BMW M3 / M4 Engine (S55): Deep Dive and Interview

[pkimM3r]

Originally Posted by Thurman Murch

Ok maybe second, but I'm not used to
Downshifting into 1

The dct/dsg in my other cars may have ruined this for me

I am more used to third gear as the go
To gear

Imagine downshifting and flooring like crazy in first w S55

new tires every month

[BMW M3 CRT]

Nice informative article on the new S55 engine. Just between the lines is a lot to experience about the character of the new M engine.

Completely without a doubt the new M3/M4 F8X will put the old E9x M3 in all the disciplines of driving dynamics clearly in the shadows.

But I 'm pretty sure that an F8X M3/M4 with an S65 and the old M- DCT would most likely beat the F8X with the S55 on the track and in any case it would be much easier with him to be fast on the track.

This is certainly not easy to explain, but neither hp nor torque make a car on the track really fast, but the "driveability" of the vehicle , ie the combination of linear power delivery, stiffness of body and powertrain , stable brakes , perfect suspension and good traction. In all respects (except for the first) , and the slightly lower weight , the new M3/M4 has increased performence and that makes him so fast, so that it does not play here the role that the engine is not so perfect in terms of " driveability " .
Sure , the S55 with its higher torque feels purely subjective considerably stronger than the old S65 , but this felt more power is much more difficult to optimally implement into propulsion , as the S65 where the power is very linear implement in perfect propulsion - extremely fast revving and perfectly linear power curve are the key words here.

Unfortunately, there is no way to get an F8X M3/M4 with S65 and the old M-DCT, so that the ultimate evidence, that an S65 would have been the better engine choice for the F8X specifically on the track, will not be rendered.

Greeting BMW M3 CRT

[clbmw]

Originally Posted by BMW M3 CRT

Nice informative article on the new S55 engine. Just between the lines is a lot about the character of the new M engine to experience.

Completely without a doubt the new M3/M4 F8X will put the old E9x M3 in all the disciplines of driving dynamics clearly in the shadows.

But I 'm pretty sure that an F8X M3/M4 with an S65 and the old M- DCT would most likely beat the F8X with the S55 on the track and in any case it would be much easier with him to be fast on the track.

This is certainly not easy to explain, but neither hp nor torque make a car on the track really fast, but the "driveability" of the vehicle , ie the combination of linear power delivery, stiffness of body and powertrain , stable brakes , perfect suspension and good traction. In all respects (except for the first) , and the slightly lower weight , the new M3/M4 has increased performence and that makes him so fast, so that it does not play here the role that the engine in terms of " driveability " is not so perfect.
Sure , the S55 with its higher torque feels purely subjective considerably stronger than the old S65 , but this felt more power is much more difficult to optimally implement into propulsion , as the S65 where the power is very linear implement in perfect propulsion - extremely fast revving and perfectly linear power curve are the key words here.

Unfortunately, there is no way to get an F8X M3/M4 with S65 and the old M-DCT, so that the ultimate evidence, that an S65 would have been the better engine choice for the F8X specifically on the track, will not be rendered.

Greeting BMW M3 CRT

I bet someone somewhere will put an S65 into the F80 at some point (as long as it physically fits)

[CSanto]

Originally Posted by Sir Loin

How can you make these statements before you have driven the new M3/M4? Or have you already driven the new Ms? Give us the juicy details!

No no I mean current gen M3

[MParallel]

Would have been nice if the E36 M3 (2nd gen) also listed the 3.2 model figures. The 210kw/320nm are of the M3 3.0.

The 3.2 figures are 236kw/350nm.

[V1.47fan]

Originally Posted by BMW M3 CRT

Nice informative article on the new S55 engine. Just between the lines is a lot to experience about the character of the new M engine.

Completely without a doubt the new M3/M4 F8X will put the old E9x M3 in all the disciplines of driving dynamics clearly in the shadows.

But I 'm pretty sure that an F8X M3/M4 with an S65 and the old M- DCT would most likely beat the F8X with the S55 on the track and in any case it would be much easier with him to be fast on the track.

