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Yeah I ran a crappy track time. Sometime in the new year we (a bunch of us with 300hp+ cars) will be going down to the plex again (when they set they prep it properly) and running a set of slicks. Recently a r33 with a gt2540 and 306hp ran a 12.3 with a 2.0s 60' time on slicks he didnt want to launch too hard, if he had he probably could have gotten into the 11's. So we will re-tune mine for a bit more boost, probably 1.2bar, and head down with the slicks and should run a high 11.

Car looks great Wild Bill. Mick finally got off his butt and finsihed it? How long was it in the shop for?

Twin plate in mine is taking some getting used to.

I get back from Perth on the weekend and plan on driving the Great Ocean Rd next week if your keen to catch up.

Hi grepin, I like it, it has....

270 rwkw at 7,300 rpm

277 rwkw at 6,300 rpm

246 rwkw at 5,300 rpm

210 rwkw at 4,300 rpm

That's an average of 251 rwkw over the useable rpm allowing for gearchanges. There are plenty of cars with over 300 rwkw that don't average 251 rwkw.

I think it would be a nice car to drive, fast and progressive.

BTW guys, notice this dyno run was not in Shoot Out Mode, so no ambient air temperature compensation. If it was a 31 degree day, then on a 19 degree day it's gunna make a smidge over 300 rwkw with an average around 270 rwkw.

Wanna guess what the A/F ratios would be then? In my opinion Mick has done a good job, looks to be both safe and powerful, you don't see that everyday.

As I said at the start, I like it!

Hi grepin, I like it, it has....

270 rwkw at 7,300 rpm

277 rwkw at 6,300 rpm

246 rwkw at 5,300 rpm

210 rwkw at 4,300 rpm

That's an average of 251 rwkw over the useable rpm allowing for gearchanges.  There are plenty of cars with over 300 rwkw that don't average 251 rwkw.

I think it would be a nice car to drive, fast and progressive.

BTW guys, notice this dyno run was not in Shoot Out Mode, so no ambient air temperature compensation.  If it was a 31 degree day, then on a 19 degree day it's gunna make a smidge over 300 rwkw with an average around 270 rwkw.

Wanna guess what the A/F ratios would be then?  In my opinion Mick has done a good job, looks to be both safe and powerful, you don't see that everyday.  

As I said at the start, I like it!

hi sydneykid :)

wouldnt running less boost and evening out the a/f ratios make the same power more efficiently and make the engine last just as long as the way it has currently being setup??

Compared to a standard turbo it has a little lag however not far off the stock. Mainly feel it after gear changes. It is a great setup for driving the hills. The boost is more progressive and maintains good throttle respnse mid corner. I have been in a RB25 with form memory a TD06 20g which had a lot more lag. I love it. Its a joy to drive. Oil cooler and brakes to go and shes nearly where I want it.

I have been upgrading my R33 GTS-T along with Grepin however I have GT30/40 internal gate Garrett hybrid. With conservative tune it has 253rwkW at 1.15 bar, with stock inlet and exh manifold, stock throttle body, stock cams, no cam gears. 550cc injectors, Microtech, FMIC.

I plotted Grepin's, mine and JMS 300rwkW dyno on same chart, interesting results, similar to what Sydneykid was saying about average power over rev range.

I am looking to increase power over rev range with mine, particularly top end, options?

Intresting stuff Freebaggin.

Any chance of getting the results of the HKS2530 that's posted up to that chart?? :(

Here's the link: http://www.skylinesaustralia.com/forums/sh...ead.php?t=30077

It would give a good comparison between the HKS2530 and the HKS2535 Pro :P

J

Hi INASNT, you asked "wouldnt running less boost and evening out the a/f ratios make the same power more efficiently and make the engine last just as long as the way it has currently being setup??"

Ahh no. When you lean it out;

1. the combustion chamber temperature would go up, this means hotter water and oil and a higher propensity to blow a head gasket.

