HKS Turbo's vs Garrett Turbo's...

[Merli]

There's absolutely no difference.

Since Garrett manufacture the turbos for HKS, they MUST be the same.

[GTS-t VSPEC]

I'd be putting the extra money saved by buying Garret into forged internals or cams etc. The HKS turbo's are overpriced and I've seen excellent results with the Garret turbos:D

[TurbostyleR]

ive heard nothing but bad stuff when it comes to hks...for example people put on a 25/35 and they end up making less power to what they originally did, i think the reason (someone else mentioned it) is that you need to run 2 bar plus to see the hks turbos shine, and i for one dont plan on running close to 30psi of boost!

as for the difference HKS refine their housings, i dont think they do much with the actual wheels or bearings, but i do know they spend a lot of time fine tuning the compressor and exhaust housings to make them flow better.

p.s. does anyone wonna buy my SAFC II??

please pm me if you do...

[Sumo]

I hate the idea of a turbo having to run high boost levels to be in its efficiency range.. Wonder what the engine would prefer? At least if your running low PSI spikes aren't too much of a worry.

Sumo

[Steve]

Originally posted by Merli

There's absolutely no difference.

Since Garrett manufacture the turbos for HKS, they MUST be the same.

[Sydneykid]

Hi JimX, you can buy Garrett style actuators with various spring rates, we get ours from GCG but other turbo specialists should have them. There are also HKS branded ones around, I have seen them at Croydons for a couple of hundy.

Re Garrett versus HKS.............

I have always been of the opinion that on a tuned engine, a correctly chosen Garrett can give the same horsepower as an HKS but at lower boost levels. Now this is a good thing if your engine is efficient enough to swallow the airflow without needing high boost levels. On the other hand an inefficient engine may need the extra boost from a HKS turbo to "push" the airlfow through the restrictions to make the power.

So if your power target is within the efficiency envelope of the engine, then a Garrett is the go. If your power target is really stretching the engines efficiency then (price asside) an HKS may well be the better option.

Hope that makes sense

[Guest Z1 Performance]

Here is the scoop, since we deal directly with both Garrett and HKS. While HKS does use Garret for their turbo assembly, the units are designed by a joint venture between the two firms. Now, what is the difference with the HKS version and the Garrett version you ask? I have been told from both sides that the wheel combinations that HKS uses are proprietary to HKS, and cannot be ordered through Garrett directly, although you cn often get close. It's basically the same deal with GReddy/Trust turbos and Mitsubishi, Blitz and KKK, and Power Enterprise and IHI. While all must reply on the actual manufacturer for the general supply, the specs each offers are unique to that particular manufacturer..

As an aside, I have been itching to get my hands on the Garrett equivalent of an HKS T51R KAI or SPL, as we have a few supra customers running the HKS versions on their car....hopefully one of these days we can get down to it and do a back to back swap.

Adam

[Sydneykid]

Hi guys, the old HKS versus Garrett discussion, I have used the following example to explain my stance a number of times ………………..

An RB25DET has the following upgrades;

GTR fuel pump

GTR intercooler

Z32 AFM

Power FC with boost controller kit

3.5” turbo back exhaust with standard cat

POD heat shield & CAI

It’s turbo upgrade time and let’s say I want 250 rwkw from this RB25DET and I have $7K to spend, now I could achieve this 2 ways;

Buy a new HKS 2540R ($5,035 + fitting $500), stick a thick headgasket (HKS $640 + fitting $400) in the RB25DET and run it at 1.7 bar (25 psi). I have to run it at 1.7 bar to make that 250 rwkw because that’s where its efficiency is and thus I have to lower the compression ratio to avoid detonation. Tuning cost is $500. Total spend $7,075

The other alternative is a Garrett GT25R ($2,750 +$500 fitting). I run it at 1.3 bar to make 250 rwkw, because that’s where it’s efficiency is and thus I don’t have to lower the compression ratio. Tuning cost is $500. Total spend thus far $3,750

So I have $3,250 left to spend on this option. A set of Tomei 256 degree camshafts for $1,700 + $400 fitting. Plus I swap my combined dump for a split dump $500 and a hi flow cat $320 + fitting for both $300. Total spend is now $6,970 (close enough to the 2540R total spend).

Now both examples will produce 250 rwkw, but the GT25R alternative will produce more off boost performance because the compression ratio has not been lowered. It will also come onto boost earlier because of the camshafts, split dump and the hi flow cat. Plus these additional mods will give it stronger mid range and, combined with the higher compression ratio, better throttle response. It’s average power over the whole rev range will increase, I would say by at least 20 to 25 rwkw.

This will make it both faster and more pleasing to drive.

Obviously this is based on new prices and paying for fitting labour, but the point is still valid. Well I think so anyway.

[R34GTT-R]

so a hks 2540r will make 250rwkw at 24.65 psi(1.7bar) and a garret gt25r will make 250rwkw at 18.85 psi (1.3bar).so why would hks make a turbo that needs more psi to get same power that the garret did.in effect they have taken a garret turbo and f**ked it so it makes less power at same psi.what is hks good for then???coz i just bought a 3037s 56t

[Steve]

Because you dont want to compromise.

