M4cs Power output analysis - This S55 variant is quite potent

[mechanic75]

Originally Posted by shortseller

I too prefer a more linear power band and the CP seems to have delivered that to me based on what I had with my non CP 2015. But pretty sure most reviewers I’ve read seem to really like the CS variant the best of all the F series Ms, Joe Achilles comes to mind off the top of my head, even over the 2018 CP he did beforehand(where he was having major traction issues). But he did say the CP with a set of correct tires would be extremely close enough to consider if one wanted to save the money. So many might argue the CP is the sweet spot in the variants.

I was referring specifically to the power delivery. On certain roads (tight and twisty and short runs between corners) I think the CP power delivery is slightly better than the CS, or suits how I drive perhaps. In every other area the CS wins.

I have a long drive in my CP tomorrow so will get a refresher in before I hand it to the new owner.

[franzzz]

Originally Posted by mechanic75

I was referring specifically to the power delivery. On certain roads (tight and twisty and short runs between corners) I think the CP power delivery is slightly better than the CS, or suits how I drive perhaps. In every other area the CS wins.

I have a long drive in my CP tomorrow so will get a refresher in before I hand it to the new owner.

True.
It's very hard to drive CS in the "street performance" conditions like mountain o road in not perfect conditions

[shortseller]

Originally Posted by mechanic75

I was referring specifically to the power delivery. On certain roads (tight and twisty and short runs between corners) I think the CP power delivery is slightly better than the CS, or suits how I drive perhaps. In every other area the CS wins.

I have a long drive in my CP tomorrow so will get a refresher in before I hand it to the new owner.

Yeah, I get your point. Enjoy your last run in the CP, and even better will be the CS waiting on your return. Cheers!

[BlakesGarage]

I have a whole video comparing stock power Non ZCP vs CS tune on an actual dyno with 91oct "California Sucks" fuel. CS tune has an amazing power delivery.

[CanAutM3]

Originally Posted by BlakesGarage

I have a whole video comparing stock power Non ZCP vs CS tune on an actual dyno with 91oct "California Sucks" fuel. CS tune has an amazing power delivery.

Yes, I did see your video

However, it is too bad that you guys did not do the pulls over the complete power band up to redline. I would have been interesting to see how the different tunes compare in the upper ranges of the RPM band.

[overlook637]

Originally Posted by CanAutM3

Sorry to nitpick, but in general terms, gear ratio do not affect the level of power being transmitted between "the engine and the ground". Gear ratios alter the torque and rotational speed, but the power being transmitted remains the same.

So we should be able to accelerate as fast in 7th with the 0.671 ratio that divides power as we do with the 1st gear which multiplies power 4.806 times.

The engine power is "altered" by either multiplied gear ratio in 1-4. its 1:1 ratio in 5th. Then the power is "altered" by a negative ratio 6th and 7th.

Sure the engine power is the same. But the work put down to the ground is not.

________DCT________MT

1st____4.806______4.110
2nd____2.593______2.315
3rd____1.701______1.542
4th____1.277______1.179
5th____1.000______1.000
6th____0.844______0.846
7th____0.671

[overlook637]

Originally Posted by BlakesGarage

I have a whole video comparing stock power Non ZCP vs CS tune on an actual dyno with 91oct "California Sucks" fuel. CS tune has an amazing power delivery.

Did he look at temp logs or just assume/guess that the stage 1 tune caused a heat soak on a single dyno run that it had to pull timing back.

Looked to me that he just made a guess about why the power at the end was less. A simple review of the engine timing and air temp would show if heat soak was or was not a issue.

[CanAutM3]

Originally Posted by overlook637

So we should be able to accelerate as fast in 7th with the 0.671 ratio that divides power as we do with the 1st gear which multiplies power 4.806 times.

The engine power is "altered" by either multiplied gear ratio in 1-4. its 1:1 ratio in 5th. Then the power is "altered" by a negative ratio 6th and 7th.

Sure the engine power is the same. But the work put down to the ground is not.

________DCT________MT

1st____4.806______4.110
2nd____2.593______2.315
3rd____1.701______1.542
4th____1.277______1.179
5th____1.000______1.000
6th____0.844______0.846
7th____0.671

You are confusing power and torque. Further, don't forget the final drive, even in 5th, 6th and 7th the torque is augmented.

