Here we go again LOL.

Both mine (171mph 350bhp CVH) and Gary's (700bhp Evo) are mapped 100% on the Rolling Road. Ross W's Evo was mapped 100% on the Rolling Road too, that made 775bhp and won the MLR 30-130 event this year. Also, Ken's LS2 V8 200SX, which made 665bhp (65bhp above the 'bullshit' American figure we never expected to hit!!) a few weeks ago was mapped totally on the Rollers too. Very few of our cars have any road mapping atall.

You cannot effectively map big power cars on the road, it's always a comprimised map. Whereas on the Dyno, you can force the engine into all kinds of different load scenario's to make sure that it is as safe as it needs to be. There is just as much chance of the load varying on the road with headwinds, hills etc.

This is bound to turn into a multi-page thread. LOL.