[mtenhoven]

I'm ready to order ACS springs for my 2015 328i xdrive without adaptive suspension and was wondering if upgraded dampers (Bilstein B8s) would be needed or if the stock dampers would work without adding bounce during the ride. Don't want to pay twice for the installation.

My question arises from the H&R spring threads I've read here. Haven't seen any definitive discussion on this with the ACS springs.

Any feedback would be appreciated.

Cheers!

[NorthNJ]

I have ACS springs with stock shocks on my F31. I drive only in sports plus and have never had the issue you mentioned. The ride is firm but not too firm or bouncy. It's just the way the pairing should've come from the factory.

[mtenhoven]

Thanks for the feedback.

[scostu]

Originally Posted by NorthNJ

I have ACS springs with stock shocks on my F31. I drive only in sports plus and have never had the issue you mentioned. The ride is firm but not too firm or bouncy. It's just the way the pairing should've come from the factory.

Do you have Adaptive suspension or just base Xdrive suspension?

And what is your tire setup? Square, staggered...18s or 19s?

[NorthNJ]

scostu I have the base xdrive suspension on the wagon. I currently have the 18' m sport wheels with 12 and 15 mm spacers.

I have 19' titanium BBS CHr that I plan on putting on sometime in the near future. But I've had them for a year and they're still sitting in storage. So I can't tell you what the springs would like with 19' wheels.

[RM7]

I have the adaptive suspension and am planning on doing the shockware upgrade when I get the ACS springs installed. That's what Dinan recommends when installing their springs (but they don't make them for x-drive F36) and it reasons that higher spring rate=higher damping rates. I know the OP doesn't have the adaptive, but this is probably the only reason I went this route rather than full coil over, which is more $$$.

[E90X]

NorthNJ do you have any pics of your car before and after install? Before after fender height measurements? I've been wanting to pull the trigger on these and the only real info I can find is on the euro forums. Everything over there makes them seem like the best suspension mod for the money hands down.

Originally I wanted to just do sway bars and leave the rest be for starters... Then I saw what was required to do the rear bar. The body lean on my F31 is killing me. Had a f10 xdrive loaner and was blown away at how flat it handled in comparison. The f10 is supposed to be the boat!

[scostu]

Originally Posted by E90X

NorthNJ do you have any pics of your car before and after install? Before after fender height measurements? I've been wanting to pull the trigger on these and the only real info I can find is on the euro forums. Everything over there makes them seem like the best suspension mod for the money hands down.

Originally I wanted to just do sway bars and leave the rest be for starters... Then I saw what was required to do the rear bar. The body lean on my F31 is killing me. Had a f10 xdrive loaner and was blown away at how flat it handled in comparison. The f10 is supposed to be the boat!

My wagon feels like a boat. I looked into ARBs as well and then saw cost for install-.... and ugh.

Torn between springs and maybe these.....

http://f30.bimmerpost.com/forums/sho....php?t=1200991

[E90X]

I was thinking the same thing... But it's a lot of money for just shocks. Once investing that much might as well just go full on PSS10 comfort. To me it feels like the car is more under sprung than under dampened but I'm definitely not a suspension engineer. I know the B6s will firm it up no doubt but just have to wonder if they will really do much to fix the body roll. It would be nice if we could just buy some tall linear rate springs, about 20% firmer than stock and call it a day. I don't care about wheel gap. I care about snow clearance. With that said, I'd love to hear from more people who have gone the B6 route with the stock springs. Made a massive improvement on the e90 xdrives.

[Polo08816]

Originally Posted by E90X

I was thinking the same thing... But it's a lot of money for just shocks. Once investing that much might as well just go full on PSS10 comfort. To me it feels like the car is more under sprung than under dampened but I'm definitely not a suspension engineer. I know the B6s will firm it up no doubt but just have to wonder if they will really do much to fix the body roll. It would be nice if we could just buy some tall linear rate springs, about 20% firmer than stock and call it a day. I don't care about wheel gap. I care about snow clearance. With that said, I'd love to hear from more people who have gone the B6 route with the stock springs. Made a massive improvement on the e90 xdrives.

It's basically the same issue with the xDrive and suggesting people get the DHP option.

It will reduce body roll in some ways. For example, if you are going through a slalom it may reduce body roll because there is increase resistance to compression. However, it can't reduce body roll through a long sweeper because effective spring rate plays more of a role there.

