GCG or HKS 25** Turbo

[Sydneykid]

Everyone says dont run over 80% efficiency, obviously this is so you have some fueling capability in reserve, but can someone who knows the actual technical reason tell me why if my absolute max peak duty is just under 100%, and AFRS are fine, knock is fine, what is wrong with running such a high duty cycle? do the injectors wear out or something?  Is my setup a time bomb in its current high duty-cycle state?

There are many reasons, let's try 2..

#1. When you put your foot down quickly, the ecu adds extra fuel momentarily to help accelerate the engine. This is called acceleration enrichment, if you don't have it the engine won't accelerate. If you are already at 100% duty cycle, then there is no capacity in the injectors to do acceleration enrichment. Generally acceleration enrichment is expressed as a percentage, ie; current fuel requirements plus X%. Commonly X is around 14%.

#2. The ecu has bult in safety measures, one of them is richening up the mixture when the inlet air temp gets too high, another is when the water temp gets too high. If you are already at 100% duty cycle there is no capacity in the injectors to add some fuel to protect your engine. :Bang:

I am sure others (smarter than me) can add some more.

[RBVS]

SK: have you pushed stock injectors to 250rwkw with out the use of cams?

I think saying you can get 250rwkw out of stock injectors may be a bit missleading as many people will just bolt on a bigger turbo and just crank the boost up to reach 250rwkw and think every thing is ok because they have a fuel reg.

If you have done it and the engine has run efficiently I stand corrected.

[Sydneykid]

SK: have you pushed stock injectors to 250rwkw with out the use of cams?

I think saying you can get 250rwkw out of stock injectors may be a bit missleading as many people will just bolt on a bigger turbo and just crank the boost up to reach 250rwkw and think every thing is ok because they have a fuel reg.

If you have done it and the engine has run efficiently I stand corrected.

Cams or no cams, did I say 250 rwkw out of standard injectors anywhere in this thread?

[B-Man]

21 psi thru a GCG hi flow - wow........

When I had mine - we got 240 rwkw no mater if it was 14,15,16,16,or 18 PSI...... I think it had something to do with the integral wastegate.

[RBVS]

Cams or no cams, did I say 250 rwkw out of standard injectors anywhere in this thread?

no not in this thred, i got confused bettween this and the ''cheap injector upgrade'' thred. Im not having a go just arsking if you have done or know of a 250rwkw 25 with stock cams and injectors. I had in my head that you have said 250rwkw in other threds.

can you kind of see what im getting at. I can see that you always list mods to show, so thiers no fualt on your behalf just that people might interpret differntly, thinking the stock injectors can support their boosted 25 with only the use of a reg. or maybe its just me

[Lepperfish]

21 psi thru a GCG hi flow - wow........

 

When I had mine - we got 240 rwkw no mater if it was 14,15,16,16,or 18 PSI...... I think it had something to do with the integral wastegate.

Whats wrong with 21psi? i might crank it up some more!!!! :headspin:

[Sydneykid]

no not in this thred, i got confused bettween this and the ''cheap injector upgrade'' thred. Im not having a go just arsking if you have done or know of a 250rwkw 25 with stock cams and injectors. I had in my head that you have said 250rwkw in other threds.

can you kind of see what im getting at. I can see that you always list mods to show, so thiers no fualt on your behalf just that people might interpret differntly, thinking the stock injectors can support their boosted 25 with only the use of a reg. or maybe its just me

Personally, no I have never achieved over 220 rwkw out of standard RB25DET injectors and that was with a small increase in fuel pressure. Others have though, Steve-SST seems to be able to do it, but he is a better tuner than me.

[B-Man]

Whats wrong with 21psi? i might crank it up some more!!!!    :headspin:

Nothing - I'm impressed

[Sydneykid]

Ya, better than nothing, never said it was useless... you just wanted some rice SK    

Invisible rice, it's going where I don't have to look at it all the time. :angel:

[Sydneykid]

When I had mine - we got 240 rwkw no mater if it was 14,15,16,16,or 18 PSI...... I think it had something to do with the integral wastegate.

There are lots of things between the turbo and the rear wheels, why do you think it was the wastegate?

[B-Man]

There are lots of things between the turbo and the rear wheels, why do you think it was the wastegate?

