Hi guys.

I am looking at light weight options for car batteries to suit my track car.

The car is a low budget AU XR6. No electrics other than the ECU and fuel system.

What have people used that saved a few kgs but didn't cost the earth?

In CCA terms what' is the minimum i would need to start the Ford 6?

Many thanks!

The lowest CCA I got my AU to start on was 350-375a. If your engine has a higher compression it will need more amps. If you need to keep weight to a low use a small 100-200cca battery to power accessory's and use a large starter battery to jump the car.
I would op to use something in the home of 200cca as if you stall on the racetrack you can start the engine but the battery will be toast after that.

I personally have no idea on what battery to use as cost>cca as I just use a 650cca supercharge for all my cars.