HKS turbo's & Garrett equivelants?

[Anquetil]

I'll be looking at upgrading the stock turbo in a few months, I currently have my sights set on a 2nd hand HKS 2530 or 2535, something thats very torquey/responsive down low.

I'm not familiar with what the comp and housing specs mean on turbo's? But the 2530 has had good reports from what i've read, so without stirring up another HKS v Garrett debate I was wondering what turbo's on each side are closely spec'd

E.g.

HKS 2510 similar specs too Garrett GT??

HKS 2530 similar specs too Garrett GT??

HKS 2535 similar specs too Garrett GT??

HKS 2540 similar specs too Garrett GT??

Thanks for any info.

[Roy]

See you local Garret distributer, amongst others perhaps try Locations

Look at the GT25 and even the GT30 range of turbos. Be sure to shop around, prices vary.

[bbenny]

i wouldnt go anything smaller than a HKS2530 i have one on my RB20 and its very responsive, but for your RB25 it would be even more so, i wouldnt go any smaller.

from what i have ready the HKS turbos tend to make more positive boost at lower RPM than garrett spec turbos, so if you are after low down response go HKS.

[Steve]

HKS turbos are made by garrett.

You will not find a garrett turbo that will match a HKS turbo.

HKS has proprietry on the compressor wheels, also its turbine housings and compressor housings are made for HKS only, by garrett - they will not sell these to anyone else but HKS.

If you want a garrett turbo, best bet would be to pick a compressor (via compressor map), then look at getting a similar (you cant get the same) sized housing to the HKS equivilant that is recommended for your car.

If you are patient, and scout around, you can pick up a good second hand HKS turbo for a reasonable price - just takes time, keep an eye out, and be ready to pounce. Word of caution though, make sure you check the turbo out properly, as once they go, you need to replace the entire centre as they arent rebuildable.

[Sydneykid]

Hi Steve, I have heard this before" you need to replace the entire centre as they arent rebuildable".....

It is simply not true, we get cores upgraded all the time. Same size or bigger ball bearings, same size or bigger shafts. Next time we have one for repair I am going to post the photos, kill this stupid myth once and for all.

In my humble opinion, the best value for money new turbo for a standard internals RB25DET is this spec of Garrett GT25R..

0.64 A/R Turbine Housing

0.70 A/R Compressor Housing

48 Trim Compressor Wheel

45 lbs/min Comp Flow Max.

76 Trim Turbine Wheel

It has an internal wastegate and a watercooled centre , and can be ordered with the correct flange and upgraded wastegate actuator. We use a 12 psi, so it saves the boost control solenoid bypassing so much.

To fit it to an RB25DET, it does require some fabrication (inlet pipework, outlet pipework, oil and water supply etc ). If you don't want to do that (or pay someone to do it) then I would suggest a ball bearing hi flow of your standard turbo is a very good option.

Hope that helps

[Steve]

That is confusing, but interesting news. I have been told by a turbo repair facility that the only way to rebuild them was to replace the core, that it wasnt repairable on its own.

I also have a mate who took their advice and ended up buying a core for his GT25, at around 1.5K, they arent cheap.

Do you have any idea why places like GCG dont sell repair kits? I would love as much info as you have on this, and some photos with step by step would be awesome.

Thanks for the info, sort of makes HKS turbos look even more attractive second hand:D

[Sydneykid]

Think about it Steve, if they can hi flow an RB25DET Garrett or Hitachi based ball bearing turbo, why can't they repair one? They replace the ball bearings with larger OD ceramic ball bearings. This, of course, requires machining of the core to suite. All you need to know is the relevant part numbers of the bearings and have a line borer.

There is no black magic here, a plain bearing turbo has exactly the same issues when they are repaired. Larger OD bearings are fitted and the core machined to suite. It is just that the holes are bigger.

The only thing I can think of is, some turbo shops simply don't want to do it. So they tell you it can't be done.

I'll post some pictures next time we have one being done.

[Steve]

The only high flow I have seen of an RB25 turbo, that wasnt just a change of wheels and machining of housings, used a garrett core - its the one B-man bought from GCG. This also explains the greater than off the shelf cost for their high flows.

Eagerly awaiting the phots:)

[Sydneykid]

Hi Steve, there is one issue here that I should point out, Garrett don't sell some individual parts as "spares" for some ball bearing turbo’s. So what you have to do is use an "equivalent" part. So maybe the "you can't service ball bearing turbo’s" comes from this.

