I've been looking for weeks now for more information on the GTIII-RS "GT8262" turbo from HKS (newer version of the old GTII 7460), and there's little I can find. Based on HKS's own *very technical* graph (https://www.hksusa.com/products/sports-turbine-kit/4), it should be equivalent to the old GT-II, but I'd love to know for certain for I drop $3k on it.

I'm considering this turbo because it fits within the very narrow ruleset for the class of time attack I compete in, and I'm looking for any advantage I can get over stock turbo, even if it's marginal. FP-Green or something like that is not within the ruleset.

Anyone have specs on lbs/min, A/R, compressor wheel sizes, is it ball-bearing? Alternately does anyone have any dyno comparisons of the GTIII vs stock? I can understand why a turbo like this at this price point no longer has mass appeal, but the drought of information is wild.

Appreciate it, guys.

 

Rumor is that HKS is already moving on to new turbos with Garrett G-series CHRAs: https://www.sau.com.au/forums/topic/...omment=7955493

 

Ah, interesting, never would have found that thread. So the GTIII is journal-bearing according to them. So strange that they would go from BB on the GTII to journal for the follow-up. Thanks for linking.

 

Bump. Has anyone else got any hands on experience with this things?

 

Hey Ben, I really doubt anyone here has ran that turbo. When the original GTII came out, it put out pretty much the same amount of power that a stock IX turbo puts out. Can you run a smaller FP turbo than the green? Like the 18K or 71HTA? If not, I’d message “artgennari” on Instagram for some help with a stock frame turbo, he’s up in the northeast also.

 

l888pex, benjibop,

In interest of ensuring facts are shared, and not speculation....
I've owned 3 HKS GT2 7460, on different Evos,
My original HKS 7460 - first one I purchased - was from the Launch Special when they offered it with HKS 274/278 cams for ~2100 - I ran until 2 years ago, now resides my close friends Evo 8 MR.

7460 puts comfortably +50whp over stock Evo 9 turbo, and spools faster. This has been shown more than once, and it has been my experience.

I nver dynoed my car on Dynojet, rather- FFTec in Hayward California Mustang:
Stock Evo 9 put out 215whp on this dyno on 91 California fuel
Stock Evo 9 put out 375whp on E85 pushed to max with S2 cams and all supporting mods - this on FFTec's own Evo 9
HKS 7460 375whp on 91 octane through 100 cel cat and MAF
HKS 7460 425whp on E85 as above

I don't remember exactly how much was E9 stock turbo with all supporting mods and S2 cams pushing on 91, but I estimate 325-330whp maximum.


HKS 7460 is not about peek numbers, it is about OEM quality of superb response at any rpm, and worst case same spool as OEM, while giving clear 50whp advantage.
It is an amazing turbo for California backroads, on stock block.

It may be a great choice for some Time Attack/Autocross class where power-to-weight is limited, one can ramp up fast and than keep long continuous powerband.

I will say that FP 71 is really great value if say you are fine with something "between" OEM E9 turbo and HKS 7460.
FP 71 is really durable, economical, and if you are limited in power it will do the job fine.

FYI: regarding any concern with durability, my original is going super strong 11 years later and uncountable miles later.
1 out of 3 - that I purchased used - had an issue with wastegate bearing seizing. I had it repaired, by having a fresh bronze bearing installed: this was creative fabrication, but works still on friends car maybe 2 years now.
E9 turbo is known to crack exhaust housing, as it ages, so any turbo that is somehow abused may get damaged, HKS and E9 OEM are no exception.

What I think is key, is to pre-load hard HKS wastegate. And ensure it's pre-loaded, so that door closes regularly and dissipates heat into the housing. If treated like that, bearing will not seize.

 

I was reading on a big GTII thread from like 2010 when it debuted, it seemed like the turbo was making 50whp over a 9 turbo, with people estimating the flow rate at like 47-48lbs/min. People like IveyTune were posting in there with results. Funny how excited people were 10 years ago and how much the market/HKS's offerings have changed 10 years later.

Unfortunately as foolish as it sounds the only turbos the rules explicitly say I can use are this or a Blouch 16G-XT, which I've done extremely little research on. These two turbos are cited as examples of what are allowed within the ruleset.

 

Thanks for you input, alpina. I've read on multiple threads that the 7460 was a good turbo, people were excited about it when it dropped back in the day. Unfortunately, it's not explicitly approved for my class. I can perhaps present my case to the competition director, pitching the GTII as an old version of the GTIII. You would intuitively assume that the GTIII would just be an updated turbo, but it seems it's no longer BB, and perhaps not even as high flow-rate. I have no idea unfortunately.

For reference, my car is currently running a high-comp, 10.5-1 bottom end, built head with GSC S2s and all the other bolt-ons, making 397whp on a Mustang at 25psi, stock turbo. So that's why I'm a bit concerned by these numbers of 430whp Dynojet i've seen thrown around in relation to the GTIII. If that's where the turbo taps out I probably don't want it. If I could find out the flow rate or a comparison between it and the stock 9 turbo, then I'd have some information to go on.

