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Interesting space to watch with this G series .

Wheels aside its interesting to note the cast in compressor back plate , and that the overall length is shorter than the current GT25BB based center section .

I don't think many would argue that the EFR turbos aren't good things but their overall length is an issue .

Also Garrett may have seen the light with stainless steel turbine housings . Fabrication is far easier with stainless nowdays and I believe the Ni Resist turbine housings were always difficult and expensive to produce . 

If Garrett can come up with single and twin scroll integral gate turbine housings similar to the EFRs BW may have some serious competition .

Roll on a slightly larger hot side G30 and G35 series . 

A .

No no, Garrett have changed their new turbos to be 11hp per lb/min but continued rating their older turbos with 10hp per lb/min.  They may as well have just made their dyno read higher for all their newer turbos [emoji6]
Flow numbers make a lot more sense, you work out how much your engine needs - you pick a turbo from it and if you've done a good job - profit!  It'll make what it makes on your chosen dyno.
 
Wonder why they'd switch to 11hp/lb.. stupid and I'd only rate it at the original 10. Still impressive for such a small frame turbo.

They did that with the Gen2 turbos and started saying "WAY MORE HP LOLZ" when a big chunk of the extra power claims for the Gen2s simply came from that.  To be fair I suspect they are just aligning themselves with how much more power people are getting from the same airflow with more efficient engines etc etc, and no doubt if they changed the claims for the old turbos to align with it (ie, a GT2871R becomes a 520hp turbo,  the GT3582R becomes a 750hp turbo and the Gen1 GTX3582R becomes an 840hp turbo) then no doubt people would start asking questions.

Edited by Lithium
  • 2 weeks later...

How hard would it be to custom setup a couple of G25s in twin configuration? V band outlet is a bit of a barrier?

Currently building a 26/30 for response and a stockish engine bay appearance is a must, hence reluctance to do anything single turbo and I had -9s on it before the 30 conversion.

But this range is exciting me and I might be happy to guinea pig the potential of the smaller ones / find out where they choke out on my 30 if we can make them fit. Could we see ~1000hp on E85 from some tiny turbos?

4 hours ago, Birds said:

How hard would it be to custom setup a couple of G25s in twin configuration? V band outlet is a bit of a barrier?

Currently building a 26/30 for response and a stockish engine bay appearance is a must, hence reluctance to do anything single turbo and I had -9s on it before the 30 conversion.

But this range is exciting me and I might be happy to guinea pig the potential of the smaller ones / find out where they choke out on my 30 if we can make them fit. Could we see ~1000hp on E85 from some tiny turbos?

Won't be making 1000 hp through factory restrictive OEM piping!

6 minutes ago, Piggaz said:

Won't be making 1000 hp through factory restrictive OEM piping!

Haha feck.

I'm happy to change things as long as they can pass for looking somewhat factory. Black piping etc. Granted they've been pretty good the last few years of ownership - now that Skylines are getting less common on the road - but police attention in Melbourne is still a problem!

After response more than power though. Don't want to do gearboxes and would just like to do something different given everyone seems to chase 11ty kw with GTRs. I want something that pulls pleasantly from say2500rpm :D 

11 hours ago, Birds said:

I want something that pulls pleasantly from say2500rpm :D 

I'm sure your garden variety dash 9's will do that. But I predict it'll die off 5.5-6k rpm with 3L thou.

17 minutes ago, Count Grantleyish said:

You mean two of them.

I mean one of them... I think a (supposed) 660hp turbo is pretty perfect for a 2.5 or a 3L.

Just need someone to be a guinea pig to see if the wild claims are true.

2 of them to go and make 1300hp is just going to end in tears, or running them very lazily making them less than effective.

The correct answer is get RWC then go single and keep the old ones in a box.

He also have a GTR and wants it stock looking-ish hence two of them.

Plus saying he needs two of them big ones is cooler cos he can also say "and I need it by tonight Harry"

Ok so I realised that was a bit of a vague question, I'll try again,  I have an R34 GTR with a 3l bottom end and an wondering by going off the compressor maps if anyone would guesstimate if the 550s would be capable of passing the 500kw mark at the tyres as a twin setup on an ideal setup ?

 

 

Edited by MIX-GTR
10 minutes ago, MIX-GTR said:

Ok so I realised that was a bit of a vague question, I'll try again,  I have an R34 GTR with a 3l bottom end and an wondering by going off the compressor maps if anyone would guesstimate if the 550s would be capable of passing the 500kw mark at the tyres as a twin setup on an ideal setup ?

 

 

I would say quite comfortably yes.   Well and truly.

I have bolded and underlined a VERY key word there.

Edited by Lithium
  • Like 1

Actually I have a habit of understating things, but I might spell this out - I saw in your previous post you mentioned your "-5s".  When I highlighted "ideal" setup, I would rate the stock location twin configuration as FAR from ideal - so if you are hoping to put G25-550s in the stock configuration then my response doesn't apply to that, at all.

 

Thank you for the reply Mr Lithium, my plan is not to use factory GTR housings or manifolds, I have an electric steering pump so I do have some room to play with 

 

I just find the power figures claimed a little unbelievable from turbos that size and I'm no good at reading the compressor maps hence the question 

The power figure claims are pretty big, but Garrett tend to be pretty good with their turbine and compressor flow maps and they certainly indicate some impressive performance potential.

On your typical Oz dyno I think of 500kw @ wheels as needing around 80lb/min of compressor flow when running E85, give or take - and so long as the turbine flows sufficiently to allow that.

The G25 turbine wheel with all but the smallest option seems more than up to supporting that from what I've worked out and that is supported by the fact that Garrett are using the same turbine wheel on the much larger "G25 660" turbo.  As a general rule of thumb it seems that your "decent" 26 headed RB needs near 30psi to make 500wkw assuming the Oz dyno/E85 combo, the G25 550s flow can flow ~48lb/min EACH at that level.  That is a combined flow of around 96lb/min.

If you managed a setup capable of utilising 90+lb/min of combined compressor flow then you are going to be comfortably north of 500wkw....

Edited by Lithium
  • Like 1
11 minutes ago, Lithium said:

The power figure claims are pretty big, but Garrett tend to be pretty good with their turbine and compressor flow maps and they certainly indicate some impressive performance potential.

On your typical Oz dyno I think of 500kw @ wheels as needing around 80lb/min of compressor flow when running E85, give or take - and so long as the turbine flows sufficiently to allow that.

The G25 turbine wheel with all but the smallest option seems more than up to supporting that from what I've worked out and that is supported by the fact that Garrett are using the same turbine wheel on the much larger "G25 660" turbo.  As a general rule of thumb it seems that your "decent" 26 headed RB needs near 30psi to make 500wkw assuming the Oz dyno/E85 combo, the G25 550s flow can flow ~48lb/min EACH at that level.  That is a combined flow of around 96lb/min.

If you managed a setup capable of utilising 90+lb/min of combined compressor flow then you are going to be comfortably north of 500wkw....

Thank you, that is exactly the response I was hoping for 

i came across a fellow a while back that had an r34 like mine and the engine bay looked pretty much standard exept for the engine breathing pipe work, but he put out just shy of 500kw which I thought was very interesting, my hope is to pass the 500 mark while keeping a relatively stock looking bay 

I am in Australia and the person I use to tune my car uses a Mainline dyno 

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