XR1 Fast for 10 laps then goes extremely tight

[Cranky]

We have an XR1 that is very fast for the first 10 laps or so and then will go extremely tight and start pushing the nose bad. Driver is not changing his line or doing anything different than he did the first 10 laps. Track is dry slick, LR tire is very hot, RR not as hot. Seems to me to be a bite issue or something getting hot and giving up. Just put shock on dyno Friday night, checked the gas, all was normal. Has anyone run into this that could maybe point us in the right direction?

[CCHIEF]

What tires are on it and where? How many laps are your races?

[Cranky]

1350's across the front and 1600's on the rear. They were freshly ground and grooved and siped. They were not sealed over after the feature.

[JustAddDirt]

Whatever you run on the left rear you should run on the right front. The 1600 is firing and over powering the 1350 on the right front.
Or run the 1600’s on the right side 1350’s on left

[Cranky]

Rules

We run the All American Crate Series and by the rules we have to run 1600's on the rear. Perhaps we should put one on the RF as well?

[Punisher88]

Or get aggressive with the lr to keep it cool with siping possibly?

[CCHIEF]

Likely the car is too tight and spinning to free up, catching up to you. Try more stagger ( less wheel spin)if tires are mandated.

[Jking24]

Definitely sounds like your pushing the rf off when the lr gets going. I would run a 1600 on the rf before I went chasing the setup and see how that goes. Their is virtually no burnoff to be concerned about in ten laps with a crate.

[keeks]

Could you have a shock that's failing when it gets warm/hot?

[ZERO25]

I would try lengthening rs bars 1/4 inch at a time, and/or raising the left bottom rod a hole or two.