BMW 2002 5 Lug Suspension Quandary: E30 M3 VS. Z3 M

[RCM3]

Hey guys,

I need some help in figuring out which of the following suspension options is more ideal for the 2002 project I am just about to begin. I tried to post this on r3v last night, but since I couldn't access it you might see it up on the FAQ too. R3V just seems to have more knowledge and experience with these matters so I'm looking for a little help. I am trying to make my mind up quickly so I can sell the 5 lug set up I don end up using to further fund the project.

I am positively going to 5- lug swap my 2002. I enjoy not only the wheel choices and brake upgrades, but also I enjoy putting in the time and thought on the more unusual and challenging projects. I want this 2002 to stand out, and for all the modifications to flow well together. So a 4 lug BBK set up isn't my first choice...

Background information:
The chassis is a 1974 2002, no sunroof. The car will be getting an m20b25 temporarily until my s14 can be reworked and built up to one day be swapped in. I’ll be running a Getrag 265/5 dogleg close ratio gearbox behind the m20/s14 (I have both bell housings to make this work). Also being used are both e30 front and rear sub frames modified to bolt onto the 2002 chassis. The sub frame swaps allow for a Z3 steering rack to be installed, engines mounted simply, and of course allows for the 5 lug trailing arms to be bolted up in the back of the car.

(I looked up the measurements on brakes late last night so if they're incorrect in any way let me know so I can update things...)

First swap option: full e30 M3 suspension components. This set up offers 280mm/ 282mm rotor sizes front/ rear. Larger wheel bearings over the factory 2002 are an advantage, and this set up changes track width exactly the same as the standard e30 4x100 trailing arm (this measurement I cannot accurately find, to those who have done it please chime in). 15” wheels are the minimum size using e30 m3 parts.

Second swap option: full Z3 M suspension components. This set up offers 315mm/ 312mm rotor sizes front/ rear. Also, the wheel bearing is even larger than the e30 m3 equivalent and this trailing arms is braced and reinforced. This set up does change track width even more drastically, increasing the width ~20mm more over the e30 M3 (which is already wider than that of the factory 2002). Another notable item is the weight change; the MZ3 components weight another ~12 lbs more average per corner than the e30 m3 parts, due mainly to the much larger rotors and calipers. 17” wheels are held as the minimum size to clear the Z3 M brakes, although a handful of 16 inch wheels are reported to fit.

So to the enthusiasts, modifiers, and/ or racers out there, which set up sounds more appealing? I’d like to keep this thread on topic with just discussing which 5x120 swap is more “ideal”. Either way, this 2002 will require some fender flares; I am aware of this and have been searching for weeks as to which flares I like best. I enjoy the turbo flares look most of all, but these cannot be utilized if the MZ3 parts are used. I would probably go with the Schnitzer flares, if they could be sourced, if the MZ3 parts are installed. Are the bigger MZ3 brakes a better way to go despite the weight and track width increases? Are Z3M brakes on a 2002 with ultimate power goals of ~200whp from the 4 cylinder s14 overkill? Or are bigger brakes at the end of the day always more ideal on a car that will see much spirited driving. Keep in mind wheel sizes, 17s on a 2002 are large, but they do offer better tire sizes. However, should the 2002’s suspension be as light as possible and thus use the e30 M3 parts to keep the feedback from the car optimized, matching the lightness of the overall chassis?

I have the full e30 m3 suspension set up, and the rear Z3 M parts on stand-by in the barn sitting next to the 2002. I just cannot decide if I should run the e30 M3 bits or scoop up the front Z3M/ e36 M3 suspension and go the full blown crazy route with the more extreme parts.

Any insight, comments, concerns or questions appreciated!

Hopefully this is in the right section, since its not e30 related I stayed out of the suspension->5 lug swap section...


-Ryan

[anokES]

I would say m3 just because it would seem a little ridiculous to put 17" wheels on a 2002. Also I think with the s14 you don't need brakes that large, and with the m3 set up you're saving weight. But you know. Do what feels right for your car

[ClayW]

I am interested in watching this conversion. You're going to have to do a lot of cutting and welding to get the suspension components to the right points. You might start with a scratch-built subframe and then figure out what you're going to do with the upper strut mounting points.

I suppose you could cut the pan out of an E30 and weld it to the 02 body.

[SkiFree]

??

http://www.bmw2002faq.com/topic/152078-5-lug-suspension-quandary-e30-m3-vs-z3-m/

[kronus]

You can't fit an e30 pan to the 2002 body too well. Swapping frame rails (what you actually need to do) is complicated, I have not seen it done and I doubt it can be done well.


OP: z3M brakes are overkill for your application. The 2002 is a very light car even with e30 components and an S14.

