e30 hubs and suspension questions

[mybimr]

:eyes1
Two questions:

1 - what are your recommendations on changing the 4 bolt hubs to 5 bolt on an '89 325is? I've noticed Zionsville replaced the rear hubs with those from a 318ti (I forgot what they used in front). The e30 325ix and e30 M3 both had 5 bolt hubs. Can I simply replace mine with stock hubs from these two models? I'd like to give myself more wheel options and prepare the car for future power upgrades.

2 - I have available to me a set of e30 M3 shocks and springs. Will they work on the 325? Will they lower the ride height? Are the springs rates not correct for the heavier engine in front? Let me know your thoughts....

Thanks in advance for your responses.....

mybimr

[wicked]

Hi welcom to the forum:wave:
Sorry i cant help but thoes are good questions.
I would like change my hubs too, it's hard to find a set of wheels for E30's most 4x100 pattern rims only fit on lug nut type cars not lug bolt types like BMWs:devillook

[Derek 350i]

I am in the process of doing this now, and the recommendations I got were these
1- Go with e30 M3 complete trailing arms & front suspension.
2- Go with MZ3 or Std Z3 complete trailing arms & reg e36 or M3 front suspension.

I got the MZ3 complete trailing arms mounted to an e30 6cyl subframe. I also got the MZ3 front spindles, brakes, & rotors and just need to buy e36 M3 front struts, offset camber bushings. Oh yeah.... and about $1700 worth of rims and tires. I am running H&R sports (e30) along with Bilstein sports.

Pretty much all I can say is this :cashwalle

Good thing my 318i was paid for 10 years ago, so I consider it basically free.

[wicked]

Thats cool:cool:
I just got my new bilstien sport shocks and H&R sprihgs from BMP.com i got them as a set only $610.00 :devillook
I also got some brand new rims and tires but i want to sell them already I want something diffrent

[dave92ic]

Hi Guys,
I have never posted here before, but I thought I would chime in, since I just finished this project.

If you do the swap, I would recommend using all e30 M3 components, so that the offset will be the same. If you use just e36 rear components, you will have to deal with fitting 2 wheels with one offset and 2 with another. I am not sure what is involved with using the e36 front suspension, but it is definitely not a direct swap.

The e30 ix does not have 5 lug hubs, it is the standard 4x100, but they use a greater offset than the standard e30.

This is definitely not a simple or cheap upgrade, so make sure you are doing this for the right reasons. Like any project, it will quickly snowball on you. You get into those "since I am replacing this, I should really replace that, and while I am at it, I should also replace..." types of situations. Although I did some additional suspension and brake mods, I spent over $3k for the swap, which does not include wheels. I also did all the work myself (with the help of some friends). The only thing I had someone else do, was the welding for the spring perches and sway bar link reinforcements.

Another thing to be careful of is getting used parts. The parts that I bought all looked fine (I took them off the M3), but it turns out that one of the front strut tubes was bent. The angle was only off by a degree or 2 (definitely not visible), but became apparent when I tried to bolt on my wheels with 225mm tires (tire rubbed on the strut housing). I ended up having to get a new strut housing ($$).

Anyway, check out this article that I put together on the suspension and brake swap (http://www.davelength.net/car/5lug.html). If you do have too much time, patience and money, than it can be a fun swap. Otherwise, I would just get some nice 4x100 wheels and a big brake kit, and be done with it.

Let me know if you have any questions.

Thanks!
Dave

my cabrio (http://www.davelength.net/car)

http://www.davelength.net/car/images/5lug/m_front_brakes.jpg

http://www.davelength.net/car/images/side.jpg

[SC87325is]

Dave is right, make sure you are doing this for a good reason.
BBS and mille Miglia make some nice wheels for the E30's, and Kosei and other have some lightweight race type wheels available.
Remember that larger wheels will be heavier and slower.
Big brake kits are expensive, no matter how you do it. They are actually relatively cheap for the four lug E30's.
Five lug conversions are expensive for something that has little relative value for performance.
To wit: The Mz3 trailing arm is identical to that used on E30's, except for a simple piece of angle iron between the front and rear support. A simple weld in job.
The rear subframe is identical apart from the exhaust hanger being on the opposite side.
All of the differential ratio's you would want to use are easily available (and cheap) for E30's-3.73 and 4.10. No reason to go to one from a higher HP car unless you plan on running higher then the 145 MPH top speed (at 6000 RPM) of a 3.73.

For the amount of money you would spend on this swap you could either get custom wheels, or a big brake kit, and have money left over. Unless someone is giving you the parts from another car (as is the case with a lucky friend of mine) there is no reason to do it, apart from the technical challenge.

[mybimr]

:smoke: Thanks everyone for your input....Dave your sight describing the upgrades to your cabrio is an excellent resource thanks for taking the time to document your work.

I was coming to the same conclusion as the advice that's just been posted. I'd rather spend the money on brake upgrades and good 16" wheels. I just can't find the wheels I like.....

I have a silver '89 325is and would like two-tone wheels with brushed rims and graphite/grey centers.

Happy motoring all :buttrock

mybimr