late_bloomer

Show pics of your RS4 please! Your c63 BS is sick!

anthonymckay

Yeah, this is throwing me off as well, though I have seen some dyno data posted somewhere on the forums that seemed to back this up to an extent. Something about the actual hp at the crank of a c63 w/ p31 being more than the advertised 481, and in the graphs, showed it being nearly the same as their ecu tune applied to a basic c61. Hearing that it's not much different than the c63 BS is a bit surprising though... I'd really like to the graphs from a p31 vs BS comparison.

anthonymckay

Here's a video kind of demonstrating what I had read about somewhere previously. Anyway, this is why I'm wondering if it's worth getting a tune on my p31 c63 if it's not going to make much of difference. ~$2 for a tune is a lot if the improvement is extremely minimal.

Race 1 & 2: non-p31 stock vs. p31 stock
Race 3: non-p31 tuned vs. p31 stock

Higgs Boson

almost makes you wonder if those 1000 dollar tunes are simply a p31 map loaded onto your non p31 ecu.....that's steep....how much is a p31 ecu and can it be installed on a non p31 car?

Even Money

ECU costs about 1500, IIRC. Then it would have to be VIN coded to the car. That's where you would run into issues, since the computers in Germany would recognize that the car is not a P31.

neoprufrok

Here's a shot.

mainly

well, if the factory hp ratings are accurate, then the CBS(factory 510 hp) SHOULD dyno higher than the p31(factory 481 hp)


doesnt make sense to say the factory ratings of two different cars are 481 and 510 but they both dyno the same...



this would suck , especially if you have just spent the price of two c63's on one CBS.

NellyRod

My BS stock put down 429-432 RWHP on 3 separate dyno's, on 3 separate days. Very consistent results. If we're using the 18% drive train loss rule, then that would put the BS at roughly 525 HP stock. MB typically under rates their numbers from what I've seen.

Mort

I have seen 2010 P31 results of ~425 rwhp on a dynojet. Using the 18% drivetrain loss rule results in ~ 518hp at the crank.

neoprufrok

This is what its' sounding like. That the P31 C63 dynos the same as the C63 Black engine.

Higgs Boson

so is the black over rated or is the development package under rated?

how about through a limited slip diff? those "can" rob some power and if the black comes with one and the dp car doesn't have on it can bring the rwhp closer but not 30 hp.....

BerBer63

BS is under powered...kinda sad

anthonymckay

I dont know that I'd call the BS under powered by any definition. It sounds more like the p31 has been under rated a bit. I'd still really love to take my p31 to a dyno the same day as someone with a BS to do a side by side comparison. If anyone in the Bay Area has a stock BS and would like to do this, let me know!

Zod

power is nearly the same, saw one run at the Bahrain gulf run track, think it did 12.6 116mph so yeah same ball park avg

Higgs Boson

too many variables to compare a car around the world. a c63 in Dallas will run 12.5 but in El Paso the same car will run a 14.

neoprufrok

Should have taken you up on the offer before I ecu'd it.