been testing open sled with timer. what is a good time in 660ft 290hp sled

4's someplace in the 130's? Good guess?

When you say open sled, are you saying this is a laydown in the area of 300lbs? If so, I think gpxsrx made a good guess! If fact, that kind of hp in a Pro Stock sled would be close. Sounds fun in any case! Where are you seeing?

its a xcr 800 with htg 1250, it still has most of the coolers still in it ,so it is still heavy. it has wahls 136" speed track , with wahls shocks on the front. have had little time for testing. been running stock primary clutch. just ordered new quad cam clutch, hoping it will be easier to put power on the ground. any advice would be great thanks.

then i would look for low 5.3's @ 120-125mph, thats what prostock 1000's run.

What does your sled weigh? A respectable Improver ET would be in the 5.6 second area. Record for legal PS1000 (625lbs driver and sled) is 5.13 at high 120's mph. Some local HTG 1200 lake racers (full body pro stock sled about 550 lbs sled and driver) run 5.0's.