My 2 cents.
If you weight more than 185 lbs. and can actually rail on the track, yes, you need some modification to factory suspension.
That rear shock is sheet man. Thats the flat out truth. Ask anyone out there racing on the track. I just resprung the rear and went thru the factory shock and HAD it reshimmed too. I think 2 or 3 mm.
Should mention, all done at GP Suspension in Oregon City, OR.
Also revalved dampner at the same time. Less to worry about when it is all done right.
Front end revalved and resprung. I spent the better part of the trackday working on set up and tire pressure. Got it dialed up shortly after lunch.
Ok. I do not have times to compare. But, I can tell you that my tires will now last much longer. I was going thru a set of Super Corsas every day. Now I can get maybe 2 days out of the. 1 1/2 days for sure.
My buddies could not believe the difference since none of them could play in the corners with me anymore. Now I can turn inside them much quicker. Power still going down at the same time, but with more throttle. Braking is insane, and where I kill my friends. But there are MANY others that can brakes as well or better. It a pucker limit though for sure!
I just can't rave enough about the change. Getting it dialed in though was the must that came thru in the end. I had the factory setting dialed, but the front bottomed out under hard braking, which sends the bike into a controlable tremmor. And the rear just didn't have enough dampning and overheated fast with my harsh style. This problem just made breakfast out of the rear tire on PIR's track.
If you are into the track. This would be monies well spent when compared to other costly mods. Just make sure you have someone that really knows suspension set-up to help you make changes as you come off the track.
Best track day I ever had. Man I was fast. Haha :moped:
Oh. 2 more cents. Tire pressure on the track is everything. Ask racers or especially tire vendors. Visit the track on trackdays and talk to people. Lots of trial and error there.

ccasion1