Jump to content
SAU Community

Recommended Posts

I know a lot has been written about HKS turbos, done the search and read whats been said,

but, so much of whats written is stuff like "ive heard" or "so and so's car makes xxxkw" Mostly hear say info on these turbos.

Please post only if you've had direct experience with these turbos, and facts not hear say:-

1. On an RB25 what power can you make at the wheels, whilst running "efficient" boost ie, not stretching to the limit, with a 2530 and the 2535? -plz post boost with power figs.

2. When does boost start, and when is full boost hit for each of these turbos?

3. I hear that the 2530 is a really good turbo for street, is this still the same for the slightly bigger 2535? (as i hear that the 2540 is a bit too laggy).

I'm trying to get all the facts sorted as i'm about to purchase one or the other. (yes i've thought about high flows, GCG etc, but am going for HKS)

THANKS, SLY33

PS, REV210- not interested in hearing that these turbos will only make their "rated" power at the engine, as there are too many of them making way more than that :D -but by the way congrats on your time!

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/
Share on other sites

JMS has a GT2510 on a R32 making 220od RWKW 1.3bar.

Tilbrook has also had a GT2530 on a RB20DET making 220rwkw at 17psi Tilbrooks told me the GT2530 made full boost at around 3700rpm on the RB20DET.

The HKS turbo's are more efficient at higher boost levels compared to the same HP Garret unit. Hence why the HKS make more power.

My info is probably useless to you but may give you some idea.

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/#findComment-331196
Share on other sites

Hi SLY33, no experience with 2535's, but we find 2530's to be really good. Single for 230 rwkw or twins for 390 rwkw has been our exerience and good power spread as well.

If you are going to run a fair bit of boost (more than 1.3 bar) then HKS turbos are very hard to beat. But you will have to do a lot of support systems upgrading to take advantage of their good performance at the high boost levels. I strongly suggest you think about how much power you are targeting at what boost and then work out the budget for the project. You may find that you are spending money on a "high boost" turbo and that the support systems to take advantage of that turbo are outside your budget.

We see this lots of times with uncompleted projects where the owner has run out of money to finish the job and ends up with a dog of car that doesn't run properly.

Hope that helps.

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/#findComment-331770
Share on other sites

I'm also very interested in this topic as I'm running an RB20DET with a T3/T4 GCG modified R33 turbo and am having surging problems. I'm sick of messing around and am now looking into a HKS GT2530 as I'm told ( by all in Japan ) that it's the perfect turbo match for the RB20DET and the HKS GT2535 for the RB25DET. Unfortunatley I too have heard nothing while in Aus about the pro's and con's. P.S. What's a good price for a GT2530 new?

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/#findComment-332576
Share on other sites

Hi FAT32, I am really concerned with your comment "I'm running an RB20DET with a T3/T4 GCG modified R33 turbo and am having surging problems". We have around 10 cars (both RB20 and RB25) running GCG hi flow RB25DET turbos and none of them exhibit any surging. They range in output from 190 rwkw to 260 rwkw and have a multitude of different support systems for the turbo's (big I/C', std I/C's, hi lift camshafts, std camshafts, split dumps, combined dumps, Power FC's, Chipped Std ECU's etc etc).

Consequently I would be most interested in your set up as there must be something/s unique causing this problem. I also suspect that if you are having a surging problem with your hi flow then it will still be there with a 2530.

Further details would be a great help.

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/#findComment-332760
Share on other sites

Joel,

On a cool / cold day on part throttle going up a hill with boost I get a rapid choofing noise and the boost gauge bounces around then the power dies off. I then have to pull it back a gear a nail it as it seems that I need revs to swallow the air that the compressor is supplying. I also get minor surging when I nail it from about 4500rpm to 6000rpm then it just pegs 1.2bar and climbs to rev cut.

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/#findComment-334519
Share on other sites

The Hks gt2535 has a fair amount more lag than the standard unit. In my application it is fitted to an rb20 using a front mount cooler (lots of pipe work ), matching dump pipe ect. ect.

