Hi, welcome to TRS.
I can't help on the duratech but you should give some details of you race car and the type of racing you do.
I assume you have taken out as much weight as you can....
Your wheels and tires are as light as possible and the smallest overall diameter feasible....
Any friction in the drivetrain and braking system is as small as possible....
And finally, but not least...
We really, really like pics!