Hi-Flow Turbo (RB25DET)

[tang0]

presa - not possible to tell if that is from a series 1 or 2, they are identical, could even be from an r34 ... the only markings - 43v2 tells you that its a version 2, although have seen a 96 series 2 with a v4, and an r34 with a v1 ... go figure ...

[Abo Bob]

Not identical. Plastic/nylon compressor wheel on series 2. It's black.

[Reedy]

Most appreciated 4door_Sleeper.

Some of you were mentioning how workshops don't really have many good things to say about the standard hi-flow's.

I spoke to a workshop last week to see what they reckon... The standard hi-flow includes bigger turbine/compressor wheels, however the turbo housing stays the same.

Their point being that you'd be pushing more air into the turbo but with the standard small housing the air wouldn't be able to flow that much quicker.

They also said for the price of a hi-flow you could buy a second hand HKS something rather (forget the numbers they gave me) but that would pull an easy 260rwkw on lowish boost, however then I thought to myself you'd probably need new dump pipe and flanges and a few extras which would build up the price.

Damn its a tough decision =

You can get a HKS GT-RS kit from nengun for $2900 and they go straight on rather than hi flow which I believe is $2150 and you can sell your old turbo which I did for $300 so only about $500 more for a new turbo. Also got 270rwkw with an exhaust cam and pfc at 17psi and there not to laggy.

[Sydneykid]

You can get a HKS GT-RS kit ........they go straight on

I am interested, when you say "go straight on" you mean you didn't have to make or modify anything or buy extra stuff (it was all in the kit)?

The GTRS bolted straight up to the exhaust manifold with no mods?

The standard flange pattern dump pipe bolted straight up to the turbine housing?

The standard compressor inlet pipe clamped over the GTRS compressor snout? Or was there an adaptor in the kit?

The compressor outlet fitted straight up to the intercooler inlet pipework? Or was there an adaptor in the kit?

The standard water inlet and outlet pipes bolted straight on? Or where there replacement ones in the kit?

The standard oil inlet and outlet pipes bolted straight on? Or where there replacement ones in the kit?

[jazza08]

cant just accept anything hehe, i know HKS make kits to suit the engines (sr20 and rb20/25 are common).

How much approx does it cost to rebuild and hi-flow a turbo btw??

[|PRESA|]

I was quoted from GCG $1950 and I have heard nothing but good news from them.

I have a couple local turbo builders around my area and I was quoted $1400 however I don't know what they offer compared to GCG.

Abo Bob - As you said the nylon/plastic compressor wheels is series 2, I guess mine is a series 2 cos thats what it's got.

but i guess with a high flow they replaced all that anyway.

So can someone confirm that a series 2 turbo bolts straight onto a series 1 engine.

And whats the deal with series 1.5, is it a rumour or true? cos a mate of mine has a series 1 and our engine bays are slightly different and the car came with a series 2 wing. However the front is of a series 1 style. =

So my question, does a series 2 turbo bolt on to a series 1.5 or 1?

[Sydneykid]

So my question, does a series 2 turbo bolt on to a series 1.5 or 1?

I have had a Series 1 on a Series 2, I will shortly have a Series 2 on a Stagea, I have a Series 1 on a R32, I had a Series 2 on an R34GTT. The water and oil pipes needed changing on the R32GTST, but nothing on the R33's, R34's or Stagea.

[jazza08]

Im 99% sure there were series 1.5's, these came wit some features of series 2 (things like HICAS etc dont quote me what exactly) and a series 2 wing, but had series 1 interior (nicer seats) and series 1 headlights. My old man has one you see...

Didnt expect turbo hi-flowing to cost $1900.. damn lol

Any R32-R34 turbo will bolt onto any of the other models! Sure some may have small modifications but nothing major

[Cubes]

Do you mind posting the dyno charts & Injector size & injector duty cycle at peak power?

[Cubes]

People seem to quote pretty massive power figures on here, for example an RB20 pulling 200rwkws on its standard turbo, with a fmic and thats more or less it... even though you run out of spark after 13ish psi.....

I think your confused with Skylines Downunder.