This is certainly not easy to explain, but neither hp nor torque make a car on the track really fast, but the "driveability" of the vehicle , ie the combination of linear power delivery, stiffness of body and powertrain , stable brakes , perfect suspension and good traction. In all respects (except for the first) , and the slightly lower weight , the new M3/M4 has increased performence and that makes him so fast, so that it does not play here the role that the engine is not so perfect in terms of " driveability " .
Sure , the S55 with its higher torque feels purely subjective considerably stronger than the old S65 , but this felt more power is much more difficult to optimally implement into propulsion , as the S65 where the power is very linear implement in perfect propulsion - extremely fast revving and perfectly linear power curve are the key words here.

Unfortunately, there is no way to get an F8X M3/M4 with S65 and the old M-DCT, so that the ultimate evidence, that an S65 would have been the better engine choice for the F8X specifically on the track, will not be rendered.

Greeting BMW M3 CRT

The same thing was said about the E9X M3 compared to the E46 M3 by people who thinks anything new is better.

In reality if you participate in some grassroot racing you know it's all marketing bs both cars run similar times and when both modded the E46 M3 has an edge.

Unlike the E30 M3 or E36 M3 that did really well in their SCCA classes when they came out this car like the E9X M3 wont be competitive in AS.

[ASAP]

Originally Posted by damnitBobby

Most likely succumbing to pressures by BMW head honchos about improving fuel efficiency across the boards, including m cars

turbo cars are more efficient in that you get more hp/liter displaced.. especially when just cruising at relatively low rpm (e.g. 1.8k) turbo's really aren't in use and you are getting the fuel efficiency of a smaller displacement motor (3L vs 4L)

S65 was a marvelous engine.. i think it was just robbed of it's glory by the porky weight of the E92.. high rev motors shine in cars that are light on their feet (think rx8 and s2k).. both ridiculously fun cars to drive.. now imagine putting those motors in a car like a challenger... i think you get my point

I think bmw also realized how they screwed up when modded N54s for 20k less were running away straightline. An M3 is still an M3 but to not believe that for 80% of people straightline speed is key is simply not true.

The difference between the non m and m motor was never as small as it was in the e90 generation. I mean let's be serious, could anyone even remotely compare the s54 to one of the 330i models of the e46? not a chance

With the e90, this all changed and bmw wants to make sure this doesn't happen again. The way to do this is to provide a considerably less tunable non m motor (n55) and an M motor that is significantly better.

[TunedM2C]

^Terry said this after a quick view of the new M3 engine:

"Overall the packaging in the engine bay looks impressive. And I'm confident the F30 Stage1 & JB4 tuning we've developed will mostly carry over. It runs dual electronic wastegates. Also runs a 3.5 bar MAP sensor so I expect it makes some decent boost from the factory. Hopefully more when we're done with it."

[CanAutM3]

Originally Posted by coloradoe92m3

Gearing :
So check my math but 1st bear choice is crazy. I can't use 1st in my e92 due to traction limitations so talk about hard to launch. F80 will be really tough to put power down in first. 2nd gear is going to be downright freight train. But e92 is quite a bit shorter gearing from 2nd on.

So you can't only compare dyno plot as gears are the other half. If someone wants to create a plot with gear ratio differences taken in to account, the f80 will be way faster but not quite as much as it has seemed thus far.

Keep in mind at WOT you don't see below 6500 ROMs in e92 dct so you can't draw a line straight up as they do as you need to account for e92 power band .

So love to see area under curve of each cars WOT power band with gearing taken into account

Here you go:

I agree with you, 1st gear will be pretty much useless for maximum acceleration due to traction limitations. I am guessing that such a short gearing is necessary to maintain drivability and decent acceleration in day-to-day puttering around when the engine is not on boost.

I also agree that comparing the two engines power charts as a function of RPM is pretty much useless because it does not factor in the gearing. I plotted the max available engine power vs road speed for DCT optioned F8X and E9X on the graph below. From 35mph to 155mph (2nd gear and up on the F8X), the F8X produces an average 423hp compared to the E9X that produces 391hp. That is 8% more (not considering any underrating of the S55). It is not negligible, but not as much as the graph in the interview leads one to believe.

