Surprisingly, either there's not many cars running this kit or they don't care to publicize it. Besides that article I don't know anyone with that kit.
 

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If the target was 600-700bhp what kind of early spool could you get on twin Borg Warners?
displacement has a lot to do with spool on an RB26, my experience with 2.6L RB twin EFR's in 4th gear sees 1bar boost ~3600rpm. for a 2.8L 1 bar is reached ~300-400rpm earlier so 3200-3300rpm



Besides that article I don't know anyone with that kit.
The twin EFR kit has been popular for us in australia. A couple guys that come to mind with Full-Race twin EFR kits, easy to talk to if you care to dig up more info (theyre all really friendly)

the guys at pride performance in the US bought (3) of these kits and started with twin 6758, but now on twin 7163 - they are nuts, 20+ ets-pros for their japanese customers:
https://www.facebook.com/prideperformanceonline?fref=ts
https://www.facebook.com/realtalib?fref=ts

wtac competitor - John Bright "BPG performance" R32 gtr at WTAC: Open Class: BPG Racing R32 GTR John Bright | World Time Attack Challenge

wtac competitor danh tranh twin 6758: https://www.facebook.com/danh.tran.10?fref=ts

wtac competitor chris alexander: Insane carbon GTR to debut at WTAC | World Time Attack Challenge -- hes been running a single 9180 but the plan is to change to twin 7163s
 

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I have been thinking of uprating my -5s at some time and going single . I will seriously look at this kit if it spools up like 2530s.
The -5s are on a 2.8 they spool up great but max out around 625.

These could be what I'm looking for as have always liked twins
 

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Group buy??? I would be up for it :)
I keep looking at these.
Do like the EFR series and would love to see how they compare to my billet -5s on my RB28.

Currently I'm maxing out around 635bhp with amazing spool. Almost 450lb/ft at 3,300rpm or so.
If I could retain the spool but get more power and torque I am in.
 

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What would be nice would be two twin top mounts like below image but using modern spec turbos. The full race ones the way they are positioned look a bit clumsy - aesthetics are just as important when spending a fair chunk of money.
 

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What would be nice would be two twin top mounts like below image but using modern spec turbos. The full race ones the way they are positioned look a bit clumsy - aesthetics are just as important when spending a fair chunk of money.

I'd imagine it's because of the length of the efr what make them awkward to fit in?
 

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Geoff, what is it about a twin EFR kit that makes it more efficient than a twin scroll single EFR kit? I was under the impression that a single would be more efficient due to... Reasons.
 

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Geoff, what is it about a twin EFR kit that makes it more efficient than a twin scroll single EFR kit?
ultimately, this boils down to basic physics. The diameter of the smaller wheels and the lower inertia that comes along with this is impossible to get around. The smaller EFR's can spin their brains out and do it earlier than a larger comparable flowing larger EFR.

I was under the impression that a single would be more efficient due to... Reasons.
Despite the latest MotivDVD claims, if modern turbos with comparable blade aero are used - a single is not more efficient. We saw this with 2.2L 6cyl Indycar engines. Honda's teams ran a single EFR9180 twinscroll and Chevy/Lotus ran twin EFR6758. Honda would repeatedly get spanked on small courses (where response was paramount), but they could compete on the bigger/higher speed tracks. Honda engineers could not wait to switch to twins. Once the rule change for 2014 went into effect, all teams ran twin 7163s, the level of play evened out and now its more about aero differences in the kit at speed than about the turbos. nobody misses their single. I've seen this play out with the RB's at Full-Race, driving both the twins get it done earlier and give nothing up at the top RPM

Still looks cramped in there. 6 cylinders powering one single billet turbo just seems better!
single turbo is certainly easier to install and service. no question there (Thats why my personal car has a single EFR on it), both setups have their pros and cons. If it is a max HP effort, i think twins are the clear choice. for a 550-700hp setup a single 8374 is really, really good.


Do you think it's any longer than the GT2835 turbos? Iirc these turbos were making 800plus on RB26's
yes, EFR is longer than the garrett units. due in large part to the bearing housing span and the aerodynamic turbine housing. gt2835 is old tech, they did make some power but did so very laggy. turbos have evolved a lot since those early days!


What would be nice would be two twin top mounts like below image but using modern spec turbos. The full race ones the way they are positioned look a bit clumsy - aesthetics are just as important when spending a fair chunk of money.
its the only way to fit these shape turbos on an RB... with all due respect, if you are concerned that 2x Indycar turbos looks "clumsy" then you may be missing the point
 

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That's interesting. I'd always assumed that even though you have smaller rotating masses in a twin setup, their lack of mass would be counteracted by a lack of exhaust volume available for each turbo. I also assumed that larger turbos were inherently more efficient for a handful of reasons that I'd butcher if I tried to articulate without a white board and dry-erase marker.

If only there was a car with this setup near me. I'd love to see how the butt dyno likes it.
 
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