It bothers me that the rear brakes on the clk55 have been upgraded by amg and the c55 has not. Does anybody know if the rear brakes on the clk55 will fit on the c55 for a direct swap?

 

Maybe because it's not necessary. If the engineers at AMG thought that the current brake setup is not sufficient for the "spirited" driver, I can assure you that they would have put larger brakes on the car.

Most people really don't understand nor appreciate the benefits of a larger brake setup. It is one thing to upgrade brakes for optics, and if this is the case, then just buy larger discs. The current setup on our C55 is more than you will ever need on the street. IMHO the only real justification for replacing the stock C55 brakes, is if you want a true track/autocross car. If that is the case, then you would be much better served buying a porsche 964 (or something akin) and completely stripping and solely using it for the track.

What most people don't realize, is that a larger brake setup won't necessarily decrease stopping distance (it could even increase slighlty). The true benefit is reduced fading. That is, after repetitive braking (such as on the race track), the braking performance will not be as affected. My point, unless you truly plan on autocrossing or tracking your car, you will never be in a situation (on the street) where "fading" is a significant factor. Save your money and buy something that your C55 really needs, such as limited slip differential.

 

Good points..and add to this that the front brakes do a much larger percentage of the work to stop a vehicle..upgrading the rears amounts to nothing more then an appearance upgrade..

 

Point of clarification. Neither the C32, nor the C55 have adequate brakes for repetative braking even on public roads. If you are limiting your braking to stop and go traffic on the blvd., or the occational drag race, than I will agree with your points. If you think the brakes on this car are adequate for a fast canyon run on a public "street", I will tell you from first hand experience that they will fade badly after seven minutes.

You can't just buy larger disks and keep the stock caliper without changing the mounting points and the sweep area will be off and not proportional to the rotor.

The C32/C55 can be made to be a respectable track car in the hands of a good driver. We are down to 1:33's at SOWS which is a great time for any street car. Than again, I did like my 1986 944!

"...If the engineers at AMG thought that the current brake setup is not sufficient for the "spirited" driver, I can assure you that they would have put larger brakes on the car..." Then why does the lighter SLK55 get the better brakes over the heavier C55? Is the more spirited driver going to by the SLK55 over the C55 according to the MB marketing department?

Both of you have also forgot to mention the benefits of unsprung weight with a BBK upgrade, even for the rear. It is significant.

 

Your line of reasoning can be applied to the need for a mechanical LSD. The standard ESP system acts like a pseudo mechanical LSD. It is equally unlikley that you will ever need a mechanical LSD on every day roads, even for "spirited" drives.

 

I disagree with you. ESP and a limited slip differential act in two totally different ways. The LSD allows the power to be transferred to the wheels, whereas the ESP prevents it.

An LSD will provide the most benefits on the track, especially on cornering. However, the benefits extend far beyond that into the realm of everyday driving as well. I think that most C55 owners on this forum will agree that it is really frustrating how temperate one must be with the throttle to avoid the ESP light from constantly illuminating. All of this actually goes without saying if you look at the level of interest for a limited slip for our cars in other recent threads (e.g Quaife group buy, etc.). Given the amount of torque these cars have, an LSD should be standard in my opinion. It truly baffles me that they don't come with one stock.

 

Yes.

https://mbworld.org/forums/c32-amg-c55-amg-w203/119000-latest-project-progress-pics.html

 

I've posted this before, so I've just pasted it here. Have a read.

"ESP stands for Electronic Stability Program. It is an umbrella term which combines 2 features:

1) Traction Control (what Mercedes calls ASR)
2) Stability Control

Traction Control (ASR) is exactly what the names implies. It will brake individual wheels or cut engine power if there is excessive wheelspin in either drive wheel in low traction conditions when you accelerate (from a stop or while in motion). In a way, it can act like a pseudo limited slip differential, but it is reactive in nature (a wheel has to start slipping before the brake activates to stop that excessive spinning). When accelerating out of a corner, the inside wheel often will "slip". The benz should detect that slip and brake that wheel slightly. The open differential should then transfer more power to the outside drive wheel which has more traction. So in a way, it does help in a turn like a LSD would. At least this is what is claimed in the promotional materials of the C55.

