posted on March 13, 2013 00:00
Project E36 323is: Part 1, Building the Poor Man's M3 Part 1
- Suspension Overhaul Basics
By Jonathan Lawson
The BMW 3-series has been widely accepted as one of the best handling cars for many decades. That holds particularly true for the E36 chassis, which had some nice technological advances in suspension layout over its E30 predecessor, and could also still be considered fairly light and "tossable" by modern standards.
|Prior to starting our modifications, the 323is had H&R Sport springs on OE dampers and AC Schnitzer replica wheels. It looked OK, but it was definitely not up to MotoIQ performance standards. With the shot dampers and worn out bushings making the car feel less than fun to drive, we started the hunt for some suspension goodies to bring back our ultimate driving machine's steering feel and give us the adjustability we crave. Our end goal is to exceed the handling capabilities of the coveted M3 without breaking the bank or compromising daily driving comfort. Regular E36's are cheap and plentiful on the new car market and best of all rear wheel drive. This makes them excellent candidates to build track, autocross and drift cars out of. Good aftermarket support also helps the cause.
Of course, ending production in the late-90s, the E36s have grown a little long in the tooth. Regardless of how well they've been cared for, age rears its ugly head when it comes to many parts, specifically anything made of rubber that sees stress in the form of heat cycles or load-based usage, like suspension bushings and dampers.
That's what we're focusing on first with our 323is project. The car has been sitting for a couple of years and we wanted to get the handling back to where it's supposed to be, but with upgraded components geared more towards performance. We decided to start the suspension rehab in stages, which allowed us to feel exactly what was going on with the new and upgraded parts we were using.
Another goal is for us to build the "Poor Man's M3". The price of regular old 323's is very reasonable, within the range of budget minded enthusiasts and we feel it will be easy to exceed the performance of the coveted M3 with some well considered mods.
|Whiteline's rear trailing arm bushings have the benefit of being stiffer than OE and thus keeping rear toe changes in check a bit more. You'll be happy to know that they are also much cheaper and easier to install than the factory rubber pieces - now that's a win-win situation! Note how big the bushings are in relationship to the inner sleeves. Now picture that made out of soft rubber. Now you can get an idea how much geometry altering movement the stock suspension allows back there, not good for sticky tires and high speeds.
The first stage of the project's trip back to greatness would be to tackle the badly worn OE bushings. Lucky for us our friends at Whiteline have quite the extensive offering of E36 parts and were a great source for the bushings we desperately needed to replace. For the rear of our E36 we opted to use their lower inner, lower outer and upper outer rear control arm bushings to get the rear end back under control.
|Whiteline's upper outer bushings for the rear control arms are not only helping keep our rear alignment settings in check, but the eccentric inner sleeve will also allow for camber adjustments. The kit also comes with all the new hardware you see here. Notice that the hardware is treated with yellow chromate. Yellow chromate is one of the most corrosion resistant treatments for steel bolts. Corrosion resistance is very important for an all season daily driver.
Wednesday, March 13, 2013 7:52 AM
I've been waiting for this build for a while now and am glad to see it heading in the right direction.
Are there major construction differences in the M3 and 323 suspension from the factory (not counting things like stiffer spring rates)?
Wednesday, March 13, 2013 9:09 AM
The rear suspension isn't vastly different. As you mentioned, spring rates are a given, but I believe the shocks are also valved differently. Rear sway bar is also different between models. Half shafts are also different between M and non-M cars.
The front has a few more differences. Sway bars, again, are bigger on the M3, as well as attachment points (control arm on non-M, strut housing on M). Obviously, because of the mounting points, the entire strut housing is different (including valving) and I believe the strut hats are also different. Control arms and bushings are different (non-M has replaceable ball joints, M3 requires full arm swap) and the control arm bushings are also different.
Brakes and spindles/hubs are different between the models as well, so while you can interchange M3 parts onto a non-M, it's a bit more involved and usually requires more parts in order to get a single item to work.
I'm probably missing a few items, but will come back and post as I remember.
Wednesday, March 13, 2013 10:54 AM
Surprised you picked an E36 over an E30. Still, I bet it's gonna be a neat car. They're getting pretty damn cheap. I had an E36 M3 back in the day and it did everything pretty damn well. You're gonna need to upgrade that clutch if you put any power in it. Even my factory M3 clutch couldn't handle the power STOCK...
Wednesday, March 13, 2013 10:58 AM
The rear subframe mounting points are known weak spots on these cars. If you guys are going with more power, youre going to want to get rear subframe reinforcement plates, to prevent the subframe from tearing the sheetmetal its mounted to.
great cars though. lots of fun.
Wednesday, March 13, 2013 10:59 AM
@Priapism - Rumor has it there might be an E30 project in the works... it's a ways out though
@OMGWeasel - Already working on it, that issue will be addressed in a future installment.
