Interview w/ M chief engineer Biermann hints at M3/M4 0-60 in 4.3 seconds and 26 MPG

[CanAutM3]

Originally Posted by e39>all

The 0-60 time will be as good as the m5's. BMW simply will not list a lesser model's performance better or equal to their flagship models that cost much more. Also, I would wager the actual power of the new m3/4 is at least 450hp, and around 400 ft lbs torque.

When it came out, the E92 DCT M3 had the quickest advertised 0-100km/h of all models in the BMW brochures, including the E60 M5 and E63/64 M6...

It was the same when the E46 M3 came out compared to E39 M5.

I still have those brochures .

I don't see why it could not be the case with this new generation

[swamp2]

Originally Posted by CanAutM3

I am curious on the mathematical formula you used to calculate 0-60mph from a 0-100km/h number

A very rough approximation is the following:

t(100km/h) = t(60mph) * 1.036

This simply assumes that the acceleration from 60 mph to 100 km/h (about 2 mph change in speed) occurs at a constant acceleration and is equal to the average acceleration during the 0-60 mph portion. This is accurate to only about 25% for the M3, it predcts 0.15 s but the actual result is about 0.2 s. The largest error is due to the fact that most of the 0-60 time is in 1st gear but the 60 mph to 100 km/h is in second gear.

For cars of this rough power to weight 0.2 - 0.3 is a very good rule of thumb and better than the formula.

[JoeFromPA]

Originally Posted by CanAutM3

When it came out, the E92 DCT M3 had the quickest advertised 0-100km/h of all models in the BMW brochures, including the E60 M5 and E63/64 M6...

It was the same when the E46 M3 came out compared to E39 M5.

I still have those brochures .

I don't see why it could not be the case with this new generation

Huh, that's interesting. The e46 m3 was ultimately slower in a straight line than the e39 m5. Didn't know it was quoted by BMW as being faster.

The e39 m5 consistently ran faster and trapped higher. Not by much though.

[CanAutM3]

Originally Posted by swamp2

A very rough approximation is the following:

t(100km/h) = t(60mph) * 1.036

This simply assumes that the acceleration from 60 mph to 100 km/h (about 2 mph change in speed) occurs at a constant acceleration and is equal to the average acceleration during the 0-60 mph portion. This is accurate to only about 25% for the M3, it predcts 0.15 s but the actual result is about 0.2 s. The largest error is due to the fact that most of the 0-60 time is in 1st gear but the 60 mph to 100 km/h is in second gear.

For cars of this rough power to weight 0.2 - 0.3 is a very good rule of thumb and better than the formula.

Agreed. This is in line with what I would have predicted.

I expected 4.1-4.2 0-60mph from the advertised 4.4 0-100km/h. Not 4.3 as the OP posted. This is why I asked what formula he used.

[CanAutM3]

Originally Posted by JoeFromPA

Huh, that's interesting. The e46 m3 was ultimately slower in a straight line than the e39 m5. Didn't know it was quoted by BMW as being faster.

The e39 m5 consistently ran faster and trapped higher. Not by much though.

We are talking 0-100 km/h here. Not ¼ mile trap speed.

[swamp2]

Originally Posted by CanAutM3

Agreed. This is in line with what I would have predicted.

I expected 4.1-4.2 0-60mph from the advertised 4.4 0-100km/h. Not 4.3 as the OP posted. This is why I asked what formula he used.

It was a good question.

But an easy/reliable 4.1-4.2 seconds or a best?

IIRC BMW speced the E92 M-DCT at 4.7 s to 100 km/h. In reality it's best time was 3.9 s to 60 mph (thus about 4.1 to 100 km/h). With that simple math transferred to the new model we would predict a best 0-100 km/h of 3.5 s (4.1 - (4.7 - 4.1)). That could be as low as 3.3 s to 60. Now before anyone get's too excited, not that is clearly not the best way to predict this! This really crude extrapolation is probably not very accurate at all and almost for sure under predicts the time. I've predicted (through simulation) a 3.4 - 3.8 s for its 0-60 mph run (here). Either way it's darn clear it will be a sub 4.0 s car to 60 mph (some still actually don't believe this...)

