Hks Gt2835Kai Still A Good Option?

[Torques]

I think Simon's suggestion at post #2 made the most sense given the OP is in the UK and not running E85.

Looking at this thread, if the OP's setup consists of bolt-on airflow modifications only (inlet pipes, turbo, FMIC, poncams and exhaust), I'd suggest his dyno might be happier than the typical Australian spec. 260rwkW from 13psi on an RB25 is not something generally seen.

It's 252RKW (301KW crank) @ 6300 @ .9 BAR /13PSI

In the attached file you can see how boost creeps out.

My target pressure was 18PSI

[89CAL]

Hmmm looks like there is a real issue there, exhaust/inlet restriction?

Mine held 18psi near perfect with the Power FC boost controller. I did have a few problems with the bost fluctuating up and down between 15-18psi pretty rapidly but ended up sorting that out.

[Torques]

Hmmm looks like there is a real issue there, exhaust/inlet restriction?

Mine held 18psi near perfect with the Power FC boost controller. I did have a few problems with the bost fluctuating up and down between 15-18psi pretty rapidly but ended up sorting that out.

Hello,

Was your Turbo the HKS Pro S?

Mine is just a Hybrid rated at 380HP.

If I set it to say 14PSI target the boost curve would be more linear

I guess I am just asking too much from a small turbo.

I could double check if the gate opens too early but have no high hopes.

Otherwise I see no restricting factors.

Blitz FMIC

HKS DUMP

Tomei 4'' downpipe / Pon Cams

HKS 3'5 exhaust

[89CAL]

Mine was a 2835KAI

[Torques]

Mine was a 2835KAI

Would you have any dynos? (HP/Torque/Boost)

And were you happy with the KAI, or did you move on?

Edited July 10, 2014 by Torques

[Mick_o]

The kai will NOT go 300kw on petrol.. Probably Wouldn't make the power you have now. As earlier stated your best/only real option will be a GT30 if you wanna do 400hp on the tarmac

[Torques]

The kai will NOT go 300kw on petrol.. Probably Wouldn't make the power you have now. As earlier stated your best/only real option will be a GT30 if you wanna do 400hp on the tarmac

Thanks,

GT30 would mean high mount / ext gate then ...(?)

Would need to do some research on that I guess.

If the KAI would do 280KW+ that would be enough for me but I think it is rated at about 400HP?

Making less power than I have is not really an option

[89CAL]

The Pro S was a better turbo and despite all information to suggest that the KAI should be better it does not live up to they stats HKS post. I was disappointed as I originally ordered a PRO S and Nengun said it was discontinued and the KAI was better. So I eventually moved on to a hypergear turbo. Was frustrated with the lack of support from HKS who basically said the turbo wasn't making the power because of the tune or something that I'd done and after only 1 or 2 replies began to ignore my complaints

The KAI is not a bad turbo, im not going to say that at all, it's pretty great for a street car. However it doesn't produce the power of the old PRO S so as above don't expect it to go to 300rwkw, even on E85 I don't think you'd quite get there. The most I've heard of is about 260rwkw on a 25 neo with poncams

[Torques]

How happy are you with Hyper-Gear?

Spoolup should be somewhat worse compared to the HKS.

Here the PRO-S making 320KW on E85

http://www.skylinesaustralia.com/forums/topic/412682-300-rwkw-gtst-top-shelf-parts-only-price-drop-for-members/?hl=hks+pro

[M@&k]

Joeyjoejoe....'s result is often quoted for the Pro S, but I think even he admitted it seemed to be freakishly good compared to others. More common was around 260rwkW, and a touch more with cams.

I've spent a lot of time trying to find a turbo like Pro S, but haven't got there yet. Shame the Kai wasn't a worthy successor. Also, by the way you can buy the Garrett equivalent of the Pro S, but the issue is trying to find a decent turbine housing.

[75coupe]

My proS is 290 on 98 stock head

[discopotato03]

We have to remember what was available when HKS put those GT Pro S turbos on the market - SFA . There were no Garrett IW GT30 turbine housings then so you were pretty much stuck with a Pro S or an external gate . Or some bastardised machined out dinosaur T3 IW housing .

If you can't rat up a Pro S turbine housing then you may need to look at the GTX3067Rs , we haven't seen one yet on an RB with the 0.63AR IW turbine housing but its worth consideration .

The 2835 KAI looks like a band aid for the Pro S version . It's basically taking a GTRS and putting a cropped GT30 turbine in it so the value is a slightly larger and heavier turbine in a T3 flanged GT28 0.64 AR turbine housing . It bolts straight up and takes the standard dump flange .

I personally reckon that if you can't get a Pro S housing and its unique dump pipe (or make the dump) you are better off with a GT30 based turbo even if it means using the smaller 0.63 turbine housing . Once your set up for the manifold spacer and GT30 IW dump pipe you open up a range of turbo options you don't get with much else .

Had Garrett had the GT30IW housings back in the day there probably wouldn't have been Pro S housings and dump pipes .

Also consider Hypergears turbos , cheers A .

