I decided to make my seat first then design the pedals and steering around to comfort, so that would mean getting a seat first. The racing seats that i have laying around are just around 2 inches too wide each, so that idea is out the door, so i decided to make my own seats, I found a 1" thick 4"x8" shet of padding for $20 US today.

My plan was to make a base out of 3/4" square, and the attach mdf wood to it, then spray glue the foam over top. Then when i'm done I'll bring it to an upholsterer to get it covered.

My question to you is what are the dimensions of the lower (arse support) and back support. I need to know the width and length of the lower part and the width and height of the back rest, any help would be appreciated.

I did something similar al la uncle Ron's book...See pikkies in my archive
The seat bases are 15" wide and , from memory (cos they're away being covered ) about 20" long as they fit under the backrest. You're best measuring the width/height etc in your particular chassis though I would have thought..
I should be getting them back from the upholsterers this week I'll post up a pikkie of the finished items when I do