Big.b

Finally, my 507 had a few runs on the dyno in 4th gear.
The numbers are not that impressive but I am told at this elevation it can be a challenge. Any way, I have to say when I compared it to my M3 I am pretty happy. My c63 is completely stock vs my 2008 BMW M3 E90 at the following mods;

Turner Race Software
SuperSprint Race Exhaust - catless...
4.10 rear diff

507 HP - 384.90 Torque - 356.96
BMW M3 HP - 354.46 Torque - 259.59

I was really surprised that the 507 had almost 100 more torque at the wheel across the rev range.

roadtalontsi

no replacement for displacement. the 507 is hard to beat in the value/fun department. Enjoy them both! interesting to see the power difference in stock vs minor mods. thanks for posting this.

Big.b

Thanks!
The M3 is long gone by the way.

odonnks

What elevation was that ?

Baked

How is there that much of a loss? I had my stock viper dyno'd years back at davenport prior to supercharging and it was rated at 450hp at the crank and the dyno read 405 hp at the wheels.
How can this go from a crank rating of 507 down to 385 at the wheels?

Big.b

1,084 m (3,557 ft)

Big.b

Not sure why there was that much loss...
To be honest I am not overly concerned.
I just wanted to share the comparison between the two cars.

odonnks

Generally speaking, elevation caused horsepower loss at the crank will could be estimated by:
hp loss = (elevation x 0.03 x hp @ sea level)/1000

Then add the drivetrain losses of another 15% (estimated)

I come up with 385 hp at your elevation of 3557 ft.

Thanks!

Big.b

Thanks!

Big.b

Interesting fact,
My old M3 after the mods would keep with with a 2010 M5 down the front straight at Race City in Calgary. For those who don't know Race City, before it closed it had the longest front Straight of any race track in N.America.
So to see that my 507 puts down noticeably more torque and almost 10% more HP, I am okay with the numbers.

coladin

Using that formula, the calculation is a 53bhp loss then? I found info stating that 3500ft would be approximately 17.5% loos of hp, 5% per 1000 ft, which using the numbers of the dyno would be 520bhp at the crank.

Ingenieur

the 53 HP is for altitude
add another 15% for driveline losses
0.85 x (507 -53) = 385

when you use a proper density calculator works out to 4.5%/1000' above seal level

in this case 0.85 x (507 -0.155 x 507) = 365

papashango

So P31 at same elevation would do;

0.85 x (481-53) = 355.85?

Got to say that's pretty disappointing for a car that says it has 481hp

Ingenieur

Physics does not play favorites
Without knowing the temp, humidity or atm pressure hard to compare

Ramp dynos are useless, chances are more slip with the AMG since it has so much torque
Steady state is the ONLY valid test
Run up to peak hp rpm at light throttle
Increase load and as rpm drops give it throttle
Once throttle is 100% and rpm is at hp peak
Hold 10 sec and take a reading

Or run some times at a strip
Amg much heavier and much faster
So it has much more torque

Ingenieur

Here's another way to look at it:
3600' asl
Relative hp 0.85
Amg 507 to 430
M3 420 to 357 (stock hp)
Measured with alt and driveline losses
Amg 385 from 430 or 13% in losses
M3 355 from 357 < 1% losses

The m3 mods must have made 10 to 15% more than stock
But the torque doesn't lie
Mods don't really change it
Only displacement , comp ratio and boost mone of which none apply

Can't draw any real conclusions

benyl

NA cars suffer huge in Calgary due to density altitude.

25c and we are over 6000' DA. 30c and we are over 7000'.

I remember ripping a new one for a troll on Beyond for arguing that an E46 M3 only makes 270hp (220rwhp) in Calgary on a hot day. I'll see if I can find the thread.

Big.b

I really appreciate the info.
I am new to the dyno world.

HardC63

Dyno numbers mean squat!

Dynos are just a tuning tool, do not get hell-bent on dyno numbers - elapsed times is what matters - whether you race in the 1/4 mile, 1/2 mile of full mile.

Remember, your old bimmer had gears (4.10 or 4.11) and typically, vehicles with gears will show lower dyno numbers, but accelerate much harder in the real world - on the road. Again, dynos are just for tuning, not for racing or predicting the outcome of a particular race.

Keep in mind that Mercs are typically heavy vehicles - so even if your Merc may have dyno higher vs your old bimmer, the true measurement of speed and NOT the dyno HP lies underneath a clock use to measure your times. Meaning, which ever car achieves whatever racing platform you choose first is the winner - plain and simple.

Hope this helps

dubzAMG

My p31 dynoed at 400 whp, 370 ft/lbs-stock.

Big.b

I agree 100%!!!
I am curious if anyone has done different gearing on the C63 and if it has made a difference? For me it was the most important mod on my old M3. The drive out of the corners on the track was noticeably better...

Thanks for the feedback

roadtalontsi

first of all vipers are under rated in power just like most of the lsX gm products (wifes 02 trans am ws6 is rated at 330 crank hp 350tq stock, with headers only it made those numbers at the wheels on a mustang dyno). Dynos will alway vary. Mustang awd dynos being tend to give very conservative numbers compared to others. I've dyno'd on a couple different dyno jets and it just depends on how they are calibrated and modified as to the accuracy. Also there is a much larger power loss between automatics and manual transmissions. Even with mct it's still an automatic, just uses wet clutches rather than a torque converter. Im no physicist but typically you're looking at 15% loss from crank to wheels on a manual, add another 5% for automatics, and another 5% for awd. Im interested to see how some of these new awd's will put down the power, since mb 4matic isnt really awd and more of a selective 1-3wd. lol.

benyl

Here is the thread. The 220 rwhp number is calculated based on 1/4 runs on youtube at race city and looking up the density altitude at the time of the runs.

http://forums.beyond.ca/st2/2002-bmw...98#post3610098

Excuse the attitude. Luxor is a troll. haha.

The youtube videos of the runs seem to be gone though.

chris135b

I found a link that does a 3% loss per 1000 feet: http://www.wallaceracing.com/braking-hp.php
Either way (3% or 5%) it is good to see the car making in, around or above 500 HP. Depending on an 15% or 18% drivetrain loss, I come up with 489 hp or 502 hp from the 3% loss which is right on par with the original branding from MB: "The Edition 507 with a 37 kW (50 hp) to 373 kW (507 hp) and 10 Nm to 610 Nm combines performance, dynamic design and a sporty interior design. The standard-fit AMG Driver's Package increases the top speed to 280 km/h." The 5% loss is even better!


Also, it's good to see the torque numbers! We see higher torque numbers than what is advertised! No wonder winter was a bit interesting...even with the Winter Tires!



It just goes to show us how truly special these cars are and the fact that we have the privilege to have a collector's item in our possession.

Happying everyone.


-C

ML63 AMG

altitude is hell on power... Numbers look right on.

I couldn't believe it when I saw your barometric pressures in the 26.xx range, wow that is low (high altitude)

coladin

Which is nice to see as many in another p31 v 507 blah blah blah thread stated that the 507 would be just a number and realistically a p31 with a fancy shmancy look.