MB AMG55

I was just wondering if someone could shed some light on rear axel ratio's. I was looking at the specs on the C55 and the E55 and they have different ratios. Which is fine. But I was just wondering why that would be the case as they both are V8 engines, though the E55 puts out substantially more power.

Does the E55 use the higher 2.65 ratio instead of the lower ratio C55 3.08 because it is set up to put more of its torque and power out at lower RPM's? Both are excellent cars but I was just wondering if someone could provide some insight into this topic. I found a website that was useful, but as always, you want more and more and more info.

http://www.carcraft.com/techarticles/1007/

Also, if a supercharger is added to the C55, eg. Kleeman, Renntech, does that effect the engine RPM's at all and put any additional stress on the driveline components?

Any extra knowledge would be appreciated.

rbc55

e55 uses the 2.65 ratio,3.08 would be nice but would create even more traction problems

Noredline

Dont know a lot about the techy stuff, but I do know that the SL has a 2.85 which would improve traction I was told. The local Kleeman guy here is putting one in his E as a test before he will price or sell to anyone though. He said that along with the LSD will greatly improve traction/times.

E55AMG99

Lots of reasons why a car has a particular ratio these days. Fuel economy, , chassis weight, towing capacity, engine output/power curve, noise, traction, drivability, top speed, cruising RPMs, performance times, fuel efficiency, etc. are all considered by the engineers before selection. When considering a change to the factory gearing, remember to look at all of them again. If your goal is to improve 0-? times and you think that a lower gear set will offer more torque multiplication and therefore make the car quicker, you'd be right. However, traction and shift points might be negatively effected to the point that your $$$$ gearswap wasn't worth it.

M5KILLR

talked with cory at kleeman and he said they has 2 different gear sets. both net quicker 0-60 but both negatively effect 1/4 mile times b/c they shift into another gear. our gears are perfect the way they are.

thearle

Speaking of diff ratios, just wanted to share that if the SL600 and the SL55 have the same rear gear ratio, the SL600 will be quicker than the 55 AMG version.

AMG/Mercedes realized this and so they put a smaller gear ratio on the SL600 to slow it in order to keep the finesse and reputation of AMG cars.

E55AMG99

My point exactly.

E55AMG99

How do you know both of these statement to be true? Have you tested or seen the results of such a test? With whom at the factory did you speak to get confirmation on the latter?