R34 Gtt Rb25Det Weird Dyno Results

[Lithium]

First of all it appears the Standard Dyno meter interpretation used in NZ is DIN. Using that interpretation, the reading is higher then what it usually would be is in OZ.

The Blue run of 285rwkws had a different name on it, That is not from your car is it?

The power level seems to be ok for the amount of boost given and auto transmission.

+1 with the latter two comments there, though with the top one - there is no standard here, different tuners opt to use SAE/None or DIN - STHitec and STM are a couple of the most respected tuners and both use DIN, a lot of others use SAE which gets a bit higher results. The SAE J1349 you are used to reads higher, by a relatively trivial (read <10kw) amount at this power level.

[hypergear]

There is nothing wrong with DIN or SAE configuration, I'm building VW turbos for few Chinese and European work shops, and their standard dyno meter configuration is in DIN, Many Jap dyno meters uses DIN configurations as well. Americans uses SAE. It is up to how people interpret what a horse power is. Just like the French might have an different opinion on what a Kilo-gram is.

Trent at Chequrered Tuning said the difference between the two is 15%. I can't yet judge that. I will ask Trent to do a run on both configuration on my next tune.

[Soltek2002]

OK so I went back and got a tidy up this afternoon. I didn't manage to get a print out but will do this weekend if I get the chance.

Final result was 254kw at 1.15bar he said this was the best result, with the best curve. And confirming this is with DIN standard.

I believe he's done the best of his abilities with the knowledge he has and the car.

Few Details

Full Boost - 4250rpm at 1.15bar

Top RPM increased to 6800

Limiting factors

The drop in boost pressure while small is due to the boost controller.

The Automatic transmission is eating power and made him tune in 4th*

Something strange was happening in regards to a speed sensor (This may be half my issues) Drives normally when not on dyno though...

ECU - slow to respond and he said it was a limiting factor

Turbo - It wants a lot more boost. (I'll check with the manufacturer of the turbo as the 60-1 series is meant to only be responsive unto 22psi. It does have different wheels on it that may have changed this)

It would have been interesting to change the vct switch point, as the power really picks up at 5500 which is where vct turns off.

You were right about this when vct was turned off at 4750 the power curve straightened out

The Blue run of 285rwkws had a different name on it, That is not from your car is it?

Yes the 285kw is from my car jus the name isn't changed on the sheet. and they pulled back due to the dip and high boost

Edited July 16, 2014 by Soltek2002

[Manuel Kasko]

Few Details

Full Boost - 4250rpm at 1.15bar

ECU - slow to respond and he said it was a limiting factor

Nistune just uses the stock ECU so it shouldn't be a limiting factor, I guess that shows his not confident with the ECU.

There are a few cars here in Aus that are pushing 300+kw using nistune.

[GTSBoy]

One thing to be aware of (and beware of) is that the Neo ECU has a VE map and if you're not familiar with how to tune them they can play merry hell with your attempts to make changes to the fuelling. Especially if you have changed the AFM and/or injectors and so have had to rescale the maps because of changes in K.

[Badgaz]

It would have been interesting to change the vct switch point, as the power really picks up at 5500 which is where vct turns off.

I noticed on the nistune site you posted your tune, can't you look at it and and see what he did with vct? It looks like if the vct was switched off earlier the curve would be nicer.

had a look at the tune map, vtc rpm enable =4700rpm, vtc rpm cut=5500rpm. ....seems weird to me...isn't vtc meant to be on much earlier?

[GTSBoy]

VTC cut and enable are supposed to be set to the same value. In the base maps they are both set to 5400rpm.

it doesn't work the way that most people think. It isn't turned "on" at some rpm and then turned "off" at some other rpm. The trigger to allow it to come on is load based (TP>56) and then it switches off as it passes the cut rpm. The enable rpm is not really looked at by the code (as far as I know). It's just in there as a legacy.

[hypergear]

Ok, for the first dyno run, depending on how much boost used. It looks like an valve floating behavior. Dyno result below represent my R33 skyline with valve bouncing issue. This was at 22psi of boost on an old ATR43G3 turbocharger:

[Ben C34]

had a look at the tune map, vtc rpm enable =4700rpm, vtc rpm cut=5500rpm. ....seems weird to me...isn't vtc meant to be on much earlier?

GTSBoy has nailed the answer.

I have been meaning to ask matt if he can make the 2 tables into one, or at least a check box to tick so both get changed. And perhaps rename it.

As GTSBoy said, it's actually the point vct switches off. They are normally the same value, and when I adjust I adjust both .

I'm not sure what happens when they are different like that, it might affect it turning back on somehow...

[Badgaz]

VTC cut and enable are supposed to be set to the same value. In the base maps they are both set to 5400rpm.

it doesn't work the way that most people think. It isn't turned "on" at some rpm and then turned "off" at some other rpm. The trigger to allow it to come on is load based (TP>56) and then it switches off as it passes the cut rpm. The enable rpm is not really looked at by the code (as far as I know). It's just in there as a legacy.

yeah that makes sense....just no sense to have the enable rpm setting.

might have to read a nistune manual.

[Soltek2002]

Might have a play around with it on Saturday night and make sure they are set to the same value

[Lithium]

Let us know how it goes

There is nothing wrong with DIN or SAE configuration

Trent at Chequrered Tuning said the difference between the two is 15%. I can't yet judge that. I will ask Trent to do a run on both configuration on my next tune.

Yep agreed - they all have different purposes, I get a bit irritated when people call some dyno "inflated" or another one "low reading" - they're just tools and you have to just pay attention to progress on the same car, and can't really compare between dyno setups unless you REALLY know everything is comparable. For what it's worth (I've mentioned this before) I've tried all three correction types a few times on Dynapacks and it absolutely is not 15% different, at least any time I've ever checked it. Tuned a result from an SR which I tuned in the Kando thread and posted up a 250kw @ hub result using SAEJ1349 (like Chequered) correction so it was on an SAU friendly scale for a car I tuned last year, but we have actually filed it for our own reference in DIN - purely because it's what we are used to after using Dynapacks that correction for nearing 15 years now.

[Soltek2002]

Ok, for the first dyno run, depending on how much boost used. It looks like an valve floating behavior. Dyno result below represent my R33 skyline with valve bouncing issue. This was at 22psi of boost on an old ATR43G3 turbocharger:

that does look very similar to the 285kw graph.That run was completed at 1.3 bar of boost. It has Tomei cams in it and the engine has 150k on it. Could it require new valve springs?

[KiwiRS4T]

I would have thought that with higher lift cams you would have put in new or stronger valve springs. Having said that I still think you would get better results (more low down power) with stock cams. Here are my charts (you have to allow for the bigger capacity) but with stock head cams and springs:

[Soltek2002]

The Poncam is a drop in set up that doesn't need different springs. Maybe new springs may have helped but those will have to wait for another day. The other suspect was driveline slip at high power and torque