[CanAutM3]

Originally Posted by MParallel

Would have been nice if the E36 M3 (2nd gen) also listed the 3.2 model figures. The 210kw/320nm are of the M3 3.0.

The 3.2 figures are 236kw/350nm.

I guess they only show the launch engine on this plot. The E30 also had a 175kW engine, the E46 a 265kW engine and the E92 a 331kW engine.

But it is true that the 236kW engine was available on the standard edition of the E36, while all the bigger engines were only available on special editions for the other models.

[bradleyland]

Originally Posted by coloradoe92m3

Gearing :
E92 dct
Final-3.154
1-4.78
2-2.933
3-2.153
4-1.678
5-1.39
6-1.2
7-1.0

F80-
Final-3.46--9% shorter
1-4.8 --same-----9% shorter overall
2-2.593 14% taller------6% overall tall
3-1.7. 21% taller_------12% overall tall
4-1.27----25% taller---16% tall overall
5. 1.0-----29%_--------21% tall overall
6. .84-----30% taller----21% overall
7. 0.67...---32% taller----24% overall

So check my math but 1st bear choice is crazy. I can't use 1st in my e92 due to traction limitations so talk about hard to launch. F80 will be really tough to put power down in first. 2nd gear is going to be downright freight train. But e92 is quite a bit shorter gearing from 2nd on.

So you can't only compare dyno plot as gears are the other half. If someone wants to create a plot with gear ratio differences taken in to account, the f80 will be way faster but not quite as much as it has seemed thus far.

Keep in mind at WOT you don't see below 6500 ROMs in e92 dct so you can't draw a line straight up as they do as you need to account for e92 power band .

So love to see area under curve of each cars WOT power band with gearing taken into account

A few things to keep in mind:

1) Gearing doesn't directly effect power, it effects torque. However, side-effects of gear selection can still have an effect on measured horsepower, but that effect is spread over the entire power curve, so relative comparisons of the curve shape (like the one in the chart) remain valid. It also depends on the dyno. An inertia chassis dyno is more susceptible to these fluctuations than a load dyno, so you can still work around those inaccuracies by choosing the right chassis dyno.

2) Most chassis dyno runs are conducted in the gear ratio closest to 1:1. Differences in final drive will affect torque output, but this is easily corrected by compensating for final drive with a percentage.

3) It's unlikely that BMW used a chassis dyno for that plot anyway. Manufacturers typically have access to an engine dyno, where the engine is placed in a mount and connected directly to the dynamometer.

I don't mean to talk down to you. You probably know all of these, but sometimes things like this get overlooked because we (as enthusiasts) spend so much time looking at the information that is available to us, which is usually chassis dyno information.

Your point regarding RPM offset is well made, but if you calculate the area under curve for the S55 from 5500 to 7300 RPM, it's still going to be greater than the S65 from 6500 to 8300 RPM. I get the sense that your point isn't that the S65 would win that comparison though, just that it's not nearly as lop sided as it first appears. You can't simply draw straight lines like that.

I wish BMW provided the raw data for those charts

Also, I reformatted your gear comparison in to an MultiMarkdown ASCII table in case anyone wants it:

# Gear ratio comparison  - E92 M3 DCT vs F80 M3

| Gear  | E92 DCT | F80   | Relative Gear | Relative Overall   |
| ---   | ---     | ---   | ---           | ---                |
| Final | 3.154   | 3.46  | 9% shorter    |                    |
| 1     | 4.78    | 4.8   | same-ish      | 9% shorter overall |
| 2     | 2.933   | 2.593 | 14% taller    | 6% overall tall    |
| 3     | 2.153   | 1.7   | 21% taller    | 12% overall tall   |
| 4     | 1.678   | 1.27  | 25% taller    | 16% tall overall   |
| 5     | 1.39    | 1.0   | 29% taller    | 21% tall overall   |
| 6     | 1.2     | 0.84  | 30% taller    | 21% overall        |
| 7     | 1.0     | 0.67  | 32% taller    | 24% overall        |

[MParallel]

Originally Posted by CanAutM3

I guess they only show the launch engine on this plot. The E30 also had a 175kW engine, the E46 a 265kW engine and the E92 a 331kW engine.