I'm no expert OK. It actually could have been a melted cat - you know about that story I think SK

When I increase boost from 14PSI to 18PSI with the hi flow - no change in power, my feeling is that is turbo related - rear housing or wastegate or exhaust.

Boost guage reads more boost - so plenum pressure is increased so the air is getting in there.

I have the exact same exhaust system bar a (very) high flow cat - so I know the turbo back zorst was OK (but like I said before - could have been cat)

Not much else has changed up top except for cams and turbo and now getting 330+ and boost now is 18-21PSI. So the turbo in my books was (one of) my problems.

There were a number of other factors involved / changed - but that was my feeling - I was changing too many things at once to know for sure.

I *thought* that the hi flow efficiency topped out at about the 14-15 PSI mark - but could be wrong.

I have had two turbos from GCG now and both have not met my expectations.

That's why I have an HKS Turbo now

What is fact is that I had an GCG 3040/VG30 hybrid with GCG manifold and 250 rwkw - Exacty the same setup but swap the turbo and manifold with the HKS manifold and turbo - 330+ rwkw - 300-500 rpm more lag tho. (which is fine with me)

So there you go - could have been anything (pitch of turbine blades included)

Who knows ????

[Trust33]

Let me ask a stupid question here.Can you do sort of like a port n polish job on the housings of a stock Rb25 turbo when high flowing.By this i mean the snails.And i suppose at the same time open up the internal wastegate a bit.to give it better overall performance instead of going for boosted's approach of Vg'ing the turbine housing? :ghost:

[Sydneykid]

i suppose at the same time open up the internal wastegate a bit

I have yet to see a hi flow without a bigger wastegate, ours was 5 mm bigger in diameter.

What is fact is that I had an GCG 3040/VG30 hybrid with GCG manifold and 250 rwkw - Exacty the same setup but swap the turbo and manifold with the HKS manifold and turbo - 330+ rwkw - 300-500 rpm more lag tho.

That's a good result, can you please tell me more? I am really interested in stuff like boost comparison, manifold differences, HKS turbo specs, internal or external wastegate and anything else you can think of.

I am here to learn like everyone else and this sounds interesting.

[SATO GTS]

i'm deffinetely not going to waste my money on australian made gear as HKS have spent a shit load more on R&D then any australian turbo manufacturer..

HKS for me .. yes i know they are pricy but you get what you pay for and that is quality and performance..

[Sydneykid]

i'm deffinetely not going to  waste my money on australian made gear as HKS have spent a shit load more on R&D then any australian turbo manufacturer..

HKS for me .. yes i know they are pricy but you get what you pay for and that is quality and performance..

Hi Sato GTS, I have a couple of questions

Since HKS Turbos are made by Garrett

and

GCG (and others) use Garrett turbos and Garrett parts in their upgrades.

If they are both Garrett (one branded HKS and the other supplied by GCG), can you please expalin to me how HKS turbos are "better quality"?

Try 09 and quite a few other sub 10 sec Skylines use Garrett turbo's from GCG, please explain why you think you are going to get "better performance" than that from a HKS branded turbo?

It's your money and you can spend it how you like. But I'm not going to "waste my money" on a fancy box and a brand name unless I know all the facts.

PS; Just to complete the story;

Apexi Turbos are made by IHI

Blitz Turbos are made by KKK

Trust Turbos are made by Mitsubishi

[B-Man]

That's a good result, can you please tell me more? I am really interested in stuff like boost comparison, manifold differences, HKS turbo specs, internal or external wastegate and anything else you can think of.

 

 I am here to learn like everyone else and this sounds interesting.

                                                                               __________________

Hi SK,

Without getting too far OT, (ie the thread was not really about comparing HKS 3040 to a GCG Hybrid)

The GCG turbo I had (I was told) was good for way more than 250 rwkw. The hight level specs follow (don't know the details sorry, and this is a combination of what I saw and what I was told - as stated before, I am not an expert on turbos)

GCG - TO4e front housing 0.70 AR - Garret 3040 core, Bored & ported VG30 rear housing - bigger integral wastgatel and bigger exhaust. The manifold was a GCG tubular mid/low mount. We could not get any more than 250 rwkw out of it.