[89CAL]

Im more than happy with the hypergear so far. Stao's customer service is great and he is always updating which means you can send the turbo back to be upgraded for better performance. Also when it comes time to rebuild the turbo, I dare say a hypergear would be cheaper to rebuild. The main problem with the 2835 is the price. If it was resonably priced they would be good, but I think I payed about $3500 for my HKS turbo where as the hypergear cost under $2000. Fair enough the HKS turbo comes in a kit but it's not worth the extra money as far as im concerned

The big issue for me as well is customer support. As I already said, expect Zero of that if you go HKS where as at least hypergear is local and Stao is willing to discuss issues etc. Customer support probably isn't an issue with the HKS but for me when I originally ordered a pro s, and had seen so many pull around 280rwkw, to then have mine under perform that I was kinda after some answers. I was rather unlucky in my Situation as I would have been one of the first to get one of these so Nengun didn't know it would be worse then the Pro S so I couldn't really blame them for selling me what was essentially a super seeded part

[Torques]

@89CAL ->

That must have been a disappointment. Especially after investing quite a bit of $$.

Would you have dynos of the HKS vs / and the Hypergear?

Does the HG introduce more lag ? (it should)

What is your current power?

My turbo make 14.4 PSI (1BAR) at 3500 rpm.

That's the benchmark I compare against for spoolup.

Edited July 11, 2014 by Torques

[Torques]

Hello,

I was hoping that the bridge between low lag and high power could be drawn easier these days.

So billet wheels and ball bearing would be of my interest.

All things being equal the HKS is a bit aged now and is 'only' rated at about 410HP (CRANK) or so.

Back in the day that that was good power.

I would need to do more research on available turbo options and how well they spool up on RB25.

Making huge power is no so difficult but I need my car to be torque rich and responsive.

My current benchmark is 1 bar (14.4PSI) at 3500 RPM and the new turbo should be in that region while holding 16-18PSI at 6500RPM.

I once did the maths for this leading to the required compressor map.

I will revisit Hypergears turbos as well .. Stao has many options available.

We have to remember what was available when HKS put those GT Pro S turbos on the market - SFA . There were no Garrett IW GT30 turbine housings then so you were pretty much stuck with a Pro S or an external gate . Or some bastardised machined out dinosaur T3 IW housing .

If you can't rat up a Pro S turbine housing then you may need to look at the GTX3067Rs , we haven't seen one yet on an RB with the 0.63AR IW turbine housing but its worth consideration .

The 2835 KAI looks like a band aid for the Pro S version . It's basically taking a GTRS and putting a cropped GT30 turbine in it so the value is a slightly larger and heavier turbine in a T3 flanged GT28 0.64 AR turbine housing . It bolts straight up and takes the standard dump flange .

I personally reckon that if you can't get a Pro S housing and its unique dump pipe (or make the dump) you are better off with a GT30 based turbo even if it means using the smaller 0.63 turbine housing . Once your set up for the manifold spacer and GT30 IW dump pipe you open up a range of turbo options you don't get with much else .

Had Garrett had the GT30IW housings back in the day there probably wouldn't have been Pro S housings and dump pipes .

Also consider Hypergears turbos , cheers A .

Edited July 11, 2014 by Torques

[Torques]

Just found this ..

[89CAL]

Ignore it, it means jack shit. I remember being shown that when I was being told the KAI was the new and better turbo

Didn't happen at all. I'd have to find my dyno sheet. My current setup needs an exhaust restriction removed then a re tune but hopefully will be around 300rwkw, touch more with any luck

[Torques]

Yes, already written off the HKS.

Not worth it judging from you replies.

Which Hypergear did you go for?

Ignore it, it means jack shit. I remember being shown that when I was being told the KAI was the new and better turbo

Didn't happen at all. I'd have to find my dyno sheet. My current setup needs an exhaust restriction removed then a re tune but hopefully will be around 300rwkw, touch more with any luck

[discopotato03]

Yes it was unfortunate and hardly honest of HKS , or their reps , to claim the KAI was going to be as good as the Pro S version .

I remember looking at pics of that turbo here and thinking hang on , no way the 0.64 AR GT28 T3 housing was going to flow like the Pro S one . The machined out turbine housing may flow a little better than it would with a GT28 turbine in it but from Garretts questionable turbine maps the efficiency numbers aren't very good .

I don't think any turbo with the cropped GT30 turbine ever worked terribly well unless it had one of HKSs GT30 turbine housings machine to suit . For some unknown reason Garrett haven't offered their GT30IW housings to suit this turbine , maybe there isn't enough material in their castings .

Just on power figures and 2835 Pro S , there was an optional 0.87AR Pro S housing if you didn't like the usual 0.68 one . Don't know the boost onset difference but power limits would have been higher with it .

A .

[GeorgesR34]

@89CAL: From following hypergear's thread, I remember you've got one of their testing ball bearing ss2. I have the same turbo internally gated. Obviously not as responsive as the 2835 but pulled 312rwkws on 98 fuel, 20psi by 3800RPMs. Its more of a 3076 in .82 turbo. They have made an vnt housing for it, unfortunately only for external gate. Buy that housing and it will pulling 24psi on 3500rpms and that will be about the same or better to a HKS2835 ProS while making heaps more power.

Edited July 13, 2014 by GeorgesR34