Installed Z4 M front struts and GC coil-overs

[BMWJNKY]

I got a pair of Z4 M front struts that only had 38K miles on them for free and picked up a GC basic coil-over kit with 375LB front and 475LB rear springs. You can see the difference in height between the Z4 M struts vs the stock E36 M3 ones. You can also see my struts were leaking pretty bad. The one down side to this upgrade is the shaft on the Z4 M strut is larger and the offset E36 M3 strut mounts will not fit. I'm going to try and do my alignment after work today to see where the front camber/caster numbers are.

Z4 M left and stock E36 M3 right.
https://lh4.googleusercontent.com/-Xqs2ANyAxXs/Ul8w1STNBNI/AAAAAAAAUek/faBOURlbTcg/w625-h833-no/IMG_20131016_173348.jpg

E36 M3 compete vs Z4 M w/GC coil over installed. The overall height of Z4 M is no different with the GC stuff VS stock.
https://lh3.googleusercontent.com/-LKlduMklzDQ/Ul8_0pT3KvI/AAAAAAAAUe8/MGnJnGgJVkA/w625-h833-no/IMG_20131016_183827.jpg

Final product, not the best pic due to the poor lighting in the shop.
https://lh3.googleusercontent.com/-osk4mN66vmE/Ul9SvBdN8NI/AAAAAAAAUf4/eHiEHRGb6fo/w958-h719-no/IMG_20131016_195750.jpg

[laxeric999]

Hmm I wonder if the same will apply for Bilsteins and or Konis for the Z4M

[BMWJNKY]

Hmm I wonder if the same will apply for Bilsteins and or Konis for the Z4M

Yes, but you will need the Z4 strut mounts and bearings or aftermarket camber/caster plates that will fit the larger strut shaft of the Z4 strut.

[Eric98Sedan]

Very cool. The shorter strut is key. With those housings, and a Z4-specific Koni inserts you'd have yourself a legitimate shortened front OTS koni.

Cool that the Z4 M strut mounts fit.

Edit - I have a pair of brand new 99 M-coupe rear Konis laying around..... very very short, I ordered them by mistake.

[laxeric999]

Looking forward to seeing the alignment numbers

[Ex36]

Funny that you're doing this, yet also posted that ghetto tweeter fix!

[BMWJNKY]

Funny that you're doing this, yet also posted that ghetto tweeter fix!

Priorities, struts were so bad they were leaking onto the ground and floating like a boat along with making noise over bumps. I'm not an audiophile so as long as sound comes out of the speakers that isn't distorted I'm good, I'm not trying to win any sound competitions. If the stock suspension wasn't so bad I probably would have bought at least a pair of BSW replacement speakers but I can deal with poor sound a lot longer than I can deal with poor suspension.

- - - Updated - - -


Very cool. The shorter strut is key. With those housings, and a Z4-specific Koni inserts you'd have yourself a legitimate shortened front OTS koni.

Cool that the Z4 M strut mounts fit.

Edit - I have a pair of brand new 99 M-coupe rear Konis laying around..... very very short, I ordered them by mistake.

I'm going to measure the shock length at its current ride height an see what Koni's will work for the rear. I don't want to run the standard E36 Koni's because I don't like the compress to adjust style ones and they are probably going to be longer than I want them to be.

[5speed300]

This is really interesting, I wonder how the Z4 strut length (and corresponding Z4 specific koni insert length) compares to the shortened Konis GC and TCK sell with their e36 coilover kits.

Valving aside, it seems like you get a shortened strut coilover kit by using drop in Z4 Konis and the GC perches. I had no idea the Z4 front stuff was so similar to e36. Other than e36 strut mounts, does everyting bolt right up? The swaybar tab looks to be a good bit lower, but I guess you would use adjustable swaybar end links with coilovers anyway.

[BMWJNKY]

This is really interesting, I wonder how the Z4 strut length (and corresponding Z4 specific koni insert length) compares to the shortened Konis GC and TCK sell with their e36 coilover kits.

Valving aside, it seems like you get a shortened strut coilover kit by using drop in Z4 Konis and the GC perches. I had no idea the Z4 front stuff was so similar to e36. Other than e36 strut mounts, does everyting bolt right up? The swaybar tab looks to be a good bit lower, but I guess you would use adjustable swaybar end links with coilovers anyway.

All of the Z4 parts bolted right in. The Z4 upper strut mount is slightly bigger than the stock E36 M3 upper strut reinforcement plate so I couldn't use them but didn't need to because of the size of the strut mount. For a perfect set up the front swaybar end link would need to be adjustable but for now the stock link fit fine. The advantage to the Z4 strut is GC makes a threaded collar that just drops on over the tube and sit on top so no welding is needed, just make sure you tell them you are using the Z4 strut. The shop I work at is 20 min away from Ground Control so I was able to bring a strut with me and we were able to test fit a couple pieces to find what would work. You can see these collars in the first pic in my first post in the lower left corner.

Alignment specs, as I feared caster is lower than stock but I can probably fix it with offset bushings or the Treehouse control arm mounts. Camber plates would also fix this and the poor left to right camber split but since I have limited funds right now I'm going to live with it for a little while, I might be able to talk the GF into splitting the cost of the plates for X-mass. Since I'm running 8.5" SSR's up front wheel to strut clearance is an issue so I don't want to use the camber spacers otherwise I'd need thicker front wheel spacers.

I may go closer to stock for the front toe because it follows the ruts in the road a noticeable amount but its livable for now.

https://lh5.googleusercontent.com/-xNJo5KkHPN4/UmBNuUy_3oI/AAAAAAAAUhU/qu9v3jD9HF8/w958-h719-no/IMG_20131017_123827.jpg

https://lh5.googleusercontent.com/--r6uPzi1gFE/UmBNu8iph-I/AAAAAAAAUhY/zOthB0-b6jY/w958-h719-no/IMG_20131017_123417.jpg

[propcar]

pretty neat! Be interesting to see the Z4 Bilsteins as mentioned above.

How does it ride?

If you were to have kept the stock OEM front Z4 springs and use Z4 mounts, I'm guessing it would lower the front end? I wonder what the front Z4 spring rate is.

I did a quick search and noticed that Bilstein offers the OEM replacement Bilstein Touring twin tube shocks as well as the Bilstein HD

Also, that camber difference in the front is a bit much no?

For the rear you can use old Porsche 911 Koni's... they're shortened I believe and also have top adjusters. I believe GC and TCK would sometimes supply these with their S/A kits when they'd run out of their own 'special valved' dampers. Koni part # 8210 1159Sport

[BMWJNKY]

pretty neat! Be interesting to see the Z4 Bilsteins as mentioned above.

How does it ride?

If you were to have kept the stock OEM front Z4 springs and use Z4 mounts, I'm guessing it would lower the front end? I wonder what the front Z4 spring rate is.

I did a quick search and noticed that Bilstein offers the OEM replacement Bilstein Touring twin tube shocks as well as the Bilstein HD

Yes, if you left the Z4 strut assemblies complete if would lower the front a decent amount.

It rides pretty well for what it is, I prefer a Koni set about half way but for minimal out of pocket its a good setup.