Which Turbo For Best Response On Stagea Rb25neo?

[pixel8r]

Hi,

I currently have a GT30 hybrid (using standard R34 exhaust housing) on my stagea S2 (everything same as R34).

However its very laggy (max boost around 3500-4000rpm). To cut a long story short, I was recommended this turbo by the workshop that changed it over, and yet many people on this forum warned me against it. The workshop guy said it would give better response than a GCG highflow (GT28 based) and it turns out that the forum was right and he was wrong. Anyway, enough about that...

So i'm looking at options for what to replace it with. I'm hoping to change it over without spending much on it - ie. after I sell the GT30.

My requirements are, I'd prefer a Garrett GT28 something, due to this size being ideal for RB25's if I'm not pushing big numbers.

I want to run around 12-14psi, and I have exhaust, boost controller & safc so this should be enough to keep the same 160awkw I have now, but just with more boost.

1. Does anyone know anything about the GT28R? or any other recommendations around the $1000 mark?

I'd prefer ball bearing and definitely oil & water cooled.

2. Would I be better off keeping the stock (R34 / stagea s2) exhaust housing?

3. Also does anyone know what it would cost to change over the turbo (by taking it to a workshop)?

4. and also what would I get for a 2nd hand GT3071R (just over 12 months old, never been boosted over 12psi, and doesn't get thrashed etc)??

I dont have a large budget, and dont mind going with something that will limit max power a bit. I just want better response around 2400-3000rpm if possible.

[Syphon]

Have a read through this thread to see some dyno results RB25 Dyno Results

Otherwise do a search for HKS GTRS or HKS 2535. Also GCG's highflows. All of these are going to cost over $2000 for the turbo, although you might get the GCG Highflow for just under that.

Most people I imagine are going to recommend the GTRS to you! Awesome turbo and good for 260rwkw plus. Some have managed around 300rwkw on this turbo with supporting mods.

Hard to say costs to do a changeover, depends on what else has been modified. Presume the exhaust will need the flange changed or a different dump pipe, aswell as possibly changing the piping from the afm to turbo.

PS. The GT30 won't even be waking up with such a small amount of boost in it

[pixel8r]

Have a read through this thread to see some dyno results RB25 Dyno Results

Otherwise do a search for HKS GTRS or HKS 2535. Also GCG's highflows. All of these are going to cost over $2000 for the turbo, although you might get the GCG Highflow for just under that.

Most people I imagine are going to recommend the GTRS to you! Awesome turbo and good for 260rwkw plus. Some have managed around 300rwkw on this turbo with supporting mods.

Hard to say costs to do a changeover, depends on what else has been modified. Presume the exhaust will need the flange changed or a different dump pipe, aswell as possibly changing the piping from the afm to turbo.

Ok, say I only want about 200rwkw (approx 180awkw). And is there a turbo cheaper than a GCG that will also bolt up to the standard manifold and exhaust as well as oil & water lines etc? I believe the GT30 needed a minor adaptor to fit but the original exhaust manifold is unchanged.

PS. The GT30 won't even be waking up with such a small amount of boost in it

Yes, I realise that NOW....actually I realised it as soon as the changeover was all done. Would've been nice if the guy who did the work had told me the level of mods required to get the best from this turbo, and the fact that whilst it can handle plenty of boost, the auto gearbox wont last long if I get close to 18psi with this turbo, along with several other parts of the car that would need upgrading. For the amount of work its just not worth doing on a wagon IMO. I thought I was going to be able to get it up to 14psi and have a very fast wagon but in reality it became apparent very quickly that it would just be a lag monster that surged and pulled for only 2000rpm, which isn't really convenient for anything except a higher kw figure on the dyno...certainly not that useful in the real world.

But enough of my complaining. By the time I realised my mistake, all the work had been done and there wasn't much I could do about it. Couldn't afford to do it all over again at the time and probably still cant. The only positive spin I can put on it is that fuel economy is greatly improved...but I'd happily give up a bit of fuel economy for a bit less lag...

