ALL parts for conversion to Non-Sport

[fernando306]

Hello my friends,

Can you please check if I am not forgetting anything, before I pull the trigger on these parts?
-> Is there any "conflict" in doing this, for example, a bit higher ground clearance may call for different sway bar links or height level sensor? Something crazy like that?

Obviously the goal is to renew shocks and convert to non-sport suspension: A bit more comfy and ground clearance is welcome as this is my DD.

1 - All four Bilstein B4 struts: $397.99
https://www.eeuroparts.com/Parts/507692 ... 815606KIT/

2 - Lesjofors non-sport coils front $71.99:
https://www.eeuroparts.com/Parts/509905 ... 993779KIT/

3 - Lesjofors non-sport coils rear $105.29:
https://www.eeuroparts.com/Parts/510123 ... 001700KIT/

4 - Two Front strut mounts Lemfoerder 2730901 $46.58
https://www.eeuroparts.com/Parts/168373 ... t-2730901/

5 - Two Rear strut mounts Lemfoerder 2585301 $17.98
https://www.eeuroparts.com/Parts/87477/ ... r-2585301/

6 - Two Rear Lower spring pads: $15.18
https://www.eeuroparts.com/Parts/356353 ... 31094518A/

7 - Two Rear Upper spring pads: $29.38
https://www.eeuroparts.com/Parts/33290/ ... 531136385/

8 - Two Front Spring pads: $27.58
https://www.eeuroparts.com/Parts/28535/ ... 331096664/

9 - Two Front Spring pads: $22.98
https://www.eeuroparts.com/Parts/10372/ ... 331128523/

Thank you

[fernando306]

One more thing, should I get reinforcement plates for the strut towers? From what I've researched, they don't make those for the Z4, but the ones from E46 would fit. Anyone has experience with that?

[Jakg]

Isn't the anti-roll-bar different, too?

[fernando306]

Do you mean the sway bar? I believe it is different. The question is, if putting longer springs of the non-sport would be ok. Anyone?

[NeilP]

If you're going to be adjusting the height of the car but not changing the sway - it'll be worth measuring the distance from the bar to the mount and buying longer drop links.

As for the reinforcement plates - I am running the e46 plates on the front (bought from BMW - part number: 51717036781) and for the rears - it was from eBay (can't find the link there)

[Benderloch]

https://www.ebay.co.uk/itm/BMW-E36-rear ... 890.l49292

[RKM]

Anti roll bar is British, sway bar is American. Same thing.

[fernando306]

If you're going to be adjusting the height of the car but not changing the sway - it'll be worth measuring the distance from the bar to the mount and buying longer drop links.

As for the reinforcement plates - I am running the e46 plates on the front (bought from BMW - part number: 51717036781) and for the rears - it was from eBay (can't find the link there)

Thank you my friend!
Seems like the drop links are the same for sport and non-sport suspension, as both FCP Euro and 1A-Auto do not differentiate between them.

Should I go ahead and buy all those parts?

[Davz]

You are correct in that the drop links are the same for SE and sport, however what is the condition of the links?
The sway/anti roll bar is slightly thicker on the sport, if I remember correctly it's only 1mm, this will help with the body roll on softer springs. You could uprate further to H&R sway bars as they are significantly thicker.
Regarding what to buy, I don't think you will need any of the rubber spring pads unless you live in a very hot and dry part of the US, mine are still as good as new.
You will need the strut/damper bump stops as they are a foam like material and degrade. You may also need the gaiter/dust protector which protects the damper rod, I needed all 4 when I moved to b4's. You should also consider the rear strut/damper lower bolt which connects to the lower suspension arm. These bolts need to be torqued correctly, they will stretch/fail if over torqued. When tightening the strut/damper mounts it is best to just nip up the mounting bolts, lower the car and then torque them, this allows the suspension to settle in the correct position.
Regarding the reinforcement plates, I fitted them to the rear, tbh I haven't heard of any failures, so it is probably overkill.
You could consider suplex springs, these are OEM.
You will need a 4 wheel alignment after, avoid the stock settings, far too much toe-in front and rear which destroys the inner edge of the tyres. Best to go with a z4m setup with a bit more camber on the front (1.20 to 1.50) and then reduce toe-in, front total toe-in 0.04 and rear total toe-in 0.08. Rear camber 1.5.
This will stop the understeer the z4 is plagued with on the standard settings, provide excellent tyre life and allow some fun on the twisty bits!

