Adaptive M Suspension..Is it needed?

[BMW M4 PWR]

Originally Posted by nicknaz

I might have missed it, but from reading the M4 GTS press release it looks like it has full coilovers with mechanically adjusted dampers (i.e. not computerized adaptive dampers)

If that's true, it would be interesting to hear about why adaptive dampers weren't fitted.

Clearly because BMW's fastest car *ever* on the Nurburgring needed an "inferior" suspension to go FASTER than all the active gismo ones *on the track* where it counts... Lol

And yes, like yourself I passed on them too. M division did a phenomal job with the valving on the passive set-up. I actually drove the EDC first and was going to order my M4 with it until I managed to test drive a non EDC M4 and changed my order... put the $1000 in extra mods, money better spent in my mind...

[dmnc02]

Originally Posted by nicknaz

I might have missed it, but from reading the M4 GTS press release it looks like it has full coilovers with mechanically adjusted dampers (i.e. not computerized adaptive dampers)

If that's true, it would be interesting to hear about why adaptive dampers weren't fitted.

Agreed: obviously Porsche went the opposite way with the GT3 and GT3 RS.

[TRZ06]

Originally Posted by BMW M4 PWR

Clearly because BMW's fastest car *ever* on the Nurburgring needed an "inferior" suspension to go FASTER than all the active gismo ones *on the track* where it counts... Lol

And yes, like yourself I passed on them too. M division did a phenomal job with the valving on the passive set-up. I actually drove the EDC first and was going to order my M4 with it until I managed to test drive a non EDC M4 and changed my order... put the $1000 in extra mods, money better spent in my mind...

That's not really a fair comparison. You are talking about car that is made for the track first, not the street.

Tracks in general do not have or need the damping that street driving requires. The suspension doesn't need to deal with a lot of things that cars are subjected to on the street, nor does it need to work as hard, therefore it doesn't require as advanced damping.

Also, on that some theme, coil-overs allow for ride hight adjustment and corner weighting, another thing that isn't a top priority off the track.

I never say passive systems suck, I said they are inferior than their counterparts for what they are required to do.

Hell, on an ideal track, track cars don't even need suspension damping at all, look at go-carts.

[W///]

Originally Posted by 16M3

Whether you should or should not get Adaptive is subjective. I just test drove a '15 M3 with Passive and it was great. Firm but not jarring, damping was excellent. Not questioning the technical and overall superiority of the Adaptive. I intend to test drive adaptive very soon. However as of now I would be fine with Passive. Can't wait to order.

Agreed. I drove an M4 with passive suspension along with 19" wheels and it rode just fine

[Racer20]

Originally Posted by nicknaz

I might have missed it, but from reading the M4 GTS press release it looks like it has full coilovers with mechanically adjusted dampers (i.e. not computerized adaptive dampers)

If that's true, it would be interesting to hear about why adaptive dampers weren't fitted.

Because adaptive dampers are appropriate for street cars, and racing coil overs are appropriate for track cars. Simple as that.

Nobody has said adaptive dampers are better than track coil overs for track duty. They DO have higher capability for street comfort and light track duty than the OEM Passive suspension.

[CanAutM3]

Originally Posted by BMW M4 PWR

Clearly because BMW's fastest car *ever* on the Nurburgring needed an "inferior" suspension to go FASTER than all the active gismo ones *on the track* where it counts... Lol

And yes, like yourself I passed on them too. M division did a phenomal job with the valving on the passive set-up. I actually drove the EDC first and was going to order my M4 with it until I managed to test drive a non EDC M4 and changed my order... put the $1000 in extra mods, money better spent in my mind...

BTW, dynamic suspensions were so good, that they were banned form F-1 because they made the cars too fast

[dmnc02]

Originally Posted by Racer20

Because adaptive dampers are appropriate for street cars, and racing coil overs are appropriate for track cars. Simple as that.

Originally Posted by CanAutM3

BTW, dynamic suspensions were so good, that they were banned form F-1 because they made the cars too fast

Hmmm. These two statements seem a bit contradictory.

And if Racer20 is right, does that mean that the Porsche GT3 RS (or even the last GT2 RS) is less of a track car than the M4 GTS? Or does it mean that the BMW Adaptive M Suspension is not as sophisticated as PASM?

[TRZ06]

Originally Posted by dmnc02

Hmmm. These two statements seem a bit contradictory.

And if Racer20 is right, does that mean that the Porsche GT3 RS (or even the last GT2 RS) is less of a track car than the M4 GTS?

You can't cross compare between manufactures shocks.

Keep it apples to apples.

The same logic applies to Porsche. Non-adaptive to adaptive.

You take the same shock of any manufacture, one being adaptive and one passive and the active one will do a better job on the street to counteract being upset.