Overall, I'm not sure why you are looking to use e30 M3 front struts and e30 CAs. The 2002 front suspension is fairly primitive, but the e30 stuff is not a huge improvement. There are bearings that make the E12 5-lug hubs bolt to the 2002 struts. You can then run e30 M3 rear TAs and E12 front brakes which are beefy 4 pots with 280mm rotors (like the M3). There are numerous competitive dampers that fit in 2002 strut housings, it should not be an issue to find a good set.

Another problem is mounting the CAB to the 2002 frame rail. The rail is not designed to be loaded where it mounts, it would need reinforcements at least. It's also not a given that the CAB lollipops can be mounted in a way that makes the e30 control arm geometry work.

The e30 rear subframe is a good idea mainly because you get 188 diffs out of it. The s14 does not have enough power to damage the 2002 TAs even though they are a bit fragile. Boxing them in makes them significantly stronger, as does boxing in the front control arms.

Are you building a fully fledged stripped out track car or a car to drive 40 miles a day and sometimes on backroads with the windows down and the radio going?

[RCM3]

??

http://www.bmw2002faq.com/topic/1520...30-m3-vs-z3-m/

Ya I mentioned in my first post that I tried to upload this question on r3v last night but since the site was down I figured Id pick some brains on the FAQ in the mean time. R3V just has more to offer and more experience with 5 lug swaps so I wanted a little more advice from the pros before I start cutting into the car.

[RCM3]

You can't fit an e30 pan to the 2002 body too well. Swapping frame rails (what you actually need to do) is complicated, I have not seen it done and I doubt it can be done well.


OP: z3M brakes are overkill for your application. The 2002 is a very light car even with e30 components and an S14.

Overall, I'm not sure why you are looking to use e30 M3 front struts and e30 CAs. The 2002 front suspension is fairly primitive, but the e30 stuff is not a huge improvement. There are bearings that make the E12 5-lug hubs bolt to the 2002 struts. You can then run e30 M3 rear TAs and E12 front brakes which are beefy 4 pots with 280mm rotors (like the M3). There are numerous competitive dampers that fit in 2002 strut housings, it should not be an issue to find a good set.

Another problem is mounting the CAB to the 2002 frame rail. The rail is not designed to be loaded where it mounts, it would need reinforcements at least. It's also not a given that the CAB lollipops can be mounted in a way that makes the e30 control arm geometry work.

The e30 rear subframe is a good idea mainly because you get 188 diffs out of it. The s14 does not have enough power to damage the 2002 TAs even though they are a bit fragile. Boxing them in makes them significantly stronger, as does boxing in the front control arms.

Are you building a fully fledged stripped out track car or a car to drive 40 miles a day and sometimes on backroads with the windows down and the radio going?

I see what youre saying. This car will be a daily driver more than anything, something fun to zip around in. Ive known about the e12/ tii front 5 lug option, I guess I didnt think about making a hybrid with the e30 m3 rear parts.
I bought the Z3 M bits anticipating getting the e12/ tii parts down the road to go that route. It was then when I realized how large the rear Z3 M parts were, the wheel sizes and offsets Id be limited to and eventually led me to posting this here.

I wanted to run an e30 front sub frame so I could use the Z3 steering rack. I guess I figured making the front e30 suspension work at that point wouldnt be over the top hard, that was my logic in suggesting going full e30 m3...

Thanks again for the insight.

[88SuperETABD]

Hey man, I live in SJ as well, and have a 70 '02 im putting a forged 2.9L m20 (then turbo) into it. I'm planning to run the whole e30 drivetrain and rear subframe/TAs. (why do you want 5 lug?) PM me with your email address and there is a guy i know that makes m20 mounts/ getrag 260 trans mounts. We gotta cut the trans tunnel to fit it, unless yours was an automatic, then you may be able to just pound it out with a sledge to fit.

Also, what are you skills? sorry if i missed it, but are you ready to cut/fab lots of custom pieces to make this happen? or a lot of cash could get it done too haha.

But regardless, we should talk, share our ideas. unfortunately im still building motor.

Also you should go to BMW2002FAQ forum, cuz theres tons of info there. not so much the crazy stuff we plan to do with these cars but there is some of that too.

[RCM3]

Hey man, I live in SJ as well, and have a 70 '02 im putting a forged 2.9L m20 (then turbo) into it. I'm planning to run the whole e30 drivetrain and rear subframe/TAs. (why do you want 5 lug?) PM me with your email address and there is a guy i know that makes m20 mounts/ getrag 260 trans mounts. We gotta cut the trans tunnel to fit it, unless yours was an automatic, then you may be able to just pound it out with a sledge to fit.

Also, what are you skills? sorry if i missed it, but are you ready to cut/fab lots of custom pieces to make this happen? or a lot of cash could get it done too haha.