With everything else the same - just take off the GCG and put on the HKS top mount manifold and HKS3040 (1.12 rear AR) 330 rwkw - no problems. Oh - Trust type R 45 mm eternal wastegate too.

Now I realise that this is probablly not really a fair comparison - as I went from a internal gate to an external gate.

GCG did offer to change the turbine blades as they thought it was the problem - But I didn't have time to do R&D on my turbo and car - so I opted for a known brand and model - I haven't heard of too many un satisfied HKS owners - But when it comes to home grown hybrids and hi flows - you really have to put your trust in the supply chain.

[Steve]

Bman, I think it is a very relevant comparison. One turbo and manifold off, another on. Couldnt be a more even playing field.

SK, just because HKS are made by Garrett, why does that mean they are the same turbo?

As SATO GTS points out, HKS have spent possibly hundreds of thousands of dollars over the years doing R&D, they even do nissan turbo setups for OEM, under contract from Nissan. The end designs they come up with are proprietry for themselves so only they can sell them.

How many car manufacturers do GCG test turbos for? How many years have they been goind R&D into turbo technology, and how much money have they spend on testing different setups?

I bet you wont see one nissan sitting out the back of GCG waiting for different turbo combinations to be fitted for testing. How many unique combinations of turbo/compressor wheel, or original design compressor housing do GCG own?

Comparing a 9second drag strip car is pretty pointless, unless you are talking about building a drag car - ultimately the person who wins at the drag strip is the one with the most money to throw at it - very different ball game to what most of the people on here are looking at, with good street car combinations being the main aim.

But at the end of the day, the results such as Bmans speak for themselves, and are pretty unrefutable.

Here goes the old brand name versus generic name again:)

[SLY33]

I have had two turbos from GCG now and both have not met my expectations.

That's why I have an HKS Turbo now

What is fact is that I had an GCG 3040/VG30 hybrid with GCG manifold and 250 rwkw - Exacty the same setup but swap the turbo and manifold with the HKS manifold and turbo - 330+ rwkw - 300-500 rpm more lag tho. (which is fine with me)

So there you go - could have been anything (pitch of turbine blades included)

Who knows ????

i have nothing against the GCG stuff or aussie turbo combinations, but it does seem that with the HKS stuff you can pretty much just choose tried and tested turbos for different applications that are going to reproduce results that you expect. GCG have been making turbos for ages, but why do ppl still run into problems such as struggling to make expected power, surge, and mismatched wheels and housings?! SK has shown more than once that you can get the results your after as long as you do the RnD necessary to make sure you will get what you want. With the HKS stuff it seems more of a no brainer. I often read about turbos put together with x exh housing and y compressor housing and z trim wheels etc... fine if you know exactly how all that stuff works! but id say for a lot of us choosing a brand name that works out the box with no need to have to pull it off to cut back exhaust wheels etc is a bit of peace of mind at purchase. Then again im not saying thats worth the 2grand or so extra! (actually its not a lot more than a highflow unless you purchase it in australia! Greenline sell HKS 25**for around 2 grand plus delivery, which really isnt much more for a name) Also the brand name itself, i know it means nothing but personally i like the fact that my turbo has HKS stamped on it, and i like the fact that its a jap tuning brand performance part (ignore my turbo smart BOV )

But at the end of the day if it works it works. Id still like to see a highflow and equivalent HKS superimposed dyno runs to see if HKS really does have "power and response"

[mist]

off topic from original thread, but i thought i'd add my 2c to the old brand name vs generic debate.

do any of you know of the 'EAT22B' STi? Circuit monster, uses mostly APEXi stuff as car was built to showcase APEXi gear. Serial number on the APEXi AX53B70 turbo shows that it is the first unit made by APEXi for WRXs. That turbo has endured 4-5 years of constant super sprinting (every 2 weeks for 3 years), running minimum 1.5 bar, street drags, dyno competitions at 1.8 bar, etc... and it is still as good as new today, i kid you not. APEXi has a braidable seal of some sort which ensures perfect sealing, and is probably why the turbo is still perfect. This is apparently unique to APEXi spec turbo, and is not available on the regular IHI turbos or other competitors that use IHI turbos (e.g. Power Enterprise)

[BOOSTD]

I made 266rwkw on standard injectors, fuel reg. No cam. It went bang within six months. Lesson learnt.