M3 vs M5 0-60 - GEARING!

[swamp2]

Guys if you missed it we have all of the gear ratio information for the new beast including the final drive. This makes for some fun spreadsheeting! As you probably know the E46 M3 did not have all that great of a power to weight ratio. It did still manage a pretty impressive 0-62 (5.2 s quoted by BMW but many found more like 4.8 s). It accomplished this through a few things but mostly by low gearing (torque multiplication). The new M3 has a significantly larger final drive than than M5 3.846 vs. 3.62. Taking into account each gear ratio, the final drive, the wheel size, an estimate of drivetrain loss and weight the M3 has a significant advantage in acceleration at almost all rpms in 1st gear (the M5 gets a very slight advantage from 6k- 7k rpm from its pronounced torque peak there).

The % advantage looks something like this:

• 3000 12%
• 3500 12%
• 4000 9%
• 4500 6%
• 5000 5%
• 5500 3%
• 6000 -3%
• 6500 -2%
• 7000 -1%
• 7500 1%
• 8000 5%
• 8250 8%

I figured there would be wheel spin up to at least 3k rpm, maybe higher with a good launch. Redline in 1st gear puts the new M3 at 42 mph, the M5 at 46 mph. The acceleration advantage goes to the M5 across the board at all engine speeds during a maximum acceleration run in all other gears.

(Note: Things missing in my fairly simple analysis: rolling resistance and air resistance. These should be fairly close though for both vehicles)

OK what's next? If that was it the M3 would be the clear winner. The traction from the M5s 285 tires and the .3 - .4 second advantage from SMG vs 6MT on the 1st to 2nd gear shift will also make quite some difference. It is nearly impossible to estimate how much the stronger acceleration in the M3 will be offset by these advantages.

Put some 295 or 305 width tires on the M3 and get it with the dual clutch system and I'd place my bets on the M3 besting the M5 0-60 mph. As it is released, 6MT and stock tires it is going to be really interesting.

[esquire]

well done swamp. here's hoping you're right =)

[GregW / Oregon]

swamp2,
Did you take tire diameter into account? The E92 has larger tires than the E46, and I think the E60 M5 has larger tires still.

[swamp2]

Originally Posted by GregW / Oregon

Did you take tire diameter into account? The E92 has larger tires than the E46, and I think the E60 M5 has larger tires still.

All tire diameters are in my spreadsheet. Although the effect of tire size can be seen it is the individual gear ratios, final drive, torque curve and weight that are the dominant effects.

[MI6]

Originally Posted by swamp2

Guys if you missed it we have all of the gear ratio information for the new beast including the final drive. This makes for some fun spreadsheeting! As you probably know the E46 M3 did not have all that great of a power to weight ratio. It did still manage a pretty impressive 0-62 (5.2 s quoted by BMW but many found more like 4.8 s). It accomplished this through a few things but mostly by low gearing (torque multiplication). The new M3 has a significantly larger final drive than than M5 3.846 vs. 3.62. Taking into account each gear ratio, the final drive, the wheel size, an estimate of drivetrain loss and weight the M3 has a significant advantage in acceleration at almost all rpms in 1st gear (the M5 gets a very slight advantage from 6k- 7k rpm from its pronounced torque peak there).

The % advantage looks something like this:

• 3000 12%
• 3500 12%
• 4000 9%
• 4500 6%
• 5000 5%
• 5500 3%
• 6000 -3%
• 6500 -2%
• 7000 -1%
• 7500 1%
• 8000 5%
• 8250 8%

I figured there would be wheel spin up to at least 3k rpm, maybe higher with a good launch. Redline in 1st gear puts the new M3 at 42 mph, the M5 at 46 mph. The acceleration advantage goes to the M5 across the board at all engine speeds during a maximum acceleration run in all other gears.

(Note: Things missing in my fairly simple analysis: rolling resistance and air resistance. These should be fairly close though for both vehicles)

OK what's next? If that was it the M3 would be the clear winner. The traction from the M5s 285 tires and the .3 - .4 second advantage from SMG vs 6MT on the 1st to 2nd gear shift will also make quite some difference. It is nearly impossible to estimate how much the stronger acceleration in the M3 will be offset by these advantages.

Put some 295 or 305 width tires on the M3 and get it with the dual clutch system and I'd place my bets on the M3 besting the M5 0-60 mph. As it is released, 6MT and stock tires it is going to be really interesting.

If you look at the temperature inversion of 5% plus the aerodynamic extrapolation of .8% and using the energy formula of E=mc 2 you can see why Bernoulli's theorem gives the M3 a .5% advantage.............

