handling
GrpB was not as good, thats their main disadvantage over,todays cars, a main one too
reliabilty
About the same TBH. The GrpB cars had more BHP per litre but had NO restrictions really so didnt have to run to the extreme limit like WRC cars do.
performance
Well its hard, as handling wasnt as advanced, but watch GrpB vids, the cars were totally breathtaking. Come to the Rally day at Castle Coombe, its fookin crazy.
straight line speed
GrpB cars would leave WRCs for dead providing grip wasnt a major issue (ie you on tarmac), twice the power (and more!) and far less weight.
And round a track, i know the old ones have got more power but the new ones are surley built to handle better
Exactly. The current cars are hugely more advanced in respect to handling, you talking a good 18years development!
WRC cars handle much much better, but GrpB has the power n weight advantage, but on MOST circuits a current WRC car would win. But if you got a WRC car and took away any restrictions regarding engine spec barring capacity (a la GrpB) they piss all over current WRCs.
GrpB was the golden years of entertainment and nothing will ever come close unless they re-introduce GrpB spec or VERY similar