Chocofishez

Been seeing a lot of threads regarding tunes and wicked times at the dragstrip.

A couple people have commented that the P31 actually has more than the advertised 481 hp... that it's closer to the #s on the E63 or S63.

Is this true? Any way to know for sure? I'd love to tell my M3 driving buddy that I have 100hp more than him.

tasho3

well they are all hand built engines so they cant all be as advertised, so it might be a chance a few of them are lose to 500 if not 500, but even so the M3 has 414 so no way u got 100 hp on his M3

propain

Hand assembled yes, not hand machined. You can bet if one P31 is more than 481 all of them are with very small variations in HP up or down between them.


From what we have seen it seems that way though. They stay pretty close to a tuned C63.

DD GT3 RD

they seem to dyno around 420whp on a dyno jet so that would suggest so.

this would be at 15%, 18%, 20% and 25% drivetrain loss.

420x1.15= 483

420x1.18=495

420x1.20=504

420x1.25=525


I also raced an OE tuned C63 with my stock P31 and we were dead even.

My 60-130 time is faster than anyone has ran over here on the West Coast tune only, and 0.05 seconds slower than Jon ran in his OE tune only car on the East Coast, and well Propain just raped everybody with his 9.41, also on the east coast.

dodger63

Wait jon still has the fastest c63 ever to be produced and its not a p31

I am Jeff

LOLz

MB_Forever

The unofficial agreed upon number for the drivetrain loss (for AMG vehicles) is 18%. So it is safe to say the car produces at least 490 hp. However, I have seen a couple of them dyno at 401 whp on a dyno jet.

It is very hard to judge by dyno because they can be all over the place. I've seen E63s dyno from 380 whp to 435 whp

DD GT3 RD

I found 3 dynos online and they ranged from 417-427 so I went with 420. But you are definitely correct, stupid dynos!

Dark_Knight

at Porsche they told me all engines meet advertised hp rating, they told me that German law is that it must be within 10% and every engine they produce if it is under they dont pass it and anything over 10% has to be taken apart too, but 10% of 481 is 48hp

_AMG_

The P31 is rated at 485hp, there are some freak motors out there that will do 500 I think.

Ok, I came up with a formula for my personal results.
Baseline dyno for my car was 356HP with 2ndary cat delete on Dyno Dynamics. Advertised crank HP rating for the C63 is 451HP.

356hp x 1.267 = 451hp (crank)

Currently im at 418HP with OE Tune + MBH X pipe.
418HP x 1.267 = 529HP (crank)

I dont know how accurate this is but I figure its pretty close enough.

propain

60-130 the P31 sure did hold its own. If your back to the stock file I really want to see what it does in the 1/4. That will give more info comparing to a tuned non P31 as well.

Bigbob

If an engine is ratted at 500 hp at the crankshaft and the car has a 20% loss because of drive train loss than you would expect to see 400 hp on the dyno at the wheels and that would mean you take the 400 and use 1.25 (20%) and that gets you back to 500 hp.

1.25 is for 20% loss

ALLDATAdiy INFO

I also imagine there could be a difference within the different dyno's, air temperatures, and other varying factors as well.

Jons95c36amg

Your funny! Yes I have the fastest TUNE ONLY C63 60-130! See sig

MBH motorsports

First things first, There should be no agreed upon driveline loss number. A dyno operator should know from experience what his machine gets for parasitic power loss. Each dyno machine and the setting used bla bla bla, have to be factored in.

For a lot of people who own a CLS55 would know the rated number at the crank is 469. Those who have been any type of dyno would know the CLS 55 puts out about 500hp. With that said It would not surprise me that the P31 C63 puts out 500hp. Granted you get some SLS goodies in a P31 C63, but they bump the power up with a simple software remapping. In fact It might cost Mercedes more money to develop a new tune that makes more power than the C63 and less than an E63.

IMO, They run a full size 63 file in the new P31 C63. They just dont market it to the public that way. Why? Because they do not want to devalue their product. I mean you can have a $60K C63 making the same power as a $125 SL63. At least you don't market it that way.

