[McLaren720s]

I'm looking for suggestions on how to make the car a bit less bouncy when going over bumps on M Performance Coilovers.

Currently at "track" settings which are

Front C4/R7 ; Rear C4/R10

Any other settings people have experimented with for a less bouncy and more stiff ride?
Car handles good with little to no body roll, but want less bounce when going over bumps.
Shop advised going down 1 more click from the above settings

[Billy_BMW]

The KW/MPS dampers don’t do well at high, (stiff) compression and rebound settings as the valves aren’t quick enough to react when hitting bumps. This often causes a slow response when hitting bumps at speed, which leads to a poor ride.

Two real options - invest in more expensive coils, or use softer settings.

If you’re using the car on bumpy roads/tracks - try reducing the compression and rebound settings. Not just one click - a good few clicks softer. It’s usually better to start soft and then increase stiffer, rather than the other way around.

Faster times, especially on bumpy tracks are achieved through compliance; rather than stiffness.

I’d recommend 10 clicks open for both rebound and compression and go from there. The ideal setting will vary on the type of road/track you use. One setting definitely doesn’t work on all surfaces. Good luck!

[M Fifty]

Originally Posted by McLaren720s

I'm looking for suggestions on how to make the car a bit less bouncy when going over bumps on M Performance Coilovers.

Currently at "track" settings which are

Front C4/R7 ; Rear C4/R10

Any other settings people have experimented with for a less bouncy and more stiff ride?
Car handles good with little to no body roll, but want less bounce when going over bumps.
Shop advised going down 1 more click from the above settings

As the MPS/KW are valved to respond to high speed movements of the suspension the same way regardless of the low speed setting (so it will cope with cats eyes/potholes/rumble strips the same) maybe look at running 18s with a higher sidewall as it sounds like the bounce you're experiencing is the tires. Or just try the 'Road' settings and see how you get on.

BeePee is running MPS with 18s, so would be a useful person to ask.

[McLaren720s]

Originally Posted by M Fifty

As the MPS/KW are valved to respond to high speed movements of the suspension the same way regardless of the low speed setting (so it will cope with cats eyes/potholes/rumble strips the same) maybe look at running 18s with a higher sidewall as it sounds like the bounce you're experiencing is the tires. Or just try the 'Road' settings and see how you get on.

BeePee is running MPS with 18s, so would be a useful person to ask.

Unfortunately, 18" wheels are not an option as that would require swapping to a different brake kit

My tires are 275/30 and 295/30 MPS4S

[Bee Pee]

Originally Posted by McLaren720s

Unfortunately, 18" wheels are not an option as that would require swapping to a different brake kit

My tires are 275/30 and 295/30 MPS4S

I started with factory street settings on 19" wheels/tyres

Tried track settings on the street and it was a bit firm so backed off the fronts towards street settings and rears, one notch down for B&R settings.

Switched to 18" wheels on MPSS 245&265/40/18 then had the car fettled by Center Gravity (CG) - see thread in the link below

https://f87.bimmerpost.com/forums/sh....php?t=1633253

Post fettling by CG, my car's damper settings (18" 245/265 MPSS tyres @ 31psi cold)

Front axle
Rebound 11 clicks open
Bump/Compression 7 clicks open

Rear axle
Rebound 8 clicks open
Bump/Compression 6 clicks open

Dampers set harder in the rear than the front for 2 reasons:-

1. When assessing compression/suspension travel with all dampers set too full soft, Chris @ CG was amazed at how firm MPC front springs were. Hence, less bump dialed in as springs don't need as much support due to their stiffness. Conversely, less rebound to balance between enough weight transfer, limited body movement and optimising compliance to ensure tyre contact patch consistency.

2. The concept of bumpstops being secondary spring effectively means that they prohibit spring travel/damper stroke which, when c/w ride height, maybe sub-optimal when expecting suspension to remain effective at managing tyre contact patch/compliance. This was the case with my car, in the rear it showed evidence of bumpstop contact. Bumpstops trimmed down by 10mm. With dampers set too full soft, rear MPC spring rates are less than the front. Therefore, rear needs more support from the dampers ie higher bump setting and more rebound to re-settle springs quicker.

