GCG or HKS 25** Turbo

[Lepperfish]

270kw at the wheels. or 360hp..

Usual mods. computer,FMIC,exhaust ect...

[Guest Robo's]

Its interesting that people seem to thinkthe injectors are good for 250rwkw.  I can be done, but how many people have been running 250rwkw on stock rb25 injectors and not needed a rebuild?

I really do think if you are trying to skimp on the cost of mods, you will either end up with a dog, or it will only cost you more in the long run. You get what you pay for.  

but hey, its not my car.

So if the motor is tuned properly with good A/F ratios, how can the injectors make you need a rebuild?

[Trust33]

Hi all,when fitting a gcg hi flow 450hp turbo is there any need for an oil cooler @220rwkw?and do injectors run out of puff very often at these power levels?

[Cameron_Datto]

The GCC 450hp Turbo ,, Do you know if they use the STD exhaust housing or a VG30 exhaust housing ... To me it looks like a Standard RB25 exhaust housing and that is why they back cut the turbine wheel ,,, Hmmm any Ideas SydneyKid ??

[Lepperfish]

Trust33 : there are plenty of threads on this topic at the moment,

I do not use an oil cooler, but 1 would planned in the near future.

Injectors are good for about 250rwkw. Maybe more or less depending on other mods to your vehicle, such as fuel pressure regulator, aftermarket fuel pump ect..

Just have a read about..

[Steve]

The injectors dont, the lack of fuel does. I know, there is all this theory around how you can run 250+ rwkw with stock injectors - but how many cars have you seen sustain this and keep their ringlands in one piece. My injectors were at 85% with 200rwkw, right on the edge, tuned with 12:1 af ratios. This was on a warm 35deg C day.

Its not just the AF ratios at the time the car is tuned that needs to be considered - what about temperature change or accel enrichment?

Everyone blames the weak ringlands of the RB25, well I am not the only one with over 300rwkw on stock pistons, the ring lands are not that weak.

but like I said, if you think you can do something no one else can, go for it. I am just putting up a word of caution for those who care to consider it. At the end of the day its not my car. I would just like to see evidence when someone says xxx power with stock injectors is no probs. I think without good evidence, its misleading and could result in a very expensive problem.

knore, you may be running only 14 psi, but that means squat. Power is relative to air flow,which is relative to the amount of fuel needed. 14psi boost can mean anything until you get it on a dyno. two turbos with the same boost pressure on different engines can make different power.

The internet is a great place to find information, I just think its also a great place to be lead up the garden path. It is therefore, for me, very important that I see some sort of evidence before I believe what others say, ESPECIALLY when I have seen alot of evidence that says otherwise.

[SLY33]

the GCG option is easily the simplest, but not the cheapest if your get a 2nd hand hks turbo, but then obviously its not new! So basically i would only consider a 2nd hand turbo if it was very well priced and in excellent condition..

As far as looking stock is concerned, youd have to look pretty damn close to pick an HKS 25** sitting down there instead of the stocker. Put the heat shield back on and your definitly not gonna tell.

from what i hear the stock fuel pump becomes unreliable at 200rwkw and above.

As far as the stock injectors go, ive been running mine flat chat for just over 5000kms with injector duty constantly between 95 and 100%. I have a reg but the tuner didnt bump up the pressure when he tuned it, as it only reached mid 80's on the dyno... Recipe for disaster, maybe!

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?

[Trust33]

Thanks LEPPERFISH so as i understand it to get the most from std injectors a fuel preassure regulator is needed @ arround 180rwkw and upward to 200rwkw.Where then it would be wise to get a fuel pump @200rwkw and up.ive seen the thread and it states that when an injector is pushed to its limits it can not deliver enough fuel into the chamber in some circumstances and cause detonation @ the 220rwkw power level im aiming @.Im keen to know if feeding it injector cleaner regularly enough will combat this problem

[R31Nismoid]

Its interesting that people seem to thinkthe injectors are good for 250rwkw.  I can be done, but how many people have been running 250rwkw on stock rb25 injectors and not needed a rebuild?

I really do think if you are trying to skimp on the cost of mods, you will either end up with a dog, or it will only cost you more in the long run. You get what you pay for.

:werd: I couldnt agree more.