In some cases, you can't send your BB turbo in for service and get it back with exactly the same specification. They will have had to use some "equivalent" parts, generally still made by Garrett. Although a numbers of nuts, bolts, studs, washers o'rings and seals etc may well come direct from their original manufacturer not via Garrett.

This sort of stuff is quite common in the automotive industry, where individual parts are not sold separately, you have to buy a sub assembly consisting of a group of parts or an "equivalent" part. That's where the specialists come into their own, they know all of the "equivalents".

I have checked our list of turbo’s and spare parts today and all of them have a full list of parts to service them. Maybe we are just lucky, or our turbo specialist knows the tricks.

I don't have a problem posting pictures next time we service one. But don't hold your breath, we haven't done one turbo all this year. That's why we only use ball bearing turbo’s with water cooling, so we don't have to service or rebuild them all the time.

Them damn Sierra Cosworth plain bearing, oil cooled turbos used to need a rebuild at least once per race meeting. I have nightmares just thinking about it.

Hope that clarifies

[Sydneykid]

Ohh I forgot, Steve, ever seen a hi flow on a RB20/25DET turbo by Per4Manz in Perth? Do they use the original core?

[Sydneykid]

Sorry Shane we hijacked this thread, here is the data on the HKS turbos

.....................Compressor......................Turbine

....................Trim...Inducer....Exducer...Exducer...Inducer....Trim

GT2530..........63____1.860____2.344___1.883____2.098____76

GTRS.............52____1.997____2.773___1.833____2.098____76

GT2835..........52____1.997____2.773___2.020____2.204____84

GT2540..........46____2.016____2.972___1.833____2.098____76

As you can see the GTRS is merely a 2835 compressor (and cover)with a 2530/40 turbine (and cover). If you wanted to upgrade your 2530/40 to GTRS it is simply a matter of buying a 2835 compressor and having the 2530 cover machined to suite. In the case of a 2540 you would have to also buy a 2835 cover.

I will try and find the Garrett data as well and post it.

Hope that helps

[Steve]

Originally posted by Sydneykid

Ohh I forgot, Steve, ever seen a hi flow on a RB20/25DET turbo by Per4Manz in Perth?  Do they use the original core?

Thanks for the info Sydneykid, unfortunately I havent seen a Per4manz highflow, but I have seen some outstanding results from some of their custom turbos - I have alot of respect for them as a turbo company.

Also appologies Shane.

[Anquetil]

No probs, both your posts always make very interesting reading.

Ta for the info.

[Freebaggin]

Garret equiv....I think:

HKS = Garrett

GT2530 = GT25/T3 (446179-0030)

GTRS = GT25/GT35 (446179-0031)

GT2835 = GT25/GT35 compressor (446179-0030), GT30/T04S turbine (700177-0010)

GT2540 = GT30/T04S compressor (700177-0010) with GT25/T3 turbine (446179-0030)

Should be able to mix and match (just like HKS

)

[ylwgtr2]

Hi Steve, I have heard this before" you need to replace the entire centre as they arent rebuildable".....

It is simply not true, we get cores upgraded all the time.

I concur......A friend of mine owns a shop in japan and he offered to rebuild a clappered 2530 turbo i had for a tad over 70,000 yen....i then spoke to a few turbo guys in aust and they said you have to buy a new core....now i am thinking that maybe coz of the high use in aftermarket turbocharges in japan they may offer a better parts back up system than what we have in aust....just a thought

[Steve]

Or perhaps it is easier, or the turbo shops dont have the expertise?

Either way, it is excellent to hear, as I am sure it would save alot of money. My friend had exactly the same turbo (2530) and ended up buying the whole centre (and exhaust wheel) at a cost of around $1500. Even if you posted the turbo to Japan it would have been cheaper.

So next question, does anybody know of shops that will rebuild bb turbos, or is it a DIY job?

Cheers

[RS500]

Originally posted by Sydneykid

Them damn Sierra Cosworth plain bearing, oil cooled turbos used to need a rebuild at least once per race meeting.  I have nightmares just thinking about it.

hey dude,

please lay off the bagging of the Sierra Cosworth turbos, you know they're just a great car and the turbos did a great job pushing them to the ~600bhp region

Sydneykid,

in you list of spare parts, would you by any chance have a 56 trim (2.25"/3") T04S (GT30) wheel or the equivalent?

[Steve]

Isnt the 56T a HKS only for the GT30?

[RS500]

Originally posted by Steve

Isnt the 56T a HKS only for the GT30?

nope, it's also available with the 500hp Garrett GT30 core

http://www.turbofast.com.au/GTseries.html