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I currently have a hks gt2530 that needs a rebuilt, originally i wanted a garret gt3076r, but i also found a very cheap rb25 high flow turbo in good nick. Im hoping to get about 250-270 kw with supporting mods without killing my turbo. What should i do?

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I think it just completely depends on your intended use for the car etc. Highflow will be at its limits with that sort of power from what i have seen though. I would say the only upside to the highflow unit is that it will appear standard from the outside, making it harder to get defected etc if you dont engineer it. For the direct comparison of delivery/ lag etc your best bet is to spend some time in the rb25 turbo upgrade dyno thread. Heaps of good info in there mate.

ok thanks for the feedback, ive been looking at the turbo upgrade forum heaps lately but just wanted some opinions of people who know about these turbos. i think i might just bugger off the gt2530 and spend the extra doe and get the gt3076r

^^^ only slightly, and the 0.63AR housing tends to overboost, while the 0.82AR housing response is very close to the 3076.

The 3071 is best with a cropped rear wheel in the correct (HKS) housing....ala 2835.

My housemate makes 250kw with his high flowed Turbo @ 16 PSI. Loves it love time.

3076R will do the power you want and future proof you for when you want 300kw :D

I've got the 3076R in mine, fkn love it so much. Makes such an epic noise.

Be it myself I would rebuild the blown HKS turbo. The housings would be a sweet thing to have... I would redo it as a 2871 52t.

Send it to hypergear and tell him the specs you want. IMHO do not let him upsell you a bigger CHRA as the HKS housings are awesome and the HKS GTRS (2871 52t) is an awesome turbo for an RB25.

GL

+1 3076, it'll give you same power as the 3071 with only slightly more lag and potential for 300rwkw. Guy at work has one and its a ripper turbo.

Whats you budget? The 3076 isnt cheaper especially compared to the highflow, not to sure about highflow figures but a op6 rear housing highflow should make really good power.

I would have thought the 2530 would be to small on a 25, thats a perfect turbo for a 20 though.

Slight difference to the norm here...

Personally I think the 3076 .82 is too much for an rb25 for drift. (guess based upon your pic and the A31)

Whilst not a laggy turbo by any stretch, it is certainy a lil doughy when compared to a 2835 or gtrs equipped car.

my car (hks 2835 pro s) on LOW boost (16psi and 260rwkw) is more fun and feels faster than my mates 3076 with 18psi and 280rwkw. My car on 18 or 20 psi is a hands down winner in my opinion.

I think GT scott is on the money here.

I'd rather have a 250rwkw gtrs than a 300rwkw 3076 due to the amazing response. It's just simply a more fun drive in my books

With a street RB25DET I don't think its the GT28 turbine , HKS 2530 in todayspeak is a GT28 based turbo , thats so much the problem rather the 60mm compressor wheel .

Most here say that GT2530s , 2830 really , run out at about 220 RWKW and that the HKS GTRS or GT2871R with 52 trim compressor goes to maybe 250-260 RWKW depending on other mods and tuning .

I don't think I've seen too many people complain about these GTRSs except if they went looking for 270-300 RWKWs .

The people with GTRSs really like them for general use because you don't have to rev RB25s very much to get some squirt . Also with the right bits its a very straightforward install compared to GT30 based turbos and their non std style turbine housings .

I suggest you speak to Woolverine here as he's had RB25 Hi Flows/GTRS/GT2835 Pro S on his cars so he can make direct comparisons . Last I heard he was looking to spend more time tuning with the GT2835 Pro to try and get back some of the nice response that his , mine now , GTRS had .

My gut feeling is that GT3076Rs are a bit big in the wheel trims , turbine and compressor wheels , to have what most would call good all round performance . Garrett steadfastly refuses to reduce the trim size of GT30 and GT35 turbines like they did with the larger ball bearing GT37 and GT40 based turbos and while big trims are good for high end numbers they are hopeless when it comes to having overall power with acceptable turbo response . Its the reason why Mitsubishi TD04/TD05/TD06 turbines often work better than Garrett GT30/35s do .

Another thing we are sadly lacking is a Garrett type GT30 turbine housing with T3 flange and integral wastegate , if these could be machined to take the cropped GT30 turbine , the inaptly called 28 in 2835 series HKS turbos , these cropped GT3071 type turbos would easily bolt up to RB25s etc . Such a turbine housing in 0.63 AR should make a good thing with a 52 or 56 trim 71mm compressor .

Anyway my vote goes to a GTRS or possibly a OP6 based GCG Hi Flow . I know its hard because neither is what youd call cheap new but people have to think twice about equating $ to max RWKWs . A responsive good all round turbo sollution often costs more than one that works up high at the expense of low to mid range squirt .

The HKS turbos aways cost more than similar Garrett marketed turbos and while some of this is "HKS Tax" they went to some trouble at times to develop and fit custom housings that change the performance of Garrett ball bearing cartridges . For example those port shrouded compressor housings on Nissan RB spec GTRSs and GT2835 Pro Ss make a big difference and they were not fitted just for show .

The T3 flanged GT28 turbine housings on RB spec HKS 2530/2535/GTRS are unique and I really wish they'd made them in 0.86 as well as 0.64 ARs . All these use GT28 turbines too BTW .

These turbos may not pump 20 pounds of boost into an RB25 at 7000 revs but they pull up well down low where people drive most of the time . I think it'd be a lot easier to "fall off the turbo" between gear changes using say a GT3076R with the 0.82 AR turbine housing , if the GT30 got 270 Kw and the GTRS 250 then your not very far behind but you can use it 90% of the time rather than 60 . You can get torque from boost at more legal speeds with the GTRS and thats where cars are 90% of the time .

Anyway your call , I hate cars that you need to rev to make any worthwhile performance . They are tedious to drive and lag is NOT forplay for power IMO .

Its one thing to coax and court a bird but once you buy the book it should be down to a bunch of flowers and a bottle of somthing good . Who wants to wait a week for - what was it , yeah - boost .

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