Does the M5 have too much torque?

[dapperdan]

In deciding what car to get I was questioning if the F10 M5 had too much torque. That is, is there any point during regular city/highway driving where the car is NOT traction limited. I would be very interested in everybody's opinion.

I am taking delivery of my M5 next week and can report some first hand info then. I ordered the car based on test driving it and its competitors, loved it, and loved the torque, but got to wondering if it was all needed other than at the track.

So, being a computer type, I wrote a little acceleration simulator in Perl. It models all the following

• Engine torque curve
• Drivetrain losses
• Gear ratio
• Drag
• Downforce
• Rolling resistance
• Estimate of inertial mass of rotating parts
• Weight transfer to back during acceleration
• Traction

My understanding of the way that traction works is that for a decent road tire and with good use of the accelerator, the tire can push forward with about the same force as the downwards weight on the driving tires. An F1 car can do way better than this, and bad tires on a bad surface way less.

When the car is accelerating full out, weight transfers to the back. My modelling tells me about 66% heads towards the back. Given the car and passenger is about 4400 pounds, and downforce adds relatively little until high speed, that means the car is limited to pushing forwards with only about 4400*66% = 3000 pounds of force. Given the gear ratios and such, my little simulator says that almost right around 100 km/h (2nd gear @ 6000 RPM) all the engine torque can be put down on the pavement.

Once you shift to 3rd, the driving force on the tires at the highest part of the torque curve is about half the weight of the car, so you are golden in 3rd.

So that means when cruising down the highway at about 100 km/h in 3rd gear (a very regular happening), we are no longer traction limited and so, no, the M5 does not have too much torque! Phew!

Does your practical experience jibe with this?

[RPiM5]

I've spun the tires in 4th gear with DSC ON going UP hill when I still had my F10 M5 stock. Yes it has a lot of torque. Also read my signature.

[mindlessmark07]

There is no such thing as too much torque. Its the best feeling in the world to know its there whenever you want it. You will love your new M5!

[chrisratz]

I also have conducted a thorough scientific analysis, and have concluded with 99.97% certainty that torque is fun.

[PatrickC23]

Does the M5 have partial DSC? The C63 has three dsc settings. Fully on, partially on, or off. I do find that with DSC on i always spin the tires and kick dsc on in first. Does the M5 come with a "fun" mode that also corrects wheels spin when it feels it needs to?

[AGS]

Originally Posted by Patsc23

Does the M5 have partial DSC? The C63 has three dsc settings. Fully on, partially on, or off. I do find that with DSC on i always spin the tires and kick dsc on in first. Does the M5 come with a "fun" mode that also corrects wheels spin when it feels it needs to?

Yes, its called M Dynamic Mode (MDM). Here's the excerpt from the manual describing MDM:

M Dynamic Mode MDM
M Dynamic Mode makes it possible to drive on
a dry roadway with high longitudinal and transverse
acceleration but with limited driving stability.
Only in the absolute limit area does the system
intervene for stabilization by reducing the engine
power and by braking interventions on the
wheels. In this driving condition, additional
steering corrections may be necessary.

Limited stabilizing interventions
When M Dynamic Mode is activated, stabilizing
interventions are carried out only to a reduced
extent. You must react yourself; otherwise,
there is the danger of an accident
occurring.◀

To increase vehicle stability, activate DSC again
as soon as possible.

[dapperdan]

Originally Posted by RPiM5

I've spun the tires in 4th gear with DSC ON going UP hill when I still had my F10 M5 stock. Yes it has a lot of torque. Also read my signature.

I think there is even less traction going up hill because there is not as much weight pushing directly down on the road. I mean, if you were going up a 90 degree wall you'd get no traction at all

[uhn2000]

Torque is nuts but its so much fun even in a scary way - reminds of my recently sold K1300R motorbike, way too much power for the street. I have never driven a car that is this brutal on instant demand. Yes too fast for the street but its just one of those things where you know you won't use all the power but its nice to know its there ?!?!

[kiwistu]

My new M5 feels nearly as touquey as the 335d I had. Now that was a monster!

[mainly]

Originally Posted by mindlessmark07

There is no such thing as too much torque. Its the best feeling in the world to know its there whenever you want it. You will love your new M5!

well its not REALLY there whenever you want it.

[Rob///M5]

<edit>

Torque goooood. Moar torque.

[krispykreme]

Torque is what made F10 M5 stands out over the E60.

I love torque. The more the better.

[UniqueCheese]

I regularly get to tinker with cars that have 800 to 1200 ft-lb of torque. I don't play with the big boys that run up to 5000 or so ft-lbs, maybe more, I don't actually know. The point is, when you ask a drag racer what happened while they're stood there holding a driveshaft the resembles a pretzel their answer is always the same. It's never "too much torque", it's always "too much grip".

There's no such thing as too much torque, there's only too much grip, or not moderating your use of it properly. Learn to use the tools you've paid for properly and maintain them right and everything will be fine. That applies to more than just this car.

[boots]

I love it when I nail it from 1st to 2nd and it slides, then the same from 2nd to 3rd and it slides. Yep dsc kicks in but that is the fun of it. If your worried about the car being too much for you, there is always a mild 4 clyinder ready for sale somewhere.

[Timberwolf]

This is a fantastic argument that would have me recommend a 550i XDrive. You'll have big torque without the wheel spin. Get the Dinan tune and you have 580tq and all go no spin whatsoever. Spinning tires isn't for everyone. Some are more comfortable with it than others. I've owned Corvettes among many other cars and have developed a comfort level with a lil spin.

[dapperdan]

But it's not all about straight line traction. Torque is also useful when accelerating off the apex, and then you want good weight balance and a good diff that can properly balance the torque. And in that regard, not all AWD cars are created equal.

[RPiM5]

Originally Posted by dapperdan

I mean, if you were going up a 90 degree wall you'd get no traction at all

Challenge accepted!

[GTR-Dad]

I think your calculations are pretty good. (What did you use for Cg?) It takes a good road surface to fully hook up in second, but the fact that you need to pay attention makes it all the more fun.
I find the torque adequate in most situations, but must agree with Mainly that you can get caught flat footed sometimes. This is a very responsive turbo car, but it's still not as immediate as a naturally aspirated one.

[dapperdan]

By Cg do you mean the height of the centre of gravity? I estimated it at 0.8m by eye-balling my E60! It's the one number I am not at all confident in and can't find any reference for on the M5. Frustrating!

[GTR-Dad]

Originally Posted by dapperdan

By Cg do you mean the height of the centre of gravity? I estimated it at 0.8m by eye-balling my E60! It's the one number I am not at all confident in and can't find any reference for on the M5. Frustrating!

Yes, centre of gravity. It defines the moment arm that drives weight transfer, and is one of the spec's I've never run across either. If it's lower than 0.8m, then you're traction limited to even higher speeds because you have less weight transfer than expected. If it's higher, then you should hook up sooner.

My experience says you're pretty close.