The injectors dont, the lack of fuel does.  I know, there is all this theory around how you can run 250+ rwkw with stock injectors - but how many cars have you seen sustain this and keep their ringlands in one piece.  My injectors were at 85% with 200rwkw, right on the edge, tuned with 12:1 af ratios.  This was on a warm 35deg C day.

Everyone blames the weak ringlands of the RB25, well I am not the only one with over 300rwkw on stock pistons, the ring lands are not that weak.

I am just putting up a word of caution for those who care to consider it.  

The internet is a great place to find information, I just think its also a great place to be lead up the garden path.  It is therefore, for me, very important that I see some sort of evidence before I believe what others say, ESPECIALLY when I have seen alot of evidence that says otherwise.

Double :werd:

My injectors were being pushed at 210rwkw... taking them to 250rwkw is just playing with fire and asking for trouble... and as many here have found, trouble is certainly there waiting for ya.

Dont cut corners, it will only cost you more pain in the end.

We have one on the GTR, one on the GTST and one on the GTT.  But the Stagea is an auto so it gets an SAFC, better than nothing.

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

[franks]

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?

you have 6 injectors and 6 cylinders - it only takes a lean out in 1 injector to f&*^ your engine?

i draw samples from my wrx experiences. the EJ20 block is layed out with 2 horizontally opposed pistons. the fuel rail runs all the way around the block to feed each cylinder. the drawback of this design is quite apparent - the first cylinder on the fuel rail is always rich, the last cylinder can potentially suffer from fuel starvation.

when you start pushing the limits of the EJ20, the A/F ratios don't tell the full story, and this is when wrx owners should be most wary. the chance of fuel starvation on that last cylinder increases dramatically. ask wrx fans which cylinder is most popular to blow its ringland and it will be cylinder #2 - not coincedentally the last cylinder on the fuel rail.

the solution? they split the fuel rail and run fuel rails down both sides of the block with 2 fuel regulators...my point is, a/f ratios might not tell you the whole truth - be wary of the weakest links...

[Trust33]

For a fraction of the cost the 13b 550cc injectors are compatable with the rb25det stock and aftermarket computer.how much is it to fabric8 a fuel rail to suit them?Who does them in sydney? :headspin:

[Lepperfish]

Most people can do it I think.. Yes the 550cc injectors are cheaper and compatable but as someone here said before, the cheaper option isnt always the best option in the long run.

PM SydneyKid, he's quite knowlogable on the subject, and everything else about Skylines. LOL..

[RBVS]

I wouldnt push the stock injectors past 200rwkw mine were in the 90's with a 044 pump at 208rwkw. using a regulator to push them beyond this point may seem like quick fix to get better air fuel ratios but it will force the injectors to give a very poor spray patten. So its not very efficiant in keeping conbustion temps in control but will still give a air fuel ratio that may be the same as if you were to upgrade and this is were people think theres no point in spending the money.

Im also not a big fan of using rotor injectors as they they are said to have unusual spray patterns, but I dont know of any people breking engines like i have herd of many cases with stock injectors reg'd 25's

[Trust33]

if you build it he (rwkw) will come.lol

[rbs13]

i would even up the boost on a rb with out doing fuel pump if you have 90000km.. it could fail.. boom! i would do the support mods - fuel pump, fuel reg, intercooler, exhaust, cams if you wish cam gears if you wish too and after that get your turbo and ecu at the same time and tune.. either that or tune it twice if you buy the ecu early in the mod process.. while you have everything else you mite find out the turbo you were going to buy doesnt make the power you want or have the powerband you want. do it right the first time and reap the benifits later

[MJ]

just a quick question can someone tell me how much the GCG 450hp highflow turbo costs to get done?

[knore]

depends, prices fluctuate i think

bout 1800-2000

[Lepperfish]

I paid 2k but I got a 12psi wastegate actuator spring put in as well..

So I think its about 1800 just for the rebuild..

[lukits01]

The GCC 450hp Turbo ,, Do you know if they use the STD exhaust housing or a VG30 exhaust housing ... To me it looks like a Standard RB25 exhaust housing and that is why they back cut the turbine wheel ,,,  Hmmm any Ideas SydneyKid  ??

Im also interested to know

looks to me they still use the standard compressor and exhaust housing but machined out to take bigger turbine & compressor wheel..

some sort of T04?

[Lepperfish]

You would be correct lukits01..