Can anyone confirm 100% that the P31 cars have different bottom end internals than normal C63s? I'd like to not miss out on the trunk money but would really like to know if the extra 6 grand or so is worth it? If it's just in the tune which it very well could be then I'll pass and do everything aftermarket (evosport rotors, tune to be decided). I remember seeing early on when MB released info on the package that it did have different components but now on MBUSA when you build your own they are not listed? super gave me great advice to wait on the part numbers of the internals of the P31 cars but again now with trunk $ released I feel like I need to make a decision now. TIA for all the help guys.

There are different internals on the engine, such as: light weight forged pistons, light weight connecting rods, revised crankshaft, and a "compound braking system" the rest of the package involves the spoiler, raised speed limiter, different ECU programming, red brakes, and a softer steering wheel pretty much. You could check out the dyno for it as I poster earlier, but we still aren't sure that it is accurate.

Thanks for posting your dyno, I saw your results along with cek's and they are very impressive!I think you're right, your HP is correct but TQ is off, I'm sure if you redyno somewhere else you'll be inline with what others have posted.My question to you is, how do you know the P31 package has different internals? Did your salesman tell you, was it older MB marketing, have you had the motor apart, does it list it on your window sticker? I know it's supposed to be part of the package but in order for me to jump ship I need to know with certainty. I get the rest of the package, definitely stuff I want, but the deciding factor for me will be what's in the bottom end. Otherwise I think I can piece the brakes, tuning, and appearance together for less $ in the aftermarket. If I was a wealthier man I'd check the P31 box no questions asked. Thanks for your response, and congrats on a BAD C63!

Also is the LSD included in the P31 package or is it standalone?TIA.

The different internals are listed on the window sticker and all over online. The LSD is sadly a stand alone option for, if I'm correct $2,000. Just from my opinion, the P31 is a good package to get.

On the window sticker is awesome! Go figure on the LSD I guess I can do later later as well if I have to. Thanks for chiming in, when are you getting that monster to the track? I want to see some stock P31 numbers asap!

Haha. Since it's my dads car and I am mainly who speaks for him (he is rdl666), I'm not exactly sure when we will be able to put it on the track. We were going to last monday but not enough people signed up, so we weren't able to. Hopefully before this year ends we will be able to though!

I will hopefully dyno mine this weekend. And run some quarter miles! Will post back on Monday!!

Thanks to both of you gentlemen! Very much looking forward to your results. Are you going 100% stock or with drag radials?

100% stock on original p0 tires

Any gta guys, come up to Cayuga for eurofest this Sunday

Nothing on my window sticker about engine internals. All it says is AMG Performance Package 6000.

For P31 specs see the AMG site C63 Options:

http://www.mercedes-amg.com/#/c63-information

The LSD is a stand alone option for 2010 - 2011 with the P31 Performance Package.

My window sticker definitely says as part of the P31 package: "forged connecting rods," but I think it only says "lightweight pistons" (although I suspect they make them lighter by forging them...assuming they are equally strong), and "revised crankshaft," and then lists the brakes, titanium-colored intakes, etc.

My window sticker is Mercedes-Benz Canada Inc. and that must explain the difference in detail presented.

My dealer did not know the exact details of the P31 Package, back in February, until I did some research on it.

If somebody does not do it sooner, I can probably make a PDF of the window sticker and post it on Monday.

Assuming the same design a forged piston is heavier than a cast or high silicone content cast piston aka hypereuctectic. Same goes for rods and crank. The design of the internals must therefore be different in order to be lightweight. 500 grams is a lot easier to shave off a crank than rods & pistons but I guess it all depends on the design of the non P31 regular bottom ends. Thanks for the additional info. I really see the package with forged internals to be beneficial for someone like me, nitrous junkie

Not necessary, if you say it's on there, it's on there. I just hadn't heard it was on the window stickers. Thanks!

Didn't run that great on 3/4 tank of fuel.

I ran a 12.7 on the 1/4 @ 112 mph.

And did a dyno of 382 Hp and 353 tq. The dyno guy said the computer was restricting the runs. Is there a dyno mode for the car?

Don't sweat it, it's probably the heat unless it's cool up there?IIRC Even Money with K1 tune ran 12.6@113 this past week in 1125' air, correctd I believe it was a 12.4 run? What track did you run at and what time was your best pass? If not me someone can probably do the weather correction for you.Yes there is a dyno mode but I don't know how to engage it with a C, sorry, I've seen others on here mention it though. What kind of dyno was it and were any correction factors used?Thanks for posting!

Check my sig...last run of 8 that day, temps started near 90, then cooled to about high 70s. Get some nitto drag radials.

Dyno mode accessed by the following, i think it's on youtube somewhere.
1. Insert key, turn to first click.
2. Hold call answer button, then press OK.
3. Self explanatory menu should appear.

It was a dynojet??

I will do another one soon.

Slightly OT, but do you think a dealer would reflash our cars with a P31 tune?

Should there be a diff between Dyno mode and ESP off in a C63?

No diff, I think dyno mode just makes it easier to reset and drive the car away with full power steering, etc.

No chance. They would be shooting themselves in the foot by doing so. Besides an aftermarket tune should be more aggressive than any factory tune.