Eibach or H&R?

[M3/217]

Hello everyone,
I have E93 M3 with Apex Ec7 (F:255/35/19 R:285/30/19) without EDC. I need to lower my car but can’t decide which brand I should buy. Both Eibach and H&R lowers the same (F:25mm, R:15mm) according to their website. I don’t want to make my car get too hard on the road, that’s why I can’t decide. Please help, thanks.

[Thumbie]

Car looks HOT with those wheels.

What's the spring rate for each? I might recommend eibach between the two because they seem to pair nicely with bilstein dampers. But i THINK both are somewhat similar...

[M3/217]

Thank you so much!
I could not find any info about it unfortunately.
Both parts are made especially for E93 M3 according to their website.
I don’t want to make my car so hard on the road, it will cause hardtop sounds on bumpy roads in time. That’s why I’m looking for the softer one between them.

[MineralWhiteF80]

Both Eibach and H&R springs are progressive spring rates, meaning they get stiffer the more they are compressed. Since the spring rate is varies, you won’t find any definitive data on just how much stiffer the lowering springs are over OEM springs.

H&R states their Sport (street) springs are 10-20% stiffer than stock, but that doesn’t mean they are always, let’s say, 10 to 20% stiffer. H&R says their Race springs are “significantly stiffer” over the stock springs, but provide no percentage range.

I’d expect the Eibach Pro kit to be similar if not exactly the same as the H&R Sport kit. In my 20+ years of “lowering spring experience,” Eibach has always seemed to be a little softer and closer to stock spring rates, where H&R has always seemed to have a reputation for stiffer springs.

One other thing to consider is that the E93-specific lowering spring will typically be a little stiffer than the E90/E92 spring due to compensating for the extra weight of the convertible. It’s possible you could get an “OEM e93 stiffness” if you installed the E90/E92 version instead.

[M3/217]

Thank you for the reply!
I think %10-20 stiffer than stock should be fine. I will try Eibach for the similar stock spring rates. Let’s see how it works.

[Thumbie]

You may also want to look at dampers. While the OEM ones work with Eibach springs as they are not much stiffer than stock, they are nonetheless still stiffer. A damper that matches that will smooth out the ride quality. Especially if you have a lot of miles on the OEM dampers.