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Old 20-04-2008, 04:05 AM
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joon joon is offline
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Currently driving: E36
 
Join Date: Apr 2007
Location: Adam Road
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E36 M3 Undercarriage Retrofit

Alot of you have PM'd me about this, so I'm going to do a little write-up again..

This is how you convert a regular E36 into an M3 from an undercarriage perspective. This was done at the same time as I did my brakes. I did most of the work myself, but you really need a friend who has a hoist and a TIG welder so this is not a DIY, just to show you what's involved.

Parts needed:
1. M3 halfcut.. since it's a RWD vehicle you actually get the whole car LOL.. coupe or sedan it doesn't matter unless you want the interior bits.. coupe is more plentiful and cheaper..
2. M3 re-inforcement plates - can order from Eng Soon
3. Turner sway bar re-inforcement tabs (optional)
4. Assorted bushings etc better to just buy them all at one shot

Here is the subframe removed from the halfcut, as you know I sold off the brakes.. dismantle everything and clean it up.. you'll need 16, 17 and 18mm sockets and wrenches.. the M3 3.2L LSD differential is extremely heavy so you need to be careful



The M3 undercarriage is completely different from the regular E36 ones.. the front knuckles/kingpins are different, they have more room for a big brake setups, rear trailing arms are different, brakes, bearings are larger at 85mm vs 75... the differential is LSD-equipped and bigger, the halfshafts are bigger... the only similarities are the Z-axle's upper and lower control arms which is the same for all E36's, you can tell the undercarriage by the ///M logo on the trailing arms and the huge driveshafts





One of the key differences for the M3 are the various subframe re-inforcements used to strengthen the chassis to handle more power.. these are the subtle changes that make the M3 special.. there are 2 sets of reinforcement plates.. 4 on the rear axle carrier mounts and 2 under each front strut tower.. the rear axle carrier mounts need to be welded in but the front 2 are just sandwiched between the strut hat (or camber plate) and the tower.. you can order them through Eng Soon or PML.. these are the part numbers

E36 M3 Front
FRONT SPRING STRUT TOWER REINFORCEMENT 31312489795 x 2 pieces

E36 M3 Rear
1. SPACER RING FOR REAR AXLE FRONT L 41002256495
2. SPACER RING FOR REAR AXLE FRONT R 41002256496
3. SPACER RING FOR REAR AXLE REAR L 41112256497
4. SPACER RING FOR REAR AXLE REAR R 41112256498

I went one step further and got the Turner rear sway bar reinforcement plates -> Turner Motorsport - Item# TSU3675001 - E36 Rear Sway Bar Reinforcement Kit - E36





The front reinforcements are basically bolt-on, so I started with the rear.. I'm a fairly good welder but I got a professional to do this coz this is tricky and you only get one shot at doing this.. first you'll need to remove the entire rear undercarriage and the fuel tank.. it's not as difficult as you think.. just a lot of things to remove.. take it one step at a time and everything comes out eventually.. should take 2-3hrs and you'll see this (I hadn't removed the fuel tank yet):



After the plates are welded on and undercoating was reapplied it looks like this.. too bad nobody will ever see all the hard work you put in, but it's the only way to do a proper M3 conversion from the inside out...



Next up is the rear sway reinforcements.. these get welded onto the M3 differential carrier.. the M3 carrier is slightly larger than the normal E36 one and the 4 bushings are bigger too... everything about the M3 is heavy duty:




Once you're done with that.. it's time to see what other things you can refresh while everything is out.. I did my brakes and installed coilovers.. I also decided to change out all the rubber fuel hoses since the fuel tank was accessible.. Instead of replacing them with OEM ones, I decided to use Parker Aeroquipp aviation hoses since I don't ever want to do this again for at least 10 years LOL.. the hoses cost me an astonishing $200 but at least I know they'll never leak.. the E36 uses a unique plastic dual sump tank with an external crossover tube.. you can easily convert this to a dual-pump setup for big power (600hp+) boosted applications



You should also take the chance to replace the rubber hose that goes from the fuel tank to the fuel filler spout.. this hose gets old and can crack.. if it does.. your fuel consumption will be abnormally high.. the part number is 16111180563 and it costs a ridiculous $40 from Eng Soon.. but there's no other way unfortunately



I removed at least 2kg of mud and dirt and dead leaves and broken clips and rubber strips and all sorts of crap from the undercarriage nooks and corners.. the stuff that accumulates over 17 years is incredible.. the fuel tank was caked with a thick layer of mud which took me 1hr to scrub off... you'll never see this sort of thing unless you dismantle your car.. so I guess ignorance is bliss.. after I saw it I just HAD to get it cleaned

After this.. just re-install everything in the order that you removed it.. I used all M3 OEM bushings except for the rear trailing arm bushing.. for this one I used UUC's urethane ones.. they squeak a little over big humps but they really tighten up the car... I installed the brackets upside down the first time.. stupid of me.. so this photo is wrong.. the bushing sits inside the recess.. this is also where the alignment guys adjust the rear toe settings



The last big item for this mod was the Mason Engineering front tower bar.. this is without question the best strut bar out in the market today for the E36 -> Vorshlag Motorsports LLC This was abit expensive but it really reduces the front end flutter of the car.. you can really tell the difference over speed strips.. my car came with a cheapo replica aluminum 3-piece strut bar and to be honest the difference between this and the Mason Engineering one is tremendous... I ran out of time and didn't get a chance to do the X-brace.. I'll do that when I have time again



All in all the car drives very different from a normal E36... it's totally solid... a testament to how good the E36 M3 really was... the next step is to put in the rest of the halfcut... one thing I realised.. I get bored of the way a car looks... but I'll never get tired of how a car drives and feels just right... from the driver's seat is all that counts

Cheers to all my E36 brothers.. really hope to meet up with some of you someday I just can't find the time lately and I'm stuck with a short overseas assignment... cheers especially to Blitzer who got me into this mess!!
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