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Power loss at wheels
Posted: Sun Nov 23, 2003 2:02 pm
by 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]
Re: Power loss at wheels
Posted: Sun Nov 23, 2003 2:05 pm
by Riz_RS4
Could be semi-fault MAF pulling back the power or Flywheel problems? Just a guess.
Riz [img]images/graemlins/s3addict.gif[/img]
Re: Power loss at wheels
Posted: Sun Nov 23, 2003 2:33 pm
by 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
Re: Power loss at wheels
Posted: Sun Nov 23, 2003 3:38 pm
by 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]
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 5:39 am
by 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.
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 9:40 am
by 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.
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 10:53 am
by ChelseaMick
Here's my summary...
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 10:56 am
by ChelseaMick
Nice curves!
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 10:57 am
by ChelseaMick
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 11:18 am
by 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]
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 4:42 pm
by bjacks
Plots.
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 7:59 pm
by 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.
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 9:12 pm
by 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]
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 9:18 pm
by 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]
Re: Power loss at wheels
Posted: Mon Nov 24, 2003 9:27 pm
by 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
