Vorshlag $2010 GRM Challenge car - BMW E30 V8

[Rex1585]

I give up, there are too many fanboy sites, I can't find a reliable specs. Worse than Hondas!

I find that remark a little less than fair, I have to wade through tons of crap on here, to find the slightest glimmer of hope on info. While on the S2ki.com forums, I could find all of my information when I had an S2000, in a matter of 5 or so clicks of the mouse.



BTW I am subscribed and very interested...

[Def]

Any updates on the car?

[TOOLEAN]

Somebody go wake up Fair.

[hefftone]

Somebody go wake up Fair.

Perhaps they are busy shoehorning that infinit V8 in. I must confess, I am eager to hear what's developing as well.

[Fair]

Updated for Feb 5, 2010: We had a group of 4 of us working on the GRM $2010 E30 last night, including new team member Derek! He stopped by the shop yesterday to sell us some engine parts needed for the V8 swap, fell in love with the little E30, and now he's on board. This project seems to be a magnet for local car guys!

The main item on the night's agenda was to finish our E36 front suspension/brake/5-lug swap. We spent the entire evening mocking up, measuring and installing control arms and spindles to try to fix the "altered wheelbase" issue that accompanied our E36 front suspension swap onto the E30 chassis. We were told to try early E36 spindles with late LCAs, so we tried that - and a hullva lot more permutations.

We didn't find the magic combination that allows an E36 spindle + strut to be used on the E30 chassis - because we feel that there is no magic bullet. The "Easy 5-lug and E36 strut swap!" theory is a myth. Check out these pics and I'll explain further.



In the pictures above you an see the E36 spindle, brakes, and E36 coilover strut (not our final strut solution for the $2010 budget - just an interim AST coilover we had laying around until we found a cheaper solution!) installed onto the E30 - and the massive alteration in wheelbase. This tiny stock 205/60/15 tire and stock 15x7 E36 "bottlecap" wheel tire is rubbing like crazy at the back of the wheel arch and inner sheetmetal when turned, at this lowered ride height. Of course we had the maximum offset on the rear LCA bushings... we ran out of room there long ago.



This tire rub issue is because the front wheel has been moved rearward by over an inch, and is interfering with the fender opening and even the inner sheetmetal and unibody. It will have changed the caster in a bad way as well. Well, damn that...



Here you can see the various "non-M" Lower Control Arms (LCA) available on the E30, E36 and E46 chassis. We've tested the E30 M3 and E36 M3 LCAs and they all look very similar, but will round up examples of these M versions (all on cars in the parking lot including Matt's '95 M3, my '97 M3 and an E30 M3 we can borrow). All of the E30 and E36 LCAs we measured were IDENTICAL. To the mm. The "A" distance was the same on all of the E30 and E36 arms we tested, with only the E46 arm having a different "B" number (1" longer). The hypotenuse (and any fore-aft offset of the spindle mount) was also the exact same between all E30 and E36 LCAs we tested too - so the differing part numbers between early and late E36 LCAs seemed to be only cosmetic in nature.

We still installed and test fit wheels with all of these LCAs, "just in case" and there was no difference in the wheelbase issue, of course. The E46 LCA was indeed longer, but this only caused a huge amount of negative camber, and didn't affect the caster/wheelbase issue at all.



What's the solution? How can you use E36 suspension parts in an E30 and keep the wheel centered in the wheel opening? Well I'm fairly certain there's not going to be a solution that uses factory spindles and control arms. That parts-bin solution seems to be a total myth.



If you look closely at where the LCA mounts to the spindle on an E36 and E30, there lies the problem. On the E30, where the spindle and strut tube are one piece (a retarded and very limiting design) there's no room to get to the top of the LCA ball joint mounting nut... so this mounting hole its moved rearward on the spindle by about an inch compared to the E36. On the E36, the strut un-bolts from the spindle, so since yoiu can gain access to it they have moved the lower mounting hole on the spindle to almost right under the strut axis itself, and when this spindle is used on an E30 its going to pull the wheel backwards about an inch. Bad.


Notice the offset from the strut axis to the spindle mount on the E30. On an E36 this is very different

We're going to try to make or modify one of the many stock steel Lower Control Arms to allow the E36 spindle and brakes fit. Why? Well we REALLY need the 5-lug pattern from the E36 bits, to be able to use the cheap GM 5-lug pattern circle track wheels we scored (new 15x10's for $50 each don't exist for 4-lug BMW pattern), which will give us a grip advantage with some used 275/35/15 Hoosiers. Also, the cheap-to-free used E36 spindles and brakes are a big upgrade over the E30 bits (11.5" diameter E36 brake rotor vs 10.5" from the E30). Lastly, there are TONS of low cost, used E36 struts out there, but decent/used/cheap E30 strut inserts are few and far between.