 

The rules state up to 41lb/min turbos are allowed. That's a compressor flow rating. The reason why they call out the turbo examples in the rules is because the Subaru version of the GTIII is supposed to be the same as the OEM S209 turbo, just not $5k. The old rules said it had to be an OEM turbo which gave Subarus a distinct advantage if anyone was insane enough to spend that kind of money on a turbo. But this is racing, of course someone is crazy enough to do that.

18g compressors are rated at 41lb/min. Kinugawa sells it in a stock frame turbo paired to either a TD05 or TD06 turbine (I've already told people the loophole to these rules is use a larger turbine if they want more power). The TD05 turbine is basically what's in an S209 turbo. They sell it as either a ball bearing or journal bearing version too.


Ball bearing TD05 and TD06:
https://store.kinugawaturbosystems.c...8g-stsadvanced
https://store.kinugawaturbosystems.c...8g-stsadvanced

 

If your going down the path of piecing something together, do some homework. In my experience kinugawa billet compressors are fine, however, I found failures of the BB chra when used beyond driving to your mailbox. Also, as the turbine size goes up the criticality of having a bubble-less cast goes up exponentially. In short, I would use MHI hot parts for track reliability. My luck has been fine with their billet compressor wheels and cast covers. The td05 size turbine (9-blade) has also held up fine, and I've made 450whp through it through many track sessions. Not sure I would trust them for td06 size as that is considerably larger. A tell tale sign of a bad cast turbine is if the amount of material removed to balance it looks excessive. This means it is was off balance due to pockets of air.

 

I have zero affiliation with the company, they're just the only option I've found for an 18g turbo in MHI housings. Could probably get AGT to make a similar turbo pretty easily I'd think.

 

Austin, appreciate the recommendation. I'm drawn to the GTIII because it's explicitly cited as class legal, which removes the work of me having to argue for a turbo's legality. I know the rule of thumb is 41lb/min, although people have told me the GTIII/GTII is likely flowing much higher than that (stock 9 turbo is 41lb/min if i'm not mistaken).

What i've heard, and found some rough confirmation of is that the GTII 7460 is actually the turbo used in the Euro Evo X FQ440. That would make that turbo class legal as it's an OEM part (flow rate might be another matter). Anybody know for sure if the GTII 7460 is, in fact, what was used in the FQ440?

 

So what if just the compressor wheel and turbine wheel were upgraded on your stock turbo? Would that fall within the rules? Because a 9 blade TD05 turbine and even just a stock size billet compressor would get you at your imposed limit. If your allowed to change your compressor inlet size (but not machine the compressor backplate (keep it 68mm), then a 20g SIZE wheel (preferable 7+7 blade type as I have tried the 11 full blade as well) will allow you to run with more compressor margin (less boost).

So I guess if you can post the text of the rules, then it would be easier to figure out your options. Don't forget the JAPAN versions of the EVO had titanium aluminide wheels (aka: borg gamma-ti) as an option, so now I am wondering if that is an option too; although that is a spool increaser at the cost of overspinning damage (risk).

 

Evo X turbo is standard rotation, it won't fit on an evo 8/9 unless you make a custom hots part kit around it and it won't fit well either because everything has to be backwards.

The rules are worded a bit poorly because the HKS turbo example given is referencing the Subaru version, which is around 41lb/min (the compressor dimensions are very similar to an 18g). From what I've seen the evo version does not use the same compressor and turbine (may be wrong on that tho) so you'd still have to prove its legality, unless you're trying to exploit a word loophole.

 

I am pretty sure Evo X 440 used MHI18 turbo.

To Austin's point, Blouch XT1, i.e. BBK-Full, is nearly as wonderful as HKS 7460. HKS was a bit "better" in every way, being Ball bearing vs plain, arguably a bit sooner spooling, faster responding, and perhaps having a tiny bit on top.

Speaking of awesome turbo BBK-3B, i.e Blouch XTII is it: superb. It is perfect- say for someone having a 2.0 and wanting more but without the heavy tax of FP Red in spool.
Or 2.2/2.3 motor and best spool.

The HKS GT3 I've "met a guy" who had it, and it was as promised on HKS dyno sheets. It was slower spooling and had more on top.
It will make way more than 41lbs so it's weird to make it legal in 41lbs flow rate class.
But whateve.r


FYI: regarding your dyno 397 on Mustang.. please don't compare Mustang to Mustang. It is totally easy to calibrate it to anything.
Don't worry, Evo 9 turbo can only flow what it can, and citing a turbo making certain power is nothing without baseline.

That is WHY, I said, Evo 9 stock puts 215whp and all out on E85 Evo 9 could reach 375whp on this dyno...but this turbo will die sooner than later due to being pushed way hard.

So don't get hung up that you have some miracle child. Evo 9 turbo is what it is, and HKS is what it is, and that is irrespectable of dyno: dyno is measuring tool to measure.