Well John, you asked for it.
I went and drived the cars for which I put a new chassis (I also included the Lancia Integrale from Teamslot since I worked a lot on this model and it is a competitor to the Sierra Cosworth.
Here is a picture with two gropus (one group has the group B cars with new chassis and the other group has the cars from 1987-1993 with new chassis).
Here is a picture with the cars in order of best lap times:
1- (12.05s)
Lancia 037
Body: Fly (cockpit butchered for motor and weight considerations)
Chassis slot.it HRS
Motor AS green motor (11 UMS)
Weight body 27.9g;weight chassis 64.9g (total 92.8g)
Tires:rear slot.it P4;front slot.it Zero 17mm
--this car is from another planet, very fast and very secure (here shape and magnetic pull from motor play a role).
2- (12.29s)
Opel Manta
Body: Sloter
Chassis slot.it HRS,
Motor MB SongNa (11UMS)
Weight body: 23.3g; weight chassis: 60.3g (total 83.6g)
Tires:rear slot.it P4;front slot.it Zero 17mm
-- this car slides a lot but almost never deslots (very fun and stable)
3- (12.59s)
Lancia Integrale
Body: Teamslot,
Chassis Teamslot (guide modified),
Motor: Avant Slot Green (11UMS)
Weight body: 32.5g Weight chassis: 61.3g (total 93.8g)
Tires:rear slot.it P4;front slot.it Zero 17mm
--very fast, very tense, more stable than expected due to magnetic pull of motor and body shape and the weight distribution in the body (a bit misterious but there are theories)
4- (12.66s)
Ford Sierra Cosworth
Body: SCX
Chassis: Hobby Slot Racing Diablo Evo (had to be trimmed so that tires do not go out of the body too much)
Motor: Avant Slot Green (11UMS)
Weight body: 31.4g Weight Chassis: 62g (total 93.4g)
Tires: rear PKS 008ER, front SCX (low profile)
--Very fast, more tense than the Manta but less tense than the Lancia, so it does slide but not too much. Extra tunning might change this. The wheels and tires have to be more narrow than the previous cars 9mm tires instead of 10mm.
5- (12.69s)
BMW M3
Body: Fly
Chassis: Hobby Slot Racing Diablo Evo
Motor: Spirit 3X
comments later (very fun car to drive)
6- (12.99s)
Audi Quattro
Body: Fly (with lexan cockpit and original heads)
Chassis: Ninco Mitsubishi Pajero (with some dramatic modifications)
Motor: Cartrix TX6 (7.5UMS) very good motor it has much less magnetic pull
comments later (Extremely fun car, I am dying to do a movie of this car going fast on the track, fabulous slides)
7-( 13.03s)
Ford Cosworth
Body: SCX
Chassis: slot.it HRS
Motor: Slot.it Boxer open(10-11UMS)
Comments later (too tall and too narrow very tense but excellent finger exercise)