Experience with Bilstein B8 + Swift Springs

I have recently installed some Bilstein B8 dampers paired with Swift Spec-R springs and Vorshlag camber plates. And for the most part, it rides fairly well. However, the roads around where I am aren't always the best unfortunately, and I found numerous times going over any sort of mild-moderate road imperfections/bumps/dips (not pothole severity) to be quite harsh and unsettling—most likely bottoming out. I always try my best to avoid these by dodging them or slowing way down but it's obviously not always possible or ideal on a street setup. Just curious if others with the same/similar setup have comparable experiences?

Yes, unfortunately, IMO, swift under specc'd the front springs. Rears are pretty perfect, could be a bit higher, but the fronts are too soft for the amount of drop. You'd be better off with ZCP or Eibach or Dinan or whatever brand is less of a drop. If you want that much of a drop, you need stiffer springs truly. At least you should have reclaimed some travel with the Vorshlag plates having a thinner "Stack height" than stock mounts. You could add in a little spacer/shim to the spring to gain a little height since the low spring rate is inducing too much dive. You can also drive much slower

For reference, stock front spring rates are quite low, but you have quite a lot of ride height - macphe struts need travel. You can get some "free travel" with camber plates, but you really need to ramp up the spring rate if you want to lower the car 20-30mm.

So stock is like 160lbs or something quite low. Aftermarket springs are a bit higher, like the swift is up to 200 something, but all of those are inadequate if you want to go lower than just a 10mm zcp style drop.

I even found Ohlins 343lb(60n/mm) to be too soft, and went up to 450lb eibach for my ohlins.

I think you need at least 400lb if you're going to lower the car significantly. Then of course, you need better and better dampers to control the higher spring rates. Bilsteins really can't handle much over 300lb in my expierence. I had 325lb on my e46 with belstein b6 and it was pretty great, but I did things like modify the TMS camber plate to give maximum travel (bilsteins are travel challenged)

Bottom line, swift front springs lower the car too much, esp for bilstein shocks (versus twin tube koni, for example)

TboneS54 wrote

Yes, unfortunately, IMO, swift under specc'd the front springs. Rears are pretty perfect, could be a bit higher, but the fronts are too soft for the amount of drop. You'd be better off with ZCP or Eibach or Dinan or whatever brand is less of a drop. If you want that much of a drop, you need stiffer springs truly. At least you should have reclaimed some travel with the Vorshlag plates having a thinner "Stack height" than stock mounts. You could add in a little spacer/shim to the spring to gain a little height since the low spring rate is inducing too much dive. You can also drive much slower

For reference, stock front spring rates are quite low, but you have quite a lot of ride height - macphe struts need travel. You can get some "free travel" with camber plates, but you really need to ramp up the spring rate if you want to lower the car 20-30mm.

So stock is like 160lbs or something quite low. Aftermarket springs are a bit higher, like the swift is up to 200 something, but all of those are inadequate if you want to go lower than just a 10mm zcp style drop.

I even found Ohlins 343lb(60n/mm) to be too soft, and went up to 450lb eibach for my ohlins.

I think you need at least 400lb if you're going to lower the car significantly. Then of course, you need better and better dampers to control the higher spring rates. Bilsteins really can't handle much over 300lb in my expierence. I had 325lb on my e46 with belstein b6 and it was pretty great, but I did things like modify the TMS camber plate to give maximum travel (bilsteins are travel challenged)

Bottom line, swift front springs lower the car too much, esp for bilstein shocks (versus twin tube koni, for example)

Thanks for the in-depth explanation—super helpful!

I do drive very cautiously, but unfortunately, sometimes it doesn't take very much speed to engage the bumpstops... I've read relatively good things regarding the Swift springs and Bilstein B8's separately, but haven't seen much feedback on them paired together—now I know...

you going to experience that with swift springs, they have the best height for springs but the ride quality really sacrifices. I found that running the eibach springs with the b8 was the perfect combo, hence why they sell them together in the B12 pro-kit.
The next step is really just going to coilovers later.

GORDON.M3 wrote

you going to experience that with swift springs, they have the best height for springs but the ride quality really sacrifices. I found that running the eibach springs with the b8 was the perfect combo, hence why they sell them together in the B12 pro-kit.
The next step is really just going to coilovers later.

Funnily enough, I actually purchased the B12 kit but ultimately decided to swap out the included Eibach springs for Swift—partly because I preferred the drop, but also as I've previously had good experiences with Swift on other cars. Oh well, you live and you learn

gridworks wrote

Funnily enough, I actually purchased the B12 kit but ultimately decided to swap out the included Eibach springs for Swift—partly because I preferred the drop, but also as I've previously had good experiences with Swift on other cars. Oh well, you live and you learn

yeah there's a reason why the eibach springs didn't go as low.
with lowering springs, the rule is, the lower you go, the "crashier" the feeling of the ride will be, and on the highway/high speeds you will get that "hoppy airtime" feeling.