Where To Buy An Hks Gtrs Turbo Kit?

[discopotato03]

Now you mention it I think I did once see a pic of one of their housings .

Flange adapters are a pain and from memory the GT28 turbine housings have the flange and throat section offset with the volute for packaging reasons . Could potentially screw up and have wastegating issues with adapters .

The other half of a GTRS or GT2835 KAi is the port shrouded compressor housing and it woulde cost something to re create .

The upside of the larger AR turbine housing is it would slow the turbine down a little and offer a bit more exhaust throughput - maybe something like 20% but thats a pure guesswork going off the turbine map differences .

If you feed guesstimation into the Tardis computer does it reckon needing 20% higher revs t get it going ?

Woolverine would it be good or bad having a GTRS start boosting 400 odd revs later , what eventual difference did you find between the GTRS and 2835 Pro ?

A .

[joeyjoejoejuniorshabadoo]

It occured to me to go back and have a look at Garretts turbine maps for 0.64 and 0.86 housings on that GT28 turbine and the difference is a little better than I thought .

Have a look at the flow rates of the GT28 0.86 AR and te GT30 0.63 AR .

http://www.turbobygarrett.com/turbobygarrett/images/catalog/Turbochargers/gt28_images/739548-1&064turb_e.jpg

http://www.turbobygarrett.com/turbobygarrett/images/catalog/Turbochargers/gt30_images/GT3071R_turb_e.jpg

Interesting that the GT28 turbine in its larger housing slightly outflows the GT30 in its smallest housing . Hmmm .

Doesn't surprise me really when you consider that HKS custom optioned a 3071 with a .68 rear to make the 2835 pro s

I have driven both and would urge anyone to spend te extra few dollars on the 2835 pro s. In my car I have 18psi by 3350 on the dyno in 4th.

On the street/track it pulls like a freight train all the way to redline with a super constant surge of power. On the track it is just all power all the time as any lag you might feel is negated by the higher revs.

I found the 3076 .86 to be too big for the 25 and the gcg/gtrs to be just that tiny bi small, with the gtrs being much more fun than the Garrett.

I can't comment on the 2835 Kai as I haven't driven one biut I'm sure it will sit somewhere in-between the gtrs and the 2835 pro s. My guess is that if you can stop it surging then it might just be the best overall option.

HKS do their research on actual RB25's and the pro s' massive powerband, huge top end and blistering response is testament to this.

Food for thought

[wolverine]

Woolverine would it be good or bad having a GTRS start boosting 400 odd revs later , what eventual difference did you find between the GTRS and 2835 Pro ?

A .

They don't look worlds apart on the dyno down low and on the ramp to boost but on the road they feel very different.

It certainly don't think a housing change would equate to 400rpm difference or at least I don't think it will feel like that once you push some more timing to fill in there to fill it in.

[PM-R33]

So has any one some how managed to put a .86 housing on a GT-RS before?

[wolverine]

once you push some more timing to fill in there to fill it in.

I'm sure that made sense when I typed it.....

"once you push some more timing to fill the small hole".

[89CAL]

The problem I think with the GT2835 KAI is with the anti surge slots. Stao from Hypergear PM'ed me about it and after explaining to me the theory behind the anti surge slots and how it could affect the power etc, I thought I would try a cheap fix for now so I came up with this:

Now after I put this on the car went pretty fuely under boost, i expected it to go lean if I'm honest but anyway. I spent about an hour tuning the AFR's to be a bit better (still a bit on the safe side but dont want to push it to hard yet) and played with maybe 2 or 3 cells of timing (under load)

I have knock sensor issues ATM which is why I havent added timing in. They give rediculous readings and I never hear a hint of pinging from the engine.

Anyway, Conclusion from the front swapover - The turbo seems to boost a bit smoother (if that makes sense), drive better, I dont have the "surge" issue I was talking about anymore, and I managed a faster 1/4 mile time and MPH last time I went for a race. (13.0 @110MPH, although I think its easily got a 12 in it if I get a bit more practice)

I managed 245rwkw with the old front, I'm waiting till I have some time to throw it on a dyno again to see if the front has netted some improvement to the power but from the feel of the thing I'd say it is better. Also the front is not sealed from the rest of the turbo. So I assume the high pressure from the anti surge slots that are now blocked may be leaking to the outside of the turbo(not to mention the possibility that this is causing turbuelence)

As I said however, This is a cheap fix and if it nets a power gain I'll be getting a proper front housing for it without the anti surge slots, A Pro S housing would be ideal

[discopotato03]

Between Garrett and HKS neither really got it right with GT28 based turbos for RB25s . I get the feeling that back in the early days more emphasis was put on catering for RB20s than 25s and thats possibly why HKS had a GT28 IW turbine housing made with the T3 and single turbo Skykine outlet flange in 0.64 A/R only .

I'm 99% sure its the same one used on 2530s and 2535s for many years now and the chances are slim of them doing a 0.84 AR one now .

I think I'll just leave it as it is (GTRS)and save the involved mods for the Lancer , I want to lose the AYC for an RS clutch LSD rear end . 240-250 in the Skyline is fine for me .

A .

[SKiT_R31]

Just adding my 2c more for clarification as I have been seriously considering the GT-RS for a while now. People saying the GCG highflows are comparable...? From sheets in the RB25 thread, the GT-RS seems to be pretty comfortable at full boost by ~ 3000rpm (for average of 240kW ~16psi), I put a GCG OP6 highflow (though it was journal bearing, but most are) on a mates R33 and it doesn’t see full boost until roughly 4000rpm. It makes a great figure and holds boost (260kW @ 18PSI) but that's just 1000rpm too late for an aggressive streeter imo; or is the comparison more for R33 highflow jobbies (which are also ~ 230-240)?

[wolverine]

GCG hi-flows are ball bearing.

Back to back test OP6 housing vs GT-RS same dyno, same car, so I can only report what I saw on the dyno.

ps. I am talking where power was made and they track pretty similarly. The GT-RS had the edge and there wasn't anything like 1000rpm difference in boost threshold.

[dangerous dave]

I know this is old as but has anyone tried an 0p6 rear on a gtrs? Ive got both here and super curious as theirs a huge visible difference in size

Edited September 15, 2015 by dangerous dave

[dangerous dave]

Going on a neo det