GT2530 - Not impressed

[DoughBoy]

Ahh ok. As for my confusion, Garrett don't make a 2530 designated turbo - they have the GT12, GT15, GT20, GT22, GT32 etc. lineup. Hence why I thought you had a HKS 2530. Maybe others had that train of thought too....

[raist60]

Garret australia actually use different designations. All are in the tech section of GCG website.

www.gcg.com.au

[TokyoTaxi]

Well GCG gave me this turbo as a GT2530 so somthin ain't right.

If I had a digi camera I'd take a pic of the ID plate that they put on it.

[DoughBoy]

But are those designations a GCG special (i.e. a product made up from Garrett parts and named whatever they want) or untouched items made by Garrett specifically for the Australian market?

My bet's on the former.

[Steve]

Originally posted by FAT32

Steve,

Just the normal stuff, GT-R Fuel Pump, NISMO Fuel Pressure Reg, Pod Filter, re-chipped ECU. I think I might have to try the new pipe between the AFM and the turbo as it could be a possible cause. Are you getting yours made for $100 ?

Yep, $100 in adeliade.

If its a garrett core, not a HKS one, it just isnt the same. Although garrett make HKS cores, ONLY HKS can sell them. they put in alot of r&d, and want to protect that, and therefore have an agreement with garrett not to sell to anyone else. So unfortunately, were not comparing apples and apples.

Probably still worth replacing that pipe though - couldnt hurt.

[Steve]

Just another thought, what clutch are you running?

[raist60]

GCG Would class a GT25/30 as a GT25 Turbo using GT30 wheels.

All they get thats built is the CHRA the housings are then swapped around to designate the turbo...

[TokyoTaxi]

DoughBoy,

I'm told that they are pre-assembled by Garrett but who really knows......

Me thinks I've been fudged !!

[EVOIV]

I've heard that the GT2540 aint a very good turbo, and that it has now been replaced with the GT-RS turbo? The GT2540 gave too little top end power in return for the increase in lag. So you would be better going the GT-RS, although this is a new turbo and probably cost a bucket load.

I have read that HKS turbos are more efficient at higher boost, whereas Garrett turbos are more efficient at lower boost (eg 1bar and less). I thought HKS and Garrett turbos were just about the same, the only difference being that the HKS have specific HKS compressor trims.

[franks]

fat32, can you superimpose dyno results from your old t3/t4 and your 2530 turbo?

it'd be interesting to see how peaky your old turbo was compared to the 2530...? i suspect your 2530 is making alot more power down low so your "pin you to your seat" feeling will be less exaggerated?

i guess its all down to personal preference but the area under the curve is more important than the outright peak power figure imho.

[EVOIV]

Once again it's all to personal preference, but once you've been in a big turbo car...it's hard to go back to the smaller turbos Although I do admit that the smaller turbo cars actually feel "faster" on the street, because they are with their quicker response and you only drive upto 60km/hr most of the time.

[franks]

...and once you've owned and raced laggy street cars with big turbo's, its hard to go back too :uh-huh:

my WRX had a TD05 turbo from an MY94 WRX which was large. Subaru went to a TD04 for a reason....lag is your enemy in a street car!!!

[Lepperfish]

Wat about the garrett GT3540 ?

[predator]

I have read that HKS turbos are more efficient at higher boost, whereas Garrett turbos are more efficient at lower boost (eg 1bar and less). I thought HKS and Garrett turbos were just about the same, the only difference being that the HKS have specific HKS compressor trims

Covered pretty well in this thread ... http://www.skylinesaustralia.com/forums/sh...ight=HKS+turbos

Seems the main advantage of HKS is you get a little HKS stamp on the side and pay a lot more

[Merli]

If you bought it from GCG, I'd put money on the fact that it isn't an HKS turbo.

To whoever asked, you'll be VERY hard pressed to find the compressor maps for the HKS turbo range... They are very closely guarded secrets.

As to how do we know that they're more efficient at higher boost levels? From personal experience, from the thousands of people in Japan who use these turbos, and most importantly, from what HKS dealers set boost at for their customers in Japan.

That's the main difference between Garrett and HKS turbos. Their compressor and exhaust wheel designs. Garrett are designed for lower boost power, and the HKS turbos have their efficiency range shifted to higher rpm to produce more power...

People say the HKS turbos spool up faster than the Garrett equivalent, but I have never seen a back to back test to prove that.

All I know is that the relatively big HKS GT3040 on my car spools just as fast than stock GTR turbos and makes a crapload more power.

[EVOIV]

I think it's almost a well known fact that HKS turbo are more efficient at high boost, and Garrett turbos more efficient at lower boost. But having said this, it would be good to have a direct comparison between an HKS and equivalent Garrett turbo. I agree, the HKS compressor maps are very hard to find - if possible. They seem very secretive about their work, and who wouldn't be The letters "HKS" are just about as reknown as "GTR"

[DoughBoy]

Merli, just discussing the point - there is no "hard" data to support the arguements that HKS turbos are a) more efficient and B) make more power than an equivalent sized ball bearing turbo. That's the only point i'm making, and asking around to see if there is any actual data supporting that case.

Don't take it as an attack on you comments, I've got a HKS turbo on my car too. Would just like something more tangible than old wive's tales.

[Steve]

I have never, ever heard anyone say anything bad about HKS turbos, except the 2540. I have never, ever heard anyone who has driven cars with garrett turbos, and a correctly sized HKS turbo say they prefer the garrett.

All the evidence, be it hearsay, points in one direction only. Choices are personal, but if everybody who has used the HKS turbos comments that nothing in the garrett range comes close, you would have to be a bit niave to expect different.

Names mean alot in Japan, but generally the name is only established through performance. I find the japanese like to let their results do the talking.

Merli, what turbine AR does your turbo have? and when does it start making boost and hit full boost (however much that is)?

Cheers

Steve

[Merli]

Originally posted by DoughBoy

Merli, just discussing the point - there is no "hard" data to support the arguements that HKS turbos are a) more efficient and B) make more power than an equivalent sized ball bearing turbo. That's the only point i'm making, and asking around to see if there is any actual data supporting that case.

Don't take it as an attack on you comments, I've got a HKS turbo on my car too. Would just like something more tangible than old wive's tales.

a) they're not more efficient, they have different compressor/exhaust wheels that SHIFT the efficiency band to higher boost levels.

B) you don't believe that an HKS GT2530 would make more power at 1.6 bar than a Garrett GT25 at 1.1 bar??? Or to illustrate the point further, a Garrett GT25 at 1.6 bar, where it would just be blowing hot air and making less power than at 1.2 bar?

That's interesting, I didn't find it that hard to believe. If you believe that the HKS turbos are optimised for higher boost, the fact that they produce more power makes perfect sense to me.

And I agree with the others, although there may not be any direct "GT30 on the car... dyno it, take it off, HKS GT3040 on the car... dyno it" comparisons, I think the fact those "old wives tales" have considerable weight behind them, especially when you hear the same from all japanese tuners who have been playing with these Garrett/HKS turbos ever since the conception of the RB range of engines.

Steve, I have a 0.87 turbine housing, and I hit 1.2 bar by 4000rpm... That's all I have run, but I would assume 1.8 bar by 4300-4400rpm... I know, this turbo is wasted with stock internals

[fatz]

hey scotty

you still got the t3/4 mate

that would go sweet on my 31

pete