Rb25neo. Precision 5558gen2 or 5858 or gtx3076r gen2

[Eager]

Hi all

i have a stock rb25 neo for road use. I'm considering my turbo options, current spec is gtr 570cc injectors, hks 2530, power fc, intercooler and the usual bolt on stuff

ive had plenty of skylines and silvias but never had anything top mounted so I think it's time

i have not got massive power figures on my agenda, but response and solid boost while not pushing the neo to hard. I've narrowed it to the gen2 5558 precision or the gtx3076 gen2, any opinions ?

i will either use 6 boost, sinco or a CRG manifold, v band likely

and need advice on a wastegate too, is 40mm enough? It will run 98ron and

I have a r35 gtr afm which I hope will cope ?

thanks 

[Piggaz]

Efr 7670/1.05. And win.

[Eager]

Not something I've considered and doesn't seem as popular here in uk but I'm all ears

[Eager]

To add, I like the external wastegate idea so I think the efr is internal ?

[R_34]

Not in 1.05 rear, the .92 is twin scroll internal and the 1.05 is twin scroll external.

[Kinkstaah]

I have a 7670 and personally reckon it's a big big for a stock 25. I have a 2.8 and wished it was a little more repsonsive, I don't think i'd be happy with it myself on a 2.5.

My vote is for a GTX3071, but if you demand specific power and only have access to 98, you may need to have some lag to get there.

[Piggaz]

8 minutes ago, Kinkstaah said:

I have a 7670 and personally reckon it's a big big for a stock 25. I have a 2.8 and wished it was a little more repsonsive, I don't think i'd be happy with it myself on a 2.5.

My vote is for a GTX3071, but if you demand specific power and only have access to 98, you may need to have some lag to get there.

I'd be looking at your setup, there is an issue somewhere. Your 7670 is "coming on" at the same time as my 8374 and I don't have VCT. (All on at 3500 rpm rolling it on in second).

A 7670 would be epic on a RB25. 

[Dose Pipe Sutututu]

R35 AFM might tap out unless you run it in a larger pipe say 3.5" or run it on the cold side before the TB. 

I did a S15 running a R35 AFM, although in a 3" pipe without any air straighteners installed and it was hitting 4.8V each time it came on boost for a car only making ~240kW.

I prefer the HPX version of the R35 card as it supports more air flow in the same pipe.

[Lithium]

40 minutes ago, Kinkstaah said:

I have a 7670 and personally reckon it's a big big for a stock 25. I have a 2.8 and wished it was a little more repsonsive, I don't think i'd be happy with it myself on a 2.5.

My vote is for a GTX3071, but if you demand specific power and only have access to 98, you may need to have some lag to get there.

@bri73y runs an EFR7670 on an R33 GTS25t (still RB25) on 98 and from all I can tell he is pretty happy with it's performance, he shared this dyno plot (EFR7670 vs HTA3076 on pump gas) showing the 7670 making near 370rwkw and 200kw by 4000rpm

[discopotato03]

Mr Lith could you pass on the final results of that RB25 you knew of with the EFR 7064 , think it was T3 IWG on the standard exhaust manifold .

Sounded like it was really strong for something with number plates , and not exactly lacking round town .

I reckon this would be really nice on a street Neo powered Skyline . 

 

[Lithium]

On 16/10/2017 at 5:46 PM, discopotato03 said:

Mr Lith could you pass on the final results of that RB25 you knew of with the EFR 7064 , think it was T3 IWG on the standard exhaust manifold .

Sounded like it was really strong for something with number plates , and not exactly lacking round town .

I reckon this would be really nice on a street Neo powered Skyline . 

 

We still haven't had a good dyno session with it thanks to boost control and ignition issues - I think we hit around 280kw @ hubs before ignition break down stopped our last session, however we've got it holding around 21psi on the road now and no misfire so hopefully when we next get on the dyno all will be well.

It builds boost VERY similarly to an HKS GT2535, but with the EFR "transient response" and more turbine flow - so more power per psi, it's pretty good for a >50lb/min turbo.

Edited October 17, 2017 by Lithium

[Eager]

So to wake this up

do I need twin scroll for the above type setups or is that better on the larger power builds. 

[Dale FZ1]

https://www.sau.com.au/forums/topic/472431-r32-gtr-efr-7670-build/

Check this thread above^^, and read in conjunction with Lithium's comments in this thread to your question.

IMO the short answer is "no".  You don't "need" split pulse to achieve your performance targets.  But if you have the budget, yes you should consider it - but stay IWG for the relative simplicity of install.

There's enough accumulated experience that suggests a properly executed EWG setup will be a performance improvement on an IWG.  Comment applies to single scroll and twin scroll.

I wouldn't discount the idea of a well designed manifold/gate setup, and a reasonably high spec single scroll turbo.