We'll include these pictures and more detail on our final solution later, in a full blown tech article. There's got to be an affordable way to run E36 suspension on an E30, and by damn, we're going to find it.

Stay tuned...

[garretvs]

E30 M3 front struts & spindles

[TOOLEAN]

E30 M3 front struts & spindles

Would an e36 hub fit the e30 spindle?

[Volcom8190]

Would an e36 hub fit the e30 spindle?

could probably machine the hub/an adapter to work quite well, just make it pressfit

[Fair]

E30 M3 front struts & spindles

... are worth about $800-1000 for cores nowadays. Find me usable stock E30 M3 spindles/struts for under say... $300/set and I'll buy every one, sight unseen.

Even if we could magically find a free set of E30 M3 spindles/struts (ha!) they still suffer the same limitations as the E30 4-lug spindles: there are no affordable choices for coilovers. All you can do is use inserts -or- cut off the factory strut tubes and build your own shocks from scratch (which is how AST makes 4200s and all 5000 models. Ever priced shipping spindles to and from Holland?)



We looked into making/modifying/swapping just the E36 5-lug hubs onto the E30 spindles, too, but we lose both the cheap/available/better E36 strut choices as well as the step up to bigger E36 front brakes. We have had multiple free sets of E36 non-M spindles + LCAs + full front brakes donated. Nobody puts much value in this stuff, and its free for the taking if you know where to look. Well this stuff is still a HUGE improvement over the stock E30 non-M front brakes and suspension!



Not a big deal on an auto-x/drag car to get the bigger E36 brakes, but it matters for track use. Imagine a 350 whp V8 powered E30 with 275mm Hoosiers - Do you want to be wheeling this thing around a track with stock 4-lug E30 brakes?? I sure don't. At least with 11.5" front discs we might be able to make a few laps without the brake pads catching fire.

Again, this weird E36 5-lug swap is bigger than our $2010 GRM project - its something a LOT of E30 4-lug folks have wanted to do, and something I wanted to try for years, but nobody has just documented the problems or solutions very well. We're we're going to make it work with correct wheelbase/caster, one way or another, and show it here.

Thanks,

[das borgen]

I am going on record as saying that I lik this thread a lot.

cheap trick on the E36 to gain neg camber is to swap the tophats left to right and right to left, but I believe this can adversely affect caster and mechanical trail, which could work to your advantage

try it on the E30 and lets see

[TOOLEAN]

I use this picture to help me visualize the possible changes, first I was thinking you could simply machine a lollipop, but your geometry would go to shit. I believe your best option, with the given constraint, is custom LCA's.

[giuliettaevo]

Imagine a line being drawn from the middle balljoint( that attaches to the front axle) to the outer balljoint(spindle side) and a line from the middle balljoint to the rear fixingpoint of the LCA ( the rubber 'eye' on the body. the angle between those lines determines the location of your wheels.

The E36 M3 3,2 uses a LCA which has a slightly bigger angle, which moves the wheel forward a bit. Using the E30 M3 LCA (a-symmetrical)rubbers will also help put the wheel further forward. This info was sourced from www.e30.de they say it's not worth the hassle...

I'm very interested if you can find a solution as i have some E46 suspension parts lying around which i would like to use on my E30...

Maybe making a new rear LCA mount can cure the problem? just put everything in place except the rear rubber and then put the wheel exactly where you want it and then see if you can make a new mount for the rubber.

Or else you could place the mounting point for the middle balljoint a bit further to the front. this may require some serious fabricating...

Good luck with it...

[hefftone]

How do the positions of the inner ball joints compare between the E30 and E36?...not on the control arms themselves, but of the crossmembers.

[caperix]

I looked into doing a 5 lug E30 a few years back, from what I had found the best solution, still moves wheel back some over stock, is 96 and up m3 lower control arms with 95 or E30 M3 ofset bushings. The E36 M upper strut mount is rumored to help also. I used to have some pics of the differance between the 95 and 96 M3 lower control arms but am unable to find them at this time.

[Fair]

We're trying to round up some used E36 '96-99 M3 LCAs right now. Anybody have used ones, even if the ball joints are shot? Just need to use them for mockup, and then if they work try to find a usable set cheaply. This late E36 M3 LCA may or may not move the spindle enough - won't know or believe it until we try it here (which we'll document of course).

Otherwise we'll make/modify one of the many pairs of steel E30/E36 LCAs we have now. I suspect the easiest solution may be an LCA modification via a torch and the hydraulic press (bend/move the spindle mount end of the LCA forward). It would be tricky to get both sides the same using this method, but I've seen crazier stuff done. Might involve making a bending fixture.

A smart move might include a real scientific "test to failure" using a stock LCA and a heated/bent LCA, afterward, to make sure we don't weaken the arms with the heating/bending. If heating/bending the LCA weakens it, we could add some post-heat reinforcement.

