OcUK Rolling Road 9: Photos + Graphs

you need to fix a boo boo there.. ;)

This coast down is also the same reason why the power at the WHEEL figure is inaccurate.
 
nokinidea said:
have ninja edited my last post ;)
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oh thats alright then. Thats my dyslexia revealing itself rather than me understanding it wrong.

I edit loads of my posts, as i read them afterwards and ive written something completely different (in word perfect english) to what ive thought when typing.
 
rrday031.jpg


:D
 
I have run 5 different cars on Power stations rollers, all but one have been stock, and they have all come out within 3% of stock manufacturers figures. I think I'll trust and listen to the pro's rather than crying about something I don't understand.
 
well stock power for mine is either 276.1 or 276.3 depending on how you calculate 280 PS in bhp.

But suffice to say, 276.5bhp seems pretty much spot on to me :)
 
If your a 'Pro Tuner' you dont really care about what the figures are, all your care about is wether what you have fiddled with has pushed the numbers up or down.

Roaling roads are used proffessionally to measure performance increases and decreases, not to try to determine the BHP to within 0.1...

Its a different group of people who will argue about differing RR acuracy to try to say their car is better than others. There usually found in McDonald carparks...
 
The_One said:
No your missing the point all a rolling road does is measure WHEEL power.
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Its actually measures tractive effort it applies the rollers, it doesnt actually measure anything on the car. For that to happen the rollers would have to get to some sort of equillibrium, ie steady state with no acceleration. If the rollers ever applied the same resistance as the wheel effort the car would stop accelerating...
 
Jonnycoupe said:
Its actually measures tractive effort it applies the rollers, it doesnt actually measure anything on the car. For that to happen the rollers would have to get to some sort of equillibrium, ie steady state with no acceleration. If the rollers ever applied the same resistance as the wheel effort the car would stop accelerating...
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It can actually do that but I've never used that option.
It's called "discrete measurement"
Basically it allows the car to accelerate a little, applies the eddy current brake,then measures how much force it needs to apply to hold the car steady and then releases it until the next designated rpm point and repeats the process. 2000 rpm hold... 2500 rpm hold... 3000 rpm hold etc etc
Highly accurate but your engine will have likely melted by the time it got to 8000 rpm :D

If your tyres are sticky enough it is rated to hold 720bhp (through four rollers) at steady state. That's some ****ing force. :eek:

A similar function is also used when creating unknown "basemaps".. Tell the dyno to hold the car at a specific rpm point so where ever you put the throttle it stays put. This allows you to "map" individual cells in the ECU's load zones. Fantastic bit of kit to use when you know how. :)
 
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Yeah and there will be no time for tea and cakes at the pub either. :p

I know it can do a proper load hold mode as that how you would do some ignition timing tweaking but for you generaly power run people rarely consider that its an always acceleration system so its very much grabbing data rather than measuring it.
 
nokinidea said:
It can actually do that but I've never used that option.
It's called "discrete measurement"
Basically it allows the car to accelerate a little, applies the eddy current brake,then measures how much force it needs to apply to hold the car steady and then releases it until the next designated rpm point and repeats the process. 2000 rpm hold... 2500 rpm hold... 3000 rpm hold etc etc
Highly accurate but your engine will have likely melted by the time it got to 8000 rpm :D

If your tyres are sticky enough it is rated to hold 720bhp (through four rollers) at steady state. That's some ****ing force. :eek:

A similar function is also used when creating unknown "basemaps".. Tell the dyno to hold the car at a specific rpm point so where ever you put the throttle it stays put. This allows you to "map" individual cells in the ECU's load zones. Fantastic bit of kit to use when you know how. :)
Click to expand...

isnt that similar to how dastek dynos work ?

ive noticed the dastek ones have very definite points on the graph, wheras maha , dyno dynamics etc.. just have a curve.
 
Soon as in I dont go to bed just yet, or soon as it... before the next RR?

Come on Midget boy, be more accurate... :)

Oh and thanks for going to the effort of recorded, editting and uploading them. :)
 
rofl, midget boy :eek:

The video is on my computer, just cutting and editing it into seperate clips. I'd say about 40 minutes.

No probs btw :)
 
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