Sydneykid, I dont know where you do your shopping but you are paying (or would be if you used HKS) way, way too much.

[R34GTT-R]

I got same turbo steve.have you got on your car???

[Steve]

Is being fitted (finally) this week - should be back on friday:)

[Warpspeed]

The point Sydneykid is making, is that the HKS is more efficient at higher boost than the Garrett.

Suppose you wanted to make a certain power level, so you gab a particular turbo that was rated at say 400BHP.

Now a guy with a 1.5 litre engine is going to have to run pretty high boost to justify that big turbo.

Another bloke with a 3.0 litre engine decides to run the same turbo at the same final power level, but he can do that with far less boost.

So both engines end up having very similar airflow requirements at very similar power levels, but the little motor runs very high boost, and the bigger engine low boost, to achieve that same power.

A particular turbo might be far more suitable for one set of operating conditions than the other.

[Sydneykid]

Hi guys, this was an example using recommended retail prices. I could have used trade prices, mates rates, no gst, duty avoided, no freight, in the luggage prices etc etc. It wouldn't matter, the comparison is what it is all about, not the absolute cost.

Warspeed has got it, although I would add that an inefficient 3.0 litre would need more boost to make the same power as an efficient 3.0 litre. It's all about the airflow and how easily it reaches the combustion chamber and how easily it leaves. Boost is a measure of resistance to flow, not the flow itself.

Don't missunderstand what I said, HKS do a good job of modifying Garrett turbos so that they can be fitted to (relatively) inefficient engines and still make good horsepower. I just prefer to spend the money making the engine more efficient. In Japan, where good mechanics charge like doctors, it makes sense to design a bolt on solution.

Hope that clarifies

[rb20-calais]

Guys,

I got my new turbo last night.

Garrett GT25 with a 0.70 compressor on it. I bought it without the exaust housing and it is brand new, cost me $1000. A garrett 0.86AR exaust housing with T25 flange will cost me $560 trade from Garrett. I could also get a RB20 exaust housing for $50 and GCG say they can machine the housing and make it identical to the Garrett 0.86AR housing for $300, therefore i will have a BRAND NEW 450hp turbo for $1350 that will bolt on because of the T3 flange.

Do you guys think this is a great idea or that i should use the genuine item and get an adapter?

This same turbo retails for $2600 or thereabouts with a T3 flange so i am VERY happy with the deal that i got.

Thanx

Evan

[JimX]

What's the biggest difference between the GT25 and the T04E? I ask because mine also flows around 450hp, or so I'm told.

[Sydneykid]

Sounds like a good deal to me Evan.

GT25 is ball bearing, T04E is plain bearing.

[rb20-calais]

one more question i need an actuator... will a standard rb20 one be ok? or should i pay the $350 that GCG said one was worth with brackets? i would prefer to save money but if the better one is needed i will not compromise.

Thanx

Evan

[JimX]

It depends on what boost you are running. Garrett have a 16psi actuator which is $290. If you are only running standard boost or a little more (up to 10-12psi maybe?) then the standard actuator should be ok. I'm breaking the threshhold with mine at 15psi so until I get a new actuator I've turned the boost down.

[RS500]

i'd just like to share something with everyone.

fyi, I was actually looking at buying a HKS/garrett GT series turbo for my sierra cosworth RS500 knowing that they would give me the power and drivability that i wanted based on what people wrote/said, but i wanted to give my current turbo a go before making my decision to sell it and outlay the extra $$$ for the GTxx (as my turbo is only about 1000kms old now since new) and what i found was interesting.

Since my last dyno, i've decided to save my $$$ (or actually spend them on something else ;-) and to stick with my plain-bearing turbo (specs below) as for a decent price (under $1.5k) you can get a nice brand new plain-bearing T04B/T03 combo (i'd stay away from the T04E wheels) built up which will give you the same power output (if not better) as the GT series turbos with good drivability, response and can be rebuilt for a reasonable price (if required) unlike bb turbos.

proof for me was when i had my engine tuned with the following spec turbo;

* T04B 60-1 compressor wheel (in A/R .60) and

* T03 sierra exhaust wheel (in T03 A/R .84 housing)

this combo on my car/engine (sierra cosworth RS500) recently produced 221rwkw on 16-17psi (1.1-1.2 bar) on a Dyno Dynamics with reasonable drivability (fullboost @ ~4300rpm). This power is quite good for a 2L where the car feels very strong on the street w/out having to run very high boost.

Ok, given the A/R .84, it isn't the most responsive of engines to drive on the street but it can be bettered if i was to put an A/R .63 exhaust housing although, i'll stick with the A/R .84 for now as i can live with it for now.

my point is that people are being sucked in with the 'ball-bearing turbos are the bees knees' and 'plain-bearing turbos are old technology' and 'the difference in response will be like night/day' and you'll get your 'eg, rated 450hp at 1bar' but this to me is all crap, as u see that to get the rated hp (which garrett/hks quote), you need to push the turbo way past 1.3-1.4 + bar of boost which not every engine is built to withstand.

so what i am saying is that, look into all the options first and don't rule out the good-old proven plain-bearing turbos. Get what suits your engine/required power level and most importantly, your budget.

my rant is over, thank you ;-)