This is the equivalent of getting a built motor / upgrading internal parts to run it at stock power. If you upgraded your transmission and put in a larger e63 differential would that make the car better? Considering none of those parts are points of failure it truly makes no difference other than in your head. If you drove both cars identical other than sls internals you wouldn't be able to tell the difference. Sure it's stronger and better materials but not necessary nor important for a header and tune street car which is what the 99% will be. It's like comparing a casio to a rolex to an iphone. They all tell time. Telling time doesn't require 220 parts, or a 3ghz processor. Telling time is telling time. One does not tell time better. It would be a different story if they came with better cams, updated head bolts, bs lifters.... ya know the parts that have problems.

You don't know anything about my car, but i know plenty about yours. Want to come to tx2k next year and race?

 

Keep in mind the non P31/507/BS M156 was available in the bigger models (ML, S, R, CL etc.) with up to 525hp without any forged internals and in a much heavier car.

As long as you don’t supercharge the engine, the M156 with standard crankshaft/pistons etc. will not be an issue.

i have owned both the P31 and standard C63 with a tune and cannot tell any difference. Technically the reduced rotational mass should give you a more responsive throttle, but I don’t really feel any difference in daily driving

 

No - but they last considerably longer under prolonged severe use. I don't race for 12 seconds at a time - I drive three or four 40-minute sessions 12-18 times a year around the fastest race track in North America. In other words, my engine easily spends 1000 times as much time accelerating up to redline than yours. If you want to come to Mosport and track your car for as long as I have mine, we can have a chat whether forged internals make a difference or not.

 

If you drive it on the street where you won't be able to use more than 40% of that power 99.9% of the time, it will not make a difference. How many ML, S, R or CL class cars have you seen on a race track? And yes, you are absolutely correct that in daily driving you won't feel any difference in how fast the engine spins up.

 

You are probably right. Fortunately here in Germany we do get the chance to use our engines for what they were built

I have also driven both variants on racetracks and AMG Driving Academy Events over the years but my subjective impression could not distinguish the forged internal. The only engine where I felt a difference was the SLS with its M159, more related to to increased power and different power delivery due to lack of the geared intake manifold.

Great memories and the peak of naturally aspirated engines…

 

The M159 in the SLS is in a different league altogether. I too have done probably 10 AMG DA courses... and the only SLS I've driven on track was a Final Edition. That thing pulls like no other car. No turbos and no gimmicks... just raw power. I wish I had one in the stable.

 

If I short shift in manual mode at 3500rpm's I can keep the oil and coolant temps in check for about 10 minutes on the road course, power steering will start over heating though. lol. I also smoked an SLS on the roadcourse one time, mind you he stood no change on the straights and I was on R comps, and I was a much better driver but it's a rarity to see them on the track. With upcoming changes I doubt it will last even last 5 minutes. You're in that 1% that 7lbs it will matter to. What's your brake pad and tire preference? 40 minutes is a long *** time.

 

When I first got the car, in the summer it would overheat the oil on the third lap every time. I was then a guest of Mercedes at an F1 race and found out about the 44O package - they still used the C63 wagon as the F1 medical car at the time - and two weeks later the crate with the 44O kit arrived from Affalterbach. I know other people on here track their cars with various aftermarket coolers, but you absolutely need additional oil cooling if you don't want it to conk out on the second hot lap. I never had any issue with power steering. I also have a Weistec transmission pan that holds more fluid and is finned for cooling as well as a euro differential case with the passive cooler & fins (or rectifier as MB likes to call it). The longest I have "continuously" driven the car was actually close to two hours... with 94.9 octane Ethanol-free gas which is available at my home track I can get about 35-40 minutes on a full tank, and I've done three back-to-back full tank sessions with two 4-5 minute pit stops to refuel and visually check tires.

I use Endless MX72+ pads with RacingBrake rotors - I found that they hold up pretty well under track use and are able to get me to and from the track without having to worry about trackside pad changes. Thankfully brakes are one thing I haven't had an issue with on the C63 after switching to the MX72+. There is so much heat transfer through the front wheel hubs to the front wheels that the paint on the wheel spokes has burnt, but the brakes themselves have held with no issues.

Tire-wise I have run whatever I could get my hands on that fits, either in 18" or 19" as I have two sets of dedicated track rims for the car and the trackside shop where I get my race tires knows to keep half-decent scrubs from other track and race cars in sizes that fit. I've run everything from 100% street rubber (MPSS) to 200tw "DOT spec" endurance tires to Trofeo R1s to used slicks (Pirelli DHs and Hoosier A7s / R7s).

The biggest issue with the car by far - and by this I mean all C63s - is the weight and the relatively narrow tires for the power it makes. No matter what tires you run, you will end up chewing them up and killing them if they are on the softer side or if you set the pressures too low. IMHO the best compromise for track use on the C63 have been the Hankook Ventus RS4s... they are by far the most consistent, they come in the right 18" sizes for the car if you have the proper rims and they are relatively inexpensive. I run them at 37-38 psi hot so start at about 28 psi cold, and at those pressures they are consistent even during full back-to-back sessions. Not the fastest tire but definitely the most consistent. Toyo Proxes R888Rs are little faster to start with but they drop off considerably quicker. Ditto for the Trofeos and used slicks... they are great for three laps and then get greasy to the point where the car is undriveable.

Always start with the oil at the halfway point between the low and high marks on the dipstick. Anything higher and you're foaming it too much. I don't burn any during track use - as in at the end of the day after ~2 hours the oil is exactly where it was. I do change the oil after every track day, and completely flush the brake fluid before one. Transmission and diff fluids get replaced annually. All fluids are OE Mercedes - as in I run fresh OE DOT+ brake fluid, Mercedes ATF and diff gear oil and sometimes even their 0W-40 oil. I used to use Mobil1 0W-40, but now that Motul is sponsoring one of my race cars, I get Motul fluids for free or at cost, and run either the 300V Competition 0W-40 in the summer when I know that it will be flushed in no more than a couple of weeks at the most (you don't want to run that as a regual street oil as it can't deal with moisture and acidity), or more often, the 8100 X-MAX 0W-40 which is what always goes in in the fall for winter use (or as I said if I have no intention of tracking the car much). I don't track it as much as I used to now that I have two race cars, but it's what I usually drive to and from the track for shake-down days regardless, and I will go out with it for a session because it is fun and keeps the engine happy.

Wear-wise, the only things that the car has suffered from were front wheel bearings (expected considering the heat and lateral loads), and the glass roof cassette creaking from all the chassis flexing. Otherwise it and the diesel ML that I use as a tow mule for one of the race cars have been the most trouble-free cars I have ever owned.