[NSXR]

The problem with the stock suspension is that you can't adjust the damping. That's the whole issue. It's not the spring rate, which is relatively soft. Soft springs/hard damping. However, even with a 40% higher spring rate you can make the MPS ride softer, and with Swift springs even softer still. I contacted Swift about this exact thing and they said you really don't want much softer on the spring, just adjust the damping to your liking.

[Berzerker]

Originally Posted by NSXR

The problem with the stock suspension is that you can't adjust the damping. That's the whole issue. It's not the spring rate, which is relatively soft. Soft springs/hard damping. However, even with a 40% higher spring rate you can make the MPS ride softer, and with Swift springs even softer still. I contacted Swift about this exact thing and they said you really don't want much softer on the spring, just adjust the damping to your liking.

That makes sense, thanks.

[changster]

I still can't believe people say the stock suspension is stiff / uncomfortable. It's insane to me. Do people expect an SUV ride? Mercedes S class ride? Lexus ride? I honestly don't get it.

[NSXR]

Originally Posted by changster

I still can't believe people say the stock suspension is stiff / uncomfortable. It's insane to me. Do people expect an SUV ride? Mercedes S class ride? Lexus ride? I honestly don't get it.

I had no issue with the ride at all when it came to a smooth road or a road with smooth bumps, but the moment the road turned bad the limitations of the stock dampers was obvious, with a crash at the end of every crack, and an unsettled feeling around corners that had road issues. For sure at times the stock suspension is softer, smoother, and just better than the KWV3 (even with the damping set softer), and that's down to the spring rate. But overall, the stock suspension is just under-sprung and over-damped, meaning it really loves nice roads, but hates bad roads. If you don't have an issue with it that's great news for you, but for those with maybe rougher roads to drive will be much happier with the damping and the more settled feeling of the KWV3 or MPS.

[Neusser]

Originally Posted by Berzerker

And it seems, from people in here, the MPS and other solutions have options for softer dampers and the stock suspension is quite bad for comfort out of the factory. Is your experience different?

I do agree that the stock suspension is very stiff. That said, part of this is due to tire pressures, which these days are heavily influenced by fleet CO2 and efficiency standards.

BMW suggests 2.6 bar F/R for 19s on my Comp, which is just silly. I run 2.3 and the car is noticibly more supple, and the rear axle is much more settled.

That more or less takes care of it for me.

If you are concerned about lower pressures: Sport Auto (a very respected mag here) ran their M2 at 2.5F/2.0R on the Ring and 2.2F/2.2R on Hockenheim. Those were warm pressures, so 2.3 cold for the street is entirely safe for a half-load (2-3 people).

[NSXR]

Originally Posted by Neusser

I do agree that the stock suspension is very stiff. That said, part of this is due to tire pressures, which these days are heavily influenced by fleet CO2 and efficiency standards.

BMW suggests 2.6 bar F/R for 19s on my Comp, which is just silly. I run 2.3 and the car is noticibly more supple, and the rear axle is much more settled.

That more or less takes care of it for me.

If you are concerned about lower pressures: Sport Auto (a very respected mag here) ran their M2 at 2.5F/2.0R on the Ring and 2.2F/2.2R on Hockenheim. Those were warm pressures, so 2.3 cold for the street is entirely safe for a half-load (2-3 people).

Totally agree, 2.6 is nutty unless it's hot highway pressure. I run 1 psi more in the front than the rear, so 2.3 & 2.2 and my tire wear is perfect.

[MSH_]

Originally Posted by NSXR

I had no issue with the ride at all when it came to a smooth road or a road with smooth bumps, but the moment the road turned bad the limitations of the stock dampers was obvious, with a crash at the end of every crack, and an unsettled feeling around corners that had road issues. For sure at times the stock suspension is softer, smoother, and just better than the KWV3 (even with the damping set softer), and that's down to the spring rate. But overall, the stock suspension is just under-sprung and over-damped, meaning it really loves nice roads, but hates bad roads. If you don't have an issue with it that's great news for you, but for those with maybe rougher roads to drive will be much happier with the damping and the more settled feeling of the KWV3 or MPS.