Non-adaptive are used for racing applications because of the things listed above. Adjustability, more controlled surface/environment, etc.

No passive shock that has to be tuned for a specific range will match one that is designed to adjust on the fly in milliseconds thereby giving it a greater performance range.

Do not take that as passive systems suck, because that is not true obviously, but apples to apples, same shock , one passive the other active, the active will out perform it in chassis/body control.

[dmnc02]

Originally Posted by TRZ06

You can't cross compare between manufactures shocks.

Keep it apples to apples.

The same logic applies to Porsche. Non-adaptive to adaptive.

You take the same shock of any manufacture, one being adaptive and one passive and the active one will do a better job on the street to counteract being upset.

Non-adaptive are used for racing applications because of the things listed above. Adjustability, more controlled surface/environment, etc.

No passive shock that has to be tuned for a specific range will match one that is designed to adjust on the fly in milliseconds thereby giving it a greater performance range.

Do not take that as passive systems suck, because that is not true obviously, but apples to apples, same shock , one passive the other active, the active will out perform it in chassis/body control.

The question was: why didn't BMW fit its Adaptive M Suspension to the M4 GTS?

Racer20 offered a very general statement:

Because adaptive dampers are appropriate for street cars, and racing coil overs are appropriate for track cars. Simple as that.

My point was that such a general statement does not seem to fit the evidence, since Porsche provides adaptive dampers on its most track-oriented cars. Moreover, according to CanAutM3,

dynamic suspensions were so good, that they were banned form F-1 because they made the cars too fast

So, back to BMW's decision, why did they do that? Does the decision reflect the fact that BMW's Adaptive M Suspension is not as sophisticated as, say, PASM? Does it reflect the fact that BMW expects that a M4 GTS will spend more/less time on the track or on the street than a GT3 RS or GT2 RS? Or does it reflect some other considerations?

[Racer20]

Originally Posted by dmnc02

Hmmm. These two statements seem a bit contradictory.

Not really. My statement was in the context of the F80's adaptive system, which is probably not sufficient in stock form for an all out track car. In general, if an adaptive system and passive system are both tuned for the same application, the adaptive system should ALWAYS have more capability. It is able to provide optimum damping characteristics over a MUCH wider range of driving conditions. This is basic physics.

There's no reason an adaptive system can't be tuned to be fully capable of racetrack duty, but that's not the only consideration that BMW and Porsche had to make. Height adjustment, cost of development, marketing, etc. etc. are also reasons. Porsche decided to go one way with their system, BMW decided to go the other way. We will likely never know the real reasons.

So, to be clear,

Originally Posted by dmnc02

Or does it reflect some other considerations?

Yes.

Further, I believe (85% sure) that the 991's PASM and the F80's M Adaptive are basically the same system from the same supplier.

[dmnc02]

Originally Posted by Racer20

In general, if an adaptive system and passive system are both tuned for the same application, the adaptive system should ALWAYS have more capability. It is able to provide optimum damping characteristics over a MUCH wider range of driving conditions. This is basic physics.

Thank you for the additional explanation: that was my uneducated belief as well.

So, if I am not misunderstanding, you are suggesting that this was likely a decision based more on time/cost constraints (due to additional tuning/development of the active suspension for this application) or marketing considerations than on technical reasons.

[Racer20]

Originally Posted by dmnc02

Thank you for the additional explanation: that was my uneducated belief as well.

So, if I am not misunderstanding, you are suggesting that this was likely a decision based more on time/cost constraints (due to additional tuning/development of the active suspension for this application) or marketing considerations than on technical reasons.

If I had to guess, I would say marketing was the main consideration here. GTS owners want some fancy colored racin' shocks on their $150k M4, not just a retuned stock system.

[TRZ06]

Originally Posted by dmnc02

The question was: why didn't BMW fit its Adaptive M Suspension to the M4 GTS?

Racer20 offered a very general statement:



My point was that such a general statement does not seem to fit the evidence, since Porsche provides adaptive dampers on its most track-oriented cars. Moreover, according to CanAutM3,



So, back to BMW's decision, why did they do that? Does the decision reflect the fact that BMW's Adaptive M Suspension is not as sophisticated as, say, PASM? Does it reflect the fact that BMW expects that a M4 GTS will spend more/less time on the track or on the street than a GT3 RS or GT2 RS? Or does it reflect some other considerations?

I think Racer answered your question pretty well, but I will add by saying BMW's adaptive suspension (in its current generation) is pretty damn good. I had it on my E90, and while it was decent, it was far from perfected as far as body/chassis control was concerned. From my limited 1 hour test drive in an adaptive equipped M4 that I drove solo, they have greatly improved it.

