I can't imagine not having it now. No question after the 'new car' honeymoon phase is over the non P31 buyer will be regret not ticking the box.

 

Unless you really care about the goodies added to the P31 package, getting a tune will be substantially cheaper than P31. There are dealers out there who are mod friendly. I am not saying you are not running a risk even with those dealers.
It is just a matter of preference.
If you will NOT mod the car at all, then P31 is probably for you.
If you will do mods like X-pipe, headers, intake, etc... you will run the risk of the dealer denying your warranty and the tune vs P31 becomes a cheaper alternative.
OP: thanks for the detail and tests you ran on both cars. Very interesting.

 

+1. P31 is a great extra fun factor and tid bits (suede wheel, calipers, CF tail etc etc.., a lot of people actually don't like the alcantara on the sides of the wheel and say it looks worn over time), But it shows up in top end, shy of 6000 rpm. The identical mapping is cool to know. Just have to weigh out cost vs. need. Great info. If everything else is the same, I would love to know what exactly the restrictions are...

 

It may just be my humble opinion, but wouldn't P31 be good for those who want to mod as well as those who don't?

Those who want to mod are pushing the engine further, so the forged rods and pistons of the P31 would be of benefit. Also, if you're modding the car you're obviously looking for performance, so you should be taking into consideration the performance benefits of the lightweight crankshaft (which will benefit regardless of RPM's).

The maps are the same for the P31 and non-P31 per RobB, so arguing that getting a tune is a "cheaper alternative" to the P31 is invalid as a tuned P31 will run stronger than a non-P31, will be able to handle more horsepower due to the forged internals, and will have an easier time delivering said power to the wheels via the lightweight crankshaft.

Mod for mod, P31 will be faster/stronger.

Someone correct me if I'm wrong.

 

You are bang on the money here, as we then went on to map both the standard and P31 car. The standard car now feels awesome, but the P31 feels like a complete animal trying to wrench your neck off under WOT. The P31 also gained more than the standard car, due to its ability to breath better. The standard car obviously got some gains from things such as spark advance, but in the end its still struggling to breath up top and as a result the torque still falls off faster than the P31.

I'm going to do my damn hardest to try and find out why the P31 doesn't gasp up top like the standard car.. and if I do find anything, I shall be back to report the difference!

 

Stock the P31 produced 27bhp more than the standard car at the rear wheels... With both cars mapped the P31 then produced 35bhp more than the standard car at the rear wheels. Bear in mind that as they both had the same software stock, we wrote the same tune for them both too... but obviously the P31 can take better advantage of this.

 

For anybody interested in looking at more pictures of C63's.. these where our two test cars. The white car is the standard car, the black is the P31 :-)

 

Again, VERY good thread Rob.
So, with the tune you did on P31, with another 35HP at the wheels, that would take it up to around C63 B.S. power, would it not?
In that regard, taking your "testing" one step further, wouldn't it be good to a put standard B.S. on the SAME dyno, standard, & see what you came up with?
Cheers, Pickles.

 

It would indeed, but I think i'll struggle to find a Black Series owner willing to let us play with his car for a day....

 

I'd be particularly interested in this, to see if the software is simply more aggressive on the black-series and thus the car isn't really tuneable, or... to find out if the black series has physical modifications over and above the P31's ability to flow better... and if thats the reason behind the power jump, then a remap on a Black Series would yield even greater power from this 6.2 AMG V8...

Anybody got a black series I can borrow?? :P

 

Out of curiosity, are both these cars the same year?

 

Yup - both 2010 cars.

 

The Standard car was registered 18/08/2010
The P31 Pack car was registered 27/09/2010

As mentioned before, the same software came off both.

 

Yeah, well you're probably right there!......But, in all honesty, you wouldn't really be "playing" with it would you....ya'd just run it up a couple of times on the rollers & see what it makes...stock.
So, come on, B.S. owners.....give Rob a call!
Cheers, Pickles.

 

Well to be honest if I got hold of a BS I'd also want to take a BDM read from the ECU to see what the software looks like =D.