[|PRESA|]

I have had a Series 1 on a Series 2, I will shortly have a Series 2 on a Stagea, I have a Series 1 on a R32, I had a Series 2 on an R34GTT.  The water and oil pipes needed changing on the R32GTST, but nothing on the R33's, R34's or Stagea.

Thanks for that info.

I had a look at the nengun website and yeah they said that the HKS GTRS kits bolt straight onto the RB25.. the kit supplies additional oil lines and flanges and stuff. It's only a bit over $2700 delivered and they are garuanteed to hit 250rwkw.

I think I will save my doray for one of these, knowing me I will get the power bug and after running a hi-flow for awhile I'll be wanting more and more

[Reedy]

I am interested, when you say "go straight on" you mean you didn't have to make or modify anything or buy extra stuff (it was all in the kit)?

The GTRS bolted straight up to the exhaust manifold with no mods?

The standard flange pattern dump pipe bolted straight up to the turbine housing?

The standard compressor inlet pipe clamped over the GTRS compressor snout? Or was there an adaptor in the kit?

The compressor outlet fitted straight up to the intercooler inlet pipework?  Or was there an adaptor in the kit?

The standard water inlet and outlet pipes bolted straight on?  Or where there replacement ones in the kit?

The standard oil inlet and outlet pipes bolted straight on? Or where there replacement ones in the kit?

I didn't install it myself but I know I didn't have to buy anything extra fit it and they charge me for having to make or modify anything.

I do remember there was an adapter in the kit which joins the intercooler inlet pipe, also the are oil and water pipes where replaced.

I belive the standard flange pattern dump pipe bolted straight up to the turbine housing and the standard compressor inlet pipe clamped over the GTRS compressor snout but not completely sure about this.

I can try to find the manual or send some pics if you really want to know.

[drewecrome]

Hey i can tell you that your hi-flow will make 250rwkw's with a GCG HI-flow, they are awesome. My car made 217rwkws on 11psi with the following mods, hi-flow, CES dumps, fuel pump, kakimoto exhaust, hi-flow cat, intercooler and pod. If i had a power fc and injectors and say 16psi maybe it would have made 250 easy. Talk to either APC in brissy or even CES in brisbane, or if you want it from the horses mouth so to speak call GCG.

[Reedy]

Hey i can tell you that your hi-flow will make 250rwkw's with a GCG HI-flow, they are awesome.  My car made 217rwkws on 11psi with the following mods, hi-flow, CES dumps, fuel pump, kakimoto exhaust, hi-flow cat, intercooler and pod.  If i had a power fc and injectors and say 16psi maybe it would have made 250 easy.  Talk to either APC in brissy or even CES in brisbane, or if you want it from the horses mouth so to speak call GCG.

How much do these cost?

[benm]

but every tuner i have spoken to has told me to stay clear of them if i wanted any more than about 220rwkw... i guess it depends on who you listen to at the end of the day.  

i would agree with LANFOH that around 220rwkw would be around the mark.

I think the problem is that some people upgrade their turbo on only a half assed job. What I mean is they upgrade their turbo when they are only pushing ~175rwkw from an RB25DET when their is much more left before a larger turbo is needed.

I've read many threads over the last 1-2yrs on here about people with aftermarket $2,000+ HKS turbo's only pushing 210-225rwkw on an RB25DET, that to me is an absolute waste of money, better off spending it on women. They are using an SAFC instead of PowerFC, no exhaust cam gear or cams, still on the std front/dump pipe etc etc and are complaining that a $2-3k turbo upgrade only bumped them to 220rwkw.

If im going to fit an aftermarket turbo I want 50rwkw alone just from that turbo otherwise it's simply not worth it (cost vs power).

I think if you aren't making up around 185-190rwkw on the standard turbo you simply aren't trying hard enough

[paulr33]

I am interested, when you say "go straight on" you mean you didn't have to make or modify anything or buy extra stuff (it was all in the kit)?

The GTRS bolted straight up to the exhaust manifold with no mods?

The standard flange pattern dump pipe bolted straight up to the turbine housing?

The standard compressor inlet pipe clamped over the GTRS compressor snout? Or was there an adaptor in the kit?

The compressor outlet fitted straight up to the intercooler inlet pipework?  Or was there an adaptor in the kit?

The standard water inlet and outlet pipes bolted straight on?  Or where there replacement ones in the kit?

