Hks Gt2835 Pro S

[woolls]

I had a hks gt2530, 3inch system, high flow cat, split dump front pipe, ebc, power fc, pod. With this set up, it was making 212rwkw @15psi. I wanted to get up around the 270rwkw mark. So I did plenty of reading and decided going with a New hks gt2835 pro s bolt on kit.

My new mods are, gt2835 pro s, 550cc injectors, z32 afm, evc V ebc, 040 fuel pump, and i put a set of slitfire coils in just for good measures.

I thought I might get around 250 rwkw as here in tassie we have only got 95 ron pulp. But when i went to pick my car up and was told it made 222rwkw @15psi, 198rwkw @12psi, wtf! i was so pi$$ed off. just spent 5+ grand to get a 10rwkw increase. My tuner said its because we have shit fuel down here. Would 3 ron make that much difference? Anybody got any ideas why it would only make this amount of power?

thanks

Edited May 2, 2006 by woolls

[infected flow]

I had a hks gt2530, 3inch system, high flow cat, split dump front pipe, ebc, power fc, pod. With this set up, it was making 212rwkw @15psi. I wanted to get up around the 270rwkw mark. So I did plenty of reading and decided going with a New hks gt2835 pro s bolt on kit.

My new mods are, gt2835 pro s, 550cc injectors, z32 afm, evc V ebc, 040 fuel pump, and i put a set of slitfire coils in just for good measures.

I thought I might get around 250 rwkw as here in tassie we have only got 95 ron pulp. But when i went to pick my car up and was told it made 222rwkw @15psi, 198rwkw @12psi, wtf! i was so pi$$ed off. just spent 5+ grand to get a 10rwkw increase. My tuner said its because we have shit fuel down here. Would 3 ron make that much difference? Anybody got any ideas why it would only make this amount of power?

thanks

post ya dyno graph up that will give us something to start with....

[paulr33]

a few suggestions;

1) try a tune/run with premium fuel (or make some up)

2) try a tune/run with the exhaust dropped off

95ron fuel is likely to affect it quiet a lot as it will knock significantly more, which is why the power figure is much lower.

[grepin]

I had a hks gt2530, 3inch system, high flow cat, split dump front pipe, ebc, power fc, pod. With this set up, it was making 212rwkw @15psi. I wanted to get up around the 270rwkw mark. So I did plenty of reading and decided going with a New hks gt2835 pro s bolt on kit.

My new mods are, gt2835 pro s, 550cc injectors, z32 afm, evc V ebc, 040 fuel pump, and i put a set of slitfire coils in just for good measures.

I thought I might get around 250 rwkw as here in tassie we have only got 95 ron pulp. But when i went to pick my car up and was told it made 222rwkw @15psi, 198rwkw @12psi, wtf! i was so pi$$ed off. just spent 5+ grand to get a 10rwkw increase. My tuner said its because we have shit fuel down here. Would 3 ron make that much difference? Anybody got any ideas why it would only make this amount of power?

thanks

Take it to 20 psi. The turbo can take it. I have the same turbo. I have made 310rwkw all be it with head work, greddy plenum and exhaust manifold. This could be worth 30rwkw extra so yours should reach at least 270rwkw. You may need some octane boost as we have 98 RON. Run 12 AFR and maybe 15 deg base timing or a little more conservative if your worried and slowly lean on it. Keep an eye on detonation etc. 250rwkw should be easily achievable.

[R31Nismoid]

Yes, the turbo can take it.

No, the fuel being used cant

I wouldnt be using octane booster all the time though, its just a band-aid

If your going to run on 95, then thats about as good as its going to get im afraid.

You might be able to get a couple more kw but your tuner is obviously taking the smart approach

I know some other tassie guys get drums of Ultimate shipped down... one assumes they still do, maybe you should do the same?

[muaythailuke]

This might be a stupid question but was the previous 212kw made on the same dyno as the 222kw run? Different dynos different numbers

Im in tassie also and have a 3037proS and I made 270kw at 1bar with similar mods so with the smaller 2835proS 220-230kw at 15psi would sound about right, I would think, with the shitty fuel you get down here.

I looked at shipping a higher octane fuel down in 205 drums but to make it cost affective youd have to buy 2-4 drums of the stuff, have you got 2 grad to spend on fuel? but there is a place down the coast you can get even higher octane fuel from for not much more if you wanna get pretty serious, so.... If I were you id be waiting for another 6-12 months untill we get 98ron at the pump.

[woolls]

This might be a stupid question but was the previous 212kw made on the same dyno as the 222kw run? Different dynos different numbers

Yes same dyno.

thanks for the replies. Looks like I will just wait till we get som 98 ron pulp.

[JaFF]

spewing, I take it you've already sold your 2530?