But it is true that the 236kW engine was available on the standard edition of the E36, while all the bigger engines were only available on special editions for the other models.

Exactly. Could not have said it any better.

[ASAP]

If I just get a 1/4 mile run time and trap speed... all of my questions will be answered. How long must one wait?

Still saying 12.1-12.2@116-117

[bradleyland]

Originally Posted by BMW M3 CRT

Nice informative article on the new S55 engine. Just between the lines is a lot to experience about the character of the new M engine.

Completely without a doubt the new M3/M4 F8X will put the old E9x M3 in all the disciplines of driving dynamics clearly in the shadows.

But I 'm pretty sure that an F8X M3/M4 with an S65 and the old M- DCT would most likely beat the F8X with the S55 on the track and in any case it would be much easier with him to be fast on the track.

This is certainly not easy to explain, but neither hp nor torque make a car on the track really fast, but the "driveability" of the vehicle , ie the combination of linear power delivery, stiffness of body and powertrain , stable brakes , perfect suspension and good traction. In all respects (except for the first) , and the slightly lower weight , the new M3/M4 has increased performence and that makes him so fast, so that it does not play here the role that the engine is not so perfect in terms of " driveability " .
Sure , the S55 with its higher torque feels purely subjective considerably stronger than the old S65 , but this felt more power is much more difficult to optimally implement into propulsion , as the S65 where the power is very linear implement in perfect propulsion - extremely fast revving and perfectly linear power curve are the key words here.

Unfortunately, there is no way to get an F8X M3/M4 with S65 and the old M-DCT, so that the ultimate evidence, that an S65 would have been the better engine choice for the F8X specifically on the track, will not be rendered.

Greeting BMW M3 CRT

Your entire argument is predicated on the notion that the S55 will be less drivable than the S65. That is based on assumptions about turbocharging, but no one outside of BMW has even had a chance to drive the car yet. We don't know what the drivability is, so how can anyone agree or disagree with what you've said?

Simply swapping an S65 in to an F80 chassis is unlikely to produce the results you anticipate for many reasons. Not the least of which, the fact that the chassis and engine are tuned together for optimal handling and road holding. The F80 chassis is not tuned to the S65. Even if you were to tune it, the tractability of the S65 would have a difficult time overcoming the power deficit that it suffers against the S55.

I love the S65. I love high-revving, naturally-aspirated engines, but I won't delude myself in to believing that they always win against a turbocharged engine. More often than not, they lose, even given their superior tractability. That doesn't change my feelings about the N/A engine, but it keeps me objective.

[BMW M3 CRT]

Originally Posted by Taigar

Hi All,

Trying to learn something here. Engine wise, seems S55 is better every way than S65 - power, fuel economy. Why then did it take so long for BMW, Merc, Audi, VW and many others to jump on the Turbo technology only now? Is it turbo engines cost more to build, shorter life span, higher maintenance.. don't seem to be from my past Evo X experience.

Thanks for sharing.

Can not say this for Mercedes, Audi, VW and many other (form me VW and Audi makes turbo engines since a long time ago!) but for the BMW M-GmbH the answer is simple and clear ... "driveability" is the main credo of the M-GmbH since the times of the legendary first E30M3 ... "driveability" is the reason what makes all previous M3s faster than even competitors with much more hp.
And for "driveability" an linear power output is much more important than high low-end-torque ... or better high low-end-torque reduces the drivability of cars on track, simple because its an great problem to bring this torque on track without wheel spin.

So until now turbo-engines where an NoGo for the M-GmbH and high-reving N/A-engines were the perfect way to solve this problem ... an small displacement turbo-engine is perfect for an regular streetcar because you can drive it confortable without much gearchanging, but for an real sportscar an HDZ-N/A-Engine with an fast DCT-Gearbox is the perfekt solution.

