My Bad Boys are here (GTRS Turbo's)

[third]

Who is doing all your work !!!!

[gtr13]

Any more news on these turbos what was the final dyno numbers like? whats the response like down low ?

[OZ GTR35]

Run into the xmas problems, will have it done next week hopefully.

[PurpleR32]

How it going Oz? A lot of people are very anxious as the GT-RS are a much hyped up turbo and are awaiting real world experience in Aus.

Cheers

[OZ GTR35]

Well All, the verdict is in. The GTRS's are a bit big for a standard GTR donk, If I was to do it again, GTSS would be the go. The exhaust hausing on the GTRS is just on the too large side and for the 1.3lt worth of air.

Yesterday I went down to UAS, to get it dynoed and tuned.

Firstly Ben from UAS was fantastic! and I will defiantly get him to tune my apexi again. His attitude to tunning was constructive, conservative and worked with you openly, sharing ideas and experiences. We discussed most changes before doing them and he was always happy to tune as I asked, but always explained clearly why he personally would or would not do it that way. As a bonus I learnt heaps over the time and he knows his sh!t.

In the 4hrs of Dyno time, we set 4 boost setting, tried about 10 different Cam adjustments combo's and played with heaps of fuel and timing maps. Both cruising and cold start runs were completed. The car had a base timing at –5 Deg to start with, so the first job of the day was to get the Apexi reading the same as the timing gun.

Fuel, we played at around 12:1 but then riched it up for safety at about 11.8 to 11.9.

Boost setting on the Apexi, were set at follows.

.7Bar (God knows how, as the GTRS turbo's was suppose to have a 1Bar actuator?)

1Bar

1.2Bar

1.4Bar

At all boost settings we tuned to about 10 knock and at 19psi it was just under 20 knock, which is really safe.

Now for the power figures, remember this is a 2WD Dyno, Im very much looking forward to testing on a 4WD dyno to see what the actual drive train losses are on 4 paws.

Starting Dyno 29 Deg outside temp last night.

236KW, Default apexi with the mods listed in the 4th post.

Today at lunch outside temp was 34 Deg and were settled runs on a hot engine. BP Ultimate, not additives.

10 PSI (.7Bar) (Who cares, this one is only for the missus)

14.5 PSI (1Bar) 250Kw

17 PSI (1.2Bar) 280Kw

19 PSI (1.4Bar) 300Kw

We decided no to go any higher on the boost, and added some fuel and retarded for safety to ensure the engine does not go pop. It’s not worth 10 kW on a dyno graph, if it costs you an engine. We got a peak spike of 330Kw at one stage, which was our highest reading for the day.

The best CAM sprocket settings were at +6 and -6 Deg, the GTRS keep the top end high and the sprockets added about 5-15 KW though the 3000-6000rpm marks. While the peak power only dropped by about 5kw.

My duty cycle topped at about 75% so there is heaps of fuel still in the inj. I could probably put the STD ones back in if I really wanted too.

The bad news? The bad boys are very laggie, I did not hit 1bar of boost until 5000RPM, but then they would sing. Target boost was hit about 6000rpm.

The good news was the dyno graph was unbelievably linear. The thing drives like a STD GTR around the street, and then when you hand the rev's up, you know your not in a STD car. It should suit my day to day driving and keep me happy on the track when I sit around 5-7000 rpm.

The GTR needs to be bought by someone who want to do some serious work to it. Cams, forged oversized pistons, 3lt bottom end. The turbo's are capable of 100+ more kW if the engine was set up to use it.

All in all Im happy and assured of the cars longevity, I will run day to day at 17 PSI so it will be fun.

Again, my praise to Ben from UAS, job well done. And John thanks for looking after me on the price.

I will post up the dyno info once UAS send it to me.

[Guest 570CK]

The bad news? The bad boys are very laggie, I did not hit 1bar of boost until 5000RPM, but then they would sing. Target boost was hit about 6000rpm.

