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Guest Robo's

Well looking for an easy turbo upgrade to an RB25DET with minimal instalation troubles and these seem to be a reasonable comparison.

Some guys are getting good results with the HKS 2530,2535 turbo's, but these still require some mods to install in favour of the factory turbo. Mods include intercooler piping and some water and oil line mods. The turbos can now be bought 2nd hand from $1,500, but you still need some extra $$ for the above mods to fit. Now if you get the GCG turbo highflowed, 450 or 500 versions, this would be a straight bolt up with no modifications. So wouldnt this be the favoured conversion. Plus its new.

So, the big question is, for power, which one would be better??? Or is there another alternative?

Opinions!!!

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https://www.sau.com.au/forums/topic/41886-gcg-or-hks-25-turbo/
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Hi rob. You wont need to modify any of your intercooling piping when installing a 2530/35. What really matters is if your lucky enough to get the compressor outlet elbow with the turbo. Even if youre not lucky enough to get it... it really is such a small and simple item to get fabricated, or even fabricate yourself.

But yes, oil and water lines. But even that's just a single trip to Enzed.

I'm thinking the same as you Robo. A big trusted brand like HKS with thousands of turbo's in circulation or a small Sydney workshop that have found a way of getting more power out of the standard unit.

I like the idea of the GCG Turbo's because it looks totally standard and nothing needs to be modified and the price is rather attractive compared to the HKS units.

I'd love to see a GCG500 vs GT2535 comparison on the same car/dyno just to see if the GT2535 is really worth that extra $700-1000.

Edit: I'm still about $5,000 away from a bigger turbo so it wouldn't be until the end of the year anyhow :D

Guest Robo's
off topic, but remember to budget for (if u haven't already got them): injectors, upgraded fuel pump, and preferably an aftermarket ECU as well as labour + tuning

Injectors should be fine i beleive, pump im not sure, the SAFC will have to do for awhile yet, plus its going quite strong now. Labour and tuning, thats me :Bang:

Guest Robo's
Hi rob. You wont need to modify any of your intercooling piping when installing a 2530/35. What really matters is if your lucky enough to get the compressor outlet elbow with the turbo. Even if youre not lucky enough to get it... it really is such a small and simple item to get fabricated, or even fabricate yourself.

But yes, oil and water lines. But even that's just a single trip to Enzed.

Well if i dont have to modify the intercooler piping that would be great, actually thats the part i was dreading as i just bought a new kit. Actually i wasnt too worried about the water or oil lines but seeing its easy to do, then the HKS 2535 looks the goods.

Hi guys, currently we have 2 X GCG 450 bhp ball bearing hi flows, one is on an RB20DET that makes 220 rwkw and the other is on an R34 GTT that makes 265 rwkw. On the RB20 that is around the same power as a 2530 but on the RB25 it is 30 rwkw more than we have been able to get out of a 2530. It is about the same as what we get out of a 2540 on an RB25, but it has way less lag.

Note that the RB20 is very old and tired (170,000 k's), we could probably get more out of it if it was fresher. The RB25 is probably more of an indication of what is possible out of a GCG 450 bhp ball bearing hi flow. We have not had as good success with the 500 bhp version, they run very close to the compressor surge line on a standard internals RB25. I would not consider one for an RB20, where a 2530 is very hard to beat for all round performance.

We have a Stagea coming and it is getting the GCG turbo off the RB20, I have several other choices. But I believe that is the best all round turbo for that application. It is getting an SAFC (it's an auto), FMIC, Jamex panel filter, CAI, Autospeed (Norgren valve based) boost controller, split dump, (very) hi flow cat and a 3" exhaust. So it will be fairly typical of mild tune RB25. The bottom line for me is, I don't believe that I can find a better turbo for that level of tune.

Hope that helps

G'day SK, what sort of boost levels are you guys running on the R34 GTt to get the 265rwkw ?? What other mods does the GTt have??  Sounds pretty impressive for a bolt on highflow. J

Oh yes Jay, the R34 GTT has a full bolt on kit (no internal mods though);

Tomei 260 Poncams

Split dump

Hi Flow Cat (very hi flow)

3.5" exhaust

Pod filter

Heat shield

CAI (big one)

R33 GTR standard intercooler

Tomei injectors

Tomei fuel pump

Power FC with boost controller

Low/rear mount exhaust manifold (like an R31 GTSR)

Electric fan

OS Giken twin plate (very light chrome molly flywheel)

Oil cooler

It runs 1.3 bar (all the time, none of this hi/low boost crap)

Fitted 2 years ago, done 45,000 k's and still going strong. Did an 11.9 on Goodyear Drag Slicks last winter, might have a go again this winter.

Injectors should be fine i beleive, pump im not sure, the SAFC will have to do for awhile yet, plus its going quite strong now.  Labour and tuning, thats me :Bang:

Injectors wont be fine. You'll need bigger ones.

Pump, you'll need a bigger one no questions.

SAFC - that wont do at all. You may aswell not put the turbo on as the difference between an SAFC/Stock ECU and a PowerFC setup if phenominal.

Put a PowerFC on with the stock turbo and power delivery is much better than the SAFC, which is just a cheap, ricer band-aid

And i see you said no mods to the cooler piping... does that mean you still have the stock I/C ?

If so, that needs changing too.

Maybe i sound negative, but i dont think you realise the full list of things that must be done in order to make the purchase of the turbo worthwhile, and get the most of ouf your dollar.

Putting a turbo like that on without changing much else is just a waste and money could be better spent elsewhere

Guest Robo's
Injectors wont be fine. You'll need bigger ones.

Pump, you'll need a bigger one no questions.

SAFC - that wont do at all. You may aswell not put the turbo on as the difference between an SAFC/Stock ECU and a PowerFC setup if phenominal.

Put a PowerFC on with the stock turbo and power delivery is much better than the SAFC, which is just a cheap, ricer band-aid

And i see you said no mods to the cooler piping... does that mean you still have the stock I/C ?

If so, that needs changing too.

Maybe i sound negative, but i dont think you realise the full list of things that must be done in order to make the purchase of the turbo worthwhile, and get the most of ouf your dollar.

Putting a turbo like that on without changing much else is just a waste and money could be better spent elsewhere

Injectors i hear max out at 250rwkw!!

Pump im not sure!!

SAFC will do temporarily, with the stock turbo im reeping the rewards from it, so i can only praise it at the moment.

FMIC, ive got , as i said, ive just installed a FMIC kit, i dont want to really go around refabricating my pipes.

Put a PowerFC on with the stock turbo and power delivery is much better than the SAFC, which is just a cheap, ricer band-aid

We have one on the GTR, one on the GTST and one on the GTT. But the Stagea is an auto so it gets an SAFC, better than nothing.

Its interesting that people seem to thinkthe injectors are good for 250rwkw. I can be done, but how many people have been running 250rwkw on stock rb25 injectors and not needed a rebuild?

I really do think if you are trying to skimp on the cost of mods, you will either end up with a dog, or it will only cost you more in the long run. You get what you pay for.

but hey, its not my car.

I plan on controlling the power of my car purely with boost.

I wont be boosting over 14psi and will be using stock boost (avcr off) when im driving around normally. My car is only driven about 300km a week anyway.

Ill be able to see the injector duty on the avcr, but if i dont need to spend a grand on injectors, then i wont.

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