I suppose it's all subjective. Is the stock suspension ideal...heck no. Do I plan to move to a solid coilover set up eventually?...absolutely. Plan to move to 3dm ohlins or MCS 1WNRs hopefully in nxt yr. With that said I drive pretty aggressively on Colorado canyon/mtn roads and the roads here are terrible...far from smooth and I think the stock suspension handles the crap roads pretty darn well.
some examples here--> https://www.youtube.com/@pushdaenvelope
"M2C Cold March Saturday Rip!" in particular shows how bumpy many sections are with loads of crack sealed sections

Originally Posted by NSXR

Totally agree, 2.6 is nutty unless it's hot highway pressure. I run 1 psi more in the front than the rear, so 2.3 & 2.2 and my tire wear is perfect.

exact pressures I run on mine as well...275/30/19 fr 295/30/19 rears w/ Millway streets @ -2.5

[NSXR]

Originally Posted by MSH_

I suppose it's all subjective. Is the stock suspension ideal...heck no. Do I plan to move to a solid coilover set up eventually?...absolutely. Plan to move to 3dm ohlins or MCS 1WNRs hopefully in nxt yr. With that said I drive pretty aggressively on Colorado canyon/mtn roads and the roads here are terrible...far from smooth and I think the stock suspension handles the crap roads pretty darn well.

It's very possible that you're a more competent driver than I am. All I know is that beyond the smoother ride, the MPS' less nervous damping was a blessing to me.

EDIT: Looking at your videos, I think you'd love the MPS, and could sure put it to good use! Great videos! Car sounds menacing!

[changster]

Originally Posted by MSH_

I suppose it's all subjective. Is the stock suspension ideal...heck no. Do I plan to move to a solid coilover set up eventually?...absolutely. Plan to move to 3dm ohlins or MCS 1WNRs hopefully in nxt yr. With that said I drive pretty aggressively on Colorado canyon/mtn roads and the roads here are terrible...far from smooth and I think the stock suspension handles the crap roads pretty darn well.
some examples here--> https://www.youtube.com/@pushdaenvelope
"M2C Cold March Saturday Rip!" in particular shows how bumpy many sections are with loads of crack sealed sections



exact pressures I run on mine as well...275/30/19 fr 295/30/19 rears w/ Millway streets @ -2.5

Nice videos! Lots of higher speed sweepers. Not a ton of big bumps (but sometimes it's way different watching a video vs feeling it) but I can see the surface unevenness.

Stiffer springs goes a long way in these types of sweepers where the car is "held" for extended periods. However, just like you said the stock suspension handles these types of roads/turns very well. Manufacturers in my opinion usually taylor their suspension for roads like this as most people see these types of situations quite often. It's kind of like on the freeway and you enter a long sweeper as well.

Contrast this with how we run here with tight twisties over and over with many corners that need higher steering angles (tarmac rally driving). The stock M2C suspension is way too soft for this. I guess this is why I never understand when people say stock suspension is too stiff.

[Track/S]

Originally Posted by changster

Contrast this with how we run here with tight twisties over and over with many corners that need higher steering angles (tarmac rally driving). The stock M2C suspension is way too soft for this. I guess this is why I never understand when people say stock suspension is too stiff.

When you mount a set of coilovers on M2C you will immediately realize why we say that the M2C's suspension is too bad, especially at low speed bumpy roads.
Nice video!

[CSBM5]

I think the majority of people "feel" rear stiffness much more so than front. If a sharp input is felt from the rear, say traversing a pavement discontinuity, it gives that ugh feeling as it is like a direct input to your spine through the seat.

So here I go pondering once again...BMW M loves rear compression damping...too much imo. Well too much in certain regions of damper performance (high shock piston velocity with high piston acceleration). If you think of two regions of damping control, it helps to separate out ride quality: 0-2 inches/sec is what the driver can impart into the chassis with steering/brakes/accelerator; anything above that level of shock piston velocity are all road induced. So it is in that upper region where, for whatever reason, BMW seems to prefer stiffer damping on compression in rear shocks/struts. It also comes down to how the damper handles piston acceleration and the rate of change of acceleration (2nd and 3rd derivatives) imo. It's in those aspects of shock piston movement where the magic happens and likely were something like MCS, Ohlins, etc excels.

