HKSGT2530 Results on RB25.

[Guest INASNT]

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.  

Steve how did the car go with the 0.87 rear housing

[Turbo Tits]

Here you go Sly.

[Merli]

If you email me the dyno graph, I can throw it up for you...

[email protected]

[Merli]

Here's the dyno sheet:

[Steve]

Very nice power curve, I see what you mean about it dropping slightly at the top. At least you have warning before you hit the rev limiter:)

INASNT, not too well with the exhaust manifold unfortuneately. Just doesnt seem to be enough exh gas velocity to bring the turbo on to boost early enough for my liking. I want to try a smaller housing, as with the 0.61 it hit 1 bar around 3000rpm, now its around 5,000 rpm. I dont think this is the fault of the turbine housing, as they are the recommended size for RB25 by HKS BUT they sell the kits with very short manifold runners, and a progressive collection of the gasses. Mine has long runers and a 6:1 configuration which is where I think the problems start.

Sly, sorry for the whoring:)

[Sydneykid]

That's a nice power band, assuming it doesn't get much below 200 rwkw at 7,250 rpm that's an average from 4,250 to 7,250 rpm of 211 rwkw. Very nice, you gotta be happy with that. I have seen plenty of 260 rwkw cars that don't have a 211 rwkw average over a 3,000 rpm range.

[Guest INASNT]

Steve

I got a 0.82 rear on my turbo.

Will let u know how it goes when it gets tuned finially homefuly on monday

[Simonster]

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.

Thanks for the reply Sydneykid, maybe i'm a little naive but i thought tuners would spend more time tuning at partial openings as like you say, WOT is only one position.

[Simonster]

Simonster' date=' dont want to swap your 0.73 for a 0.87 do you?:DQUOTE']

Hi Steve,

Actually, you are the reason I went for the 0.73 housing as I saw your post a few months ago re: 256kW@1 bar & 1bar by 3500rpm. I thought that was terrific response but in my limited knowlege may become a little "choked" near max rpm so I thought I'd go for the slightly larger ex housing.

I'm getting my manifold made in a few weeks and I definately won't be using long runners ;0 but was going to use 6-1 at the collector- maybe I'll re-think that now?

I didn't use any formulas or logic for going the 0.73, just a stab in the dark. I'm after response down low and more mid range than top end. I've forgotten, are you still using the standard engine?

My engine is a little more than "light tune"

[Steve]

do have a look at my threat on manifold design and turbine housing. I learnt an expensive lesson. The 6:1 collector 'seems' to be causing a bit too much turbulance and slowing down exhaust gas flow.

The japs, like HKS, use 3:2:1 then turbo, which is what I would highly recommend (pictures on the above thread) - alot of R&D, dont try and re-invent the wheel.

Serious, with the right manifold it will be killer.

[MRK25T]

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

Nice!

Ive got a very similar setup. My high boost is set at somewhere between 10 and 11psi where it peaks at 270ish rwhp. I like this turbo a lot better than my high flowed R33 turbo. The car is pure pleasure to drive on even low boost (250ish rwhp @ 7psi)

Quick question, my AFR is very very constant according to my dyno graph but yours seems to be like a dogs breakfast. Is that because you dont have a Z32AFM as I do?

Sorry I cant post my graphs - they are sitting at work and I dont have a scanner.

PS. Merry Christmas and drive sensibly over the Christmas break!

[Steve]

Adding a bit more fuel at peak torque (around 4krpm) is done as a bit of insurance against detonation, AFAIK

[franks]

so sly33, have you driven the car yet?

give us a review!

[Turbo Tits]

yes guys ive driven it, im holding off the review as im hunting down a good split dump pipe, as the stock one is no good for this turbo!

Also we had to change a few boost signal lines to EBC to the correct tubing, as it was all thrown together at last minute- vaccuum hose and not pressure hose was used (that was all that was available in the middle of the night when it was fitted!!) so when it heated up, it swelled, and boost got sent off the dial (over 20psi)- i got a shock when i planted it in third on slightly damp road and nearly lost the back end!

the boost lines are now sorted, but the stock dump is so restrictive, apparently the wastegate is larger than the stock, and the stock dump has bugger all room for it, and you can hear/feel it. It comes on to boost real fast, then as the wastegate opens the exhaust note fully changes, the boost flutters a couple of psi, and you can just tell its not flowing properly.

As it was overboosting ive only been babying it around, and now im waiting for the dump. But it does spool very early and i think it hits 1.2bar in the 3k range, sorry i cant be too specific as yet as ive just been ironing out the bugs!

ill be back when its all done.

[SLY33]

yes guys ive driven it, im holding off the review as im hunting down a good split dump pipe, as the stock one is no good for this turbo!

Also we had to change a few boost signal lines to EBC to the correct tubing, as it was all thrown together at last minute- vaccuum hose and not pressure hose was used (that was all that was available in the middle of the night when it was fitted!!) so when it heated up, it swelled, and boost got sent off the dial (over 20psi)- i got a shock when i planted it in third on slightly damp road and nearly lost the back end!

the boost lines are now sorted, but the stock dump is so restrictive, apparently the wastegate is larger than the stock, and the stock dump has bugger all room for it, and you can hear/feel it. It comes on to boost real fast, then as the wastegate opens the exhaust note fully changes, the boost flutters a couple of psi, and you can just tell its not flowing properly.

As it was overboosting ive only been babying it around, and now im waiting for the dump. But it does spool very early and i think it hits 1.2bar in the 3k range, sorry i cant be too specific as yet as ive just been ironing out the bugs!

ill be back when its all done.

[SLY33]

Brand new HKS split dump pipe ordered, should have it in a couple days.

MRK25T, i have no idea about your AFR question, but it looks similar to my old AFRs, and similar to others ive seen. Maybe its another one for Sydneykid

[SLY33]

MRK25T, i have no idea about your AFR question, but it looks similar to my old AFRs, and similar to others ive seen. Maybe its another one for Sydneykid

[Anquetil]

SLY33, any idea what duty cycle your injectors are now runnning at?

[SLY33]

Dump pipe came in today and is installed.

WHAT A DIFFERENCE!!!!!!!!!!!!!!!!

The car is completely different to drive! Instantly noticable even from when you fire it up, as it seems a bit louder.

Boost comes on smooth and hard and zips to the redline.

The feeling of running out of puff up top is gone! I have only run just over 1bar so far, as im so busy with xmas stuff i dont have time to set up the e boost again, but it wont be long.

It will be back on the dyno asap, and it will be real interesting to see the difference.

Lesson learned: stock dump pipe just doesnt work with an HKS GT series turbo! i tried to get away with it to save some dollars, but it just didnt work. Boost couldnt be accurately controlled and wastegate was fully restricted.

Shane, ill check next time im out as to what duty cycle they are running.

[whatsisname]

Sounds like the car is progressing well Al