Hi All. I don't have much knowledge when it comes to tuning the E55 and it's motor, and I'm more doing this on behalf of my father who's recently just bought an E55 (His first Merc, actually, and he's always wanted one.)

One thing that he would really like to do to it when a suitable time comes around, is to potentially get a new set of headers and change the exhaust some. Whether he goes the route of C63 Mufflers, C63 Resonators and X-Piping, I don't know. When it comes to the headers, is it worth changing the headers out? If so, is it worth going for Long Tube Headers? I've seen that they're not too easy to come by in the UK, and a suggestion would be to get Mid-Length. Is there much of a difference between the two? Noise, Power, etc.

Another thing - down the line we may swap out the Supercharger Pulley for possibly an 83mm or 77mm Pulley with an ECU Map to compliment it. I'm aware that these engines can run pretty hot, so what else would need to be done to run it safely with that installed?

I'm free to answer some questions if needed. I've probably written this pretty sloppy since I'm tired, but I'll do my best to answer things in the morning.

 

You are kinda asking us, "What should I do?", which is kinda like asking, "What should I eat for dinner?"

It seems like you've done some research, but you don't need to do everything that's possible to be done to have an enjoyable car. Seriously...don't do that. I say choose mods that address a particular need or desire, don't just do them to do them. Because, most mods have some downside to them.

This kinda stuff comes up in every car forum. I've been modding cars for decades and I've always said that the first mods should be simply refreshing the car. Meaning, fixing trim, making sure that every function/button works (no matter how small), and fully detailing the car, leather, paint, and engine bay. Those alone will make any older car immediately feel more special. I mean, this car was dope as f*** when it rolled off the lot new several years ago...you can get it close to that point now with no mods. That'll hit harder than another 50hp.

 

Sage advice from CQ - make the car cosmetically and mechanically sound and fully detailed. Leave the car as it is and enjoy the already high level of performance. Just don't get the rush to mod the M113k engine when it already has terrific performance. The value of the car will decrease and the maintenance and troubles will increase.

 

Agree with all. You don't want to end up with one of those cars I see for sale that has all the mods, doesn't work right, but, on a good day, will run 11s. Unless the car is purely a toy, you will be much better served to fully sort the car and enjoy/assess it stock before doing much of anything. Maybe even drive it that way for a full year to get a sense of what it takes to keep it on the road, before you go modifying stuff all over the place.

Also, don't be those people who drop thousands on wheels but their check engine light is on....