More soon.

[Gnarles]

you need 96+ e36 m3 spindles and LCA's along with offset LCA bushings to get the proper caster angle on the E30 with the E36 setup.

[Fair]

you need 96+ e36 m3 spindles and LCA's along with offset LCA bushings to get the proper caster angle on the E30 with the E36 setup.

If that's the case then we'll have to alter the lower control arms instead. We don't have room in our $2000 budget for this car to afford M3 spindles and all of that. We've already gobbled up too much of the budget with the purchase of a running and complete V8, the car, and the 15x10" wheels. We could only afford M3 spindles if we used Enron Math.

[Def]

Why not just cut and weld the outboard side of the LCA? Just make a laser/waterjet model that has a built-in indicator(such as angle of the sides) for how much you need to bend the arm then weld it on there in a sandwich configuration. Should be plenty strong and not use much weight. Pretty easy for an average DIY guy to do if they just have to cut 90% the way through, bend to shape, put the plates on, weld, done.

Not the ideal way, but a few 1/4" steel pieces are going to be more than strong enough for any suspension loads going through the arm.

[CrazyCoder]

Any news?

[e30polak]

This is crazy and I love it!!!

Good luck with everything you guys!

[Fair]

Any news?

The '96 M3 Lower Control Arms showed up, thanks to a cool BF user, and they look great.



They are actually going to help... it might not be enough different to completely fix the wheelbase problem, but it might be enough with the shorter 275/35/15 Hoosiers we are using.



The plan is to get these on the car tonight and test it.

[speedracer9923]

Looks great!

I will be cheering for you guys!

I only wish I could be doing this for a living!

[VaTechE36]

Looking good Terry, hopefully those will work out for you!

[Fair]

Update for Feb 18, 2010: With last week's Thursday work night snowed out (we had over 12.5" of the white stuff - a 24 hour record for Dallas) and some missed work nights over the holidays, the team was getting itchy. We had 6 of the $2010 Team members here Thursday night to turn wrenches on the E30 again - it was bedlam! I'm behind on posting pics so here goes:


Chris and Paul pressing in the '95 LCAB bushings. We might go back with poly or Nylon (we'd machine them to save $). The "composite" bushings (aka: wood shim!) had to go

We had 2 different teams working on different things to stay busy, and in less than 2 hours we had the pair of '96 M3 LCAs on, new offset '95 M3 bushings (eBay) in the LCAB "lollipops" in, the E36 steering rack installed, with trial fits along the way. We also decided to up the scheduled "first test" date by 3 months, including some road course testing (more on that at the bottom).


Costas, Dave and Derek thrashed on the LCA's and E36 steering rack

The old E30 steering rack brackets were bent up pretty well. Once we finalize the up/down location we're going to beef up the lower mount with some steel. Hopefully this will then withstand the higher cornering loads of 275mm Hoosiers at high speed track events.


The rack mounts were cleaned and straightened


The E36 rack has about 1/2" gap to the factory E30 mounts. This is nice - it will allow us to shim the rack up/down to correct for bump steer

The holes on the E36 rack lined up perfectly with the E30 brackets, and the end-to-end length was fairly close to the E30 rack. The E36 rack moves the power steering hose ports to the outside of the rack, away from the V8 motor we're adding. Its also a lot faster ratio rack than anything that came in an E30 - and was a freebie! A cool customer who had swapped in a Z3 rack into his E36 track car donated this well used (275K mile!) E36 325is rack to the cause. Don't let the cleanliness fool you - that's just my pressure washing and OCD detailing on what was a dirty old rack. :p


The '96 LCAs on and the rack in place

The wheel has indeed moved forward, but as expected after reading the great write-ups on these swaps on R3vlimited forums, this is far from perfect. The right fix probably does involve E36 M3 spindles, but we cannot and will not do that for this project car. Why? It will pound our budget, and doesn't fit the theme for this car - a fast car built with cheap parts that nobody wants.

Going to E36 M3 spindles mean we'd need M3 rotors, calipers, and more. We're not going to even try to pull that one over. The two sets of E36 non-M spindles/rotors/brakes we've picked up were free because nobody wants them, and that's why we're going to use them. The non-M E36 brakes are still 1" larger than the E30 4-lug garbage, so its still an upgrade. The stock 24" tall tires on the car now just barely clear the inner unibody structure at full lock, which they didn't even come close to doing before. If the shorter (275mm) Hoosiers can work like this, we'll keep it as-is. Otherwise we'll modify or build a LCA to correct for the E36 spindles in the E30 chassis. We came up with a game plan if this proves necessary, but we're going to move onto the rear 5-lug swap next, for now.

more below...

[EThirtySicks]

Lots of good info in here about the whole 5lug front swap, good for you guys for documenting it so well.