But the times has changed, and also for BMW M-GmbH cost savings and Ebit/Debit are the key factor in all development and therefor also an not soal and even a little bit heavier S55 engine is the way to go, because it share probably many parts with the future BMW AG inline 6 engine family and could be produce cheaply the regular BMW engine plant. The unique S65 is made of many unique and costly special parts and must be produce in the special "Sondermotorenbau" in Munich, so that its totally clear that in the world of costs such an engine has no chance to get the okay from the shareholders.
So the M-GmbH make the best of the situation, and refines all other parts of the new M3/M4 that are possible under the cost conditions, so that they can live with the cheaper but less ideal engine solution.

[bradleyland]

Originally Posted by V1.47fan

The same thing was said about the E9X M3 compared to the E46 M3 by people who thinks anything new is better.

In reality if you participate in some grassroot racing you know it's all marketing bs both cars run similar times and when both modded the E46 M3 has an edge.

Unlike the E30 M3 or E36 M3 that did really well in their SCCA classes when they came out this car like the E9X M3 wont be competitive in AS.

Competitiveness within an SCCA class is not the same as comparing two cars directly against each other. The environment in which the E46 competed is not the same as what the E9X competed.

The E9X out performs the E46 M3 in every measurable way. The one objective thing that works in the E46's favor is its lower curb weight. Qualifying that with "when modded" is a rabbit hole. Once you start modding a car, you confound the argument to the degree that there can be no clear winner. It becomes tit for tat. Either car may be better, depending upon the modifications.

[CanAutM3]

Originally Posted by BhamDavid

Yes but they do that with 6.3 liters of displacement.

Nope. 6.2 liters

[ASAP]

Originally Posted by BMW M3 CRT

Can not say this for Mercedes, Audi, VW and many other (form me VW and Audi makes turbo engines since a long time ago!) but for the BMW M-GmbH the answer is simple and clear ... "driveability" is the main credo of the M-GmbH since the times of the legendary first E30M3 ... "driveability" is the reason what makes all previous M3s faster than even competitors with much more hp.
And for "driveability" an linear power output is much more important than high low-end-torque ... or better high low-end-torque reduces the drivability of cars on track, simple because its an great problem to bring this torque on track without wheel spin.

So until now turbo-engines where an NoGo for the M-GmbH and high-reving N/A-engines were the perfect way to solve this problem ... an small displacement turbo-engine is perfect for an regular streetcar because you can drive it confortable without much gearchanging, but for an real sportscar an HDZ-N/A-Engine with an fast DCT-Gearbox is the perfekt solution.

But the times has changed, and also for BMW M-GmbH cost savings and Ebit/Debit are the key factor in all development and therefor also an not soal and even a little bit heavier S55 engine is the way to go, because it share probably many parts with the future BMW AG inline 6 engine family and could be produce cheaply the regular BMW engine plant. The unique S65 is made of many unique and costly special parts and must be produce in the special "Sondermotorenbau" in Munich, so that its totally clear that in the world of costs such an engine has no chance to get the okay from the shareholders.
So the M-GmbH make the best of the situation, and refines all other parts of the new M3/M4 that are possible under the cost conditions, so that they can live with the cheaper but less ideal engine solution.

I am gonna stoop the point of saying that you are starting to make stuff up or are blindly infatuated with an outdated motor.

Have you ever seen any of the following on a track?

Mclaren MP-12C?
911 turbo s?
Ferrari F40?
Nissan GTR?

All turbo cars with turbo engines that would blow away nearly anything NA... in fact the only credible NA cars around the Ring that are left are the Vettes, Vipers and the Lexus LFA. Two of those have gigantic motors that are unfit for an M3 and the latter is a $375K supercar.

[bradleyland]

Originally Posted by CanAutM3

I agree with you, 1st gear will pretty much useless for maximum acceleration due to traction limitations. I am guessing that such a short gearing is necessary to maintain drivability and decent acceleration in day-to-day puttering around when the engine is not on boost.

