Suspension Confusion....

[unluky]

I am easily confused, so not a shocker, but I am confused by the different suspensions. I have a 2004 and it seems like there is a base, a sport (what I have) and of course the M.

So are all the suspensions the "same" but the components are different? Or are they entirely different all together? As in will the same shocks and springs fit on a base and sport, but the ones that come on the sport are just stiffer, etc?

I want to lower my car a bit and I like that the H&R drop the nose a little extra - but I have the sport package, so will the springs listed for the 2004 Z4 non-M still work on it?

Or this kit? Site says it will fit, but they have no option for sport or non-sport and I know when I changed my lollipops out it made a difference. Maybe it does not here??


http://www.turnermotorsport.com/p-21...n-package.aspx

When I look up springs and shocks on OEM sights, they are listed as different - but again they might be the same fitment, but just stiffer, etc internally.

Anyone with a sport package that has put in new springs or shocks help direct a guy where I can read up on this?

[Steeler]

As you likely know the M didn't come in to effect until 2006.

I do believe you can fit the sport suspension to an originally non sport car without modifications. You cannot fit the M suspension to a non M car.
The springs and shocks are different in regards to spring rate, height and valving between the sport and non sport.
I actually looked for a long time for a stock sport suspension that someone had taken off for my daughters 2003 2.5 to no avail.
She only wanted a slight drop and so we went with ST springs and Koni yellows.
The package you note from Turner seems reasonably priced and is comparable to what I paid for ours as single components from ECS.
The ride is a little softer than the Eibach and Koni set up on my supercharged 2004.

[GuidoK]

The official name is "M sports suspension", there's no such thing as "M suspension"

So you have "standard suspension" (which fits on regular z4), "M sport suspension" (which fits on regular z4), and the suspension of the z4m (which only fits on the z4m).

On the normal z4 "M sports suspension" means: heavier swaybars, heavier springs (and lower in height) and stiffer dampers. Thats all 100% compatible to z4's with standard suspension.
From the z4m you could use the front swaybar, the springs (front and rear), and rear shocks, but apart from the swaybar I wouldn't recommend that.

As for spring rates, springs do not have a fixed partnumber. Afaik the specific spring is fine tuned to your car's specific weight due to different factory options (so different vins get different springs). These are pretty small differences, so you could use e.g. both front springs from a different car, but I wouldn't recommend using just 1 different spring on 1 side as the side to side balance is very important.

[unluky]

OK - that is exactly what I was wondering. It SEEMED from my searching that all the parts were the same size (swappable) but were just different internally between the Z4's with and without sport package as far as the springs and shocks went.

I also wanted to go with the Eibach (I had them on my 300ZX TT and loved them), but I think the extra drop in the front on the H&R's will help take way the high front look some and give it a bit more "rake" that I personally prefer. A little softer does not scare me now....I am a bit older than I was with the TT and might actually prefer it, although my TT was never harsh. It had head and shoulder better seats in it than my Z4 does though, so that might have helped.

Sounds like this package will fit my car as they claimed it would and will get me where I need to go.

Thanks for the clarification.

[unluky]

Also - while I am installing springs and shocks - what else would I be stupid not to do? I already replaced the lollipops and sway bar bushings awhile back. I know the rear shocks are a pain on the roadsters, so I want to get whatever I need replaced in there while I am there this time.

Hate to learn later I should have replace something while I was in there after the fact.

Plan to do new spring pads, bump stops, etc. Any other suggestions are appreciated!

[GuidoK]

If you install new rear shocks, install also new rear shock mounts. Maybe uprated ones from rogue engineering or powerflex.

They usually have a longer life than is depicted by most, but while you're in there....

Also inspect the front top mounts and replace the swaybar end links (in case you didn't do that last time)

[unluky]

Added to the list - thank you!

[unluky]

So I see the rear spring pads come in different thicknesses??? I assume that is just if you want to add a little height to your rear spring? No other reason besides that??

[StickMon]

This?

[unluky]

Perfect!!! Thank you! I will stick with the stockers then, but change to the 15mm if I do not get the "rake" I want with the H&R springs.

[Twixboy]

Interesting, I didn't know the Z4 came with 3 different rear spring pads. Is the thicker pad compatible with all aftermarket lowering springs if you feel the drop is too low? e.g. they are matched to the car, not the brand of spring you use?

[Steeler]

Originally Posted by Twixboy

Interesting, I didn't know the Z4 came with 3 different rear spring pads. Is the thicker pad compatible with all aftermarket lowering springs if you feel the drop is too low? e.g. they are matched to the car, not the brand of spring you use?

I added the 15mm spring pad to the rear. It is sized to the car not any particular spring. You will need to look under E46 listings for thicker pads.

For a bit more drop in the front you can go with the lowered perch.

http://www.supremepower.com/suft015-...perch-bmw.html

A combination of pad and perch makes a nice rake on stock springs

[unluky]

Another good option! I don't want a huge rake, just get rid of the sagging ass end look. At work one side of our parking lot is SLIGHTLY inclined and when I back into a spot, I can't believe how much different the car looks. That is what got me thinking about it. I think with H&R springs I have on order it will help and if I need a little more the 15mm would give me another .40" in the back - that might be perfect. If not, I will check these out. Hate to drop the front end much more that the H&R will unless I have to.

Thanks for the great option!