Do you have to strap a car town to get acurate tourque figures etc? As its all to do with somthing about the loading on the rollers a car produces? or is this crap? its only what i have been told, but dont want to go on about it unless its 100% lol

 

Rhys - think most people seem to be concerned about a car being strapped down to stop it going sideways or forwards off the rollers rather than the fact of accurate torque figures (it shouldn't go forwards as the car is stationary and there is no inertia in the car). If a car trys jumping out of the rollers then it obviously isn't an accurate figure - strapping the car down and/or sitting on it would help stop this, so i suppose yes it does. But if the car isn't jumping out anyway then probably doesn't affect it.

Think you might open a can of worms with this one though...

 

They all bollocks, any wheelspin affects figures.

Hub Dyno is the only accurate way with the engine in the car.

Plenty of them around these days tho

 

To produce a Torque figure, the RR needs to have a Resistance factor, decent RR's will have this facility. Strapping a car down to aid the Torque Figure is cheating.

Single Roller RR's are pretty good and don't suffer from much in the way of wheelspin.

With Twin Roller Systems, alot of operators think you must pull the car as hard into the rollers as possible. The problem is that if you do this you will bias it towards one roller or the other (depending on whether the strap goes forward to backward). By doing this it will encourage wheelspin as the wheels will be 'light' on one of the rollers. The Tie-down straps should only really be used to apply gentle pressure to stop the car buggering off sideways and 'just incase' it decides to climb the rollers and make a bid for freedom.

 

So Christain, it shouldnt make any difference if the car is straped down to change the torque figure etc? And its just a saftey precaution?

If so cool, just goes to show what i have been told is crap, as been told by not straping a car down it will try to climb out of the roller thus corruptinf the torque figure.

 

Bollocks...bollox you say!

Well bollox to your comment

I agree in principle with your comment on wheelspin and whilst im not naive enough to belive all figures taken from all rolling roads are 100% accurate, I do realise that there are good and bad rolling roads, some of which eliminate wheelspin completely due to there size of rollers, gearing etc etc.

I appreciate you have yet to experience a proppa rolling road; doesnt excuse your ignorance though

 

Straps just help to keep the car straight, ran one tonight without them no probs

 

I think they call it tractive effort

rhys straps dont effect hp,,,, aslong as the load you place on the rollers is the same for the power ramp up,, and the ramp down loss measuring (so no jumping out of the car before it stops if people are sat in the boot )

 

Ok, put it this way, MOST rolling roads, 99% of the ones youl ever experience in this country, are wank.

There are good accurate ones, but am i fuck driving all the way to AVA

Is the G-Force one good? I know they well over exadurate theri transmission losses

 

Itsmeagain, once the line is on the road i bet you'll razz it upto AVA no probs to get a good shot of it

 

Will i fuck go to AVA! Thatl be 8 hours drive

Il go down to G-Force, about 30mins away from me, really sopshisticated RR that all the big EVOs etc use, and they calculate 4wd tranny loss at somthing craaaaaazy like 27% so il get a huge number

Only thing is they let off after peak power, so cant see how it drives after that, but maye they will if asked nicely