 

If the maps are the same, and better breathing in the P31 is producing more hp/tq then it has to be something in the intake and/or exhaust such as different airboxes (i know the euro verions look like they should breath better) different intake ducts (althought i don't know how they could fit anything bigger in). A restrictor plate would be so obvious everyone would have pulled them off by now. Has anyone found any differences in the exhaust system?

 

Very interesting thread now that we have gotten past the confusion between engine speed and vehicle speed. I for one have more questions than ever.

1. The intake system is very straight forward, did you consider swapping the 2 units? I would think that once inside the manifold things would be identicle. Has anyone checked to see if there are any MB part number differences between the 2 cars other than the internals?

2. Granted I am not a physics professor, but I would have thought that the mechanical advantage of the crank/rods/pistons (flywheel?) being 7 pounds lighter would benefit the most power in lower rpms. This due to less inertia during spin up? Once up to speed the 7 pound difference should be of lesser impact and IF this was the source of additional power it would have to be present in the entire rpm range.

3. It is very curious how the P31 difference happens in the upper rpms only just like the other M156 motors that MB doesn't detune. Most of the other models also had slightly larger exhausts but the primary difference was the throttle body programing above 5,000 rpm.

4. I am not sure anymore what the official MB stance is on the subject. It has been reported that the car recieved lighter internals and revised software but I can't speak for the validity of the source. I would like to hear from some other tuners on this topic but it looks as is they are taking a pass. You would think if the P31 difference was purely mechanical, they would be promoting like crazy to P31 owners that you will still be 30 whp over a standard C63 once tuned. I would like to see another model M156 run on the same dyno before and after tuning for some additional reference. Doesn't have to be a CLK Black either, an E63 would do fine.

For now it looks like the mystery remains, just wish they had a P31 back in 2009.

 

I believe the major difference in the Standard and P31 Tune is the fact that the P31 opens the throttle bodies wider above ~4500 rpm than the Standard tune does. This allows the P31 to breath better and make more HP and torque above that rpm range and you can see that in the graphs. Otherwise the tunes may well be identical.

 

Very interesting to see that a tuned P31 is getting more hp than a tuned P30.
Doesn't the software tune play with the throttle bodies so that they can be opened wider for more hp. If that is the case and since you applied the same tune to both cars, then it would sound logical to assume the P31 hardware internals are the cause for the extra hp.

Vash: you are correct that modders could also go for the P31. I did not mean that they would not, it is all a matter of preference. For the P31 cost, you can get a set of headers that would lead you more hp than what the P31 costs. You obvioulsy would end up with more hp when you add headers to the P31.
Based on the OP's great research, it would seem that if your ultimate goal is to mod your car and get the most hp, starting with a P31 would be the way to go as trying to change internals on a non P-31 would not make financial sense.

 

Guys the 2011 P31 in the Video is my car. I ran Xtyper in his 2010 C63. My car was obviously faster.

I then ran him when he got a tune and our cars were dead even.


I dont believe a tune for the P31 does anything at all.

 

Is RobBentley a tuner? Just trying to figure out his history here, only started and posting in this thread, because I've heard completely opposite (in regards to the ECU being the same) from every other tuner I've spoken with.

The P31 has better breathing up top because it opens up the throttle bodies. Just like a non P31 tuned c63 would. We have a boat load of C63's here, and I've ran with a lot of them.

non P31 tuned == p31 stock == p31 tuned (waste of money)
non P31 stock is slow.

There is no mystery. P31's have been out for 2.5 years now, if there was some magic bullet for breathing without opening the throttle bodies at high rpms, everyone would've jumped on it and selling it already.

 

Yeah - I work for a tuning company, but I am not going to start self promoting here, so the tuning company shall remain nameless.

I too was in full belief that the P31 must open the throttle up more, until we took the software off my standard car and a customers P31 to find exactly the same throttle mapping... I honestly don't know what the difference is, but it doesn't look like software and unfortunately I don't have a P31 to take to bits, as we borrowed it from a client.

 

I'm not 100% sure of my answer to this.......but I believe the SLS internals in the P31 were NOT in the MY2010's tested in this thread. I think this is new to the 2012's.

 

My 2010MY has the SLS internals in the P31.

 

All P31's had the SLS internals.