Hello,

I am looking at purchasing a GTX28 series turbo for my 20vt, but these do not come with the turbine housing. Could anybody point me in the right direction to what I need to buy? 0.64 A/R preferred.

David

I purchased a GTX 28/67 from CR turbo engineering last year for a project so try them for a price.

01425 638426

Ebay - plenty of stuff available from Kinguagwa, Mamba and similar companies. Search for used if you don't mind and get gt28xx turbine housing or even a gt2560 housing will be OK after machining for slightly bigger turbine wheel (I used the later for a gt28rs which came without the turbine housing). M

Edit - when buying a copy from say Kinugawa make sure that you buy housing for a ball bearing not journal bearing turbo.

Which manifold type do I need to look out for? T3?

BTW, how did the gtx2867 work out? What sort of performance did you achieve? I'm personally looking at the gtx2860r for quick response. Or would you say this is too small for a 20vt?

It's a T25 David, I can supply the complete unit if you want to go GTX

However, if you want fast spool then there is not a single turbo out there to beat my hybrids, I have tuned them all.

Lieghton, what's your experience with GTX turbos? I did a lot of reading before choosing my turbo and saw a lot of back to back test of GTX vs GT series. Tests revealed that a GTX turbo will spool slower than a GT turbo but then will blow more air in higher revs. So, if dw89 is looking for a GTX as he wants faster spool then that's not the best option. I guess that your hybrids are the way to go though .

I've been looking at the compressor maps of the GTX2860r vs a GT28r. The GTX has a very similar efficiency down the bottom of the graph, but is able to blow out enough air for approx. 400bhp..if one were to run as high as 1.6bar.

Leighton, I have been very tempted with the Hybrids, but have been interested in just trying something new...which will probably just burn a hole in my pocket without any gains over the hybrids...

Well, you can buy a GT2860RS, then buy a GTX 11 blades billet wheel, slightly machine the compressor housing to accommodate for the tip and you got a GTX2860R minus anti surge for less money. Just saying what I would do.

I've been looking at turbo's too, and from what I can tell the GTX2860R is a development of the GT2860RS (aka GT28rs) whereas the GT28r is aka GT2560R which is just what I have taken off my Coupe.

It depends what power you think you want and whether you want to stick with standard internals or go forged? And isn't the extra "X" in GTX for the turbine with 10 blades, not 11?

But I don't understand this idea of selling without the turbine (exhaust) housing, that's just asking for trouble with mis-matched setups surely?

AFAIK, the idea of selling GTX without turbine housing is that it is an upgrade for the Gt series so you reuse your old turbine housing.

Of course it is a matter of what power, torque and spook you want. Whether you want to go forged or stick with standard engine internals.

Difference between GT and GTX is not the turbine wheel but he compressor wheel and its housing. Even though Garrett says that the compressor wheels for GT2660 and GTX2860 are the same size is no the case. The GTX uses extended tip technology and because of this it is 2mm wider in diameter. So, naturally it can flow more air plus it is different designs wheel with 0/11 blades (billet for GTX) instead of 6/6 (cast iron) in GT2860.

Slightly off topic, in the real world, is there a noticeable difference in response between the GT28R and the GT28RS?

As i have been doing some reserach, overlaying the compressor maps, and due to the GTX2860r being smaller then the GT28RS, it has the same characteristic low down as the GT28R (GT2560), but with the mid of the GT28RS

Yes, there is difference between GT28R and GT28RS. Why do you think that there is a hybrid called GT28RSR?
- GT28R faster spool (rated up to 300bhp)
- GT28RS more power as you go up the rev range (rated up to 350bhp)
- GT28RSR best of both worlds

You are incorrect. GTX2860R is bigger then GT2860RS.

I know that the GT28R is the fastest spool and the RS and RSR..etc..but I was wondering if anybody has driven them back to back, and if there is a noticeable difference between the 2/3 turbos?

Also, regarding size, i was just going off the Garret website which states the GTX2860r has a Compressor ind Diameter of 45.70mm as opposed to the RS which has 47.2. Exd diameter is also smaller by 0.1
This is what lead me to believe that the GTX2860r is smaller, coupled with the fact it is applicable to a smaller engine size range and is efficient enough to be run at a lower power band.