Skyline 300Gt 83.5Kw At The Wheels Wtf?!?

[Soltek2002]

Hi All

was at a Skylinesdownunder Dyno day here in Auckland this weekend and thought I'd throw the car on the dyno just to see what it was made of. After 3 runs the most the tuner was able to get out of it was 83.5KW which I was shocked at.

So a bit about the car

2001 V35 Skyline 300GT

VQ30DD Engine

5 SPD Auto

170k on the clock

Running 95 Octane (Its my daily and lives in traffic)

Has an O2 sensor issue but we cleared the ECU first.

The tuner said Run 98, new intake, full exhaust and a Trans Flush I might break 110kw

The engine standard is 185kw (at the fly) I'm just trying to find out where my other 100kw ran off to

Any ideas?

Dyno Sheet

[Seano350GT]

Sheeeeeet.

[Soltek2002]

Sheeeeeet.

Yup thats what I thought considering a RB20DE got 93kw :S

[PN-Mad]

Lol. Forget it. Doesn't even look like a good representation of an engines power band.

My guess is that the thing was set up really wrong for your car, or something else weird. If you can be stuffed, go and get another power run and get them to set it up right. It's not the power figure thats all that wrong, but the rpms look sus too, max power at 4400 rpm? Don't think so.

I would expect 110-120rwkw from a healthy motor on a normal dyno.

[Soltek2002]

yeah it looked weird to me too.

I'll be doing a few things to the car before I put it back on the dyno but if thats actually what my engine is currently putting out I'd be wondering where all my horses went

has anyone on here with a 300GT been on a dyno?

[Seano350GT]

Think your horses have galloped away out of the engine. But yeah that dyno isn't correct nor is the RPM.

[Soltek2002]

So basically dyno was set up wrong for the engine....

Sigh $90 wasted haha

[PN-Mad]

The flywheel power does not equal what a dyno will read. Ok?

The reason for this is that only part of the power makes it through the whole drivetrain, other power is used up turning the auto gearbox, turning the diff, wheel bearings, and lost in friction between the rollers and your tyres.

Therefore, use a dyno as a comparative tool. Once you do mods, you can see an improvement or loss. If you put the car on 5 different dynos, you'll most likely get 5 different figures.

[Soltek2002]

Oh I totally understand that a dyno will never read flywheel power due to the loss of power through the drivetrain.

Its just the amount of loss was unexpected possibly due to a trans issue or the idea the the hub dyno was set up incorrectly.

The dyno sheet itself seems to read strangely as well but that could just be me.

I'll redo the dyno after I have done the recommended changes by the tuner and see what comes of it

A guy on SDU mentioned it could be a case of the timing chain actually stretching and that this was a common fault on the VQ25DD and the VQ30DD. Has anyone here had that issue?

[PN-Mad]

What gear was it done in? if it was 4th then you'd be in the speed limiter I think. Should be done in 3rd so you can use all the rev range. Hub dyno = less loss = higher figure than a roller.

If your going down the path of mods, there is no point on the basis of this dyno graph. Get it done properly, by someone who knows what they are doing/ can dyno a auto car. Otherwise you might as well squiggle lines on a page.

Re cam chain, I believe there is a self tensioner in there. It's not a service item, if it has stretched it'll skip a few teeth and destroy your motor. Don't think it's going to be that mate. Doesn't lead to a loss of power, just catastrophic failure like a cam belt.

Go back to the place and ask for another dyno set up properly, at a discounted rate. I mean it even says 4wd vehicle at the top of the page ffs.

[Soltek2002]

Cheers I think I'll try a different tuner as although the tuner who ran this dyno is highly respected in his field it might be time to try another.

I think he did the dyno in 1st and 2nd due to it being an auto.

[interfooler]

1056 Nm of torque??

[Soltek2002]

divide by the ratio on the print out to get actual toque at the wheels (that's what I was told)

sooo err 223nm of torque

[scotty nm35]

A guy on SDU mentioned it could be a case of the timing chain actually stretching and that this was a common fault on the VQ25DD and the VQ30DD. Has anyone here had that issue?

If your chain has stretched or the tensioner has failed your engine will have the death rattles. It wont change power output though.

Why are you so hung up on the figure? Dyno outputs are so easy to fudge it's a joke. Be happy it's all running smooth and gets you around, it will never be a race car.

[Soltek2002]

If your chain has stretched or the tensioner has failed your engine will have the death rattles. It wont change power output though.

Death rattles?, would this sound like a misfire and would it be constant or intermittent?

Why are you so hung up on the figure? Dyno outputs are so easy to fudge it's a joke. Be happy it's all running smooth and gets you around, it will never be a race car.

Oh I'm aware it will never be a race car but I'd like a base figure as I do plan on doing some basic mods as mentioned earlier in the thread.

If the base figure isn't a true reading then as mentioned by PN-Mad "You might as well be looking at squiggly lines on a page".

Its unusual here to do anything to a V35 or Stagea so I want to be different and I'm sure you can understand that as your build on a Stagea is amazing and but also very thinking outside the box.

Cheers

[Blade NZ]

Hey Dion! Here's what we need to do! Meet up for a comparo. Find a 'private road' and line up for a test!!

My 300 stag feels plenty healthy so it should give you a reasonable benchmark. It's well serviced by City Nissan Takapuna and goes better than the SV6 I had before. If it's close then your ok. They probably weight about the same...haven't checked lately but I think mine's about 1550kg. You should have a slight edge if all is well.

[Blade NZ]

So I went and checked the weight...1589kg. I was close .

[Soltek2002]

Hey Mike

That sounds like a good idea. If you want you can take mine for a spin and see how you think it compares

Send me PM with your contact details and we'll sort something out

[StealthX]

I can't believe no ones mentioned that f**ked up torque curve, or slope i should say... max torque right at the start of the run?

Dyno is definitely set up wrong.

its probably more accurate to take your car to the drag strip, have 3-5 runs, get an average ET and trap speed then use a few equations to estimate power, rather than comparing dyno figures. You may not know exactly how much power your car makes, but you will know how fast it is

[NISMO-61]

that's totally wrong mate. I do have the same car 2001 300GT, and they do a lot better than that. Well it might be 185 rather than 85kw. When I went to Tasmania, I gave it a go and the car hit 180km/h and it was like driving at 100km/h. It was still speeding up. So what i'm trying to say is, this car with this engine and the design would do way better than that.

Ask them to do it again (for free) and do it appropriately.