[monsta]

Originally Posted by swamp2

Guys if you missed it we have all of the gear ratio information for the new beast including the final drive. This makes for some fun spreadsheeting! As you probably know the E46 M3 did not have all that great of a power to weight ratio. It did still manage a pretty impressive 0-62 (5.2 s quoted by BMW but many found more like 4.8 s). It accomplished this through a few things but mostly by low gearing (torque multiplication). The new M3 has a significantly larger final drive than than M5 3.846 vs. 3.62. Taking into account each gear ratio, the final drive, the wheel size, an estimate of drivetrain loss and weight the M3 has a significant advantage in acceleration at almost all rpms in 1st gear (the M5 gets a very slight advantage from 6k- 7k rpm from its pronounced torque peak there).

The % advantage looks something like this:

• 3000 12%
• 3500 12%
• 4000 9%
• 4500 6%
• 5000 5%
• 5500 3%
• 6000 -3%
• 6500 -2%
• 7000 -1%
• 7500 1%
• 8000 5%
• 8250 8%

I figured there would be wheel spin up to at least 3k rpm, maybe higher with a good launch. Redline in 1st gear puts the new M3 at 42 mph, the M5 at 46 mph. The acceleration advantage goes to the M5 across the board at all engine speeds during a maximum acceleration run in all other gears.

(Note: Things missing in my fairly simple analysis: rolling resistance and air resistance. These should be fairly close though for both vehicles)

OK what's next? If that was it the M3 would be the clear winner. The traction from the M5s 285 tires and the .3 - .4 second advantage from SMG vs 6MT on the 1st to 2nd gear shift will also make quite some difference. It is nearly impossible to estimate how much the stronger acceleration in the M3 will be offset by these advantages.

Put some 295 or 305 width tires on the M3 and get it with the dual clutch system and I'd place my bets on the M3 besting the M5 0-60 mph. As it is released, 6MT and stock tires it is going to be really interesting.

wow thats an interesting analysis, I can't wait to do some real world testing w/ my M5 boys...M3>M5 0-60 probably true since M5 is has trouble from a dig since its torque is low we'll see how we fair out but after 60 I hope we can keep up... M5

[Epacy]

Was going to make a thread about the gearing. What is everyone's take on the numbers and what do you think it correlates to?

[swamp2]

Originally Posted by MI6

If you look at the temperature inversion of 5% plus the aerodynamic extrapolation of .8% and using the energy formula of E=mc 2 you can see why Bernoulli's theorem gives the M3 a .5% advantage.............

Is this admiration of science or dising me for being too technical?

[ndahbar]

Also note that the new M3 uses the exact same gearbox as the 335i, but of course with a much more aggressive final drive ratio (3.846 vs 3.08).

Of course, this is referring to manual 6-spd in both cars.

If you want to verify this, look at the recently-released press kit PDF (all the way down) and then look up the 335i manual ratios on bmwusa.com, for example (under technical data).

[swamp2]

Originally Posted by ndahbar

Also note that the new M3 uses the exact same gearbox as the 335i, but of course with a much more aggressive final drive ratio (3.846 vs 3.08).

Of course, this is referring to manual 6-spd in both cars.

If you want to verify this, look at the recently-released press kit PDF (all the way down) and then look up the 335i manual ratios on bmwusa.com, for example (under technical data).

I noticed the exact same thing immediately as well doing my spreadsheeting. One thing I conclude from this is that the 6MT in the M3 will actually be the tranny from the 335i. Since the two cars produce about the same torque the 335i unit should serve the M3 just fine. All gears exactly the same is just too much coincidence. BMW needs to save every penny they can, many engine parts from M5, many chassis parts from 335i, brakes from M5, ... tranny from 335i. Makes no difference to me, but I think Scott, our insider, claimed that the 6MT was developed specifically for the M3.

[Epacy]

So, does the gearing lend itself to low-end acceleration?

[M3onTwomps]

Here's a neat tool posted by Carver on M3forum.com:

http://www.bgsoflex.com/shifter.html

[M&M]

SMG doesn't have a 0.4 sec advantage shifting from 1st to 2nd.

[Sharpshot]

Originally Posted by M&M

SMG doesn't have a 0.4 sec advantage shifting from 1st to 2nd.

Okay, then tell us what it has. Can't just say that without proving yourself.

[M&M]

It has no advantage over someone who can shift.

[Driver72]

Why do people really care about 0-60 mph times? They meant something way back in the day when that was a big test of performance for cars.

Now, 1/4 mile is what you need to look at for acceleration from a dig.
And I wish their would be more tests of acceleration times of 30-100 mph starting in 2nd gear for all cars and for faster cars a 50-130 mph starting in the best gear for each car.