IMO, the best active systems today are the magnetic shock technology that uses magnetic particles in the fluid. That technology is so quick acting that they have to program a limit on how fast to make it react.

I had it on my Audi TTRS, and no matter what I threw at it, it stayed 100% controlled and composed at all times, under any circumstances. VERY confidence inspiring.

It is used by Ferrari, Audi R8, TTRS, and now the lesser S3. Also used on CTS-V, ATS-V, and C7 Corvettes.

With active systems today performance is more based in processor reaction times and the coding software used in its algorithm profile.

[dmnc02]

Originally Posted by TRZ06

I think Racer answered your question pretty well, but I will add by saying BMW's adaptive suspension (in its current generation) is pretty damn good.

I feel exactly the same way as you (I have it on my car): that is why I was curious as to what might be reasons behind BMW's decision not to use it on the M4 GTS.

[nicknaz]

Originally Posted by Racer20

Further, I believe (85% sure) that the 991's PASM and the F80's M Adaptive are basically the same system from the same supplier.

Thanks for the info!

I also came across an interesting article about the 991 gt3 suspension

http://www.elephantracing.com/tool-box/specs/991/GT3/991-gt3-suspension-overview.htm

Author is suggesting its closer to 997 cup car than base 991.

Suspension is a full coil over with adaptive dampers.

My read is that bmw went with a half measure for f8x adaptive dampers while porsche went "all in" with gt3 adaptive dampers and implemented the superior system that you described.

[CanAutM3]

Originally Posted by nicknaz

Thanks for the info!

I also came across an interesting article about the 991 gt3 suspension

http://www.elephantracing.com/tool-b...n-overview.htm

Author is suggesting its closer to 997 cup car than base 991.

Suspension is a full coil over with adaptive dampers.

My read is that bmw went with a half measure for f8x adaptive dampers while porsche went "all in" with gt3 adaptive dampers and implemented the superior system that you described.

I had read the same article a few days ago, a very good piece for technical geeks .

Simply put, it seems Porsche went for an adaptive coilover system on the GT3 while BMW went for a passive coilover on the GTS.

[Racer20]

Originally Posted by nicknaz

Thanks for the info!

I also came across an interesting article about the 991 gt3 suspension

http://www.elephantracing.com/tool-box/specs/991/GT3/991-gt3-suspension-overview.htm

Author is suggesting its closer to 997 cup car than base 991.

Suspension is a full coil over with adaptive dampers.

My read is that bmw went with a half measure for f8x adaptive dampers while porsche went "all in" with gt3 adaptive dampers and implemented the superior system that you described.

The 991GT3 dampers shown in the elephant racing link above are Bilstein adaptive dampers. They are likely not the same adaptive dampers used in the base 991. I think those are ZF.

[dmnc02]

Originally Posted by Racer20

The 991GT3 dampers shown in the elephant racing link above are Bilstein adaptive dampers. They are likely not the same adaptive dampers used in the base 991. I think those are ZF.

Do car manufacturers like BMW and Porsche develop their own software for the adaptive adapters (or customize the software to some significant extent), or do they basically buy a complete hardware/software package?

[Racer20]

Originally Posted by dmnc02

Do car manufacturers like BMW and Porsche develop their own software for the adaptive adapters (or customize the software to some significant extent), or do they basically buy a complete hardware/software package?

BMW develops their own. GM buys it from the supplier. Not sure about Porsche.

[dmnc02]

Originally Posted by Racer20

BMW develops their own. GM buys it from the supplier. Not sure about Porsche.

So, going back to why BMW did not use adaptive dampers on the M4 GTS, is it also possible that ZF did not offer an adaptive coilover system like the Bilstein one used in the GT3 RS and developing the software for the Bilstein dampers would have been too involved? Or is it easy to port the software from one brand of adaptive dampers to another?

[Racer20]

Originally Posted by dmnc02

So, going back to why BMW did not use adaptive dampers on the M4 GTS, is it also possible that ZF did not offer an adaptive coilover system like the Bilstein one used in the GT3 RS and developing the software for the Bilstein dampers would have been too involved? Or is it easy to port the software from one brand of adaptive dampers to another?

It's not hard to port the software if it's developed by the OEM. I'm not sure why BMW made the choices they made. It is possible that the ZF system is already getting close to its limits with the stock M4 application, and would need significant re-engineering to meet the needs of the GTS, but that's just semi-educated speculation.

[dmnc02]

Originally Posted by Racer20

It's not hard to port the software if it's developed by the OEM. I'm not sure why BMW made the choices they made. It is possible that the ZF system is already getting close to its limits with the stock M4 application, and would need significant re-engineering to meet the needs of the GTS, but that's just semi-educated speculation.

Great info, thanks.