Gt-rs Vs Gcg High-flow Vs Hks Gt2835 Pro S Vs Gt3071r

[zafeniak]

Hi guys,

I went through the RB25 dyno thread very carefully and found these results:

Basically, I averaged all the power outputs for each turbo and averaged the PSI the person was running.

Here it is:

HKS GT-RS: Cost $2,850 (full kit)

Average output was 243rwkw at 15.5 PSI

HKS GT2835 Pro S: Cost $3,600 (full kit)

Average output was 244rwkw at 15 PSI

GCG Highflow: Cost $1,950

Average output was 230 at 14.5 PSI

Garret GT3071R by GCG: Cost $2,600 (full kit without intake pipe)

Average output was 248rwkw at 15.4 PSI.

Now, I want to achieve around 260rwkw +- 7rwkw, thus, the GCG highlow is automatically out of the picture.

I am beginning to doubt that the GT-RS can make figures of around 260rwkw, unless you push the hell out of it (18 + psi) which wont be too good for the rods at that level of pressure.

I am intending to run 16 PSI and I want to achieve no less than 253 rwkw.

I am supprised how crap the results were for the HKS GT2835 Pro S, I thought most people would be getting around 270 rwkw, considering how much people talk up that turbo.

Anyone had any personal experience with GCG and their GT3071R turbo? any reviews?

I guess it's really a toss between the 2835 Pro S and the GT3071R. Considering the GT3071R is $1,000 cheaper, seems like a pretty good buy?

What do you guys think?

The HKS GT2835 Pro S is such a nice, very well talked about turbo, just the results aren't up their, sooooo disappointing.

There's hardly any difference between the GT-RS and the 2835 Pro S, and people pay an extra $800? soooo not worth it IMO.

[bnr#@]

What you have to remember is that HKS turbos are desighned to give their best at a fair bit more pressure then 15 psi, closer to 22 psi would suit them better and then they would realy start to show what they can do

[zafeniak]

I also forgot to add, the HKS GT2835 Pro S kit comes with a split dump, whereas the GT-RS doesn't I dont think, am I right?

[paulr33]

average power makes a car fast - i would be looking at which turbo has the better average power curve

id say the 2835pros 0.87 on rb25 would have the best average power

[zafeniak]

What you have to remember is that HKS turbos are desighned to give their best at a fair bit more pressure then 15 psi, closer to 22 psi would suit them better and then they would realy start to show what they can do

22 PSI?! Yeh, and watch you standard internals go BOOM in a couple of weeks lol.

Decisions Decisions..... I seriously don't know which one to go for.... I love the HKS turbos, but they are so expensive when you take into account what you are getting.

[zafeniak]

average power makes a car fast - i would be looking at which turbo has the better average power curve

id say the 2835pros 0.87 on rb25 would have the best average power

Maybe so, nonetheless, the 2835 Pro S kit only comes with the 0.68 A/R.

[LouLou]

I think the GCG hi-flow is good for over 250rwkw.

My car made 228.7rwkw on only 12psi at Racepace the other day so im expecting it to make over 250rwkw once i get a good set of injectors and a pump.

Alan.

[zafeniak]

I think the GCG hi-flow is good for over 250rwkw.

My car made 228.7rwkw on only 12psi at Racepace the other day so im expecting it to make over 250rwkw once i get a good set of injectors and a pump.

Alan.

Yes, cars do differ with the same turbo. Don't forget, once the GCG turbo is pushed (16 PSI and above) You will need a stronger diaphram for the wastegate or a stronger spring as you will see alot of wastegate creep.

GCG turbos become VERY inefficient after 16 PSI and are un reliable from what I've read.

More importantly, we are looking at averages here, yes, you do get the occasional turbo that pulls good results such as yours. I also found a GT-RS turbo pulling 300 rwkw. THis is why I am working based on averages.

[180or200]

I think to get a honest 270 rwkw you need to start looking at external gate options, the flappy flap things either spike or creep and anyone getting higher on those turbos is useing a happy dyno or is pulling them selves! IMO.

[Roy]

22 PSI?! Yeh, and watch you standard internals go BOOM in a couple of weeks lol.

Decisions Decisions..... I seriously don't know which one to go for.... I love the HKS turbos, but they are so expensive when you take into account what you are getting.

I think you are best run 17psi and just make sure the tune is on the money. 17psi isnt a lot of boost for a well tuned std engine. Its not boost that you have to keep an eye on. Its rpm, knock and engine temps. Keep those under control and a std RB25 will take a fair bit of boost reliably.

So, that said. I would go the HKS 2835 and give it a sniff more boost

[R33silverS2]

isn't the HKS gtrs about 2200 from nengun not 2800?

