HKS3037S 56T Retune

[Cubes]

Could it also have some thing to do with it not being a HKS GT30?

Hence why they say the HKS cores are better if you want to run high boost otherwise stick with the standard Garret?

[Steve]

Not too sure Joel, HKS dont have cores, they are a standard garret item - HKS only have proprietry on the comp and turb cover and compressor wheel.

I think it would be more likely to have something to do with turbine AR and comp wheel trim - bigger turbine AR will flow more, but will take longer to build boost, bigger comp wheel will flow more, but if too big could (in theory) result in a miss match to the turbine and result in surge. Always a trade somewhere.

The reason I said it was because he originally said he had a 0.68. I would like to know the exact spec differences to give a better idea of the comparison between the two. Without knowing all the specs, it would be useless comparing;)

At the end of the day, the only true way to compare would be on the same car, cos lots of things can make a difference. I noticed a considerable loss of power when I swapped my N1 exhaust for a nismo dual muffler one.

My big problem at the moment is that I want to try a bigger turbine AR, as I feel the 0.61 is maybe causing a bit too much back pressure. It is interesting that the HKS 3037 kit for RB25 uses a 0.87 AR. Might be worth giving it a try, but at well over $500-$750 a pop for the housing, I am not going to rush out and buy the full range to see the difference:D

[rob77]

This is the same with the trust turbo. I cant find anywhere any information on the compressor housing or both wheels, the onloy information I can get is that the exhaust housing is 16cm squared. The next 4-5 weeks are going to go so slow, I want the wolf3d in now

[BOOSTD]

Steve: I now have a .81 A/R Ex Housing and noticed a large difference in detenation(spelling?) levels. In my early stage I had the same tuning, same turbo specs apart from the bigger A/R ex housing and my detenation levels reduced by 1/3. I have put this down to less back pressure, less heat , and less cylinder back filling on cam overlap. Obviously my turd is no were near standard now.

The spool up difference from .6 to .8 A/R was hardly noticable. Smoother maybe.

[RS500]

Steve,

i could swap you for a genuine HKS A/R 1.01 housing if u like

[EVOIV]

Great results GTS-t VSPEC!! Wow, it really seems that the GT30 turbos are responding well on the RB25s. 270kW@wheels on 13psi is a $#!T load!! Sure you'll be having traction problems. The only problem I see with comparing dyno figures is that they can vary from dyno to dyno. Also depends on the air temperature of the day. For example, the JUN s15 equipped with T88 (in Perth I think) produced something like 700rwhp on one dyno, only to get 550rwhp on another dyno. Something like that anyway, I read it in a Fast Fours mag. Anyway, point being that there is a difference between all dynos. To compare two cars you really need to dyno both on the same dyno on the same day. In the end, it's really how fast you run the 1/4 mile which is going to judge how quick your car is. Still, very impressive figures to both!

[rob77]

1/4 mile times would have to be compared on a same track and day basis and probably running together at the same time. Different tracks different prep work and also different ambient temp's as well, just like dynos.

[EVOIV]

Yes, that's also true.

[GTS-t VSPEC]

I'm running a Wolf3D, excellent ECU, much better than PowerFC IMHO.

I'll check on the turbo size, but I'm sure it's the smaller one.

The dyno I use has been checked by Dyno Dynamics and was 0.2% from perfect.

[EVOIV]

I think most companies use the Dyno Dynamics dyno (?). Very nice results, will be interesting to see how the turbo fares as the boost is increased. It does seem to produce more power than Steve's HKS one, but it also seems to have more turbo lag. Maybe there is a noticeable difference between the Garrett and HKS turbos afterall?

Once you guys start increasing the boost, then we should be able to see what happens. I've heard that HKS turbos are more efficient at a higher boost level (eg 1.5bar), and that they spool up faster. I've heard that Garrett turbos are more efficient at lower boost (eg 1.0bar). Guess time will tell...keep up the good work!!!

