RB26 GTX Cores in factory housings best choice?

[RB335]

Hi Guys.

I'm wondering has anybody experimented with GTX cores inside factory turbo housings, it doesn't seem these are widely available but people such as Munro do offer rebuilds
using GTX Cores.

I'm wondering if I could get for example -5 like top end, with -7 or -9 like low and mid range, I'm keen to hear you guys experiences as I can't quite find too much information on
the internet on it.  Cheers.

[Leroy Peterson]

There is a whole thread on this in the forced induction section, if you cant find anything on the SAU search function use google to search SAU

[sneakey pete]

Yeah. Got it done, didn't end up using them.

Few ways to go about it. The gtx2860 cores are the same rear as -5s, so you need to use -5 rear housings, stock ones won't work. You can make stock front housings work, at least the ones I had did though they had a 60mm wheel in them before I bought then blown. The turbo you get is going to be more of a slightly better -5 though.

 

In theory you could stick a gtx2860 front wheel onto the front of a -9 core and get a -9 with more compressor. This may work well I think, as the compressor on a -7 will max out, however yoi may find the rear chokes to much . (-7/-9 are smaller rears than -5, hence less lag). I heard rumours someone was trying to make a set of these but I don't know how they went.

 

Hks just released some new billet front wheel turbos, no results on them yet.

[Dose Pipe Sutututu]

where's Piggaz?

 

[Piggaz]

45 minutes ago, sneakey pete said:

 

Hks just released some new billet front wheel turbos, no results on them yet.

Yeah. If you look carefully they're journal bearing. Really? 

They also produced a dyno graph which I would take with a grain of salt. The overlay between 2530's and RS's is not accurate. We all know how much worse RS's are compared to 2530's.

 

 

[Dose Pipe Sutututu]

come on... where's the "throw the twins in the bin" ? LOL

[Piggaz]

here is the link to the thread mentioned a few posts above. 

[baron_von_bootsector]

I had something similar done with my -5's by Procharge and they turned out pretty well, its a very cost effective path forward if you want to stick with stock looking low mount twins.

They upgraded the compressor housing to a .60 (from .42) and put in GTX2687 wheels, while porting out the turbine housing to get the best possible flow as they are a little small for what a lot of people try to push through them.  I have been very happy with the results so far but due to the displacement bump on my car (2.6 -> 3.4) its not possible to do a fair back to back...

[Piggaz]

^^ what was the result?

[hypergear]

My experience high flowing Twin GTR turbos internally gated is the turbos has issues dumping back pressure through a 3 or 3.5 inches exhaust. -5 on stock cams is very laggy, without been able to dump back pressure, fancy billet wheels can not run into their peek efficiencies. I've personally used -9 specs in my own GTR, pretty happy with that and thats recommended for road and track use.

[baron_von_bootsector]

Piggaz - Its heading in for the final tune in just over over week but on the run in tune (standard 98, wastegate pressure (~15psi) and zip in terms of timing) it knocks out 342KW at the treads @ 4600rpm. Will post up a full build post when its tuned as my previous build post got rejected / deleted...

 

 

[baron_von_bootsector]

^^ Whoops - just checked and its actually 18psi

[discopotato03]

I reckon the best replacements based on standard sized RB26 compressor and turbine housings is the -9 turbos . They may not have fancy CNC'd compressor wheels in them but they appear to work very well in a 2568cc 1500Kg GTR . They are not a ring in but a dialed in unit so a result is not a fingers crossed guess .

[RB335]

Hi Sneaky pete

Why didn't you end up testing them?  Do you still have them?

Yes i had read that whole thread a while ago, and recently re-read it all.

There was one guy who said he had great success, e.g 80hp more than -5's with -5 like response.
But I don't get why others say the GTX will hardly offer any more efficiency when trying to use RB26 style housings,
example how Tao at Hypergear is saying it wont really work out, I'm just trying to see where the confusion ends
as so far only 1 person has sumbitted awesome feedback, but most turbo shops and builders say the GTX just wont give any real benefit.

What's the go with the new HKS units?  
Link?  Are they bolt on to replace factory RB26 units?

Edited July 22, 2016 by RB335

[TXSquirrel]

I am very interested in knowing as well.  This past weekend I talked to another guy running -5's with GTX in his R33, and he likes it very much.  But for my own setup I have been looking at standard -9's for a while, and so far I can't find any information/feedback on upgrading standard -9's with GTX. 

[sneakey pete]

It's not really similar, a gtx2860 vs -9s is like a gtx3576 vs a gt3071

[TXSquirrel]

So looking at ATP Turbo's website, they offer GTX option on -5's and -10's.  No mention of -7's or -9's.  Does that mean -7's and -9's are not worth the upgrade?

[sneakey pete]

What I'm saying is the gtx and -5 rear is a bigger wheel than the -7/-9, so it's going to be laggier but have more power potential. There isno best turbo, all depends on your goals.

Didn't know atp is making kits, go any info/links?

[TXSquirrel]

11 hours ago, sneakey pete said:

Didn't know atp is making kits, go any info/links?

ATP probably has one of the worst websites to navigate...  Go to GTX section of the website first, then click on the size of 'GTX w/o turbine' you want and you can find additional options.  Here is the link for -5/-10 housing, you have to scroll all the way to the bottom and the last option available is to add .64 a/r T25 -5/-10 housing for $225.42 USD.

http://www.atpturbo.com/mm5/merchant.mvc?Screen=PROD&Store_Code=tp&Product_Code=GRT-TBO-188&Category_Code=GTX

 

[sneakey pete]

So that's just the rear. Would then still need to get a front housing machined to fit.