Speculation on which one will be faster: M3 or M4

[Flying Brick]

Since, Majority of us believe that The New M3/4 will be faster then the M3 GTS. Let Speculation on, which one of the M's would be faster. M3 or M4?

Please state your reason.

M4/M3 Track Videos.

[ShePearl]

Performance will most likely be identical.

[GotEM4]

Since it has the same engine, it will depend on who is the better driver...

[Flying Brick]

There is a miner difference in the Curb weight between the 2 cars. Plus the chassis of the cars will be different. Which will make some difference on the track to get a better lap time.

[M4TW]

Originally Posted by Flying Brick

Speculation on, which one of the M's would be faster. M3 or M4?

Please state your valid reason.

If speculation can be validated, then doesn't it stop being speculation? Anyway I speculate that they will be about the same until higher speeds at which point the lower drag coefficient of the M3 - .31 vs. .34 - might give it a slight advantage. A .03 advantage to be precise.

[damnitBobby]

M4 is ~50lbs lighter according to the weights in the official threads

i say the difference will be negligible..

[JustChris]

Performance must be near identical but M4 looks faster

[nonagon]

Slightly lower center of gravity and slightly lower weight gives M4 a slight edge.

[CanAutM3]

Faster is a very broad term. I am assuming it means around a race track. I believe the difference will be marginal with a slight edge going to the M4 with its 50lb lower weight and lower center of gravity.

[CanAutM3]

Originally Posted by M4TW

If speculation can be validated, then doesn't it stop being speculation? Anyway I speculate that they will be about the same until higher speeds at which point the lower drag coefficient of the M3 - .31 vs. .34 - might give it a slight advantage. A .03 advantage to be precise.

According to the Tech Specs in this thread, both the M3 and M4 have the same Cd of 0.34. It is the E9X M3 that has a Cd of 0.31. The M4 also has a slighty smaller frontal area compared to the M3 (2.23 vs 2.29) that plays in its favour in terms of drag, but I don't think it will be significant.

[Flying Brick]

Originally Posted by CanAutM3

Faster is a very broad term. I am assuming it means around a race track. I believe the difference will be marginal with a slight edge going to the M4 with its 50lb lower weight and lower center of gravity.

Yes, around the race track.
I am hoping that no one is planning to do any racing with the M3/M4 on the streets .

[M4TW]

Originally Posted by CanAutM3

According to the Tech Specs in this thread, both the M3 and M4 have the same Cd of 0.34. It is the E9X M3 that has a Cd of 0.31. The M4 also has a slighty smaller frontal area compared to the M3 (2.23 vs 2.29) that plays in its favour in terms of drag, but I don't think it will be significant.

Oops I misread that. They both have the same coefficient. Wouldn't the smaller frontal area, if it did make a difference, show up in the coefficient?

I guess the M4 would have an advantage based on weight. 50 pounds is worth about 5 hp or .05 in the 1/4. Since it is a race however it will come down to the drivers and which car came out of the factory better.

[ss134]

Identical performance IMO. The weight difference is slight- a fat driver in the M4 and a thin driver in the M3 and now the M3 is lighter...full fuel tank vs 1/4 tank, heavily optioned car vs no options- this is the difference in weight we are talking about- negligible.

[Boss330]

If we are talking straight line performance, as that is what quite a few of the replies seems to adress, then those numbers are allready listed in the official spec threads and gives a advantage to the lighter M4.

If you mean lap times around a track with similarly equipped cars, the same advantage should be visible for the M4 again. It's got a lower CoG and less weight, that aids both acceleration, braking and cornering.

The above also assuming same driver and everything else equal. In real life, not a great advantage to either is my guess, as most drivers aren't able to extract 10/10ths of such a cars potential anyway

[CanAutM3]

Originally Posted by M4TW

Wouldn't the smaller frontal area, if it did make a difference, show up in the coefficient?

I am not sure what you mean with this question.

Cd is a dimensionless factor that represents how "slippery" a given shape is in an airflow regardless of its size. For instance, a cube of 1x1x1 inches will have the same Cd as a cube of 3x3x3 feet. To establish the drag force, one needs to multiply the Cd by the frontal area of the object. For instance, despite having the same Cd, the 3 foot cube will have a drag resistance force 1296 times greater than the 1 inch cube when exposed to the same airflow.

Due to its greater frontal area, the M3's drag will be 2.7% greater than the M4's (assuming that their Cd are really equal at 0.34 and not rounded off).

[M4TW]

Originally Posted by CanAutM3

I am not sure what you mean with this question.

Cd is a dimensionless factor that represents how "slippery" a given shape is in an airflow regardless of its size. For instance, a cube of 1x1x1 inches will have the same Cd as a cube of 3x3x3 feet. To establish the drag force, one needs to multiply the Cd by the frontal area of the object. For instance, despite having the same Cd, the 3 foot cube will have a drag resistance force 1296 times greater than the 1 inch cube when exposed to the same airflow.

Due to its greater frontal area, the M3's drag will be 2.7% greater than the M4's (assuming that their Cd are really equal at 0.34 and not rounded off).

Gotcha. Thank-you for taking the time to explain that to me. I always assumed that Cd was a useful comparative number to understand how a car slices through air resistance. If I understand what you are saying, for that comparison, you need to know the frontal area as well.

[BlackLight]

less weight, lower CG, smaller area.

And more skilled drivers, seeing how they choose the better car...

[Sapper_M3]

The M4 will certainly be faster. After all, it's 1 more than the M3, isn't it? Simple logic, folks.

[Blindside_137]

Is this for real?

[swamp2]

Originally Posted by CanAutM3

the 3 foot cube will have a drag resistance force 1296 times greater than the 1 inch cube when exposed to the same airflow.

No, if the cube is traveling in a direction parallel to the normal of any face, it will have a drag force 9 times as large.

[Flying Brick]

Originally Posted by Sapper_M3

The M4 will certainly be faster. After all, it's 1 more than the M3, isn't it? Simple logic, folks.

Best logic I have read so far.

[Sedan_Clan]

Originally Posted by Blindside_137

Is this for real?

I was going to pose this exact question. The difference is so negligible that it won't matter.