BTW, to the OP a 0-62.1 mph (0-100 kph) time in 5.2 seconds would be about right for a car that did 0-60 in 4.9 seconds.

Now back to the topic at hand, I think the M5 will beat the e92 M3 in acceleration, especially as speeds climb into triple digits.
The M5 is a beast above 100 mph.
But the M3 won't be too far behind

[swamp2]

I agree 0-60 is more like bragging rights and is seriously launch/traction limited. I did however, just run some E92 6MT vs. E60 M5 SMG simulations with CarTest (have you seen my other posts on this topic - the software has been shown to be quite accurate and predictive). It shows the M3 getting the jump in time to distance (not necessarily time to speed) vs. the M5 up to about 80 mph (rougly 8 or so seconds). Then as we might say "intuitively" the M5 really pulls ahead. Of couse the M-DCT will likely stay physically ahead in a drag for quite a bit longer, perhaps up to even the 150 mph territory, if it can get a good launch with that system.

[Driver72]

yeah, I have had CarTest for years.
But unless you adjusted the shift speeds of the SMG, that will be off.
Also, I noticed, CarTest doesn't do well with Forced Induced engines ( I know that isn't relative with the M cars).
And lastly, many engines are underrated (like the 335i) so it's hard to use CarTest accurately in those cases.
But granted it is pretty accurate a lot of the time, at least the ET's in the 1/4 but for some reason the 1/4 mile traps (and speeds into the triple digits) are often listed on CarTest as being a decent amount slower than what the car's really do.

Sill, I don't see the e92 doing 0-60 times better than 4.4 seconds (like the M5)
The M5's are also doing the 1/4 in the low 12's @ 115+ mph
I think with the E92 M3 you'll see the following best times:
12.6-12.7 @ 111-112ish for the manual
12.5-12.6 @ 112-113ish for the DSG version

[swamp2]

Originally Posted by Driver72

yeah, I have had CarTest for years.
But unless you adjusted the shift speeds of the SMG, that will be off.
Also, I noticed, CarTest doesn't do well with Forced Induced engines ( I know that isn't relative with the M cars).
And lastly, many engines are underrated (like the 335i) so it's hard to use CarTest accurately in those cases.
But granted it is pretty accurate a lot of the time, at least the ET's in the 1/4 but for some reason the 1/4 mile traps (and speeds into the triple digits) are often listed on CarTest as being a decent amount slower than what the car's really do.

Sill, I don't see the e92 doing 0-60 times better than 4.4 seconds (like the M5)
The M5's are also doing the 1/4 in the low 12's @ 115+ mph
I think with the E92 M3 you'll see the following best times:
12.6-12.7 @ 111-112ish for the manual
12.5-12.6 @ 112-113ish for the DSG version

CarTest FTW! You not only have to adjust the shift times manually to match SMG or DCT but you also have to change the integration time step too a much smaller value. See my post on M3 vs R8 via CarTest here then look at my post #40 where I followed up with the dialed in DCT simulations.

I also noticed the same problems with FI engines. The 335i is particularly difficult to get right as it is not only FI but under-rated as well.

AFA besting the 4.4 0-60 time I suspect we will see it. It won't be the average time reported by mags but C&D already got 4.4 and they claimed the road surfaced sucked and was quite slick. With M-DCT we will definitely see that number as you'll save about .25 seconds on the 1-2 shift before 50 mph.

I think your predictions of the 1/4 mi times are pretty close although the best yet for the MT seems to be only 12.9 thus far (but again same slick surface here from C&D).

[Driver72]

Originally Posted by Brisk

the e92 M3 6spd manual tranny is being used in the 335i manual aswell without oil cooler, and a 335i 6spd manual with chip and exhaust already kept up with a modded M5. will be interesting.

Just to be clear, the 335i I think you're speaking of (Sherwin's car) had a lot more than just the PROcede v2.0 and an exhaust.
It also had Downpipes, larger intercooler and I can't remember what else is on Sherwin's car.
And it only kept up until about 120 mph from a 50 ish mph roll), after that the lightly modded E60 M5's pulled away.
I think a PROceded v2.0 335i with just exhaust would keep up with a stock e60 M5 until about 120 mph too, but the little screaming V10 would pull after that.
I also think a 335i with PROcede v2.0 alone will run side by side with the e92 M3

[swamp2]

Brisk, Driver72P: As I have stated (too many times to recount). If all you want is a drag car you will be able to spend less than the price differnce between the M3 and 335i and best the M3. However, the if all you really want it the best drag time you should spend a lot less on a used Mustang and supercharge and nitrous it!

The M3 is about A LOT more than draging.