Gremlin9

Does P31 have more torque than Stock engine?
If not, why does a tuned c63 experience an increase in torque compared to a stock c63?
Does this mean that tuning a stock c63 is better than the p31 because they both give you about 60-70 more hp, but only the tune gives you more torque?

https://mbworld.org/forums/c63-amg-w...oe-tuning.html

gthal

I thought I read here that the torque curve shifted in the P31 package. HP is a function of torque and engine RPM so there is a correlation. It would be interesting to see the two torque curves side by side.

P.S. Even if an after market tune is better in producing a little more torque, it comes at the expense of warranty

RobBentley

I should be able to give you the answer to this next month. I have my C63 (without performance pack) and a customers C63 (with performance pack) going on a rolling road on 27th April 2012. It will be interesting to see the torque graphs side by side.

Pickles

Never seen that "side by side" comparison before, on the same rollers, on the same day....I will be very interested.
Cheers, Pickles.

RobBentley

Yeah, will be same rollers, same day. One with performance pack - one without. We'll also be remapping both, so I will have before and afters for both cars. I'll check back into this thread next month with the results :-)

Pickles

Thanks...I'll be waiting!!
Cheers, Pickles.

Gremlin9

Thanks Rob, I can't wait to see the numbers.

In the meantime, can anybody give us stock c63 torque numbers vs p31 torque numbers????

Anybody?

And yes, I've searched through all of the threads and could not find anything definitive.

C63newdude

I would expect the torque to also go up..

Mort

Car and Driver has a review of the 2012 C63 AMG Coupe and says it has 441 lb-ft with or without development pack.

http://www.caranddriver.com/reviews/...ad-test-review

Gremlin9

Can anybody provide dyno torque numbers for p31 vs stock?

gthal

Peak torque is the same but I wonder if the torque curve is different. I am no expert but because HP is a function of torque and engine speed (RPM) I would imagine there has to be a difference in some manner given HP is 30 more and I don't believe red line is different.

rage2

Peak torque is the same with or without performance pack.

Torque starts to drop at 5000rpm without the performance pack as the throttle bodies close up more, hence less hp.

Torque stays flat with the performance pack till later, hence more hp.

khmergod

Can't wait for results!

gthal

That makes total sense

RobBentley

OK guys, I'll have the rolling road print outs to upload tomorrow once I get into the office, but basic findings are....

1. The software on the standard C63 is the same as the C63 with P31 Performance Pack
2. Torque and BHP is equal until just shy of 6000rpm.
3. At 6000rpm torque falls off faster on the standard car than the P31.
4. At 6000rpm BHP starts to flat-line on the standard car and keeps climbing on the P31.
5. The P31 produced 27bhp more at the wheels than the standard car.

Given the software is the same on both ECU's, and the power is identical until high engine RPM we can derive that things such as cams (etc) are the same on both cars as these would take effect at lower RPM. Clearly the P31 breaths better compared to the standard car. We're not sure if this is intake or exhaust, but we're guessing intake as its easier to breath out than in (try this yourself, its the same for an engine). Without taking apart both engines we won't know the actual difference. It's quite feasible the standard car has a restrictor plate somewhere intake side as apposed to the P31 having an 'improvement' somewhere.. i've seen this before. It's an easy way to starve power from the standard car so you can produce a 'performance' model.

The rumours heading around the internet suggesting the throttle mapping is different between the standard car and P31 is just not true. These cars run exactly the same software, as a result we modified both exactly the same.. and again the P31 produced more power and continued to climb until the redline where the standard car again flat-lines power around 6000rpm where it simply cannot breath in enough air.

izzyAMG

This makes me feel better that I only have the standard c63. When tuned like AE, does it yeld a higher result than P31 with torque and hp?

gthal

I thought one of the tuner companies here confirmed that the PP had revised tuning/software. Maybe I'm mistaken. Regardless, I think your results confirm what was suspected... that is, peak torque is available longer hence the higher hp rating.

RobBentley

Hi - I can only confirm what we found on these two cars, both of which where 2010 cars. The software is the same, the P31 is clearly breathing better.

I'll get a Standard vs P31 power graph up shortly...

RobBentley

This is the comparison graph of the Standard vs P31 car. Same rollers, same day, same temperature etc etc... figures quoted on the graphs are wheel horsepower.

Graph: http://www.jrtuning.co.uk/temp/c63-standard-vs-p31.jpg

RobBentley

C63 AMG Standard - Peak Wheel HP: 365hp
C63 AMG P31 Pack - Peak Wheel HP: 396hp

C63 AMG Standard - Peak Wheel Torque: 355 lb/ft
C63 AMG P31 Pack - Peak Wheel Torque: 365 lb/ft

These figures are *after* the remap. I'll dig out the standard runs when I get to the office tomorrow as I don't have them here.

natman316

Have you guys found out what the restriction is? is there a way to modify standard cars so that we can get rid of that 'restriction'?

RobBentley

Using a run-down test which is a good estimate to engine power, but obviously not 100% accurate we calculated the following:

Standard C63 - 417bhp Engine
P31 Pack C63 - 444bhp Engine

I appreciate this is lower than the AMG figures of 451bhp and 481bhp but I must admit to rarely seeing performance cars produce the 'claimed' manufacturers figures with all the ancillaries connected such as water pumps, PAS etc etc.. You've also got to remember doing the runs in 4th gear means at the end of the run we're pushing around 120mph without 120mph of ram-air which you would get on the road. This is likely to push numbers down a little too - but it does show the clear circa 30bhp of the P31 (we measured 27bhp as mentioned earlier).

I'm hopefully getting some information from an AMG specialist on Monday as to the difference between the P31 and Standard car. I'll be interesting to see exactly what it is, we're convinced its the ability of the engine to breath, but I'd like to find out where/what.

Gremlin9

Rob,

Thank you so much for posting all of this information.
This should put an end to all the p31 fanboys claiming they can feel the difference between the p31 and stock configurations.
It seems like the p in p31 should stand for placebo.

All that being said, I can still change my order but I am going to keep the p31 configuration for the brakes, calipers, steering wheel, cf, etc...

I wonder why so many with the p31 have been claiming engine hp around 520???

Rsquad911

I can for sure feel the difference between the P31 vs Non P31. I drove them back to back... (my P31 vs my friends NON P31) and the feeling was night and day. The P31 pulled harder from start to finish vs a non P31.

Members on this board have dyno'd 410-420+WHP with their P31s

watch this video...

If tuners claim 500+hp for their chipped C63s then it's safe to assume that the P31 stock does too.

Sher Judge

At last the W204 C63 saga continues in a positive light.