Stability control comes on when the car senses that you are not traveling in the direction of your intended path. It measures your steering input, speed, and what direction the car is actually heading in. If it senses understeer or oversteer, it will brake the appropriate wheel or cut engine power to bring the car back in line with where you want to go."

In other words, by braking a slipping wheel, the open differential automatically transfers more power to the other wheel which has more traction. I'm not saying it is equivalent to a true mechanical LSD, as it is a reactive system and is not as responsive as a true LSD. However, you will get by unless you're really hammering the throttle such that the car has to cut engine power because the brakes aren't good enough to stop the slipping.

 

Traction Control (ASR) is exactly what the names implies. It will brake individual wheels or cut engine power if there is excessive wheelspin in either drive wheel in low traction conditions when you accelerate (from a stop or while in motion). In a way, it can act like a pseudo limited slip differential, but it is reactive in nature (a wheel has to start slipping before the brake activates to stop that excessive spinning). When accelerating out of a corner, the inside wheel often will "slip". The benz should detect that slip and brake that wheel slightly. The open differential should then transfer more power to the outside drive wheel which has more traction. So in a way, it does help in a turn like a LSD would. At least this is what is claimed in the promotional materials of the C55.

Stability control comes on when the car senses that you are not traveling in the direction of your intended path. It measures your steering input, speed, and what direction the car is actually heading in. If it senses understeer or oversteer, it will brake the appropriate wheel or cut engine power to bring the car back in line with where you want to go."

In other words, by braking a slipping wheel, the open differential automatically transfers more power to the other wheel which has more traction. I'm not saying it is equivalent to a true mechanical LSD, as it is a reactive system and is not as responsive as a true LSD. However, you will get by unless you're really hammering the throttle such that the car has to cut engine power because the brakes aren't good enough to stop the slipping.[/QUOTE]


Obviosly an argument can be made with your line of reasoning, but it is incorrect.

ESP applies braking to the spinning wheel, an LSD does not. ESP slows the car down out of a turn when it detects wheel spin, a LSD does not. An open diff is provided in our cars beacuse it costs too much to provide an LSD in the car that very few people really know the difference. A LSD is needed even on city streets going around a 90 degree corner at 30 mph.

As for the brakes not being good enough to stop the slipping, this is an absurd statement. The brakes are capable, but if the engineers were to stop the slip completely, your car would be facing traffic out of the corner due to lock up or the car would not move and you would be hit by traffic. Most of us just hit the ESP button off when merging into traffic. Too many times the car just won't get out of its own way in a tight merge situation.

 

A LSD will only help in a scenario where one drive wheel is spinning faster than the other. Without a LSD, an open differential will transfer more and more power to the slipping wheel with less traction, causing unnecessary and wasteful wheel spin and decreasing power to the wheel with traction. What a LSD does is "limit" the excess spin on the spinning tire and transfer more power to the other drive wheel which has more traction (which is good, as you transfer some of the power to the wheel which is spinning slower and presumeably has more traction).

All I'm saying is that one of the goals of the ESP is the same as an LSD. The traction control first will brake the excess spinning wheel. By decreasing the excess spinning (or creating more resistance in the spinning wheel), the open differential will automatically send more power to the other drive wheel. Transferrng more power to the wheel with more traction is EXACTLY what the LSD does (albeit with a very different mechanism). This is what I mean by the ESP acting like pseudo LSD. I'm not saying that it performs as well as a true LSD at all.

Also, I'm not sure what you mean by ESP slowing the car down when coming out of a turn. When ESP applies some brake force to the excessive spinning wheel (with limited traction), you should not lose any momentum because that wheel doesn't have traction anyways. What likely is happening is you're applying too much throttle to cause BOTH drive wheels to lose traction and spin excessively. In this scenario, both drive wheels will be braked AND power will even be cut from the engine if you don't lift on the throttle. I've also experienced this before and I agree it feels like the car is dead for an agonizing second or more. I agree that in this scenario, a true LSD will let you have wheelspin in both wheels so you don't feel like you're dead in the water.