The standard oil inlet and outlet pipes bolted straight on? Or where there replacement ones in the kit?

Hey SK,

Heres what I found about the GTRS kit

"The HKS GT-RS Turbine. This Kit comes with everything for a straight bolt on to the existing Flange. Parts included are the HKS heavy duty actuator, oil lines, gaskets and bolts. Rated at 400 PS 88.3kpa boost pressure." @ nengun

the kit comes with gaskets, elbow, oil and water lines and usual bolts etc.

---------------------------

The GTRS bolted straight up to the exhaust manifold with no mods? incorrrect

The standard flange pattern dump pipe bolted straight up to the turbine housing? correct

The standard compressor inlet pipe clamped over the GTRS compressor snout? Or was there an adaptor in the kit? correct with supplied elbow

The compressor outlet fitted straight up to the intercooler inlet pipework? Or was there an adaptor in the kit? elbow supplied

The standard water inlet and outlet pipes bolted straight on? Or where there replacement ones in the kit? incorrect, need to use supplied lines

The standard oil inlet and outlet pipes bolted straight on? Or where there replacement ones in the kit? incorrect, need to use supplied lines

so if you were to buy a gtrs turbo it wont fit, if you were to buy a gtrs kit then it will. basically gary is pointing out if just buy the gtrs turbo then it wont fit without modification whereas hiflow will. and youll have to factor in extra labour to fit the compressor elbow, water/oil lines etc.

[jazza08]

Dont forget you will have to tune a GTRS alot more than an r33 turbo... you can plug a 33 turbo on and run the car fine from my understanding!

To properly tune a GTRS ull need a new ECU, injectors etc etc

You could get abit more punch from an r33 turbo and keep your system setup as it was before the turbo. Obviously if you want major power go the GTRS and ull need those extras in the end anyway

[paulr33]

well not really. youll still need a tune with hflowed rb25 turbo. youll still need injectors, afm change, ecu change, exhaust etc. heres my config

rb25det

stock turbo

powerfc

stock afm

stock fuel pump

stock injectors

fmic

boost contorller at 0.80bar

3" dump, front, hiflow cat and exhaust

and i am maxing out injectors, afm, clutch and fuel pump

if it fitted a gtrs or hiflow id need to upgrade

afm

clutch

fuel pump

injectors

gtrs should get me to 260rwkw and hiflow to about 240rwkw without tomie cams

[jazza08]

Sorry im not 100% on that one

I thought u were able to use ur current afm/injectors and even ECU with an r33 turbo on an rb20 and it would run fine??? Obviously if u hi-flowed it and cranked boost it u will need to upgrade afm/injectors but at lower boost levels i thought it wud make more power than an rb20 turbo but still run on ur standard ECU?

I know your current dump on ur rb20 engine will bolt straight up to the r33 turbo..

[|PRESA|]

I think the problem is that some people upgrade their turbo on only a half assed job. What I mean is they upgrade their turbo when they are only pushing ~175rwkw from an RB25DET when their is much more left before a larger turbo is needed.  

I've read many threads over the last 1-2yrs on here about people with aftermarket $2,000+ HKS turbo's only pushing 210-225rwkw on an RB25DET, that to me is an absolute waste of money, better off spending it on women. They are using an SAFC instead of PowerFC, no exhaust cam gear or cams, still on the std front/dump pipe etc etc and are complaining that a $2-3k turbo upgrade only bumped them to 220rwkw.

If im going to fit an aftermarket turbo I want 50rwkw alone just from that turbo otherwise it's simply not worth it (cost vs power).

I think if you aren't making up around 185-190rwkw on the standard turbo you simply aren't trying hard enough

I pulled 163rwkw with standard intercooler and standard exhaust (only muffler) boosted at 12psi. Since then I have upgraded to HKS cooler and 3" exhaust all the way, haven't dyno'd it since then so I'm hoping I'll have around 175rwkw at a minimum.

My next big spend will go towards Power FC and large fuel pump and Z32, then I'll think about injector and cams.

Does anyone think my hopes are too high if I aim for 200rwkw with the above mods complete? Or should I take a different approach to my next few mods?

I already have an Exedy Heavy Duty Clutch (fair few K's done on it now) It seems to be working fine.