20 years ago my daughter and I were building up an E46 330i ZHP sedan (slicktop, 6MT) for SCCA D-stock autocross competition. The car was near new at the time (16k miles), so the stock suspension was fresh. We installed adjustable Konis as one of the allowed mods but did the rears first and then the front struts the next weekend.

The stock ZHP has a very sharp stiff rear damping somewhat similar in feel to the M2C (however the M2C feels much better) over rough road inputs. Just putting those Konis on the rear (btw, these were TC Kline special Konis with his unique damper valving) transformed the ride in that car. It was unreal the difference over sharp road inputs, pavement transitions, etc. Even with the rebound damping dialed up very stiff, they were never as bad as the stock ZHP dampers over the junk road stuff. They felt well-matched to the stock front struts too.

Hence I get the feeling that those looking for a large improvement in ride quality could likely enjoy just a rear damper replacement with a quality adjustable one so you can match the front to rear if needed. Those MP KW dampers would be a nice one to try, and they used to be available separately for about $500 each though.

TLDR: springs are not the problem, they're relatively soft. Damping and damping control at high shock piston accelerations are the issue, and those are easily noticed most from the rear.

[Berzerker]

Appreciate all the responses here, I'll be looking to get something in the next month.

I think I'm leaning towards the TC Kline single front/double rear setup with 300/600 springs. The MPS is still in the back of my mind but the TCK I think is the right choice for me for now.

[NSXR]

Originally Posted by changster

Contrast this with how we run here with tight twisties over and over with many corners that need higher steering angles (tarmac rally driving). The stock M2C suspension is way too soft for this. I guess this is why I never understand when people say stock suspension is too stiff.

It's because the car is supposed to be a blend of a luxury car (mostly) and a sporty car, not a race car. Most guys don't use their M2 the way you use yours but very rarely. And to be honest, what you're feeling as suspension softness is more about polar moment and weight. The stock M2C suspension on a Miata would be vastly different. Great video by the way!

[MSH_]

Originally Posted by changster

Nice videos! Lots of higher speed sweepers. Not a ton of big bumps (but sometimes it's way different watching a video vs feeling it) but I can see the surface unevenness.

Stiffer springs goes a long way in these types of sweepers where the car is "held" for extended periods. However, just like you said the stock suspension handles these types of roads/turns very well. Manufacturers in my opinion usually taylor their suspension for roads like this as most people see these types of situations quite often. It's kind of like on the freeway and you enter a long sweeper as well.

Contrast this with how we run here with tight twisties over and over with many corners that need higher steering angles (tarmac rally driving). The stock M2C suspension is way too soft for this. I guess this is why I never understand when people say stock suspension is too stiff.

Nice! Thanks for sharing and nice driving!
Yes, a lot of the videos on my channel are from a road we drive quite a bit, but as you said I show more of the high speed sections. The lower part of this road does have more tight corners if you look later in this vid that Jack White posted in another thread of me following a 991 GT3
A good example of the tighter stuff in my vids is in the "M2C Cold March Saturday Rip!" video at about the 55s mark on. I'm mainly in 2nd up to 3rd for very short periods of time. No where near the length of road though that you have in your vid or I have seen in some of Track/S videos.
I 100% agree that the tighter stuff really exposes the short comings of the stock dampers. Lots of body lean & understeer but I still have a ton of fun in this car regardless even with the sub-optimal suspension! I'm definitely looking forward to getting the Ohlins or MCS on.

[K-Fab]

I have the Ohlins R&T on mine (track oriented settings) and they are definitely stiffer than the OEM. The higher spring rate is a definite factor in ride quality.

Rough roads are felt a bit more over the stock setup but where I really notice the difference (at least for street stuff) is going over speed bumps and transitions. Even slowly it can jar ya pretty well.

[Jack White]

Originally Posted by K-Fab

I have the Ohlins R&T on mine (track oriented settings) and they are definitely stiffer than the OEM. The higher spring rate is a definite factor in ride quality.

Rough roads are felt a bit more over the stock setup but where I really notice the difference (at least for street stuff) is going over speed bumps and transitions. Even slowly it can jar ya pretty well.

What springs are you using?

[M3SQRD]

Originally Posted by Neusser

I am saying the car is set up stiff because it has to be able to provide good body control in a track situation. MPS is even stiffer.