[woolls]

spewing, I take it you've already sold your 2530?

yea mate, spewing,

Still got the 2530, going to hang on to it for a while.

[bigcarl]

definately need 98ron fuel.

[discopotato03]

If detonation is the issue can you run lower viscosity oils and lower coolant temps ? Can we assume your car has a cold air intake and filtration system thats up to the task .

I would also be doing the exhaust manifold vs boost pressure test as this will show up any higher exhaust system pressures . Not all 3" systems or cats are created equal .

You could also do a pressure test at the inlet manifold to see if theres any loss of pressure between here and the compressor outlet that would indicate a restriction or a leak .

I would be wanting to know what the air/fuel ratios are under boost as well because filthy rich mixtures can create detonation issues and cost power .

Cheers A .

[woolls]

If detonation is the issue can you run lower viscosity oils and lower coolant temps ? Can we assume your car has a cold air intake and filtration system thats up to the task .

I would also be doing the exhaust manifold vs boost pressure test as this will show up any higher exhaust system pressures . Not all 3" systems or cats are created equal .

You could also do a pressure test at the inlet manifold to see if theres any loss of pressure between here and the compressor outlet that would indicate a restriction or a leak .

I would be wanting to know what the air/fuel ratios are under boost as well because filthy rich mixtures can create detonation issues and cost power .

Cheers A .

Thanks for the info disco, not sure what the afr are, not on the dyno print out.

No cold air intake, just pod.

i use 4100 motul oil and water temps about 75 (I think, have to look at that)

will try the preasure tests

thanks again

Leigh

[Busky2k]

Lower viscosity oils have nothing to do with detonation at all really... Coolant temps might but at the end of the day its a real bandaid fix via a cooler thermostat.

I'd be using a borescope and sussing out the amount of carbon you have on the piston tops etc. Excessive deposits can raise the compression, leading to pinging. Old pinging cars are a testament to this.

Then again another 3 RON increase to 98 wont give you another 50rwkw either. Hmmm...

[whatsisname]

Did you select a maximum of 15psi due to detonation above this boost level? Or did you select this boost level with engine reliability in mind?

If it's the latter, then I'm with Grepin. I would be looking at running a little more than 15psi with the HKS GT2835 ProS. The addition of another 3-5psi will produce a significant increase in power.

As for the Tassie RON issue: When my Dad had his 2dr STI he always added 8L of toluene per tank (bought 20L drums from Shell). This was an approved and recommended practice by Subaru and Performance Automobiles - Hobart's main Subaru dealer. This is probably the best (cheapest and least destructive) option until 98RON is available.

I would very much doubt coolant temp' related detonation was a major (or minor for that matter) factor - we're talking Tassie in May, it ain't that warm! I've just come back from surfing at Seven Mile Point (near Hobart airport) and my 'nads' are yet to venture back outside my body.

At your current level of modifications I would expect ~250-260rwkw with a safe 95RON (+toluene) tune and 18-20psi boost pressure.

Edited May 4, 2006 by whatsisname

[discopotato03]

There is a train of thought getting about that lower cylinder head water jacket temps give lower combustion chamber temps so a little less heat conducted to the charge air before (and after) the plug fires to help prevent the end gasses from auto igniting .

My experience with low coolant temps was also lower running oil temperature and more drag - this was using good 20W50 mineral oils . So because the 20W50 runs cooler I use a 10W40 now in winter and the very low tech (Charade 2V G11) carby/points engine won't ping at all .

With cooling systems , if they operate as the manufacturer intended , water temperature is regulated by the thermostat so low ambient temperature such as Tassie winter should not change this . I agree with Corky when he says if there is one major issue that is the stumbling point with high performance engines its the thermal one . To use all the advantages I would be looking for the coolest air to feed the system which helps charge density and detonation resistance . I don't think the lower (not necessarily lowest) viscosity oils are an issue provided they don't get too hot and cause low pressure dramas - which are easily solved with oil coolers .

At the end of the day if you can get a few more degrees of full boost timing it can give good returns . The only disadvantage is lower heater performance but if its zero outside it should still prevent second belly button syndrome ...

Food for thought cheers A .

[Bass Junky]

Yeah, what Paul said also.

Drop the exhaust, try a run.

Also, I remember a guy who had an Apexi RS6 (or whatever those turbos are called) and he got to a point where hois exhaust manifold and dump assembly was holding him back.

He changed manifold and dump system and picked up 40kw.

Discopotato hinted to this also with the exhaust manifold pressure test.....

Might be something to think about.

[gtst25]

I've got he 2835 pro s and 255 rwkw.

I'm with Grepin as well - I say more boost - I've had mine to 22 psi and it's normally around 19-20 no problems.

Also I'm fitting a water methanol kit at the end of the year - will be interesting to see how it all goes.

Cheers