Don't know if this is of help, but here's my $.02.. Experience has led me to avoid chain-driven cars at all costs.. too many issues with chain stretch, dry chains, heat, and chain breakage.. some have ok success with a chain-bath setup, but those can be tough to fab.. (not that it can't be done) ...I've lost several fun off road riding days because of motorcycle-powered buggy chain reliability issues.. sucks to build the thing and have a stupid chain be the car's Achilles heel..
Using 'car' gears to shift a BEC.. for a short time I had a T5 inline in a former BEC project (I could shift at the bike box or through the T5).. I found the car tranny's gears were too far apart to be fun/effective with the bike engine.. after a short time I reverted to just using the bike box to shift (paddle shifted), even though I had the ability to use the traditional H-pattern gearshift-- used that only when reverse was needed, which of course was rare.. (vibration issues eventually had me pull the T5, and I didn't miss it)
If you're still interested in a car tranny, I didn't go down this road, but I thought an old-school VW trans might work if you go front/mid engine (bike) and RWD.. You'd eliminate the VW clutch bits and just use the bike's clutch.. coupling it would be work, but doable.. this puts some weight on the rear axle (ideally in a good way), IRS, reverse, and shifts like a 'car'.. Even if you learn you don't use it (the VW box) to shift (you just use the bike's tranny for that), it still incorporates reverse and IRS, albeit with a weight penalty..
Keep us updated- and don't forget to take pics
--ccrunner
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Dean
1972 Honda N600 Restomod "ccrunner's N600 VFR800 repower"
1963 Volvo P1800 Restomod
http://locostusa.com/forums/viewtopic.php?f=36&t=163091959 Berkeley SE492 Restomod...
viewtopic.php?f=36&t=19397"ccrunner's 1960 MGA coupe Restomod" found on MGExp.com