But regardless, we should talk, share our ideas. unfortunately im still building motor.

Also you should go to BMW2002FAQ forum, cuz theres tons of info there. not so much the crazy stuff we plan to do with these cars but there is some of that too.

I loved the e30 m3 stuff on my e30, and I wanted to carry that over into my 2002. Wheel choices, brakes, etc I guess would be my reasons.

Im using the euro dogleg gear box, but I guess it uses the same mounts. I do know about cutting up the trans tunnel, and I have a donor e30 for any parts I may need should I decide to graft the tunnel from the e30 into the 02. I actually have a very detailed write up from a member on 2002faq who did the s14/ dogleg swap. I use FAQ, but like you said, most do not have the wants or needs for this type of swap.

My fab skills are essentially not existent. I purchased this car as a chance to learn how to fabricate and design parts to be used on my car. I will be relying on friends helping with the early phases of the car, and the more integral and structural parts.

Ill PM you.

[kronus]

So getting rid of the steering box is actually a worthwhile goal, because they are all worn and have a ton of play in the center. It feels ok on track because most of the time your wheels are loaded from turning and you're modulating pressure, but for a DD it's not fantastic.

I've seen e21 racks swapped, but the steering column gymnastics are concerning. If it's possible to section the e30 front subframe to narrow it for the 2002 frame rails, something might be possible, but you have a lot of measuring ahead of you. Rebuilding the rail to be strong enough to support the CA (either by plating it or replacing completely, and fabricating captive nuts) is then also necessary.

You should also measure the position of the e30 motor relative to the subframe. It's not a given that an e30 motor mounted on an e30 subframe won't interact with the 2002's firewall or core support.

In any case, good luck and keep us updated. Your result will be very dependent on the quality of the fab work.

FWIW, if you're worried about e30-sized brakes not being big enough for a 2002, you shouldn't be. Bigger brakes don't make you stop faster, the stock ones can lock the front wheels if they need to. I had the upgraded volvo calipers on e21 vented rotors and had no difficulty locking up r888s. Bigger calipers and rotors really just get you heat and fade resistance, maybe some better feedback if the rest of your brake circuit is upgraded. (you should be running the e12 master and might still need a bias valve depending on the brakes you end up with to dial it in) It's difficult to get to the point where you need big brakes on a street car.

[kronus]

Also have you already found a dog box? Will you be using a 265CR or a 245/11? The 245/11 won't require transmission tunnel modification, and weighs considerably less.

I have a 245/11 I'm looking to move on, but you would need to swap the bellhousing to an M10 one to run it with the S14, which is involved but doable.

[RCM3]

I should mention that along with the e30 sub frame up front, I was going to use an e30 steering column also. I figured a lot of measuring and reinforcing would be required to make this happen, referring to it all. There is a very partial and not detailed thread I found on modding the e30 front sub frame to make it bolt onto the 2002 chassis. I believe they did it not only for the rack and pinion swap capabilities, but also to make it easier for an e30 engine swap, I think it was an m20.

So the e30 brakes are enough for my purposes, and for most applications, good to hear that from someone with experience.

As far as the dogleg, I do have one. I have the Getrag 265/5 and both bell housings needed to make it work on the m20 at first, then the s14 when the time comes.

What transmission are you looking to change to??

[kronus]

I remember this thread hazily. Somewhere in europe, right?

I never had the 245 in a car, but I am preparing to use the 265CR behind an M106. I am somewhat suprised to head that there are bellhousings that make the 265 work with an M20. Was this one of those strange ones off a european diesel car or some such?

[RCM3]

I remember this thread hazily. Somewhere in europe, right?

I never had the 245 in a car, but I am preparing to use the 265CR behind an M106. I am somewhat suprised to head that there are bellhousings that make the 265 work with an M20. Was this one of those strange ones off a european diesel car or some such?

There was a removable bell housing for the euro 5 series (528e) that came equipped with the CR gear box, and thats how the 265/5 CR dogleg box can be used behind an m20. Theyre harder to find, but the bell housings are out there.

An M106 swap would be so much fun, especially with the 265CR.

[phreshkid]

Why go 5 lug to begin with? If your end goal is a slightly breathed on s14 putting out 215whp, why make your life exponentially harder and go after e30 m3 or e36 suspension?

There are plenty of BBK options for the 2002 already, as well as suspension options that will make you car handle plenty well.

Let me ask you, have you ever been in an s14 or m20 swapped 2002? Have they been properly set up?

Do you have any idea what you are getting into? I'm not trying to bash on you, but something tells me that you have no idea what you want.

Start with the basics, get into a few 2002s that are set up correctly and you'll realize that you don't need to go the lengths that you are suggesting in your original post. A 2002 was pretty awesome right out of the box. There is a reason that people like them so much.