In other words, increasing compression and dampening isn't a solution for a car that is under-sprung. It masks the problem to an extent but does not fix it.

[E90X]

Originally Posted by Polo08816

It's basically the same issue with the xDrive and suggesting people get the DHP option.

It will reduce body roll in some ways. For example, if you are going through a slalom it may reduce body roll because there is increase resistance to compression. However, it can't reduce body roll through a long sweeper because effective spring rate plays more of a role there.

In other words, increasing compression and dampening isn't a solution for a car that is under-sprung. It masks the problem to an extent but does not fix it.

Thanks for the explanation. Nice to know I was on the right train of thought. So back to the OPs idea, ACS springs on stock struts. Anyone have any idea what the spring rate of these are for xdrive cars and how that compares to stock? Coilovers are way overkill for what I'm looking to achieve. It would be nice to hear from some more people in the states that fitted these springs as well as pics. Seems like there isn't a huge wealth of info on the various options yet. Maybe NorthNJ could upload some pics of his car?

[mtenhoven]

I'm also now considering the Bilstein B6 struts given the limited lowering provided by the ACS springs when compared to others. I'm less concerned about looks than getting a better handling daily driver.

[NorthNJ]

I can take a few pictures of the ride height over the weekend. Its currently a two finger gap both front and rear. Perfect look all around. That's one of the reason I haven't put on the 19' BBS wheels.

You'll definitely like the change in the suspension. I'm a picky person and went through three different suspension on a previous car before settling on the third and final setup. If I wasn't happy with the current setup I would've gone with the Bilstein B16 and put these up for sale.

Originally Posted by E90X

NorthNJ do you have any pics of your car before and after install? Before after fender height measurements? I've been wanting to pull the trigger on these and the only real info I can find is on the euro forums. Everything over there makes them seem like the best suspension mod for the money hands down.

Originally I wanted to just do sway bars and leave the rest be for starters... Then I saw what was required to do the rear bar. The body lean on my F31 is killing me. Had a f10 xdrive loaner and was blown away at how flat it handled in comparison. The f10 is supposed to be the boat!

[E90X]

Great info, thanks! Pictures would be greatly appreciated.

[NorthNJ]

@E90X We've had a bit of rain and overcast over the last few days. This is the best I can do at the moment.

[IMG][/IMG]

[IMG][/IMG]

[E90X]

Wow. Looks about perfect. Thanks for the pics. Any issues with the rear if you load up the back? Might have to pull the trigger...

[NorthNJ]

I had approximately 300 pounds of gardening stuff in the trunk over the holidays for my moms garden and I had a slight tuck but no major issues. It actually felt planted with the extra weight.

These definitely have my endorsement!

[scostu]

Originally Posted by NorthNJ

@E90X We've had a bit of rain and overcast over the last few days. This is the best I can do at the moment.

[IMG][/IMG]

[IMG][/IMG]

TIGHT!

Sweet wagon.

[mtenhoven]

@NorthNJ,
Did you replace the struts too or stay with stock? What's you impression on the ride especially if there are signs of undamping?

[NorthNJ]

Originally Posted by mtenhoven

@NorthNJ,
Did you replace the struts too or stay with stock? What's you impression on the ride especially if there are signs of undamping?

Only changed the springs and still have stock struts. The ride is exactly the way it should be from the factory. I only drive in sports + and I have never had a moment where I think the struts needed to be replaced.

I should add that we have some beautiful and rather well-paved streets in the District. Some of the most pristine roads.

[E90X]

Originally Posted by NorthNJ

Only changed the springs and still have stock struts. The ride is exactly the way it should be from the factory. I only drive in sports + and I have never had a moment where I think the struts needed to be replaced.

I should add that we have some beautiful and rather well-paved streets in the District. Some of the most pristine roads.

Great info. It's obvious the car is the typical undersprung BMW set up they've been doing with the OEM run flats. Any chance you'd be able to get me a measurement from the bottom of the front bumper to the ground? Thanks!

[mtenhoven]

Originally Posted by NorthNJ

Only changed the springs and still have stock struts. The ride is exactly the way it should be from the factory. I only drive in sports + and I have never had a moment where I think the struts needed to be replaced.

I should add that we have some beautiful and rather well-paved streets in the District. Some of the most pristine roads.

Just to confirm, your car does not have adaptive suspension, right? As such, driving in sport+ would feel the same suspension ride wise as comfort or sport mode. Correct?