3000rpm is 5psi

4000rpm is 15psi

and 4400 rpm is 18 psi

It has a .60 comp housing and .64 exhaust housing.

The set up has made 196 rwkw at 1.3 bar on

2 different dynos in sydney both on hot days (35+ in dyno cell). This figure does seem a little low but really only when compared to the tilbrook dyno figures for the same set up.

Tim.

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/#findComment-335678
Share on other sites

FAT32,

We have experienced surging on a RB20DET with a T3/4 combo and it took the turbo supplier 3 goes to get the combination right. We suspect the turbine side wasn’t adequately upgraded which meant the upgraded compressor was supplied with excessive work at a certain engine operating point. This caused the compressor wheel to rotate at an excessive rpm (higher boost) for the air consumed by the engine which is what you described.

Trouble is that the RB20DET has a smaller swept volume at lower rpm and if the turbo isn’t matched correctly the compressor will operate out of it’s pressure/airflow region and all sorts of converging/diverging pressure waves will be generated in the inlet tract. Not a good thing I can assure you.

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/#findComment-336702
Share on other sites

Thanks much for that info.

Since my last post I've been contacted by GCG who have suggested that I have a Stg.2 turbine wheel in my setup and that I should have a Stg.1 wheel to better suit an RB20DET for that exact reason ( although they won't admit fault or prior knowledge ). Looks like it's coming off again.

Although I would love to fit a GT2530, I don't think the extra costs associated would justify the increase in power IF my turbo surging problem gets fixed by GCG. Mant thanks to those who have help out with info relating to my problem. Will post again when I try the turbo for the 3rd time.

Scott.

Link to comment
https://www.sau.com.au/forums/topic/16164-hks-gt25302535/#findComment-337162
Share on other sites

  • 2 months later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Latest Posts

    • Yeah, that's when. I guess you could say I'm as patient as I am foolish(or just a masochist?🤔). I've strongly considered throwing in the towel and calling it all quits many times, and have almost done so. It's a first-world problem for sure, but I've had a pretty rough go of it, as well as other factors; hoping something good comes of all this; it has to. It definitely is half the price of the ATS and performs great, but I'd like to try something different for once. I've sampled the ATS in a friend's 32 and it's solid👍
    • I know mentally you're set on the ATS clutch but honestly I'm a big fan of the Nismo Super Coppermix Twin. It's much cheaper and in some ways I think it's a better design for a street/circuit car.
    • Just checked in first post and you should be able to bring it home November this year, right? I'm amazed you made it through four years of this. As hard as it feels now the rest will go by in a breeze in hindsight, I'm sure.
    • Realized I haven't been back here in a while. Still here, still alive, still waiting for the car.  I went back again the only time last year from Oct-Nov for R's Meeting and drove it around some more, including a few laps on Fuji Speedway(in the wet, sadly). The car still feels good, but have a couple small things to address. I've been getting more parts but have slowed down still, and most of the bigger purchases are now out of the way. I find myself getting impatient more and more when it comes to getting started on this project; it's quite hard for me not being able to really dive in and start making this car my own because it's halfway across the world. At times it doesn't even really feel like I own one of these. Haven't really been motivated or had the desire to document the last trip on here or social media for, well, reasons... but here's some pics...it's also still alive and well as you can see: I've narrowed down to the last large part purchases(anything over $2k) before the engine build to be: 1) Ohlins Road & Tracks 2) ATS Twin Carbon clutch 3) Endless BBK with some custom options and 4) Kansai Service carbon driveshaft I don't think the budget exists for all of these this year, but I'll try for one or two items I think. Though, every time I look at my spreadsheet I sigh, shake my head, and get depressed just that little bit more.  'til later.
    • It's a stunning location!  I've been to NZ twice but haven't made it to the North Island yet.  Definitely on the cards but the South Island is hard to tear yourself away from too... Looking forward to see what you can wring out of it once you can get it to hold together!  Be awesome to get a low 11 or even sneaking into the high 10's pass out of it.  That's a bloody quick car that most people will never experience in their life.  Enjoy!
×
×
  • Create New...