as a principle I never race 4 wheel drives as when you are eating your tires they let you in dust
A mate of mine had a Sylva Jester with Fiat Panda 4x4 running gear and an Uno Turbo engine (IIRC).
An ugly pig of a car (IMHO - have a look
http://yodaofbo.spaceport1.co.uk/features/other/Sylva/sylva_jester.html) and with that much Fiat pedigree it clearly didn't always move under its' own power but when it did - I remember being at a kit car show where they were timing standing 1/4 miles had he wiped the floor with everything - and we're talking Caterham R500s and the works here.
Embarrassed a few folk.
Of course, give it half a mile and he'd have been eating humble pie but 4wd does make a huge difference to how quickly you can launch a car (assuming you've got enough power to make it worthwhile).
Kevin