[zafeniak]

isn't the HKS gtrs about 2200 from nengun not 2800?

Yes, $2,300.00, not including the $200 delivery, $100 duty fees, and $200 GST (tax).

In otherwords, $2,800.00 delivered to your door.

[R33silverS2]

Yes, $2,300.00, not including the $200 delivery, $100 duty fees, and $200 GST (tax).

In otherwords, $2,800.00 delivered to your door.

Holy cr#p that sucks, didn't realsie it cost so much to get over here.

[wolverine]

IF you get hit for duties and gst.

[PM-R33]

Wow the gtrs went up in price from when i bought it last year, then again thats probably due to the exhange rate. Mine was $2300 delivered to my door from nengun. You wont get hit for tax from nengun, so your looking at about $2500 max.

As said above, its not boost that kills bottom ends, its detonation, overall power output, heat etc, ie most RB25s start getting weak at 270rwkw+ but then again heaps have gone further on a good tune. Its not a SR20 where you have to worry about valve bounce, so pushing 18 or 19psi isn't something you should have to worry about, as long as the tune is good.

Push 18-20psi through a GTRS or a 2835 and you will easily make your power output with supporting mods.

[paulr33]

Maybe so, nonetheless, the 2835 Pro S kit only comes with the 0.68 A/R.

14001-AK001 HKS GT2835 Pro S Spec 56T A/R 0.68 T3 Flange Strong Actuator Attached 100mm Diameter AU $ 2,272.30 AU $ 2,433.84

14001-AK002 HKS GT2835 Pro S Spec 56T A/R 0.87 T3 Flange Strong Actuator Attached 100mm Diameter AU $ 2,272.30 AU $ 2,433.84

14001-AK007 HKS GT2835 Pro S Spec 56T A/R 0.68 T3 Flange Strong Actuator Attached 80mm Diameter AU $ 2,272.30 AU $ 2,433.84

14001-AK008 HKS GT2835 Pro S Spec 56T A/R 0.87 T3 Flange Strong Actuator Attached 80mm Diameter AU $ 2,272.30 AU $ 2,433.84

[Birnie]

When calculating you AVERAGE output for the turbos, there a quite a few dyno figures in that thread (from memory) with peeps switching turbos and posting up results without the thing fully tuned and boosted up...

These results should be dropped from your calulation as they would be dropping your average.

Don't want someone with a 2835 running 12psi on a standard ECU or similar.

So, a GCG/RS/2835 should see you to 250+ with the last 2 going a few higher again.

You just need to find the right results.

[zafeniak]

14001-AK001 HKS GT2835 Pro S Spec 56T A/R 0.68 T3 Flange Strong Actuator Attached 100mm Diameter AU $ 2,272.30 AU $ 2,433.84

14001-AK002 HKS GT2835 Pro S Spec 56T A/R 0.87 T3 Flange Strong Actuator Attached 100mm Diameter AU $ 2,272.30 AU $ 2,433.84

14001-AK007 HKS GT2835 Pro S Spec 56T A/R 0.68 T3 Flange Strong Actuator Attached 80mm Diameter AU $ 2,272.30 AU $ 2,433.84

14001-AK008 HKS GT2835 Pro S Spec 56T A/R 0.87 T3 Flange Strong Actuator Attached 80mm Diameter AU $ 2,272.30 AU $ 2,433.84

The turbo KIT only comes in the 0.68 a/r. Yes, I know you can get the turbo in the 0.87 WITHOUT the kit.

[zafeniak]

When calculating you AVERAGE output for the turbos, there a quite a few dyno figures in that thread (from memory) with peeps switching turbos and posting up results without the thing fully tuned and boosted up...

These results should be dropped from your calulation as they would be dropping your average.

Don't want someone with a 2835 running 12psi on a standard ECU or similar.

So, a GCG/RS/2835 should see you to 250+ with the last 2 going a few higher again.

You just need to find the right results.

Those people have been dropped from my calculations. Moreover, any outliers (such as those people whom managed to obtain 300rwkw+ with a GT-RS) have not been included in my calculation in order to provide an accurate average with a normal distribution (otherwise, we'd have to start using medians).

Thus, the results I posted up remain very accurate. Please, feel free to do them yourself if you think I've left something out.

P.S - GCG going over 250 rwkw was VERY rare. There was only 2 people in my sample of 15 with the GCG turbo that got over 250rwkw and I believe both had aftermarket cams. Furthermore, I did not take into addition any GCG turbos with a VG30 exhaust Housing, only r33 exhaust housings.

[jase-r34]

This is a good thread.....Im pretty new and simple when it comes to all this stuff so Im enjoying the read!

Good research too zafeniak!

I have been looking at the gt-rs kit so will be keeping an eye on what everyone thinks!