[EVOIV]

Steve: Do you know what are the differences between an HKS turbo and a Garrett turbo? I heard that the cores and turbine trims are the same. The only difference are the compressor housings and compressor trims. Are the exhaust housings also different? Or is it in size where they are different? Example: I know the GT3037S can have a 0.73A/R exhaust housing, and I don't think the Garrett GT30 has the same size?

The reason I ask is because I have a broken GT3037S turbo. It has a damaged turbine wheel and I am going to try get someone to repair it - either GCG or Garrett in Sydney. If the turbine wheel is replaced with a Garrett turbine wheel, could my repaired turbo still be classified as an HKS one? Meaning that the turbine wheels are the same for both Garrett and HKS GT30 cored turbos?

[GTS-t VSPEC]

Yeah, it will be interesting to see what ends up happening. I can't push mine any further till I have forged pistons etc.

[Steve]

Originally posted by BOOSTD

Steve: I now have a .81 A/R Ex Housing and noticed a large difference in detenation(spelling?) levels. In my early stage I had the same tuning, same turbo specs apart from the bigger A/R ex housing and my detenation levels reduced by 1/3. I have put this down to less back pressure, less heat , and less cylinder back filling on cam overlap. Obviously my turd is no were near standard now.

The spool up difference from .6 to .8 A/R was hardly noticable. Smoother maybe.

Thats the thing I am thinking, back pressure with a turbo is the big killer, and I am a bit worried with larger cams, therefore more overlap, things could get worse rather than better.

But if you reckon there is bugger all difference in spoolup time between 0.6 and 0.8, I think I might have to speed up the swap.

Smoother onto boost would be good, cos at the moment its bloody violent. I tried upping the boost to 1.2bar on the previous tune and holey fark, 120kmh - 4th gear and only 1/4 to1/3 throttle and the bloody thing got severly bent out of shape, thank god no cars were beside me.

RS500, if it were a 0.73, or maybe a 0.87 ( but I think I would have to give it a spin first) I would be tempted.

But 1.01, now why would you be trying to off load that??????

EVOIV, as far as I know HKS have proprietry on the housings and the comp wheel, which is why no one can buy them except HKS.

As far as I know, exhaust wheel and cartridge can be purchased direct from garret, or be ordered in by your local turbo shop.

Anybody out there got a 0.73 or 0.87 3037 turbine housing they want to off load:D

[rob77]

Well after looking at paul's turbo the exhaust housing is tiny compared to my td06-20g with the 16cm2 housing. Makes good boost quickly though, it really hammers

[EVOIV]

Steve: As you know, I have a GT3037S in bits at the moment. Compressor and Turbine housing, and core. The exhaust housing is a 0.73A/R. I am still not sure what I am going to do with this turbo. I do want to get it repaired eventually, if I can get my lazy ass into gear Also, not sure if it can be fixed - it will have to go to GCG or Garrett first for an inspection. But hopefully it can be as I think the turbine wheel is the only damaged part. If it does get fixed, I may opt to put on a larger turbine housing (sourced from where I don't know?). So then the 0.73A/R might be up for grabs. Maybe I should buy the 1.01A/R of RS500?

[EVOIV]

Not so sure if boost is going to come on more smoothly with a 0.73 compared to a 0.61? I was under the impression that the larger the turbo (and larger exhaust housing) the bigger *thump* when the turbo hits boost? Or maybe it's just an increase in lag?

[RS500]

i'll be keen to do a swap EVOIV

[EVOIV]

RS500: Sweet! I'll have to get my turbo repaired and have a better think about it now. Just wondering, why do you have the exhaust housing? Do you have another turbo to match? Have you decided what you're going to do next to ur car?

[RS500]

i might be lining up a buy off a friend for a GT3037 with a 1.01 exhaust housing, so if i get it, i'll swap ya no probs

yeah, if this works out and i sell my current turbo, i'm ready to move into the ball-bearing world

[Steve]

EVOIV, did you see my dyno? when it hits, it hits in about 3-400rpm. Sort of weird, it builds around 4-6 pounds normally, then it just goes crazy.