I also agree that comparing the two engines power charts as a function of RPM is pretty much useless because it does not factor in the gearing. I plotted the max available engine power vs road speed for DCT optioned F8X and E9X on the graph below. From 35mph to 155mph (2nd gear and up on the F8X), the F8X produces an average 423hp compared to the E9X that produces 391hp. That is 8% more (not considering any underrating of the S55). It is not negligible, but not as much as the graph in the interview leads one to believe.

Fantastic chart. It's really amazing to look at that flat line for the F80 once you pass 70 MPH. That thing is going to be a monster on the straights.

[Black Gold]

Originally Posted by BMW M3 CRT

Can not say this for Mercedes, Audi, VW and many other (form me VW and Audi makes turbo engines since a long time ago!) but for the BMW M-GmbH the answer is simple and clear ... "driveability" is the main credo of the M-GmbH since the times of the legendary first E30M3 ... "driveability" is the reason what makes all previous M3s faster than even competitors with much more hp.
And for "driveability" an linear power output is much more important than high low-end-torque ... or better high low-end-torque reduces the drivability of cars on track, simple because its an great problem to bring this torque on track without wheel spin.

So until now turbo-engines where an NoGo for the M-GmbH and high-reving N/A-engines were the perfect way to solve this problem ... an small displacement turbo-engine is perfect for an regular streetcar because you can drive it confortable without much gearchanging, but for an real sportscar an HDZ-N/A-Engine with an fast DCT-Gearbox is the perfekt solution.

But the times has changed, and also for BMW M-GmbH cost savings and Ebit/Debit are the key factor in all development and therefor also an not soal and even a little bit heavier S55 engine is the way to go, because it share probably many parts with the future BMW AG inline 6 engine family and could be produce cheaply the regular BMW engine plant. The unique S65 is made of many unique and costly special parts and must be produce in the special "Sondermotorenbau" in Munich, so that its totally clear that in the world of costs such an engine has no chance to get the okay from the shareholders.
So the M-GmbH make the best of the situation, and refines all other parts of the new M3/M4 that are possible under the cost conditions, so that they can live with the cheaper but less ideal engine solution.

no offense, but this post is ridiculous

the m3 isn't, never has been, and never will be a real sportscar. its well over 3000 lbs and is fattened up by a ton of luxury items.

who cares if the s65 is made by gnomes, elves, the "sondermotorenbau" or whatever. I don't even know what that means, or how its relevant to the performance of a given engine / car.

the m3 is also faster than most of its competitors because it is lighter and has a superior chassis and often times brakes. its not because the motor is more "tractable". if that's the case, then why is the gt2 rs so damn fast and blows the doors off a gt3? shouldn't be the case since the motor is turbo and too powerful and not "tractable" according to you, no?

fact is that modern turbo engines are not hard to drive on the track, even for novices like myself. my 997tt had zero lag problems, crazy driveability prolems or anything of the like. it basically felt like a really good chassis with a huge motor and great brakes.

you love the s65, that's fine. but get out of here with the notion that the s65 is somehow faster or better than the s55 in terms of performance. its not, end of story. game over. done.

[bradleyland]

Originally Posted by ASAP

I am gonna stoop the point of saying that you are starting to make stuff up or are blindly infatuated with an outdated motor.

Have you ever seen any of the following on a track?

Mclaren MP-12C?
911 turbo s?
Ferrari F40?
Nissan GTR?

All turbo cars with turbo engines that would blow away nearly anything NA... in fact the only credible NA cars around the Ring that are left are the Vettes, Vipers and the Lexus LFA. Two of those have gigantic motors that are unfit for an M3 and the latter is a $375K supercar.

I understand the love affair with engines like the S65. I'm waiting on the F80 to hit the market so I can snap up an E92. I want the S65, but I'm fully aware that it will be out performed by the F82.

[CanAutM3]

Originally Posted by Skhmund

I have gotten mixed messages on this forum, but is the S55 based off the N55? Some say it is, some say it's a whole new block, some say it shares a few parts.

The N54/N55 was the design starting point, but the S55 is a brand new engine with very little parts in common with either the N54 or N55. It has a new block, oil sump, crank shaft, rods, pistons, head, turbos, intake, intercooler, etc...