Rolling Road figures

[C3WYT]

well i took the clio for a Rolling road just to see what it was pushing, so just after finding out what over people have got standard and re mapped as i was told standard they get on the rollers is about 165 to 168 is this right.

as i be-leave the last owner re mapped it but not sure what map, and it has a full exhaust, no cat and the 182 manifold

so mine ran 174.4BHP

and at the wheels 143.6BHP

 

[JonC219]

Sounds about right. Mine was 175.1 , 155 ft lbs. With a cat back milltek, ITG panel filter & ktec remap. Jon

 

[Dan519]

depends on the rollers. Unless you use the same rollers all the time for lots of cars it's hard to put specific figures to anything. All you can really do is look at before and after and see what you gain. Seems a pretty reasonable power figure you've been given though

 

[Chris205]

which rollers did you use out of interest?

 

[C3WYT]

cool thanks for the reply so far at leas it looks like the cars running ok looking at doing more thinks for power later on this year

and i went to Evotune in durham they use dyno dynamics rollers.

 

[Westyfield2]

Blow up the tyres and run in a lower gear FTW .

Dynodynamics is twin roller IIRC? The argument is that 2 rollers 'pinching' the wheel can cause additional drag which reduces the WHP figure, but using a coast down this drag can be then included in the transmission loss estimate to produce a more representative Fly figure.
Did they do a proper coastdown or just apply a percentage from a database of transmission losses?

 

[Dan519]

Blow up the tyres and run in a lower gear FTW .

Dynodynamics is twin roller IIRC? The argument is that 2 rollers 'pinching' the wheel can cause additional drag which reduces the WHP figure, but using a coast down this drag can be then included in the transmission loss estimate to produce a more representative Fly figure.
Did they do a proper coastdown or just apply a percentage from a database of transmission losses?

dynodynamics cannot do run down losses. i favour this method myself as it accounts for so much more than a calculated loss and is harder to cheat (tightening straps and forcing thr car onto the front rollers is a technique some use to cheat figures on a DD)

 

[PBCup]

Rollers mean very little imo. My old trophy ran 159 on one and 192 on another.

What's even more interesting is that on the same rollers as the 159 a mate's maped 225 ran 255 and on the one that did the 192 the same 225 ran 243.

 

[Westyfield2]

dynodynamics cannot do run down losses.

So they're just looking up in a database of losses what a previous car made on a bench dyno vs the rolling road? Surely unless you have the same gearing, wheel diameter, tyres and pressures as the base car then this is gonna be pretty inaccurate!

Doing proper coast down losses is soo much better... but TBH as PBCup said, all rolling roads are really good for TBH is comparing your pre-work and post-work figures on the same rolling road - as you can change to a different set of rollers and your shiny new Cams/TBs could show to be putting out less than you got on the first RR!