4 bolt to 5 bolt conversion

[Colorado M42]

I'm new to the forum and my son and I just picked up a nice 1991 318is yesterday.  So here we go with upgrades.  As you see in my TITLE, what parts do you need to convert our 4 bolt 4-100mm to a 5 bolt 5-120mm wheel?
Thanks!

[Hodge]

I'm new to the forum and my son and I just picked up a nice 1991 318is yesterday.  So here we go with upgrades.  As you see in my TITLE, what parts do you need to convert our 4 bolt 4-100mm to a 5 bolt 5-120mm wheel?
Thanks!

There are a few options:

Complete E30M3 front struts and hubs with Complete E30M3 rear trailing arms and hubs

or

E36 318ti rear trailing arms and hubs and E36 M3 front struts and hubs (have to use offset control arm bushings)

or

Mix of the two. I would personally rather do the E36M3/318ti conversion, so you can also get the big E36M3 front brakes.


It's alot of work, but can be done.

[Colorado M42]

Thank you HODGE.  I appreciate the info.  Is their a concensus on this conversion with everyone out there?  Also is it worth it?  I guess that's the main question.  It looks like you can get nice 4 bolt wheels and larger rotors with our existing set-up, so what's the benefit going to a 5 bolt wheel.

Thanks!
Mark

[EN318isPDX]

Thank you HODGE.  I appreciate the info.  Is their a concensus on this conversion with everyone out there?  Also is it worth it?  I guess that's the main question.  It looks like you can get nice 4 bolt wheels and larger rotors with our existing set-up, so what's the benefit going to a 5 bolt wheel.

Thanks!
Mark

Umm none really. You get bigger brakes and more OEM bmw wheel options. I don't think unless you have done a motor swap or turbo/supercharger setup there is no reason to upgrade.

[Hodge]

I agree. Not much reason to blow so much money on them unless you really NEED the extra stopping power.

There are plenty of rather nice 4x100 options out there.

[Colorado M42]

Thanks for your information and thoughts on this subject.  I was thinking I could use a set of my wheels and tires from my E28 on the 318iS.  I have a set of BBS RS 3 piece wheels and racing tires that I was going to loan my son for some autocrossing this next Spring, but even if we did the 5 bolt conversion, the offset of the wheels still might not work.  I'll probably just get him his own set.

[Colorado M42]

I'll try to send a picture when I figure out how to do it.  Here's a picture of my '85 M535i with a full Dinan suspension, 40% limited slip rear end, Blanton modified transmission, etc.

[strypt]

E36 318ti rear trailing arms and hubs and E36 M3 front struts and hubs (have to use offset control arm bushings)

I would stay away from the E36 front solution as it will give a lot of bump steer, especially if you are planning on using it as a track toy.

[kowalski]

you could also machine 5 bolt hubs to fit on the 4 bolt wheel bearings if your really wanted to.

[dude8383]

E30 M3 is the way to go if you are looking to do serious track work and perhaps put down more power.

You have a bit more options when it comes to having the 5 lug. Also, the E30 M3 setup will change the swap end link locations and I hear that it actually improves handling.

[dude8383]

E30 M3 is the way to go if you are looking to do serious track work and perhaps put down more power.

You have a bit more options when it comes to having the 5 lug. Also, the E30 M3 setup will change the swap end link locations and I hear that it actually improves handling.

[strypt]

You have a bit more options when it comes to having the 5 lug. Also, the E30 M3 setup will change the swap end link locations and I hear that it actually improves handling.

Yes its true, the M3 E30 sway bar links is bolted directly onto the spring strout and gives it more leverage compared to the E30 mount which is on the wishbone. This makes the swaybar act as a stronger one. The mouting locations on the M3 also improves roll center a bit.

You can also fabricate a sleeve that has an outer diameter the same as a E36 wheel bearing and an inner diameter some hundreads of a mm smaller than the E30 bearing so that it has grip fit onto the pin on the strout. Then you can use a 5-lug E36 bearing Of course you will have to customize your brakes afterwards, nothing oem will fit...