If you want more compliance, you need softer dampers.

This is not true. Appropriate high speed damping and a well designed high-speed compression blow-off valve (HSCBOV) can provide excellent compliance with high spring rates. The MCS remote reservoir dampers, 2WR and 3WR (and 4WR but you’re limited in the range of spring rate changes you can make), have excellent road quality and compliance due to a proprietary HSCBOV in the reservoir and reduced reservoir pressures with F/R 700/1100 to 900/1200 lbf/in (rear divorced, no aero) spring rates or 800/700 to 900/800 lbf/in (rear coilover, no aero) spring rates.

MPS and KW V3 have spring rates that are not much higher than stock f87C spring rates. I believe the stiffer front spring rate is effectively 221 lbf/in vs. ~200 lbf/in stock front rate. Rear rates are both around ~680 lbf/in.

In other posts there’s been brief discussions on dampers being “bouncy” at slow vehicle speeds. All monotube dampers will “bounce” as you come to a stop because of the required pressure in the internal reservoir with a floating piston to prevent cavitation. This pressure results in an effective preloaded compressive spring in parallel with the main spring. So there’s an undamped compressive force below which the piston rod doesn’t compress into the damper body and this produces the “bounce” feeling in rebound only as you come to a stop. It’s actually the tires skipping on bumps.

[K-Fab]

Originally Posted by Jack White

What springs are you using?

What ever it is that the Ohlins came with. They're definitely stiffer than OEM.

[Track/S]

Originally Posted by K-Fab

What ever it is that the Ohlins came with. They're definitely stiffer than OEM.

I have 140/120nm F/R spring rates and ride quality is a thousand times better than with OEM suspension.

[Neusser]

Originally Posted by M3SQRD

This is not true. Appropriate high speed damping and a well designed high-speed compression blow-off valve (HSCBOV) can provide excellent compliance with high spring rates. The MCS remote reservoir dampers, 2WR and 3WR (and 4WR but you’re limited in the range of spring rate changes you can make), have excellent road quality and compliance due to a proprietary HSCBOV in the reservoir and reduced reservoir pressures with F/R 700/1100 to 900/1200 lbf/in (rear divorced, no aero) spring rates or 800/700 to 900/800 lbf/in (rear coilover, no aero) spring rates.

MPS and KW V3 have spring rates that are not much higher than stock f87C spring rates. I believe the stiffer front spring rate is effectively 221 lbf/in vs. ~200 lbf/in stock front rate. Rear rates are both around ~680 lbf/in.

In other posts there’s been brief discussions on dampers being “bouncy” at slow vehicle speeds. All monotube dampers will “bounce” as you come to a stop because of the required pressure in the internal reservoir with a floating piston to prevent cavitation. This pressure results in an effective preloaded compressive spring in parallel with the main spring. So there’s a compressive force below which the piston rod doesn’t compress into the damper body and this produces the “bounce” feeling as you come to a stop. It’s actually the tires skipping on bumps.

No one talked about spring rates.

[M3SQRD]

Originally Posted by Neusser

No one talked about spring rates.

First of all damping is not “softer”. It’s actually higher or lower damping.

If a damper can provide COMPLIANCE (equal to the inverse of STIFFNESS = spring rate) with very high spring rates then imagine what the ride would feel like with low (soft) spring rates. The dampers provide ZERO stiffness to the system (not exactly true for monotube dampers as described in my post above but it’s true in all other driving conditions). Their purpose is to absorb energy from the springs to return the system to its original non-displaced equilibrium position. A spring force is equal to its stiffness times the DISPLACEMENT whereas a damping force is equal to its damping coefficient (slope of the pvp damping force-velocity curve or, as an example, 60%, of critical, damping) times the piston VELOCITY relative to the damper body. No piston velocity, no damping force. The HSCBOV basically bleeds off all damping force so the damper can absorb large bumps and curb strikes on track and, therefore, compliance, regardless of damper “softness” or “stiffness”; i.e., lower or higher damping settings.

[M3SQRD]

Originally Posted by Track/S

I have 140/120nm F/R spring rates and ride quality is a thousand times better than with OEM suspension.

It must be the “softness” of the damper