It does start to spool ok after around 3000rpm but just doesn't get into its efficiency range so if ever there was a mismatched turbo/setup, this is it.

I'd prefer something that started spooling around 2000-2500rpm and reached 10-12psi around 3200rpm or lower...not sure if thats possible.

If anyone wants a GT30 that has been professionally installed by a turbo specialist (who does have a good reputation for his work on turbos btw), and has never been boosted past 12psi, and for most of its life hasn't been boosted past 10psi...please PM me. I cant sell it immediately, but will be looking to replace it in a few months time. I'm moving to brisbane in January so dont want to change anything on the car before then, and maybe if someone is able and willing to give up a day to come and do a turbo swap (incl fitting and everything) or something, they could walk away with a very good deal.

will post up in the for sale section when the time comes if I dont receive any offers beforehand...details will be going in my sig shortly...

Edited December 16, 2007 by pixel8r

[Dale FZ1]

I'd prefer something that started spooling around 2000-2500rpm and reached 10-12psi around 3200rpm or lower...not sure if thats possible.

Check here: http://www.skylinesaustralia.com/forums/Gt...l&hl=gt2871

This spec is under-rated, mainly because it doesn't aim for huge power. But it achieved 225rwkW for me with ease, and remains a very driveable road-spec turbo. Running a turbotech bleed, it peaks at 14psi delivered @ 2800rpm and tapers to ~ 12.5psi @ 6000. That's probably due to the simple boost control method, and I'd say it would deliver another 5-10kW with an EBC.

I don't think it would do as well with an R34/Stagea spec OP6 turbine housing, as it would take longer to wake up and respond down low. If you've run a GT3071 hybrid, then all the water and oil fittings would be a straight fit onto this GT28 core.

Just another option but for bolt-on ease, the GT-RS is a hard thing to beat. Wolverine is running one on his Stagea from memory, and prior to that had a GCG high flow - so try a PM to him for comment/advice.

[Evil34]

Hey mate you can make 200rwkws on the stock r34 turbo pushing 12psi.

I would try and source a cheap r34 second hand unit and get it rebuilt with steel wheels and hi flowed and you will be able to make the power you want easy.

[Tangles]

Hey mate you can make 200rwkws on the stock r34 turbo pushing 12psi.

I would try and source a cheap r34 second hand unit and get it rebuilt with steel wheels and hi flowed and you will be able to make the power you want easy.

he did that already - turned out as a GT30

[Lukaz]

id be happy to swap you my brand new gcg highflow for your turbo! it was on the car for 2 days and then the bottom end started to go.

[_Ryan_]

i've been reading up on doing a 2871 based highflow for max response, with an aim of 200awkw(limit of cooler, injectors, auto, etc) Spoke to Eastern Turbochargers, and going to look into one of their 450hp highflows as he recon's he can give stock response(unlike GCG) with similar if not more power... more on that once a few other things are taken care of.

A mate of mine is selling a brand new gt28rs T3 for 1400 brand new.

-Ryan

[wolverine]

...or you can buy a HKS GT-RS which is a 2871 based turbo with the 56 trim compressor (smaller trim comp will have lower hp rating like dale's labour of love)

ultimately the GCG unit and the GT-RS are pretty close and hard to beat. there have been many turbo shops that have claimed to make something the same or better but thread after thread we see that the GCG units are well researched, well specced and deliver a good value streetable turbo. the HKS unit i think is superior based on back to back testing but for a slight price premium.

i would love to see a proven result from eastern turbos that achieves what they are claiming. if they can get better response and more ponies they will sell hundreds of them.

[Dale FZ1]

...or you can buy a HKS GT-RS which is a 2871 based turbo with the 56 trim compressor (smaller trim comp will have lower hp rating like dale's labour of love)

Minor correction. GT-RS has a 52 trim compressor, mid-size in the 71mm compressor range.

