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If you buy a new HKS turbo you will be looking at double the cost,

SydneyKid, your right about the costs of buying a new turbo and it kinda makes me think twice about the whole thing... But a replacement turbo is what i need so finding out which one to get its the toughest assignment at the moment. Sure the HKS turbos do catch my attention probably due to the fact that so many people have tried them with possitive results. Im also drawn toward the hi flowed ball bearing upgraded stock turbo as well because as its a more cost effective solution. SydneyKid, who rebuilt your turbo? Is the company called GCG? if so where are they located?

12.4 et is a great time, its around what ill be aiming for.

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We use GCG for all of our turbos,

www.gcg.com.au

They sometimes have stock, so they can do exchange on hi flows, you can take your standard turbo in and walk out with a hi flowed one. I did a hi flow upgrade in one day recently, took the standard one off in the morning, put the hi flowed one on in the afternoon and then dynoed it. It so much easier when everything just bolts straight back up. Fabricating and then making stuff takes time which = money.

Hope that is of some help.

Hi king_kw13, these are the things we change;

* water hoses

* oil hoses

* inlet pipework to the turbo from the AFM

* outlet pipework from the turbo to the I/C

* dump (you can't have a hi boost turbine design with a restrictive dump)

* heat shield

If you get the right model of turbo they will bolt up to the T3 flange on the standard exhaust manifold. Be careful, I have seen advertised HKS's with T3 flanges that had T28's when they arrived.

Hope that answered your questions

Hi Borry, I thought I covered "what does hi flow mean? "with this post...........

"They put new upgraded bearings in it, new shaft, new seals, new turbine, new compressor, machine the compressor housing and the turbine housing and micro balance the rotating bits. This means it is basically a new turbo since all of the wearing bits are new or machined to new specs. "

In more detail.....

The turbine (yes they replace the ceramic turbine with a stainless steel one) is larger (bigger diameter and bigger blades) so it introduces more torque and rpm to the turbo shaft. To fit the larger turbine they have to machine out the turbine cover. Same with the compressor (bigger diameter and bigger blades) so it pushes more air at the same pressure (boost). Due to the higher torque available it can also handle more pressure (boost). To handle the extra torque they use a larger diameter shaft and to fit the shaft they need larger ball bearings which also have lower friction and can handle higher rpm. To fit the larger ball bearings they have to machine out the centre housing (core). All this is then micro balanced, so it spins very freely with no vibration.

Not all hi flows are done this way, some use plain bearings and thrust plates, not all turbo shops have micro balancing equipement or machining facilities. That's why there is such a variation in the prices, but you get what you pay for.

Hope that clarifies

PS; We have an R32 GTST, an R34 GTT and number of R33 GTST's all with Stage 1's. I am just about to try an RB31DET with a Stage 2, I want to get over 300 rwkw out of a hi flowed standard turbo.

Sydneykid,what sort of boost do you usually run with these hi flowed standard turbos?do you need to upgrade the injectors or would an adjustable fuel reg suffice?in a rb25det with pfc,avcr,gtr cooler & split dump pipe is there anything else needed to be upgraded for optimum performance?fuel pump?if you went to the stage 2 hi flow any specfic changes required different to the stage 1?

cheers

warrick

Hi Warwick, some suggestions to your questions follow;

"what sort of boost do you usually run with these hi flowed standard turbos?"

The R34 GTT with RB25DET runs 1.3 bar for 230 rwkw. We have a R33 GTST that runs 1.1 bar for 220 rwkw but it has good support systems (cams, pulleys, split dump, hi flow cat, head work etc). I have tried our R32 GTST with RB20DET in it at 1.5 bar for 265 rwkw for short bursts, but during the race the air temps climb too much. I have heard of them being used over 2 bar, but I haven't done it myself. The compressor map noses over at around 1.7/1.8 bar, so much more than that and you are compromising the efficiency.

Boost is irrelevant anyway, it's the airflow that makes the power.

"do you need to upgrade the injectors or would an adjustable fuel reg suffice?"

Depends on how much power your are targeting and how lean your are prepared run it at. I personally reach for larger injectors at around 200 rwkw. Adjustable fuel regs are a bit of a band aid, really only useful if the injectors are just a little small for the rest of the systems (weak link in the chain stuff).

in a rb25det with pfc,avcr,gtr cooler & split dump pipe is there anything else needed to be upgraded for optimum performance? fuel pump?

Definitely fuel pump, we do that first. Adjustable pulley on the exhaust camshaft is worth the cost.

"if you went to the stage 2 hi flow any specfic changes required different to the stage 1?"

I don't recommend Stage 2 on a RB25DET unless you have done some head work and cams. You can get close to the compressor surge line too easily.

Hope that helps

Hi Robo, as the rubber pipe gets older and softer, they can suck in at high airflows. Had it happen at the drags once, very embarrassing and nothing you can do about it at the track. So now I change them on older cars with any more than 200 rwkw.

Originally posted by Sydneykid

Hi Robo, as the rubber pipe gets older and softer, they can suck in at high airflows.  Had it happen at the drags once, very embarrassing and nothing you can do about it at the track.  So now I change them on older cars with any more than 200 rwkw.

The standard ones are rippled on the inside, i suppose a smooth one would be a better option.

Hi king_kw13, you posted

"A HKS2530 from Nengun costs around 175000 Yen approx AUD 2600."

I think that is plus freight and it definitely is plus duty at 15%, plus GST at 10%.

$2600 +$100 + $405 + $311 = $3416

New oil feed bangos and bolts $80

New oil hose (braided) $60

New water feed bangos and bolts $80

New water hose (braided) $60

Fabricate inlet pipework alloy + silicone adaptor $115

Fabricate outlet pipework alloy + silicone adaptor $135

Hose clamps 8 X 18 = $144

Total $4,090

I think I posted "twice as much as a ball bearing high flow" previously. So that's about right.

Me, I would much rather spend my $1900 saving on some other parts. I have yet to see a 2530 perform much better than GCG ball bearing hi flow on an RB25DET. And 2530's are one of my all time favourite turbos, 2 of them on a GTR is heaven on a stick.

Hope that adds to the discussion.

rb25 please explain? id be interested in hearing whats been said about GCG as i may become one of their customers soon. I understand that they may only be roumers or whatever you wanna call them... but nevertheless if im gonna spend $2000+ i wanna hear what their customers have to say about their workmanship. Thanks dude

well with my HKS 2530i only had to change oil feed, water feed and water outlet lines. pretty easy to get and make yourself. i opted for braided line so it does cost a little more.

If you do get the T3 flange the turbo will bold straight up to your manifold and even match the standard dump. but i would recomend upgrading the dump and the std ones are pretty crap.

MM2death: i really couldnt tell much from that pic, but mine does have garrett on the compressor cover, i think all the HKS turbos have hks cast into the exaust housing... so try look or feel for that. mine also has a little number plate on the core with has 2530 and some other stuff stamped onto it.

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