RR Day Spoolup Time
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No it shouldn't because you won't actually see the way the turbo can perform on the road.
Because the loading of the rollers is bound to be different to the loadings on the road, the turbo can be made to produce good spool up by upping the loading of the rollers as the car is coming on boost.
Andy
Because the loading of the rollers is bound to be different to the loadings on the road, the turbo can be made to produce good spool up by upping the loading of the rollers as the car is coming on boost.
Andy
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18,129 Posts
Yes, of course it can be distorted by thte operator due to the way in which the r/road works.
All you have to do is alter the loading of the rollers in a gear to give a really high load on the engine and the turbo will spool up quickly. Put a lighter loading on the engine and it won't spool up as quick.
However, as all the cars are generally tested on the same day using the same settings on the rollers then you would be able to see the differences just from looking at a boost curve rather than needing to plot the spool up time, provided that everyone was running the same boost levels.
Andy
All you have to do is alter the loading of the rollers in a gear to give a really high load on the engine and the turbo will spool up quickly. Put a lighter loading on the engine and it won't spool up as quick.
However, as all the cars are generally tested on the same day using the same settings on the rollers then you would be able to see the differences just from looking at a boost curve rather than needing to plot the spool up time, provided that everyone was running the same boost levels.
Andy
This in away opens a can of wormsAndyF_RSX said:
To demonstrate that the loading is the same for everyone, is there a value that can be plotted and is hopefully similar to on the road value the will demonstrate all graphs are equal
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2,646 Posts
Rolling roads are not like actual roads anyway, since the engine does not have to push the entire car forwards, it only has to rotate the wheels.
Without an accurate model of air resistance at speed, coupled with the vehicle gross weight, the only thing you are measuring is how hard an engine turns the wheels in 4th gear against a set resistance.
I'm still going along to the Silverstone day, just to see how my atw figures compare to the calculated atw figures using Mitsi's nominal ATF figures for the standard car
(I'm expecting around 220ftlb and 210bhp at the wheels, give or take)
Without an accurate model of air resistance at speed, coupled with the vehicle gross weight, the only thing you are measuring is how hard an engine turns the wheels in 4th gear against a set resistance.
I'm still going along to the Silverstone day, just to see how my atw figures compare to the calculated atw figures using Mitsi's nominal ATF figures for the standard car
(I'm expecting around 220ftlb and 210bhp at the wheels, give or take)
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