912 with 2.7 motor - TB size?
 

Hi, can anyone recommend the right rear torsion bars size for this combination of car/rear weight?

The car will be be made slighlty lighter at the rear due to FG bumpers and lid but there is still the +/- 40kg extra weight of the motor over stock, hence I presume that standard recommendations as for e.g. LWB cars and springs would not apply?

Usage will be road with a monthly track day.

Rgds
Jacob

912 with 6 cyl 2.7 is a 911. Check in with the 911 gang there is plenty of info on this setup. 27mm rear 22mm front works on a mostly street / sometimes DE car and 28 or 29 rear and 22 or 23 front for more track pleasure. 23 /31 for track rats. The dampers (shocks) will need to be changed or revalved for best performance on the track and street. Some 912s and 911Ts did not come with sway bars front and rear. You should add sway bars if you don't already have them and if you have stock bars, install correctly sized adjustable bars. Adjustable bars are a good way to fine tune the handling at the track. with sways bigger is not better. Right size for the car weight, susp type and T bars is the best.

I have that exact configuration. I am running a 2.7 in my 67 912. I run 23mm up front and 28 mm in the rear. I run an S sway bar in the front and nothing in the rear for a sway bar.

The car is pretty darn neutral for a SWB. I also run Koni sport shocks...