Lowering an M coupe

[Varinn]

Z4MC has 90k km on it now and is in need of new shocks this winter, looking at going a bit lower in the process. Debating a few options, all of which were confirmed by Turner as being great matches, but with some compromises.

Looking for first hand experiences with these three exact setups, the budget does not allow for the step up to PSS10's or KW. The dollar in Canada sucks right now and I have other priorities that don't allow me to spend $4,000+ shipping for the suspension in one car. Not looking for feedback on anything that was running lowering springs with oem shocks as it isn't really comparable.

1: H&R sport springs with Bilstein B6 HD
2: Eibach Pro kit with Bilstein B6 HD
3: H&R Street performance coilover kit (confirmed through H&R/Turner that these are running Bilstein internals with H&R bodies for the shocks/struts)

All kits will be using all oem rubber mounts, maybe HD rubber in the back. I will do trackdays and autocross, and it will see daily street usage through the summer. I find the stock suspension completely pleasant comfort wise and I'm used to stiffer/lower springs after daily driving my e30 for years with big sways and H&R/billy sports. I'm looking for about a 1" drop, and a little less body roll on the track without getting into swaybars, I'm expecting it to be a bit stiffer, but it should still hopefully be smooth.

[Varinn]

Adding a fourth option to that list that I don't see as often in searching.

4: Bilstein B12 Pro-Kit (Comes with the standard Eibach springs and valved-to-match Bilstein HD's)

[NickyC]

I've had the H&R coils along with the RE RSMs (make sure you get those as well) on both my Z4Ms and I love them. Nice ride, great handling, I can't say enough nice things about them.

[Frank851]

Originally Posted by NickyC

I've had the H&R coils along with the RE RSMs (make sure you get those as well) on both my Z4Ms and I love them. Nice ride, great handling, I can't say enough nice things about them.

Is that the H&R Coil overs with Roque Engineering Rear shock mounts?

[dubsesd]

I have h&r coils as well. I'm happy with the ride and mine sits pretty low. If you were to set them Maybe 0.5-1" lower than stock the ride would probably be more compliant than stock setup

[NickyC]

Originally Posted by Frank851

Is that the H&R Coil overs with Roque Engineering Rear shock mounts?

Yes sir!

[Varinn]

Multiple points for H&R! It's the road I'm leaning towards, I've never had bad luck with an H&R/Bilstein combo, so it gets that and some ride height adjustability at the same time.

Anyone else have input?

[Cyclops]

Originally Posted by Varinn

Multiple points for H&R! It's the road I'm leaning towards, I've never had bad luck with an H&R/Bilstein combo, so it gets that and some ride height adjustability at the same time.

Anyone else have input?

Well I installed the H&R Coilover set in the spring on my coupe (stock mounts). I've since put about 5k on them and I don't know if it's the combination of Toronto roads with the 19" I'm running but I'm not overly impressed. Maybe its my age too as I dont think the ride would of bothered me 20 years ago. The car handel like its on rails when doing some spirited driving but I dont track the car to see the benifts, and just kicking around the back roads I do find it a bit harsh. I've been actually thinking of trying something different.

[Westersund]

I also have the H&R coils, very happy with them.

[yousefnjr]

Also have h&r's, and also happy with them. They are pretty firm, about as firm as I'd want a street setup to be. I have my height set somewhere in the middle (12 threads from bottom in front, similar in rear), and I'm also on 19's with VT road engine mounts, RE trans mounts, and RE RSM's. The only time that I notice it's more uncomfortable are long stretches of rough road. A bump here or there isn't bad. No squeaks or noises of any kind. Turn-in is unbelievable, night and day difference. DIY install isn't bad, but you'll need some tools (spring compressor, etc.). The fronts re-use the stock hats.

Tip if you're looking to buy new h&r coilovers - if you order through Turner, add them to your cart and leave them there for a while. Within a week they'll send you an email to finish your purchase with a 5% off promo code, save around $60 IIRC

[Steenos]

When I need suspension or get some extra cash I'm going with the H and R coils just cause of NickyC's car. Hah. Take a look at his pics.

[Varinn]

Bump!

So debating one more option but need some input. H&R or ground control with street hybrid mounts?

I know from experience on my e30 that the Bilstein shocks/struts were a much more precise but firm ride over the Koni SA's. After switching to the Koni's the car was noticeably more comfortable on the road when running the same H&R sport springs but it never has felt as stable over bumps or in corners. The Koni with adjustment are also both a benefit and an annoyance. Sometime having an engineer setup the system as a matched set (Ie H&R coils) it is a better choice than thinking I can do better myself (GC coils with Koni DA)

I know that the Koni are a low pressure setup, and Bilstein typically run a high pressure gas strut. The Koni's I have when off the car felt a bit "loose" in that they seemed to have a delay in response to direction changes where the Bilsteins were still firm and smooth (even after 50,000km of use)

[Vanne]

I've got H&R with Billie HD's.. its an awesome setup.. love it, the ride and handling is great, lowers about an inch and sits nice and firm in the turns. Only upgrading mine as picked up a different setup as ill be doing many more track days this coming winter.

[Varinn]

Originally Posted by Vanne

I've got H&R with Billie HD's.. its an awesome setup.. love it, the ride and handling is great, lowers about an inch and sits nice and firm in the turns. Only upgrading mine as picked up a different setup as ill be doing many more track days this coming winter.

What are you upgrading to and what were the downsides you found with the H&R?

[Vanne]

Zero downsides, excellent setup, its just that i got a good offer on a set of KW clubsports, to be honest, the H&R and HD shock setup was pretty much enough for my ability, and ill probably miss them when i take them off the car..

[NickyC]

Originally Posted by Steenos

When I need suspension or get some extra cash I'm going with the H and R coils just cause of NickyC's car. Hah. Take a look at his pics.

LoL thanks Steenos, I missed this post until now. Happy 2016!! ;D

[inTgr8r]

Originally Posted by Varinn

What are you upgrading to and what were the downsides you found with the H&R?

H&R have no adjustment for compression/rebound.

[coh661]

So OP, what set-up did you end up going with and what are your opinions of it? I'm about ready to upgrade as well as I just hit 50k miles. Considering all the same options you were so I'd be interested to know where you ended up.

[Varinn]

I honestly haven't done anything with it yet, paid for a couple short vacations, bought some house reno supplies, brakes, etc.

Suspension went in the background for the time being, but I had another autocross today so this question is back on my list!

[Varinn]

double post

[DaveJB]

Today I just got my Fortune Auto 500 coilovers. I got Swift springs and the radial bearing upgrade. You should seriously consider these. Among many of the good things about these is that they'll rebuild them for $55 each corner (American made). That's simply bad-ass.

[Varinn]

In the end I went with what I'm gonna call a "tried and true" option due to lots of past experience with my other cars (Bilstein and Eibach combos). Budget is killing goals to go big these days so ground control weren't in the cards. I figure if I can't make the car go round a track without coilovers then I need to fix my driving; not my suspension!

I'm expecting to see my new Bilstein B12 Pro-Kit arrive tomorrow, and the Rogue street rubber RSM and Bimmerworld camber shims the day after. $780 shipped for a set of shocks and springs. The ride height drops ~20mm F/R, about or already past my limit.

One question though, any reason why removing the little mudflaps infront of the rear tires would be a bad idea? If I'm not super careful I already scrape them on the transition between my driveway and the road. Another 20mm down is not going to help with that.