New Garrett Gtx2860R / 2863R / 2867R

[cobrAA]

After much thinking and discussion with my mechanic, a single turbo is a no-no... ( sure it's the way to go.. but its also about 7.5k once everything is done lol)

So I came back with my initial idea to get a GTX upgrade. And I would like your input, especially with the folk who had it done.

Finding a turbo tech in my area who is willing to machine/work a gt2860 compressor housing to the gtx28 cartridge seems impossible.. I would need to ship it, pay more , waiting time.. All in all, seems like I can't find anything for less than 200-400$ ( rough estimation).

So, I'm thinking how much of a hassle it is to redo some piping to make the gtx compressor housing with gt2860 exhaust housing bolt on a rb26 ??

Thanks for your input!

And if I may, do we agree by saying the gtx2860 should yeild spool similar to gt-ss and gtx2863 spool like -5s ?

[hy_rpm]

Unless you already had the comp housings

Making new piping to suit the gtx will be cheaper

If you do get stuck hypergear turbos in Melbourne can Machine you out your housing to suit and are the best priced and postage is only $20-30 a turbo

[Piggaz]

I can't see how the 60 mm gtx's will spool up like a -9. That's a huge ask for what is essentially a 400 hp turbo.

[cobrAA]

I can't see how the 60 mm gtx's will spool up like a -9. That's a huge ask for what is essentially a 400 hp turbo.

New wheel design along with ligther material and anti-surge cover could be a factor in the spool time. Food for though... I'm really not a turbo expert and trying to learn as much as I can recently.

[KING87]

How the boost control go with 30+ PSI? Must have to just preload the hell out of them

[cobrAA]

How the boost control go with 30+ PSI? Must have to just preload the hell out of them

like said before. running past 25-28 psi can be playing with fires if no good fuel. I'm running 94 octane + WMI so I don't really expect to run past 28psi.

[Piggaz]

like said before. running past 25-28 psi can be playing with fires if no good fuel. I'm running 94 octane + WMI so I don't really expect to run past 28psi.

Don't bother with GTX then.

[cobrAA]

I spoke to the guy that tunes my car and he said to go the 63's. Now considering the -5's are a 360 HP turbo, 60's are a 400 HP turbo and the 63's are a 430 HP turbo, I'm not sure if I need the 63's. The 60's should (on my engine seeing that the -5's have already done 472 rwkw) do 500 with a much better curve to match (as you have not given away anything at any point), couple that with a 250 degree at 11 ish mm lift and it would be silly. What I am really curious about is that throttle response/lag between gears. It doesn't exist!

This is what I was hoping with gtx2860.. Not really after extra whp. the extra 40hp is just a bonus for me. I was hoping the gtx didn't need to be pushed to 30psi to get this ''benefit''. Had a read on the zilvia forum today and it seems like the gtx does offer a better throttle response than the older gt28.

Edited April 12, 2014 by cobrAA

[bigmikespec]

New wheel design along with ligther material and NOT THE anti-surge cover could be a factor in the spool time. Food for though... I'm really not a turbo expert and trying to learn as much as I can recently.

Just to prevent mis-information.

[shombre]

FWIW, I recently upgraded my twin GT2860RS turbos to twin GTX2863s. I'm running Tial 0.86 AR turbine housings, externally gated with full recirculation, and I'm on a full house stroked 2JZ-GTE motor with literally all the bells and whistles.

I made ~10% more power at ~10% less boost, and the biggest difference to me wasn't just the top end, which was epic - it was part throttle and low boost. For a street car - literally daily driven, on BP Ultimate fuel and WMI - this was an ideal upgrade, and most unexpected in many ways.

The combination was a much happier one than the one it replaced, which was by no means bad. Revved easier, took more ignition timing, was less noisy - full of win.

Obviously it is difficult, if not impossible, to compare my setup directly to anyone else's on this board, but I still think that it is indicative as a data point.

[Piggaz]

Got a before and after graph for us to look at?

[afb312]

Engine details? Would help us to make a comparison...

[hy_rpm]

Were you running the same .86 tial housing with the gt2860rs as if not there will abit of the power gain and that's why more ignition timing could be added

[KING87]

So after looking into putting the 63mm wheels into my -5's i sent am email to GCG to see what their opinion on this combo would be like, and here is their response for those interested.

"We have had customer feedback in regards to this particular set up and it isn't positive, apparently they surge severely if fitted with with standard style housings on both ends unfortunately. Garrett do not do any GTX upgrades for the RB26 set up so we are currently working on a solution to this, pretty soon we will be bringing out our own range of custom stainless steel housings in 0.86a/r to replace the restrictive Garrett 0.64a/r housings (wot work with the GTX28R range), but this won't be ready until later this year.

The other thing as well, the surge slotted comp housings would have to be utilized with this set up so a custom intake would be required."

[NissanForLife]

So after looking into putting the 63mm wheels into my -5's i sent am email to GCG to see what their opinion on this combo would be like, and here is their response for those interested.

"We have had customer feedback in regards to this particular set up and it isn't positive, apparently they surge severely if fitted with with standard style housings on both ends unfortunately. Garrett do not do any GTX upgrades for the RB26 set up so we are currently working on a solution to this, pretty soon we will be bringing out our own range of custom stainless steel housings in 0.86a/r to replace the restrictive Garrett 0.64a/r housings (wot work with the GTX28R range), but this won't be ready until later this year.

The other thing as well, the surge slotted comp housings would have to be utilized with this set up so a custom intake would be required."

I wouldn't be so quick to take their word as final, I have had huge success with my -5 with GTX 2863 cores in there with machined font housings and have experienced no surge issues at all.

[KING87]

Yeah i see you have had great results with your set up with a 2.8L and head work. Maybe surge would be an issue on a 2.6 and small cams.

Iam seriously liking the idea of tial .86 V band housings and external gates just don't think there would be enough room not to mention getting custom manifolds made up hmmm..

[Piggaz]

^^ seems to be a hell of a lot of work and a potential nightmare. How much power are you after? The small housings have been proven to do over by a few people to do 500 wkw.

[KING87]

Around the 500kw mark. Yeah your right is a ton of extra work, just something different that hasn't been done before that i am aware of. Nothing is set in stone just kicking a few ideas around.

Easies and cheapest option would be just to put the 63 cores into my 2530's and get the 2.8L built with full head work.

[discopotato03]

GTSS RB26 edition was a special designed to replace the standard RB26 ones so they are customised engine/car specific units .

Part of what makes them work is the smaller than usual trim NS111 turbines , 62 rather than 76 trim . Once you start talking GTX2860 you get the larger 76 trim turbine standard so pointless comparing them to any GTX28 turbo . It's probably safe to say that the GTX2860R is like an updated GT2860R 63T (2530) which aren't exactly small for a sane RB26 . The big trim turbines that may give some initial lag I'd say help get around the surge issues so whilst not a perfect solution a workable one .

I think that if Garrett/HKS were to do GTSSs again they would use a more modern compressor in possibly a smaller diameter . RB26s are getting long in the tooth now and there probably isn't a big enough market to justify Garrett doing anything new for them .

A .

[scotty nm35]

Of course a pair of GTSS aren't going to flow 500kw very easily either.

I was in the passenger seat while Trent tuned Dez's GTX upgraded -5's and while they were right on the edge of wot surge it was quite hard to pick it. I have heard much worse surge before. Of course his engine had cams and a fair bit of work, and every engine behaves a little differently.

GCG were right to be worried, but that shouldn't put you off. They have little idea when it comes to turbo's running in the real world, they are just resellers.