Let's assume an S55 engine that makes 406lb-ft while spinning at 4000rpm, which means it is making 309hp (406x4000/5252). Couple this engine to a 1:2 ratio gearbox and the output of the gearbox is 812lb-ft at 2000rpm, which is still 309hp (406x2000/5252). Change the gear ratio to 1:3 and the torque output increases to 1218lb-ft while the speed reduces to 1333rpm, but it still makes 309hp (1218x1333/5252).

Acceleration follows Newton's second law F=ma. The force "F" is the torque at the wheel divided by the rolling radius, so a=Twheel/(rrolling*m). The 406lb-ft of engine torque at 4000rpm is much more augmented at wheels by the gear ratio in 1st than it is in 7th gear (6755lb-ft vs 943lb-ft), hence why the car accelerates more in 1st.

However, as I stated in an earlier post, when acceleration is stated as a function of power, it follows the following equation: a = P / (v * m). This implies that the faster a car travels, the more power is needed to sustain a given acceleration rate. So going back to your example of 1st and 7th gear, if you have the engine at 4000rpm, the engine makes the same 309hp of power in both gears and the same amount of power goes to the wheels, but you are travelling at 19mph in 1st while you are travelling at 136mph in 7th, hence why the car accelerates much more in 1st despite making the same amount of power.

[EricSMG]

Originally Posted by mechanic75

I was referring specifically to the power delivery. On certain roads (tight and twisty and short runs between corners) I think the CP power delivery is slightly better than the CS, or suits how I drive perhaps. In every other area the CS wins.

I have a long drive in my CP tomorrow so will get a refresher in before I hand it to the new owner.

Interesting. In what way, specifically? Bottom, mid, high end? On/off throttle response? Sudden WOT response? Etc.

I've been driving the PISS out of my CP in tight/twisty canyon runs and really getting to know its strengths and weaknesses.

[Debtm3]

Originally Posted by shortseller

I too prefer a more linear power band and the CP seems to have delivered that to me based on what I had with my non CP 2015. But pretty sure most reviewers I’ve read seem to really like the CS variant the best of all the F series Ms, Joe Achilles comes to mind off the top of my head, even over the 2018 CP he did beforehand(where he was having major traction issues). But he did say the CP with a set of correct tires would be extremely close enough to consider if one wanted to save the money. So many might argue the CP is the sweet spot in the variants.

Funny story... yesterday I was about to pick up a m2 comp then I receive A call from my dealer telling me I can get an incredible deal on a M3CS, I put the M2 deal on hold while walking and talking to everyone I know that loves cars and ask them for their opinion I was about to make The decision to pick up the M2 because of the manual but still I wasn’t 100% sure. after more pacing I found Joe’s achiles phone number on Instagram, he reviewed both cars I figured that I would call him so that’s what I did I apologize For bothering him and just said please help me with my predicament what car do you prefer? he also had another YouTuber fiend of his in the car and they both said the CS is a “much better car and it’s his dream car” anyway the guy is awesome he wasn’t upset very cool guy!

[Debtm3]

Well considering that the cs is leasing very very very close to the M3 competition after the drastic incentives BMW is giving to the dealers to get rid of the cars I think the CS is the sweet spot for the M3 lineup

[SeanWRT]

Originally Posted by Debtm3

Funny story... yesterday I was about to pick up a m2 comp then I receive A call from my dealer telling me I can get an incredible deal on a M3CS, I put the M2 deal on hold while walking and talking to everyone I know that loves cars and ask them for their opinion I was about to make The decision to pick up the M2 because of the manual but still I wasn't 100% sure. after more pacing I found Joe's achiles phone number on Instagram, he reviewed both cars I figured that I would call him so that's what I did I apologize For bothering him and just said please help me with my predicament what car do you prefer? he also had another YouTuber fiend of his in the car and they both said the CS is a "much better car and it's his dream car" anyway the guy is awesome he wasn't upset very cool guy!

Did you ask how he likes the AMG GTR compared to m3/4 cs he now call dream? GTR is about the first torquey car he's ever reviewed and look how he raved about it. He just love every single torquey car after it and the CS just happen to be one of them. He's so addicted to torque that he even complained there's nothing at the middle and low end with 610p R8 plus V10.

BMW handles the best in its class and M3/4 is much more accessible than the exotics, hence the dream. Following torque+handling logic, moving forward his financial situation improves with the growth of his channel, his dream will move up to the 992 turbo.

This can hurt to some but all you need with the S55 is a flash to 450-500ps as you wish and grippy tires to handle the power nothing else. The rest is to pick up a platform from F80/82/83/87 to your taste.

CS cosmetic is something to love, though that's another topic.