HKSGT2530 Results on RB25.

[SLY33]

Hi all,

well its finally done, the turbo was put on last night and morpowa has just finished tuning it.

The car made 230rwkw at 17psi (~1.2bar), in a 32 degree dyno cell.

They tell me that for the ambient temperature, thats pretty good power.

They were also surprised to hear that im running a standard dump pipe!

Specs of the car:

bosch 044 fuel pump

extreme single plate clutch

Hybrid FMIC

Tomei fuel pressure reg with standard injectors

Turbosmart E-boost controller

Power FC

HKS GT2530

Standard cast dump with 3 inch exhaust

I am yet to see the dyno sheets as im still in Sydney, but ill try to post them up this weekend.

Im told it drives awesome, spinning easily all the way through 2nd up to 3rd, whereas with the old turbo and 200rwkw it would only just spin in second if you dumped into it hard. So im pretty happy with the result!

[Steve]

Congrats on a good result, good power for a street car, should come on boost pretty early too.

Thats the same power it (a 2530 turbo) made on a mates RB20 at 1.2 bar.

I didnt notice a huge amount of top end difference with a front/dump pipe done, but boost came in quicker.

Please post up a dyno when you get it.

Cheers

Steve

[Steve]

Oh, and make sure you wind in a bit more boost and see the difference it make on a HKS turbo:D

[VIPERGTSR01]

how much is the HKS GT2530 turbo worth? and is that bolt straight on??

because thats the power i would like to have my R33 at soon (happy with 200-250rwkw)

[EnricoPalazzo]

Hey Sly, congrats on the new power. When u get to finally drive it i would love to hear how ur clutch is handling the power cos when i get my new turbo, ill need a clutch and only want a single plater.

Cheers.

[Sydneykid]

Hi SLY33, a split dump would add about 10 rwkw.

Hi Steve, it good to hear of another with our experience that an RB20 gives the same power as an RB25 when the same stuff is done to it. It happens at higher RPM, but it still happens.

Merry Xmas to all.

[SLY33]

the turbo new is around 4 grand?? i got mine for $1800 with less than 2000kms on it which i was skeptical of until i saw/inspected it.

it is a straight bolt on if you have the correct T3 flange on it. We had to have some braided lines made up but thats it. you also need a 90degree elbow to point the compressor outlet in the right direction, which came with the turbo.

WTF is with the file upload on here? after i click add file, the box goes blank and nothing happens?!

[SLY33]

btw the exact power figure is 227.5kw

Steve, im sure the 9.0:1 comp ratio would love some more boost! Ill prob keep the boost to 1bar unless i need it, i dont know how long it will like running 1.2bar for before something goes! Am i more likely to do the ring lands in? or does it come down to the tune?

[Sydneykid]

Hi Sly33, tuning is very important, you can kill the ring lands at 10 psi with bad tuning or you can safely run 1.5 bar with good tuning. Working on a GTR at the moment that fried the valves, bad tuning = too lean at cruise. It was using 0.5 bar for running in.

Get an A/F ratio print out every time you get the car tuned and be suspicious of any A/F ratios over 12.5 to 1 when under boost. Make sure you get a 75%, 50% and 25% throttle opening graph as well. Plus check the closed loop cruise lambda control.

Hope that helps

[Steve]

Sly, definately give it a go at higher boost. 1.5 bar wont hurt it if, as sydneykid points out, its done with a good tune and a good eye on the AF ratios.

Tilbrook now have laptop for GTS power fc, would definately be worth having a look in.

And a merry christmas to you too sydneykid, and everyone else:)

[Guest INASNT]

nice work!

seen a r34 with 2530 pull abit less power than that at around the same boost!!

does it run out of puff high up?

[SLY33]

im not sure exactly what running out of puff means? do you mean power drop off at the top end? Im yet to drive it, will find out tomorrow.

the dyno chart peaks kinda early in my opinion. It looks like it makes the peak power at 149km/hr, then the power line goes flat?! what gear do they do the run in? It must be 4th as the line goes to 170km/hr?

my old dyno sheet with the stock turbo done at RPM was done in third gear. Does the gear effect the power reading? I would have thought they would all be done in the same gear.

[SLY33]

i have the dyno sheet but i cant attach it to the post! the file attachment box goes blank after i click ADD FILE, then nothing happens... can anyone help?

[Simonster]

Hi Sly33, tuning is very important, you can kill the ring lands at 10 psi with bad tuning or you can safely run 1.5 bar with good tuning.  Working on a GTR at the moment that fried the valves, bad tuning = too lean at cruise.  It was using 0.5 bar for running in.

Get an A/F ratio print out every time you get the car tuned and be suspicious of any A/F ratios over 12.5 to 1 when under boost.  Make sure you get a 75%, 50% and 25% throttle opening graph as well.  Plus check the closed loop cruise lambda control.

Hope that helps

Hi Sydneykid,

I need some educating, what's the purpose of the 75%, 50% and 25% throttle opening graphs?

I've just recived a HKS 3037S with a .73ex for my RB25, running an SM2. Any help is appriciated

[VIPERGTSR01]

most dyno runs are usually done in third i think

[4door_Sleeper]

VIPERGTSR01, whats with the comment - (happy with 200-250rwkw)

I thoght the first rule you need to learn with cars and power is "that you never have enough" :-)

SLY - if you want to run in the turbo up the George - give me a yell, it could be fun :-)

[Steve]

Simonster, dont want to swap your 0.73 for a 0.87 do you?

Sly33, yes running out of puff is when the power drops off at the top.

The peak power will be the same no matter what gear its run in. What will be different is the power before peak will be 'fatter' in a lower gear, as power is a function of torque at rpm. Therefore the mechanical advantage of a lower gear will produce more toque (twisting effort) at lower gears, earlier in the rev range.

End of the day though, dont look at the dyno too closely, as it is an indication of power and how it is delivered - what is important is firstly that the mods make gains and secondly that the car drives better than before. With that turbo, it should be a really nice street turbo with heaps of mid range for that engine. Should be heaps of fun:)

[Steve]

Having said that, I would really like to see the dyno anyhows:)

[benm]

most dyno runs are usually done in third i think

I'd say its actually 4th gear, of all the dyno days ive been to they have all been in 4th (well over 100 cars)

[Sydneykid]

Hi Simonster, you asked "what's the purpose of the 75%, 50% and 25% throttle opening graphs".

It is very rare that an engine will have even (linear) flow characteristics at partial throttle openings, less likely they will be the same as at WOT. How often do you drive your car at WOT? Nowhere near as often as you drive it with partial throttle openings.

This is particularly important on cars with MAP sensor driven ECU's, not such an issue on cars with AFM driven ECU's. But still well worth checking.

It is so much quicker to tune a car only at WOT, after all you would need another 4 power runs to just check the partial throttle A/F ratios. How many more you need to tune it is a factor of how good (experienced) the tuner is.

By asking for partial throttle A/F graphs you are telling the tuner that he has to do it all, not take short cuts. The graphs are proof that he has done a complete job.

Hope that helps

PS; we always tune a car in the 1 to 1 gear, usually 4th. That way we can easily compare the results, if you use different gear ratios you get slight differences which can mask changes after mods are made. If we do something we want to know whether it is better or worse through out the whole RPM range, not just max power at one RPM point.