For trackdays, if need be, increase rebound stiffness in 2 click increments F&R and gauge how the car feels.

Works very well.

BP

[McLaren720s]

Originally Posted by Bee Pee

I started with factory street settings on 19" wheels/tyres

Tried track settings on the street and it was a bit firm so backed off the fronts towards street settings and rears, one notch down for B&R settings.

Switched to 18" wheels on MPSS 245&265/40/18 then had the car fettled by Center Gravity (CG) - see thread in the link below

https://f87.bimmerpost.com/forums/sh....php?t=1633253

Post fettling by CG, my car's damper settings (18" 245/265 MPSS tyres @ 31psi cold)

Front axle
Rebound 11 clicks open
Bump/Compression 7 clicks open

Rear axle
Rebound 8 clicks open
Bump/Compression 6 clicks open

Dampers set harder in the rear than the front for 2 reasons:-

1. When assessing compression/suspension travel with all dampers set too full soft, Chris @ CG was amazed at how firm MPC front springs were. Hence, less bump dialed in as springs don't need as much support due to their stiffness. Conversely, less rebound to balance between enough weight transfer, limited body movement and optimising compliance to ensure tyre contact patch consistency.

2. The concept of bumpstops being secondary spring effectively means that they prohibit spring travel/damper stroke which, when c/w ride height, maybe sub-optimal when expecting suspension to remain effective at managing tyre contact patch/compliance. This was the case with my car, in the rear it showed evidence of bumpstop contact. Bumpstops trimmed down by 10mm. With dampers set too full soft, rear MPC spring rates are less than the front. Therefore, rear needs more support from the dampers ie higher bump setting and more rebound to re-settle springs quicker.

For trackdays, if need be, increase rebound stiffness in 2 click increments F&R and gauge how the car feels.

Works very well.

BP

I'm having my car corner balanced in 2 weeks and contemplating trying out your compression/ rebound settings. The only difference is that my car is still on the 19" stock wheels.

My local track is pretty bumpy so hoping it will help settle the car better over them

Do you think I should increase rebound for both front and rear from the settings you recommended? I also want to minimize body roll and don't want the car too soft

[Bee Pee]

Originally Posted by McLaren720s

I'm having my car corner balanced in 2 weeks and contemplating trying out your compression/ rebound settings. The only difference is that my car is still on the 19" stock wheels.

My local track is pretty bumpy so hoping it will help settle the car better over them

Do you think I should increase rebound for both front and rear from the settings you recommended? I also want to minimize body roll and don't want the car too soft

Yes add 2 more clicks open on rebound to my settings and see how it drives.

If wanting less roll you may want to increase bump/compression too but I'd try it 1st with B/C settings as-is. If track is bumpy and lesser sidewall of 19" wheel/tyre combo, dialling in more damper stiffness may mean tyre contact patch becomes too variable and grip level reduces accordingly.

[x233]

Try going softer on compression, 1 click all around, and see if you like it better that way.

[McLaren720s]

Originally Posted by Bee Pee

Yes add 2 more clicks open on rebound to my settings and see how it drives.

If wanting less roll you may want to increase bump/compression too but I'd try it 1st with B/C settings as-is. If track is bumpy and lesser sidewall of 19" wheel/tyre combo, dialling in more damper stiffness may mean tyre contact patch becomes too variable and grip level reduces accordingly.

Had the car corner balanced and M Performance coilovers set to your above default specification along with new alignment.

Went for a spirited drive in the mountains and the car felt fantastic! These were mostly high speed turns with occasional bumps and the car felt smooth, planted, never destabilized with good subtle feel of weight transfer. No more jarring and very stiff ride for no reason!

Can't comment on behavior in tight corners yet until I can push the car hard at the track next month but so far I am very pleased with there new settings!

Thanks.

Thanks!