Early 318i suspension conversion to 325

[mrdane]

I'm contemplating using an early 318i for a possible M50/S50 installation and am wondering how upgradeable/suitable the early suspension is.

From what I've learned the strut housings are smaller than the 325's (and front brakes are solid rotors, rears are drums, smaller differential, etc.)

Are the smaller diameter strut housings an issue? And if so, can they be easily swapped? Any other advice would be welcome also.

TIA

[Sean]

You should just swap in all the 5 lug parts from an E30 M3. Then you'd be all set!

That, or maybe even the E36 5 lug swap, then you'd have all the braking you need for a M50!

If you wanna keep it low budget though, you can swap in 325i components, and it'll fit right in (like strut housings and whatnot - 325i shocks and struts WONT fit in a stock old 318i)

[mrdane]

Thanks Sean,

I could not find any previous posts confirming if the 325 strut housings were swappable into the 318.

I don't think I'll go 5-lug, just stock 325 parts.

[Bill 84 318i]

Upgrading to the bigger strut housings is pretty pointless in terms of durability. It's a great idea for shock selection though. You can use the vented front brakes on either the early 45mm housings or the later 51mm housings - just make sure you use the wider caliper as well.

What most people do is drop the entire rear subframe/suspension/diff and replace it with that of a 325. The individual parts should bolt up too.

[Sean]

Iff I were in your position, I'd upgrade to 325i suspension. Do you have rear drums? I'd DEFINATELY upgrade to the 325i rear discs if you're puttin in an M50. The 318i brakes are lacking quite a bit. The 325i brakes should hold up nicely though.

The ability to have a wider range of shock selection is also really nice too.

For four lug, I'd personally switch to 325i suspension.

Glad I could help.

[mrdane]

Is there a big difference in using M3 suspension vs 325i? Or do most people swap to M3 parts just for the larger selection of 5-lug wheels (and make a small gain in handling?)

[Bill 84 318i]

Is there a big difference in using M3 suspension vs 325i? Or do most people swap to M3 parts just for the larger selection of 5-lug wheels (and make a small gain in handling?)

I believe the geometry of the M3 suspension is identical to the regular 325i stuff. If not, it's damn close.

The benefit of the M3 suspension is bigger brakes, bigger wheel bearings, two piece strut housing (so you don't have to knock out ball joints every time you do shocks/springs), and a better wheel selection (not that 4 lug selection is poor).

[Sean]

I would love to have that two piece strut housing!!! YUMMY!! :shock: :D

[Digitalwave]

Iff I were in your position, I'd upgrade to 325i suspension. Do you have rear drums? I'd DEFINATELY upgrade to the 325i rear discs if you're puttin in an M50. The 318i brakes are lacking quite a bit. The 325i brakes should hold up nicely though.

The ability to have a wider range of shock selection is also really nice too.

For four lug, I'd personally switch to 325i suspension.

Glad I could help.

boom monkey did this on his 318i, he said it was fairly easy and worth the effort.