[JoeFromPA]

Swamp - I think your 0-60 time and quarter mile ranges are way too optimistic on the the aggressive end of things.

Vehicles getting 0-60 in 3.4-3.6 seconds are doing it by AWD+launch control, gearing to hit it in 1st gear, and/or a lot more power.

I've followed your analyses closely and love a lot of them. However, on the acceleration front, your linked analysis appears to favor using linear increases to acceleration times when it's truly exponentially harder to drop a tenth of a second at these stages.

[pfl]

Awesome. I hope they make the launch control as easy as other competitors... sport mode for engine and traction control, mash both pedals, lift brake... *cough* C63, RS5 *cough*...

[paddy335]

0-60, who cares. Has anyone seen or heard any mention of in-gear acceleration for the new cars? Especially 50-80, that's the most relevant to me.

[tdizzle]

Sub 4 second is going to be tough. Even if the power/torque is there traction will be the biggest issue. Maybe if you used drag radials on a perfect surface. Now if it had AWD that magically added no weight...

[JoeFromPA]

Originally Posted by tdizzle

Sub 4 second is going to be tough. Even if the power/torque is there traction will be the biggest issue. Maybe if you used drag radials on a perfect surface. Now if it had AWD that magically added no weight...

Exactly. We are well into the power range where dropping a tenth of a second has less to do with power and more to do with traction.

[basscadet]

Originally Posted by paddy335

0-60, who cares. Has anyone seen or heard any mention of in-gear acceleration for the new cars? Especially 50-80, that's the most relevant to me.

Still waiting for 60-130 times myself. Let's see what this car can really do.

[CanAutM3]

Originally Posted by swamp2

It was a good question.

But an easy/reliable 4.1-4.2 seconds or a best?

We are talking conservative BMW advertised numbers here.

The math I used is quite simple. Most magazine test data suggest a 1 to 1.2 sec time for the 60 to 70mph on a DCT M3 ("similar" power to weight). Doing a linear interpolation yields a 0.22-0.26 sec time from 60 to 62.15mph.

Originally Posted by swamp2

IIRC BMW speced the E92 M-DCT at 4.7 s to 100 km/h. In reality it's best time was 3.9 s to 60 mph (thus about 4.1 to 100 km/h).

Interestingly, BMW official numbers show only a 0.1 sec difference. The Canadian brochures indicates 4.6/4.8 (DCT/6MT) to 100km/h while the US brochures quotes 4.5/4.7 to 60mph.

Originally Posted by swamp2

I've predicted (through simulation) a 3.4 - 3.8 s for its 0-60 mph run (here). Either way it's darn clear it will be a sub 4.0 s car to 60 mph (some still actually don't believe this...)

Agreed. The F8X will be much faster than that. I also expect best runs to be comfortably in the 3 sec range for the 0-60mph as tested by US car magazines (US accepted test standards). The articles refer to a specially developed PSS for the F8X; I wonder how much improved traction will result.

[pkimM3r]

Im not liking some of the responses here in terms of an "enthusiast" community. As others have mentioned, and argued against me that bmw indeed reads these forums and delivers to "enthusiasts" in this way. But its sad that these types of "wants" exist in this community that i would expect the "other" 99% of bmw owners out there to care about eg. mpg, city usable torque, comfort, blah blah. Hence this is what we are getting. I need a supercharger and call it a day.

[IEDEI]

Originally Posted by JoeFromPA

Why are you even arguing over 0-60 times? It's a completely inadequate measure of acceleration. It's too easily influenced by gearing, computerized launch, traction influences, and mechanical abuse.

quarter mile time or trap speed, 40-100, 30-70, 60-120....fine, I get it. But 0-60? C'mon. Means so little.

agreed. 0-60 times are like judging a woman only by the perkiness of her nipples. there's always so much more to the story.....

[cjwb1984]

Thanks for the link. It was interesting to read. I'm excited. There is definitely a lot of technology that went into the M4/M3. It's important to me how all of that translates into the road.

Definitely, this M4 pique my interest.

[basscadet]

Originally Posted by pkim1079

Im not liking some of the responses here in terms of an "enthusiast" community.

So what kind of things should the enthusiast community care about?