For my hybrid, the only two options when purchasing a bare cartridge to slot between the housings was 48T and 56T. I went with the smallest size.

[_Ryan_]

I found the GCG to not really be that impressive when as a passenger... Too much lag, I want a GTRS-ish spec'd 2871 in a stock housing.... but would be happy with smaller.

Dale, How much more lag would i expect from the 56T compared to the 48?

-Ryan

[R31Nismoid]

HKS2530 would also be a good choice with a peak of around 220rwkw.

[Lukaz]

I found the GCG to not really be that impressive when as a passenger... Too much lag, I want a GTRS-ish spec'd 2871 in a stock housing.... but would be happy with smaller.

Dale, How much more lag would i expect from the 56T compared to the 48?

-Ryan

I don't understand how you can consider it laggy? Its a ball bearing unit, that would make it more responsive than the stock turbo. I know it was noticibly more responsive on my car.

[silva33]

If you want a cheaper option the HKS 2530 or 2535 would be great..

The 2530 as Ash mentioned would be a pretty punchy streeter being almost constantly ready to boost with your Auto Neo motor.

The 2535 would be my pick, It had only slightly more lag than the stock R33 turbo

[_Ryan_]

...or you can buy a HKS GT-RS which is a 2871 based turbo with the 56 trim compressor (smaller trim comp will have lower hp rating like dale's labour of love)

ultimately the GCG unit and the GT-RS are pretty close and hard to beat. there have been many turbo shops that have claimed to make something the same or better but thread after thread we see that the GCG units are well researched, well specced and deliver a good value streetable turbo. the HKS unit i think is superior based on back to back testing but for a slight price premium.

i would love to see a proven result from eastern turbos that achieves what they are claiming. if they can get better response and more ponies they will sell hundreds of them.

GTRS is detectable, so instant no-no for me. I will be trying out Eastern's highflow, might finnish the brakes on the 1600 first, but will be doing it next year.

GCG just doesnt seem to take off til after 6k rpm...

What is the Garret equivalent to the 2530?

-Ryan

[silva33]

Why not install the heat shield over the GTRS? I did this with my 2535 and you would never know..

I have been in a couple of GCG equiped cars as well and they were quite nice, and similar to the 2535..

[wolverine]

ryan i have back to back dyno tested GT-RS and the GCG unit and there isn't much in it.

if you saw nothing till 6000 rpm then this is an issue that is specific to that car, either tuning, exhaust or other supporting gear.

standard heatshield can be modified to fit exactly as described on a GT-RS.

[benl1981]

wolverine. I've got a GCG with an R34 rear housing on an R33gtst. Havent had a tune yet (running very rich). I get about 14psi by about 3500rpm in 4th. In 2nd though it is more like 4200rpm!

Hopefully with a tune it will bring it down a bit. Is that the sort of lag you had with your GCG? Is the GTRs much less laggy. Should have maybe stuck with the R33 rear housing..not swapping it now though!

1st gear sees a definite lunge as boost comes on. Feels a bit delayed if you pull out with your foot planted.

Slightly off topic but relevant in regards to boost build etc. If you only want 200rwkw stick with the stocker or HKS 2530

Edited December 18, 2007 by benl1981

[_Ryan_]

ryan i have back to back dyno tested GT-RS and the GCG unit and there isn't much in it.

if you saw nothing till 6000 rpm then this is an issue that is specific to that car, either tuning, exhaust or other supporting gear.

standard heatshield can be modified to fit exactly as described on a GT-RS.

Could you please post that graph? very interested.

Cheers

-Ryan

[wolverine]

i'm not sure if i have them lying around if i can find them i will post them.

remember GCG will be using similar stuff from the garret parts bin.

ben check the pre-load on the actuator, i reckon it should be making that boost closer to 3000rpm.