slfmde

http://f80.bimmerpost.com/forums/sho....php?t=1000992

Ingenieur

He made a quantitative and financial mistake
Must have lost his *** on that transaction
For no real world difference ( mpg will be better )

The c63 IS 2 generations old
Basically e46 era more than e9x

Ingenieur

Sportauto c63 507 test
http://www.germancarforum.com/commun...ion-507.49154/
0-200 kph 13.5 sec vs 13.7 for the m4
600 lbs heavier
Less tire
Less balance 55/45 vs 51/49
Dct vs auto ( slower shift and more losses)
And a 7 year newer design

Hmmmm...
Something doesn't compute
Hp 485 vs 507
Torque 445 vs 490
According to the op dyno numbers
The m4 has almost 10% more torque and is 15% lighter but is slower?

alexmtl

I think there is no shame admitting that the new generation of your competitor's car is faster than your old gen car. No surprises here. What's surprising is how much the M4 is underrated from the factory.

CarHopper

Sigh.

70k for an m4 that is new.
2013+ c63 is still going to run you 70k.

Why not just get a honda for 3k and drop 67k on mods? Faster than both and probably sounds better than the m4 too.

Honestly, I'm a little butthurt with both bmw and mercedes. The w205 is a miss in the design department. The German left out here? Audi. In my opinion, they have been quietly killing it. Have you seen the new line of the s6?







The best part too is that you can get a 2013+ S6 for less than the m5/c63. Just a tune on the s6 and it keeps up with the m5 and actually smashes it off the line. (I'm such a hypocrite, comparing a stock car to a modified car)

Anyway, sorry to get off topic. But Audi is killing it. The worst thing in my mind is that the RS6 isn't over in the states. I would LOVE the RS7 but you're talking E63S money at that point so it would be a tough choice.

roadtalontsi

audi's are like the lexus of luxury segment. On paper they look great but drive like cardboard.

Holy crap that sounds terrible. I wouldnt even go with the rice burner sound. Thats straight up like early 2000's v6 camaro and mustang with hacked up exhaust. i dont care how fast it is if it sounds like that.

CarHopper

^ Wait, what? Drive like cardboard? Can you elaborate because I don't understand what that means.

slfmde

Once the aftermarket catches up I bet they will improve on the sound a lot.

alexmtl

Like this ?

tofu-

new m3/4 sounds like the old n54 engine. very similar design, so that's expected. it's no v8, but it's not THAT bad. it's just different.

terry (@BMS) already has his m3 at 480whp with an alpha piggyback, which is basically just a boost controller for now. These will probably make 500+whp on meth/e85 when a proper tune is dialed in.

Mike3

As a current M3 owner, and someone who follows BMW way more than Benz. I can tell you i truly believe the next 4.0L V8 AMG is going to be a better engine than the M4 S55 engine.

The fact that AMG is going to share the 4.0L with other higher models shows how much potential this engine will have.

Its going to sound better, and make more power. These M4s also sound like crap when compared to a 5.5 Bitrubo AMG, the old 6.2L v8, and even the E92 V8.

JumpinJim

Don't get why everyone gets so up in arms over this stuff. It's a chunk of metal. Give credit where credit is due. Technology moves forward. The new M is more powerful, a lot lighter, and has a better transmission. That's a good thing. It spurs competition. Something to be outdone. You really want to buy the same car over and over with just a different face on it year after year?


It almost seems BMW is quoting their HP and TQ at the wheels, not the crank. My M5 put down 560 hp at the wheels which is the power BMW claims what I thought was crank hp. If that's what they're really doing then I like this approach much better. We drive cars, not engines. It would be nice to see what power the car is actually making instead of having to apply some arbitrary mythical drivetrain loss number. Some of which I've seen are up to 25% if they're to be believed, which on a modern car is absurd. Manufacturers and tuners like that unknown variable to hide overrated engines and tunes.

Mike3

I really want a Z06 corvette. I think it looks so badass, and that S/C American V8 is going to sound better than anything coming out of Germany.

the problem with me is that i feel the corvette are not safe cars.

