Jarring Ride Over Small Bumps/Cracks - Suspension? Wheels? Tires?

[jpy1980]

Hey guys!

I have a 2015 M3 with the adaptive suspension on Swift springs. I am also on 19 inch Titan7 lightweight forged wheels on the OEM Conti 255 fronts and 275 rears. Tire pressure are 32psi cold all around. The dealer performed an alignment after I got my springs installed by EAS.

Anyways, I've been noticing recently that when I go over small Bumps or cracks, such as those little reflective Bumps on the road that delineates Lanes, the ride is very jarring. Feels like there is no damping. Happens in all modes, such as comfort, sport and sport+. But if I go over smoother bumps, it doesn't feel as jarring.

I'm not sure if this is suspension related, or possibly the wheels being very lightweight and forged causing the jarring Ride? Would this mean that my shocks are blown? Car does feel planted in smooth rodes and not bouncy at all. It's really just those small bills and cracks. Car feels planted on curvy roads.

My friend said it could be my tires as they may be worn from a recent track day that I did, but I don't think so.

Any thoughts? Advice?

Thanks guys! Let me know if you need more info.

[Racer20]

Worn tires can affect ride more than you'd think, especially on small sharp impacts like what you're describing. If your tires are that badly worn, hold off on changing anything in the suspension until you've replaced your tires.

[drroc]

I noticed a huge difference from going from really worn Michelin Super Pilot Sports to Conti Extreme Contact Sports. The ride became much smoother.

[Rx7andy]

Try lowering tire pressure by a couple of psi. Worked for me.

[jpy1980]

Sweet! Thanks for the replies guys!

Rx7andy was right. I lowered my tire pressure by 1 psi and it made a world of difference.

My next step would be to change out the tires. Pretty sure they are in their last legs.

[Brasko]

Tires and air pressure can make a significant difference.

Also would check the OEM struts/shocks. Installing aftermarket springs alone can prematurely wear the dampening of your factory installed struts/shocks. This is mainly due to the different spring rates.

[JamesGames]

Originally Posted by jpy1980

Sweet! Thanks for the replies guys!

Rx7andy was right. I lowered my tire pressure by 1 psi and it made a world of difference.

My next step would be to change out the tires. Pretty sure they are in their last legs.

No offense, but you can't feel 1psi.. it's more of a placebo effect than you think - every time in socal now, if you get in the car the PSI will change within 3-6 psi depending on how hot it is and how long you are driving.

I am running kw club sport 3 way on track settings with 265/30 and 295/30 on 35psi front and 37psi rear, I fluctuate up to 40+psi when it gets hot and at those PSI it does seem firmer.

Parking your car at night vs driving it off in morning will vary 4psi at least!

[G35POPPEDMYCHERRY]

prolly your tires. mine are legit bald and I can feel even the slightest pebble on the road. also your car will start to feel floaty....just get new tires even if you still have 3/32. this car suffers enough with brand new tires let alone stone cold balds