You're right MBEPIC we did discuss this a few weeks ago after my run-in with the RICERS at Willow Springs, but last Sunday I spent the day at Button Willow and confirmed our opinion about the diff gear change.

Ok ! I admit this is a post that belongs in both (RACING & TECH MODS) categories and was going to post in both, but got lazy. Debated which I should post in first and decided that I would go for the Tech. Mods. because It seems to get more views and also this modification pertains to highway driving for those of us who own MAN. TRAN.

I'm in discussions with the mechanics at BergWerks which ratio will be more effective on the track, but still give me some comfort on the highway and not kill the engine and my gas mileage. Obviously the 3.69 ratio would be perfect for the small road course at Willow Springs and Buttton Willow, but impossible for the Highway. The 3.46 ratio would be great for the big road course at Willow Springs, Button Willow and Laguna Seca and much easier on the car on the highway, but still geared too low for the small road courses which are very tight turns with short straights.

HMM !!!

I am leaning toward the more conservative 3.46 gear ratio change at first. This is the same OEM stock ratio on the SLK32 AMG and the SRT6 which represents a 7% change from stock.

The 3.69 ratio is a 13% change from our car and a 6% change from the SLK32 AMG / SRT6, but I think I would be running somewhere in the 3.5k RPM range in 6th gear at normal highway speeds. That would probably limit my top end at somewhere around 130 mph before the rev. limiter kicks in at 6.2k RPM.

BergWerks says the differential swap out is a DIY 2.5 - 5 hours, but I am going to have them do the install since I want their warranty if it F's up. Appx. cost will be 2.2k...

Will keep you guys posted...