Originally Posted by Mike Rainbird

COMPLETEY DISAGREE, on the road you can not hold the load points very easily. Both an engine and chassis dyno can do this and REPEAT each point and CHECK for any losses or gains.

On the road, how do you know if you have made ANY improvements (unless of course you have "The King's" Arse Dyno ).

In my opinion, the car has to be set up accurately on a dyno (TUV) (chassis or bench) and THEN checked on the road with the correct airflow etc to make sure all is okay (unless of course you have a chassis dyno that can accurately represent the airflow achieved on the road) .