hi there
would like to know what i could do to improve rear end traction in a 1981 rx7 with a 13bt swap.have 16' wheels on at present with 205/40/16's all round.Have lowered car 25mm.Cant take off hard ,anything above 2000/2500rpm and the back end just lights up the tyres.Running 1bar boost ,330 rwhp @ 6800rpm best ET12.74 /119mph on gtech at the strip 13.1 /187kms.
Am putting on 225/40/16's on the back wheels.
Any ideas will be appreciated!!!!

 

By lowering your car you have limited the amount of weight transfer it's capable of, so you might want to reconsider that. If you want straight line traction, remove the sway bars, put the softest springs you can find in the rear and add front struts with a high rate of dampening. All of these things will increase the amount of weight transferred to the rear wheels. Wider tires can't hurt either. Have you considered race slicks? Of course, these changes will have an adverse effect on street handling, but if you want to go fast...