I have asked for more power, more than anything else, and I am being told that I should buy a muscle car if all I care about is straight-line performance.

[pkimM3r]

Originally Posted by basscadet

So what kind of things should the enthusiast community care about?

I have asked for more power, more than anything else, and I am being told that I should buy a muscle car if all I care about is straight-line performance.

it should come with slicks, jaw jarring suspension and a cage and no airbags .... what else would you need?

i think the new m3/4 is going to be more muscle car like...c63ish perhaps. since everyone complains about tq, which i still can't understand.

[ersin]

Originally Posted by IEDEI

0-60 times are like judging a woman only by the perkiness of her nipples. there's always so much more to the story.....

Never underestimate the importance of perkiness.

Just for comparison...
Vette: 3444 lbs / 460 hp = 7.49 lbs/hp
M4: 3306 lbs / 430 = 7.69 lbs/hp

The best time I've seen recorded for the C7 Vette is 3.7 seconds to 60. The M4 has more weight to horsepower. But also note that, IRL, some are reporting the 1/4 for the vette running 11.4 @ 119 mph, and 11.5 @ 120, which are pretty respectable.


Cheers.

[swamp2]

Originally Posted by JoeFromPA

Swamp - I think your 0-60 time and quarter mile ranges are way too optimistic on the the aggressive end of things.

Vehicles getting 0-60 in 3.4-3.6 seconds are doing it by AWD+launch control, gearing to hit it in 1st gear, and/or a lot more power.

I've followed your analyses closely and love a lot of them. However, on the acceleration front, your linked analysis appears to favor using linear increases to acceleration times when it's truly exponentially harder to drop a tenth of a second at these stages.

Thanks.

Can you expand on the important bold part above? I don't understand that at all.

My estimates for all performance results in the new M4 are based on CarTest physics based vehicle performance simulation software. It generally handles vehicle launch, wheel spin and the differences between friction coefficients for spinning vs. non-spinning conditions all quite well. It it a perfect launch algorithm, certainly not but the essence of the physics is captured. Now why have I reported a range of numbers? Again that was from a simple bracketing approach allowing for reasonable estimates of the uncertainties associated with underrating and vehicle weight.

The current M3 has already done a 3.9 s 0-60 (with standard US 1 foot roll out). What makes you think that with a significantly improved power to weight ratio, significantly more power at low rpm, very likely a new improved tire and also very likely improved LC software that at least a couple tenths better than that won't occur? Look I am not saying that your average everyday M4 driver will consistently get 3.5 second 0-60 runs. However, I am also virtually guaranteeing we will see one or more magazines run 3.8 s or less.

Not entirely directed at you but: 0-60 certainly is not the "end all be all" or the most important metric I care about. However, good results do show a combination of good engineering and design all working together, engine, transmission, differential, software, chassis, tires, etc (and of course driver). Some other metrics indeed are better at "displaying" the true power to weight of the car (and not much else...).

[CanAutM3]

Originally Posted by ersin

Never underestimate the importance of perkiness.

Just for comparison...
Vette: 3444 lbs / 460 hp = 7.49 lbs/hp
M4: 3306 lbs / 430 = 7.69 lbs/hp

The best time I've seen recorded for the C7 Vette is 3.7 seconds to 60. The M4 has more weight to horsepower. But also note that, IRL, some are reporting the 1/4 for the vette running 11.4 @ 119 mph, and 11.5 @ 120, which are pretty respectable.


Cheers.

We also need into consideration that the S55 is most likely underrated at 430ps. On the other hand, I doubt we will see many cars at 3306lbs...

[Sapper_M3]

Originally Posted by CanAutM3

We also need into consideration that the S55 is most likely underrated at 430ps. On the other hand, I doubt we will see many cars at 3306lbs...

Agreed, but if it's even POSSIBLE to spec a 3306 lb M3/M4, it will be a huge victory. I'm cautiously pessimistic (my heart can't take anticipating a 3306 lb vehicle and receiving a 3506 lb vehicle).

As a side note, thinking about the area under torque vs RPM curve is still eating away at me. If we integrate force vs time, do we get work?? Do we need to integrate twice with respect to time in order to find power???