How to correct "bouncy" coilover?

[BoostinLI]

So, my coilover journey on my F82 hasn't been the most pleasant as some of you have seen from my previous post, but we are heading in the right direction 🙏.

After having everything squared away with the suspension, the initial ride quality felt way better than stock, but as Ive driven more aggressively, the car starts to feel "floaty and "bouncy" removing confidence in the car's handling when pushing it. Spring rates are 400f and 700r and it rides soft as a town car.

Is there anything that I can adjust mechanically, that maybe causing this float/bouncy feeling? Asides from the compression/rebound adjustments?

Thanks fellas

[hC1001]

No, the shocks control that. Compression and rebound is what needs adjusting for those symptoms.

[fiveohwblow]

Inb4 the $10,000 suggestion because these cars suck without 10k in suspension because the internet said so.

[melanthius]

Not sure why you are hesitating to use the damping adjustments to adjust the dampening.

Springs will oscillate forever "in theory".

They don't truly oscillate forever in reality because they are not ideal springs, but if they aren't damped they will certainly feel very bouncy.

Dampers will extinguish the oscillation the more they are damping (closer to hard setting).

I'd probably keep compression loose to begin. First dial up rebound 20% at a time, then dial up compression slowly to finish.

Different street or track conditions (or even different driving style) will have different optimal settings. The key is only adjusting one thing at a time, and don't go so slow that you can't feel a difference.

[BoostinLI]

Originally Posted by melanthius

Not sure why you are hesitating to use the damping adjustments to adjust the dampening.

Springs will oscillate forever "in theory".

They don't truly oscillate forever in reality because they are not ideal springs, but if they aren't damped they will certainly feel very bouncy.

Dampers will extinguish the oscillation the more they are damping (closer to hard setting).

I'd probably keep compression loose to begin. First dial up rebound 20% at a time, then dial up compression slowly to finish.

Different street or track conditions (or even different driving style) will have different optimal settings. The key is only adjusting one thing at a time, and don't go so slow that you can't feel a difference.

Wasn't hesitant, had them set per the spec sheet and it was pretty bouncy so was thinking maybe something else was off. I turned them up and feels much stiffer in the rear... Def will take some time finding the sweet spot.

[stevehifi]

bouncy either means too much dampening (car is going up and down over every bump) OR not enough dampening (car is not composed and jumps around).

best to use the middle setting on your dampers and then either go up or down in small increments.

[robbo mcs]

What are the shocks, or have I missed that.

Over or underdampened springs are often due to a mismatch of shocks and springs, ie not having the damping force and valving setup appropriately for the spring rate.

Often it is just cheap / trashy quality shocks as well.

[AlterZgo]

You did not mention how low your car is. Many people slam the shit out of their cars and expect coilovers to perform miracles. It doesn't matter how much one spends on coilovers. If the car is slammed, you cannot violate the laws of physics and the car will feel bouncy because there is not enough suspension travel and the car is likely bottoming out causing the harsh ride.

OTOH, if your car is not slammed, then you just need to adjust the dampers.

Also, what rims/tires are you using? Set tire pressure to 32/32 when car is cold. I have found that worked well with both my stock 19s as well as my 20" rims/tires right now. Good balance btw ride and handling.

[deli333]

Originally Posted by fiveohwblow

Inb4 the $10,000 suggestion because these cars suck without 10k in suspension because the internet said so.

you just need 2-3.5k coilover setup with rebound and compression adjustability. that is it.

yes btw, stock suspension is beyond shite regardless of model.

[M4UFO]

Originally Posted by AlterZgo

You did not mention how low your car is. Many people slam the shit out of their cars and expect coilovers to perform miracles. It doesn't matter how much one spends on coilovers. If the car is slammed, you cannot violate the laws of physics and the car will feel bouncy because there is not enough suspension travel and the car is likely bottoming out causing the harsh ride.

OTOH, if your car is not slammed, then you just need to adjust the dampers.

Also, what rims/tires are you using? Set tire pressure to 32/32 when car is cold. I have found that worked well with both my stock 19s as well as my 20" rims/tires right now. Good balance btw ride and handling.

I had the same bouncy feeling on 2019 M4 Comp stock dampers with 20mm lowering springs after 4wks of fitting them on brand new car. Users on this site recommend Bilstein B6 damptronics so got a set and was installed this April gone, car felt great but now feeling bouncy again and not composed and jump around. I can feel some oscillation in the suspension and its like the front and rear axle not talking to each other. Strange it felt like that the oscillation when I fitted the springs with the stock stocks so am wondering if the springs are just crap? or surely its can't be the Bilstein's?