Ingenieur

You need to be objective
It's not faster. Dynos are BS
I'm no fan boy, 6 BMW's before this (3 m3, 535i, 2002 and my wides 735i, over a 30 year period and well over 1/2 mil miles)
My first MB

The numbers are BS
507 445/507
M4 485/490 according to this dyno
M4 600 lb lighter, dct, better balance,larger tires
Yet to 124 mph the c63 is faster

Same driver, test procedure, location, alt density
How can this be?

Look at torque / weight
Why? Everyone uses wt/power
F = ma or a = F/m
F = torque x gear ratio / tire radius - losses or thrust
So t/wt is proportional to acceleration
Lets assume
Wt = 4000 lb
Tire r = 1' to make the math easy
Losses 10%
Avg torque x gears ~ 2500 lb ft net 2250
F or thrust = 2250 lb ft / 1' = 2250 lbs
a = F/m = 2250 lbs / 4000 lbs = 0.56 (lbs cancel...what unit?)
Since we used lbs for wt and did not convert to slugs
a = 0.56 is in g force
The true measure of a cars ability to accelerate is t/m

t / m
M4 0.136 no units since gearing and r not considered
507 0.107
Both with 200 lbs of load
The M4 is almost 30% higher accel factor
Why then is the 507 faster to 124 mph

Do not take numbers at face value
Think for yourself
Convince yourself

Anyone who equates shame or pride with car speed is a douche
It's easy to say the new z06 will smoke a c63
It's not as clear with the m4

Ingenieur

Then compare the new w205 with the new m4
Your comparison is not valid
Like comparing a c63 to an e46
Almost as silly as your honda bs

tofu-

erm... if you want to be objective, you should be looking at trap speeds, not ET.

Ingenieur

Rate of accel determines trap speed
V = a t
For a given time, the bigger a, the higher the velocity
Or trap speed
Both cars could have the same trap but one has a lower et
Do they both have the same power? Obviously no
No, one has more torque or higher accel ( or at least puts it down better)

We KNOW this
Same driver, test, etc
0-124
507 13.5
M4 13.7

tofu-

That doesn't make any sense. you can't determine trap speed from 0-124 times. ET does not take wheel spin into consideration. I could run a 13.5 1/4 mile in a stock 335, while you spin your tires into oblivion with a c63, somehow pulling off a 13.8. That doesn't make the bmw faster.

Ingenieur

Hockenheim
Same driver

M4 is 1.2 sec faster on 72 sec lap
About 1.5%
Why so close?
It's 15% lighter
Wider and better tires pss vs 5p
Ceramic brakes
Better weight
Much higher lb/hp ratio 7.4 vs 8.3 10% better
So why slower straight line
And barely a second on the track?
???

tofu-

for the record, the stock m3/4 trap speed is 118mph, tuned (480whp) 125mph, based on a single vbox sample.

tuned c63 trap 121 on average. not sure about stock.

the numbers add up fine.

tofu-

the problem with your analysis is that it is susceptible to human error.

like i said, look at trap speeds to determine which vehicle is quicker.

Ingenieur

Take it up with Newton

You have to assume equally efficient runs
0-124
M4 13.7
C63 13.5
It is FACT that the m4 will be going LESS THAN 124 at 13.5 sec
Probably 2 mph or so
So thecis accel faster
To do so it must have more thrust or torque

Ingenieur

Same driver
1000's of laps
He sets times faster than factory drivers
They do numerous laps and take the best
Not my analysis
It is fact
As measured with the same instruments that measure trap and et lol

tofu-

ok. the vbox is all a lie then.



i won't bother arguing if you're going to base your numbers on lap time stupidity and mere theory.

we already have the hard numbers.

m3/4 is the quicker car. it's also the newer car, so that's completely fine.

Ingenieur

So they trap the same stock or close
Yet the m4 has 10% more torque and is 600 lbs lighter
Not in this inertial reference frame lol

0-124
M4 13.7
C63 13.5
How???