Remember they need to sell SL63's, S63 and what not to the guy who has the loot and wants the baddest of the bad. Also, the C63 guys with a p31 package, will never complain about to much power. So by simply stating the p31 C63 has slightly less power than an E63 or SL63 is just how Mercedes words it on paper to keep everything in order. With the old saying, You spend more you expect more.

c32AMG-DTM

Hey DD - just FYI, I think your formula for calculating this is incorrect.

If: bhp x (1 minus driveline percentage loss) = whp

Then: whp / (1 minus driveline percentage loss) = bhp... not "whp x 1 plus driveline percentage loss = bhp"

So,

420/.85=494

420/.82=512

420/.80=525

420/.75=560

FWIW, 18-20% are the most commonly accepted driveline loss estimates I've seen suggested for running an AMG on a DynoJet. YMMV.

A car mag (Modified, perhaps? Don't recall) ran an interesting tech article awhile back about how driveline losses aren't a fixed percentage anyway, and to truly know the bhp of your modified engine, you'd really have to put it on an engine dyno. So these estimates aren't really worth much other than bragging rights among each other. But fun nonetheless

propain

What is your opinion on Mercedes putting up 36XX pounds as the curb weight of the C63 on their site and in their manuals?

I am sick of debating with rilval cars that the C63 is really 39XX without the driver and the rival cars always say "Well then why does MB say its 36XX"

khmergod

BHP/1.xx loss=WHP
WHP x 1.xx=BHP

khmergod

I have no idea why they put 4000 lbs on my pink slip.

c32AMG-DTM

Both incorrect.

If one assumes that there's an 18% driveline loss estimate, it means that 82% of the horsepower/torque generated at the crank makes it to the rear wheels. Dividing by 1.18 is not a correct formula to apply when estimating an 18% loss from the original value.

I'll prove it to you. Switch to something easier to understand... dollars. Joe has 500 dollars to invest. He loses 18% of his original investment. That means he lost 90 dollars. So he should have 410 left. Using your formula, 500/1.18 = 423.73. Obviously incorrect. 500 x (1-.18) = 410. See the difference?

If Y is the percentage-loss-estimate expressed as a decimal, the algebraic formula is

BHP x (1-Y) = WHP, or WHP/(1-Y) = BHP

@ 18% estimated loss, BHP x .82 = WHP, or WHP/.82 = BHP.

khmergod

Thanks for clarifying. Let me go to my corner and contemplate my failure.

Chocofishez

I definitely see the logic in this post which is why I think it's likely the P31 motor has all that power. Why would MB spend more to give less? Easier to just put a lower number on the spec sheet.

But to know for sure...Is it not as simple as looking at a bunch of different 'baseline' numbers? put 2-3 'normal' C63s on the dyno then do the same with some P31 cars and check to see if there is more than a 30hp difference on average?

Surely the shops offering aftermarket goodies for the C63 would have baseline data for the two types of cars before they add modifications?

c32AMG-DTM

Well, there's another way to do that too. Look at dyno results from pre-MCT E63s, S63s, et al. Many of them dyno right around 420 whp... which is where the P31 C63 seems to be as well. So, I think it's extremely plausible to state the car is underrated from the factory, and actual output is in line with the other non-restricted M156 variants.

Mort

I just checked out the C63 Curb Weight in several places.

MBUSA AMG site: Curb Weight = 3924 lbs.

Canadian 2010 C-Class brochure = 3916 lbs.

GVWR on B pillar of my car = 4862 lbs. (2210 kG) Less Max Load 847 lbs (385 kG) = 4015 lbs.

I am not sure where MB says the curb weight is 36xx lbs. but that is not what the above sources indicate. Perhaps that is the dry weight of the car without fluids.

Even Money

I weighed at some scales, stock, with me(180lbs) and full tank...4220. I figure the gas about 120 lbs....so around 3900 empty seems right.