Power loss at wheels

[DuncS3]

Does anyone know much about what is meant by power loss at the wheels on a RR?

I ask because Sita has the same car as me, same wheels, same brakes, same spacers and his car shows a 38% loss but mine showed a 51.1% loss?

Dunc [img]images/graemlins/s3addict.gif[/img]

[Riz_RS4]

Could be semi-fault MAF pulling back the power or Flywheel problems? Just a guess.

Riz [img]images/graemlins/s3addict.gif[/img]

[DuncS3]

Not sure about that as the power loss figure at the wheel were different for a few other cars too. CliveDs TTR showed 53% loss (but with good figures) and Simon Elman had 60% loss (his car appeared to be down on power too - 269bhp 323lb/ft)

I had 150 bhp at the wheels

Dunc

[sitas3]

Dunc, for what it is worth, I intend to discuss a few things with AmD next week so I'll get them to explain the measurements in more detail and I'll post this on here for us to all mull through.

Personally i have to say that things need some explanation and clarification regarding these results.

[img]images/graemlins/thumbs.gif[/img]

[kiwi_mtm]

~27 / 28%

How did you get 50% ? Are you calculating RR power down againt factory spec ? If you, you probbaly have a boost leak.

[bjacks]

I had 180BHP at the wheels with a 40% loss through transmition etc.
I'll get the graphs etc scanned this morning and post them up.

[ChelseaMick]

Here's my summary...

[ChelseaMick]

Nice curves!

[ChelseaMick]

[DuncS3]

~27 / 28%

How did you get 50% ? Are you calculating RR power down againt factory spec ? If you, you probbaly have a boost leak.

Thats the thing I dont understand why/how/what this percentage means. Apparently my car wheels are a bit bent and the car was causing a lot of vibration on the RR. I have done some logging on my MAF, Timing and also requested vs actual boost, and there does not appear to be any obvious problem with the car.

Dunc [img]images/graemlins/s3addict.gif[/img]

[bjacks]

Plots.

[sitas3]

hmm bit of a booost spike there Ben... I wonder if that is due to adaptation. Without that spike, it looks like your torque would have been about 270 ish consistently before tailing off.

[bjacks]

Apparently it could be when the wastegate closed. But to be honest I don't have a clue [img]images/graemlins/grin.gif[/img]

[Riz_RS4]

I wonder if that is due to adaptation.

i thought ECU adpation only worked when the engine ECU settings had been altered...... so in theory if you`ve not changed any settings prior to the RR day then no adaption should happen.

Could your spike be a hose on its way out?
MAF could be faulty and wont always show problems..... one of those once in a blue moon problems or under non-common useage, i.e. a RR.

On the road the MAF may be running under optium specifications and ranges.

Sticking DV?

The only other thing it might be is loss of grip on the roller.... tyres?

Riz [img]images/graemlins/s3addict.gif[/img]

[bjacks]

I wonder if that is due to adaptation.

i thought ECU adpation only worked when the engine ECU settings had been altered...... so in theory if you`ve not changed any settings prior to the RR day then no adaption should happen.

-I changed settings on the SPS a moment before it went on.



Could your spike be a hose on its way out? -

- They would have said if a hose was bad, you'd hear it anyway.


MAF could be faulty and wont always show problems..... one of those once in a blue moon problems or under non-common useage, i.e. a RR.

On the road the MAF may be running under optium specifications and ranges.

- Had a new MAF recently.


Sticking DV?

- DV is a good 'un mate.

The only other thing it might be is loss of grip on the roller.... tyres?

- Take more than 260BHP to get wheelspin on those [img]images/graemlins/grin.gif[/img]

Riz [img]images/graemlins/s3addict.gif[/img]

[color="red"] Good ideas all the same [img]images/graemlins/colflash.gif[/img] [color="red"]

Cheers

Ben