[fernando306]

You are correct in that the drop links are the same for SE and sport, however what is the condition of the links?
The sway/anti roll bar is slightly thicker on the sport, if I remember correctly it's only 1mm, this will help with the body roll on softer springs. You could uprate further to H&R sway bars as they are significantly thicker.
Regarding what to buy, I don't think you will need any of the rubber spring pads unless you live in a very hot and dry part of the US, mine are still as good as new.
You will need the strut/damper bump stops as they are a foam like material and degrade. You may also need the gaiter/dust protector which protects the damper rod, I needed all 4 when I moved to b4's. You should also consider the rear strut/damper lower bolt which connects to the lower suspension arm. These bolts need to be torqued correctly, they will stretch/fail if over torqued. When tightening the strut/damper mounts it is best to just nip up the mounting bolts, lower the car and then torque them, this allows the suspension to settle in the correct position.
Regarding the reinforcement plates, I fitted them to the rear, tbh I haven't heard of any failures, so it is probably overkill.
You could consider suplex springs, these are OEM.
You will need a 4 wheel alignment after, avoid the stock settings, far too much toe-in front and rear which destroys the inner edge of the tyres. Best to go with a z4m setup with a bit more camber on the front (1.20 to 1.50) and then reduce toe-in, front total toe-in 0.04 and rear total toe-in 0.08. Rear camber 1.5.
This will stop the understeer the z4 is plagued with on the standard settings, provide excellent tyre life and allow some fun on the twisty bits!

My friend, that was a super comprehensive answer - thank you!
I did buy the new drop links, as I'm pretty sure mine are busted (I hear clunks), so we're good there. I'm also going to get the bump stops.
Great advice on the wheel alignment, as soon as I do this job I'll take it to the shop to do specifically the alignment you recommend.

Speaking of torque specs, do you have the torque specs for the suspension parts?

[Davz]

You used to be able to get the specs from newtis.com but BMW forcibly closed the site so you have to pay a subscription..... haven't BMW got enough money!
I dug out a piece of paper where I wrote down the torque specs, but please check these before use, you can probably get the specs from another BMW forum. If you can't find the specs for a z4 then I would've thought an e46 would be identical.


Rear Shock Top Bolt 20 ft lb
Rear Lower Shock Bolt 28 ftlb

Front Sway Endlink to Strut (I think m10 ) 43 ftlb
Front Strut Pinch Bolt 34 ftlb
Front Strut Top Hat Bolts 25 ftlb
Front Strut Top Bolt 47 ft

Can someone on here check these?

[fernando306]

That's gold my friend!
By the way, parts shipped already...

[rdm05z4]

Roll bar / Sway Bar I believe is the hand railing out side of a pub.

[fernando306]

You may also need the gaiter/dust protector which protects the damper rod, I needed all 4 when I moved to b4's.

HA! Just checked... Guess what, they're toast, like you said. In fact, I saw that my front strut driver's side has some oil marks, must've leaked.
Got dust protectors and the bump stops as well.

[fernando306]

My friends,

Today I changed the front struts, haven't done the back yet.

The original struts and strut mounts were completely wasted with 89k original miles.
Here's a video of how crappy it was: https://drive.google.com/file/d/1s38nIb ... sp=sharing

You can observe that the original mount lost some height, as the bearing got pushed into the rubber. The rubber itself also deformed to the inside and became protuberant.

The springs of the non-sport vs sport aren't a whole lot different. The non-sport is just a bit bigger, but not by much. The let down of the Lesjofors springs, is that at the base, it does not have a special shape like the original ones do. This causes them to not sit perfectly on the strut. Despite that, they seem to work just fine.

Sway bar links, identical. Notice that I took the sway bar off the car, because I couldn't remove the sway bar links otherwise because of the space limitation.

The bump stoppers are quite different, the non-sport being bigger. Thanks to Davz, I got those new, as well as the dust boot. It was completely destroyed and really needed new ones!

I was worried that the car would look funny with non-sport suspention front and sport suspention, but quite frankly, it's barely visible that the front is a bit higher.

The ride quality has improved A WHOLE LOT, it's actually very nice now, even with the rear struts not addressed and probably wasted as well. I remember that the first advice I got, was to ditch the RFTs. I'm happy I did not go in that direction, because what good would be to have non-runflats with worn out struts. Now, even with the RFTs, it rides super nice and I am happy with it.

Looking forward to doing the rear suspension, just need a friend to step on the axle so I can fit the darn spring!