2. detonation would be closer, obviously the higher combustion temperature has more likely hood of causing pre ignition. The main thing though is it is closer to the limit and when you have a very hot day, high humidity, a dirty intercooler (bugs, dirt, dust etc), a slightly bad batch of fuel etc etc you could end up in trouble.

3. the exhaust gas temperature would be higher, this is not good for the turbo.

The only issue with running rich is stripping oil off the bore and resulting premature wear, but that is not even a remote possibility at these A/F ratios.

That leaves less boost? I really can't say whether less boost and leaner mixtures at the same power output would be more reliable when everything is going OK. But what I can say is, that when things aren't perfect, I'd go for richer mixtures every time.

Maybe that's what Mick was aiming at, safety when things aren't perfect. I don't know, maybe ask him directly.

Hope that adds to this interesting thread.

Hi freebaggin, you asked "I am looking to increase power over rev range with mine, particularly top end, options?"

My experience has been that a set of mild camshafts does wonders for an RB25DET all through the rpm range. Even off boost performance is improved and they build boost faster.

My favourites are the Tomei Poncams around 256 to 260 degees, they work a treat with the VVT. Plus they don't need dialling in, their standard timing is spot on, so you save on buying and tuning an adjustable exhaust camshaft pulley.

That aside, your power curve drops off at 6,000 rpm, which is a little low in my experience, it's usually around 6,250 to 6,500 rpm. I would do a quick check of the back pressures, both exhaust and inlet just to make sure there are no weak links there. Once you have eliminated any restrictions, then I'd do the cams.

Hope that helps

Guest INASNT

sydneykid

I was referring to the lesser boost pressure inside the combustion chamber not neading to have so much fuel to cool it down.

I got a GT30 rated at around 600hp in the final stages going on with my internally stock engine. What a/f ratio do u recommend i run for everday driving of around 250rwkw and drag 300rwkw so the engine last a while before i do the internals?

Its very interesting to compare non shootout mode graphs I have ran on a few different dyno's in the last 6 months and the power curve always seems to change a bit could it be how the driver brings on the power? the ball bearing turbo really brings the power on nicely in the early rpm range I plotted mine for interest too I had to use a older power figure/sheet as its the only one I've got that has km/h and not rpm across the bottom and isn't in shoot out mode

comparing the 2 average power levels is interesting too I use a few more rpm though and mine is at 1.35bar as my turbo is non ball bearing and a touch laggier by the looks of it and

7600=324

6600=317

5600=280

4600=205

Average power over my useable rev range 281rwkw

Though I have ran it on shootout mode 03 a few weeks ago by/on an approved dyno dynamic dyno and operator like you WA guys like :P at 1.5bar which slowly bleeds back to 1.35bar due to my wastegate spring I think, it was very different for starters it made 355rwkw I know I made a fair bit more mid power by upping the boost but don't know what difference the shootout mode made is in would it be reading XX higher then on a different dyno on non shootout mode like the first figures I posted

7600=350

6600=353

5600=318

4600=246

which makes an average of 316rwkw the dyno operator tells me would be exactly the same if I was to run in SA,WA or QLD on an approved shootout mode/dyno/operator so maybe they are the only figures we can safely compare?

It really amazes me the differences in the dyno's in Sydney alone I'd hate to think what interstate would be like, Sydneykid how did you transfer the speed points to RPM points to get the average power?

Greppin it is awesome power your making though all through the rev range If I was you I'd be very very happy,its great to see all these RB25's making big useable power no need for a rb25/30 here :(

It really amazes me the differences in the dyno's in Sydney alone I'd hate to think what interstate would be like

Me too.

Why is it so difficult to have the same brand+type dyno's all calibrated the same way to give the same results (obviously air temps, fuel etc would need to be identical) but even ~12% is a massive difference between 2 different dyno's (ie; I got 23rwkw less on a dyno that was done on a ~25c day compared to a dyno done on a ~35c day even after more mods and my car being noticably better to drive).

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