[NoVaRob21]

Does anyone have any advice on what to do for bump stops with lowering springs? It seems only Dinan makes a specific non-stock option. I would assume they work with other springs in similar lowering ranges like AC or Cobra, but wasn't sure if anyone has some real world experience. From what I have read, going stock with lowering may not be ideal.

[SJA05]

I have H&R lowering springs and I used the Dinan bumpstops on my car. I got the H&R springs because Dinan still doesn't have springs for the X-drive M340. Although the Dinan bumpstops are "technically" for non X-drive cars, there were no issues with installation or driving.

Hope that helps.

[TheDudeMan]

Originally Posted by NoVaRob21

Does anyone have any advice on what to do for bump stops with lowering springs? It seems only Dinan makes a specific non-stock option. I would assume they work with other springs in similar lowering ranges like AC or Cobra, but wasn't sure if anyone has some real world experience. From what I have read, going stock with lowering may not be ideal.

Yes, you can go with any other shorter bump stop. In fact, I believe F30 Msport bump stops are shorter and can be utilized. You can even cut the factory bump stops in half and use the top half. Replacement bump stops are used to maintain proper travel and not much else. If you were to use the originals, you'd constantly be riding on them since the suspension travel is reduced. It would be one jarring ride.

[NoVaRob21]

Originally Posted by TheDudeMan

Yes, you can go with any other shorter bump stop. In fact, I believe F30 Msport bump stops are shorter and can be utilized. You can even cut the factory bump stops in half and use the top half. Replacement bump stops are used to maintain proper travel and not much else. If you were to use the originals, you'd constantly be riding on them since the suspension travel is reduced. It would be one jarring ride.

I figured as much for needing to do something with them, does cutting the originals have any impact on how they function or are they not progressive?

[TheDudeMan]

Originally Posted by NoVaRob21

I figured as much for needing to do something with them, does cutting the originals have any impact on how they function or are they not progressive?

If you look at the Msport or Dinan bump stops, they are shorter and fatter, so any progressiveness of the originals is lost. I don't see a difference if you cut the two lower narrowing rings off your existing bump stops.

[RobG_M340]

Pardon my ignorance, never done lowering springs on my previous cars, but considering on my m340. Is the ride with just the springs and stock bump stops bad or just better with proper ones? Also, how big a difference in drive quality?

[TheDudeMan]

Originally Posted by RobG_M340

Pardon my ignorance, never done lowering springs on my previous cars, but considering on my m340. Is the ride with just the springs and stock bump stops bad or just better with proper ones? Also, how big a difference in drive quality?

When you lower any car with springs, you shorten the stroke/travel of the shock. The factory bump stops were not engineered for this travel difference and are too long. This causes the car to bottom out and ride on the bump stops which feels really stiff and abrupt. A shorter bumper reduces this issue and improves the ride.

Based on what I've seen, the Dinan bumpstops are all the same for the G20 chassis - so they are by no means tuned specifically to each model; probably chassis only, if that.

[Ikester19]

Originally Posted by NoVaRob21

Does anyone have any advice on what to do for bump stops with lowering springs? It seems only Dinan makes a specific non-stock option. I would assume they work with other springs in similar lowering ranges like AC or Cobra, but wasn't sure if anyone has some real world experience. From what I have read, going stock with lowering may not be ideal.

I've had my M340ix lowered on ACS lowering springs which are engineered to work with stock bump stops. ACS springs only lower the M340ix by an inch (which is why I went with them) and I've never experienced bottoming out, in fact they have greatly improved handling. The ride IMO is much better than stock with a lot less body roll in cornering and the car feels super planted. They are a little more expensive than other spring kits but but well worth it IMO.
Here's a pic for reference.

[TheDudeMan]

Originally Posted by Ikester19

I've had my M340ix lowered on ACS lowering springs which are engineered to work with stock bump stops. ACS springs only lower the M340ix by an inch (which is why I went with them) and I've never experienced bottoming out, in fact they have greatly improved handling. The ride IMO is much better than stock with a lot less body roll in cornering and the car feels super planted. They are a little more expensive than other spring kits but but well worth it IMO.
Here's a pic for reference.

Msport bump stops are shorter, so I believe it when you say you haven't bottomed out. However, the bottoming out in some instances isn't easily felt, especially if you have limited experiences - not intended to lecture you or pull a knowledge card, just saying.