My standard Sr20 spools a GT3540 with GT42 compressor @ 4,500 RPM which is around the same HP rating as 2 GTS-R turbos. If not more. Full boost by 4,700rpm.

A rb26 that spools 2x GTS-R should spool better then my car

[B-Man]

Nice one Oz - Yes Ben knows his shit. Nice guy too ! I'm glad everyting worked out OK - 310rwkw in a noice number too ! Well done !

CHeers,

[Merli]

Interesting results to say the least!

Looks like your results concur with the GTROC UK guys who have had extensive testing on the GT-RS over several cars and found that they are only suitable for 2.8L and up

I'd love to be able to post how my GT-SS turbos go soon, but my mod list keeps growing and now I'm waiting for forged conrods to arrive

It will be another month AT LEAST before my build even starts :crying:

[OZ GTR35]

Merli,

Although your engine will not be standard as is mine, it will be interesting if you push the GTSS to the limits. You never know we may need to swap turbo's????

[Sydneykid]

Hi OZGTR97V, 1 bar at 5,000 rpm would be 4,200 rpm with an RB31. My cams come on a little learlier than that and with 9 to 1 compression ratio, I reckon maybe even 1 bar at 4,000 rpm. A pair of GTRS's have gotta be worth looking at.

[Roy]

Next time i whore a ride around Eastern your likely to scare the pants off me with the new found power...congrats.

Not wanting to start a dyno debate, but what sort of dyno do UAS have (Shootout mode???etc etc)

Yeh, Ben is on the balll, only have to look at his little 1.6L which is probably quicker then most cars on this forum.

[Merli]

Ben's "little 1.6L" has a LOT of thoughtful and ingenious modifications. Open the engine (boot lid? ) and you'll see why it runs so well, with much more to go as well!

Also, new dynodynamics software version was rolled out late last year, and apparently Shootout Mode is the ONLY mode to use now for the most consistent readings with accurate corrections to take into account atmospheric factors. This is apparently what DynoDynamics training staff are telling all their customers (the workshops we goto)...

[Duncan]

excellent result Paul, now we all need to get out to the creek to run them in

[Roy]

Ben's "little 1.6L" has a LOT of thoughtful and ingenious modifications. Open the engine (boot lid? ) and you'll see why it runs so well, with much more to go as well!

Yeh James (Groove Rider Fabrications) does nice work, certainly a well thought out and well built/tuned car.

[fatz]

considering how max boost is hit at 5k they are very liniar

from my ride you wouldnt even think the car was turbo it was that smooth

P

[OZ GTR35]

My Dyno Graphs are in. I made a mistake, the peak was 300 not 310

[Steve]

What size turbine housings are fitted? What sort of exhaust system?

[OZ GTR35]

For everyones info.

.....................Compressor......................Turbine

....................Trim...Inducer....Exducer...Exducer...Inducer....Trim

GT2530..........63____1.860____2.344___1.883____2.098____76

GTRS.............52____1.997____2.773___1.833____2.098____76

GT2835..........52____1.997____2.773___2.020____2.204____84

GT2540..........46____2.016____2.972___1.833____2.098____76

[Steve]

What size turbine housings are fitted? what type of exhaust?

The reason I ask is it appears from your dyno that you arent getting the gas velocity needed to spin the turbos up. the boost response is very gradual, which is very uncharacteristic for HKS GT series turbos, that tend to hit pretty hard when they come on boost.

Few things come to mind, either turbine housings are too big, exhaust is generating too much back pressure, manifold poorly designed, or all three - assuming the tune is OK.

[Emre]

I don't want to offend but i would be fairly disappointed with a graph like that, they don't seem to be any different than the 2540's. 301kw @ 19psi is definitely a good result but that midrange is just hopeless mate.

+6 on the inlet cam timing is certainly quite different, to far advance i would've thought.

Can anyone explain the values on the bottom of the page regarding the shootout settings.