[scottj]

Here are a few things I’ve learned for the track running that much power with 13” Hoosiers, 3.54 gears, and a Richmond 5spd. To start with, I need to run the rear percentage in the 55-56% range. I also need softer rear springs and stiffer front springs (with matching shock valving) than would be optimal for maximum skid pad performance. I need the smallest rear bar available for my chassis.

This set-up will get full power down in 4th while 3rd takes a little throttle modulation off corners. With 335/35-17 street tires and 58% rear it, it will spin the tires some from a 3rd gear roll-on and continue spinning slightly in 4th. I can’t hook up 1st or 2nd at all with either tire and I’ve never run a drag slick to compare.

Re: "at what level power becomes a waste" and "bottom end torque vs. top end HP". If I were to do another engine I would reduce the stroke from 4” to 3.5”(380cid) to lose some of the bottom end torque and turn more RPM. I would build 700hp with around 550 ft/lbs torque, making it more usable than what I have now. With less torque and more rpm(hp), I could balance the chassis for better handling and improved laps. In my opinion the throttle should be an asset not a detriment to good laps.
Scott