[AlterZgo]

Originally Posted by M4UFO

I had the same bouncy feeling on 2019 M4 Comp stock dampers with 20mm lowering springs after 4wks of fitting them on brand new car. Users on this site recommend Bilstein B6 damptronics so got a set and was installed this April gone, car felt great but now feeling bouncy again and not composed and jump around. I can feel some oscillation in the suspension and its like the front and rear axle not talking to each other. Strange it felt like that the oscillation when I fitted the springs with the stock stocks so am wondering if the springs are just crap? or surely its can't be the Bilstein's?

Not sure why you have having that problem w/ the B6 Damptronics. I've never used them so can't speak with any experience. However, looking at the description on Bilstein's website, it indicates these are designed for OEM springs. So, I assume using them on 20mm lower springs would cause them to wear prematurely? Though it shouldn't destroy the damping in just a few months. Not sure if you install in April 2020 or April 2021. They should last at least 10-15K miles and still feel like they have a good amt of damping force.

What springs do you have? If the spring rates are very high, like say with Progress springs, they have a greater propensity to wear out the shocks - OEM or damptronic, doesn't matter. Throw stiff lowering springs on there and shocks just wear out faster.

[M4UFO]

Damptronics fitted April this year, Bilstien also said on their website that the B6 can be used with lowing springs. What I don’t understand from Bilstiens is that they’ve a shorter shock B8 but it’s not a damptronic but recommend you can use the longer B6...bizarre. Am also wondering if I hitting the bumps stops? Got spring from a company called Motech the springs are call “stance” look great on the car but performance rubbish after 3/4 months on the stocks shocks and same again now with B6.

[jfritz27]

Originally Posted by tonyadams

There are several things you can check and adjust to help correct a "bouncy" Coilover including Preload, Dampers, Ride height, Alignment, and Tires.
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Skynet, is that you?

[ellipsis212]

Originally Posted by jfritz27

Skynet, is that you?

Chatbot practice

[FrozenGT]

Sounds like your riding ontop of your stock bump stops.. had the same issue on my 2020
m4 comp with MP HAS Kit. My shop had to readjust the entire ride height to get it perfect.

[M 4 FUN]

first of all i would check suspension travel if the car is lowered beyond recommendations. After that i would loosen everything up (comp and rebound), and start to increase rebound in quite big steps to be able to notice the difference and get a feel for the adjustments. After that i would do the same thing with compression. the harder the spring is the less compression damping you need and the more rebound you need.

[heyyouduh]

Originally Posted by BoostinLI

So, my coilover journey on my F82 hasn't been the most pleasant as some of you have seen from my previous post, but we are heading in the right direction ��.

After having everything squared away with the suspension, the initial ride quality felt way better than stock, but as Ive driven more aggressively, the car starts to feel "floaty and "bouncy" removing confidence in the car's handling when pushing it. Spring rates are 400f and 700r and it rides soft as a town car.

Is there anything that I can adjust mechanically, that maybe causing this float/bouncy feeling? Asides from the compression/rebound adjustments?

Thanks fellas

what coilovers? aside from checking the typical install/height stuff, describe what you're actually feeling? bouncy could be the damper not controlling the spring's stored energy or just how a stiffer, properly damped stiffer set up feels like as you feel the undulations of the road.

[williamliz23]

Originally Posted by M 4 FUN

first of all i would check suspension travel if the car is lowered beyond recommendations. After that i would loosen everything up (comp and rebound), and start to increase rebound in quite big steps to be able to notice the difference and get a feel for the adjustments. After that i would do the same thing with compression. the harder the spring is the less compression damping you need and the more rebound you need.

five nights at freddy's 4

This is a quite effective solution in this case. The possibility of success is also high.

[M3SQRD]

Bouncy suspension setup usually means rebound and compression damping settings are set too high. If you have DA dampers, try reducing compression damping by a large amount and see if that reduces the bouncy motion of the suspension.

Another potential issue could be if your ride height is set really low you could be riding the bump stops which significantly increases the spring rate on the compression side only. You’d have to raise your ride height if this is the case.

Also, could be a combination of too much rebound and compression damping + riding bump stops.

Don’t be afraid to play with damping adjustments. Once you sort out the bouncy issue, try playing around with damping adjustments to see how individual changes affect suspension handling characteristics.