Wednesday, March 13, 2013 12:11 PM
This is perfect timing for me, I just saw a very affordable E36 that just went up for sale and your article just popped up while browsing here...looks like I might be spending more money very soon....
Wednesday, March 13, 2013 12:33 PM
Personally even though I like the classic lines of the E30, the semi trailing arm rear suspension sucks balls from an engineering standpoint.
Wednesday, March 13, 2013 1:47 PM
If ya plan to rip out much that stuff to convert to ///M parts,
I would have waited on some of those bushings..
also since most of the original bushings & joints were already dust..
Should have gone with all the various sheet metal & subframe reinforcement 1st, to avoid doing work twice..
Wednesday, March 13, 2013 3:15 PM
@Lessendz - we're not planning on converting anything over to ///M parts however you are correct we should of done the subframe reinforcement when we had the rear apart but live and learn right?
Wednesday, March 13, 2013 3:25 PM
I just did that reinforcement on a friends E46 as well as we are switching to M3 rear end...i HATE working on this car now. Dose not help that he didnt do enough research into the swap so it has been sitting in my driveway for 8 months...
Wednesday, March 13, 2013 6:11 PM
Can we expect an LS1 swap like the Vorshlag E36? :) http://www.vorshlag.com/forums/showthread.php?t=7740
Wednesday, March 13, 2013 6:19 PM
@speedball3 - No LS swap in this one... going to need to keep it CA smog legal for a while. (and doing a legal swap would be way too much $$ for what the car is) There are engine building plans though, eventually the car will be raced in the MPTCC series...that's the goal anyways.
Wednesday, March 13, 2013 7:14 PM
LS swap would be very interesting, but then there might be a lot of fighting for keys on track testing days.
Wednesday, March 13, 2013 7:42 PM
I thought the E36 M3 was the poor man's M3. Why this instead of a cheap M3? They are pretty cheap nowadays since they're not "special" like all the rest of the M3s.
Wednesday, March 13, 2013 8:02 PM
Because already available project cars from people already in MotoIQ social circles is a whole lot easier to turn into constant, repeat articles than scooping some unknown history M car. Id be willing to bet the actual owner of this car has had it for quite some time already.
I thought that was common knowledge as to how magazine project cars are decided on ;P
Wednesday, March 13, 2013 9:17 PM
Sell 323. Save up another $1000 and buy an m3 (much cheaper and better than trying to make a 323 an m...) Project finished.
Wednesday, March 13, 2013 10:31 PM
Wednesday, March 13, 2013 10:55 PM
All things considered. Body and interior accoutrements, engine differences, rims and suspension parts. There is a stark difference in cost. And it depends on the year as there are vairous differences in the design of the engine from early to late model. But if you are talking about truly making it "m" spec, the differences are fairly detailed. Both of which will require parts replacement due to age and wear. Dont forget to make sure the subframe isnt ripping its mounts out of the car yet.
Wednesday, March 13, 2013 11:04 PM
Remember, this is a 323is, not a 323i. It already has a few goodies from the M division baked in.
Still, American E36 M3s ARE very cheap nowadays. My father purchased a very solid '97 four-door, five-speed model (only needed a clutch) for $7700. Honestly the advantages of the M3 over the 323is are at least as much in the engine than the chassis. The S52 might be a bit low-revving and has reduced power output compared to the European motors, but it has a LOT of potential. If you are going forced induction the S52 is one of the best options BMW ever made. It is ABSURDLY over-built with its iron block and forged internals. Hydraulic lifters limit how much it can rev, but it can take A LOT of boost.
Wednesday, March 13, 2013 11:58 PM
@Hubert - I hope you weren't being serious, it would take a lot more than selling the car plus $1000 to get an M3. It would be more like plus $5000. We do have budgets to work with. There are plenty of articles on the M3, and who's to say we're not working on an M3 Project right now? This is a $2500-$3000 chassis compared to a $8000+ E36 M3, it's meant to be a fun and inexpensive track car. Plus when we completely tear it apart and make it a dedicated race car we won't feel as bad....
@Drunken Messiah - The M52 block is an iron block in North America. The S52 is by far a superior motor but we have ways of catching up.
Thursday, March 14, 2013 8:10 AM
Just saying that this is "The Poor Man's M3" doesn't mean we're trying to swap everything out for M3 parts. The argument about selling a car and starting with another that has a perceived better starting point can always be made. Why start with a 323is when you can start with an M3. Why start with an E36 M3 when you can start with an E46, or spend a bit more and get an E39 M5 sleeper. By that though process, we probably should've just found a really poorly maintained E60 M5.
Besides... Insurance is cheaper on a 323is, and it gets better gas mileage, too. :-P Seriously, though, as Nick B stated, there's a good chance an E36 M3 is in the works.
Saturday, March 16, 2013 5:19 AM
Good info on my coming E36 refresh, subscribed.
Tuesday, March 19, 2013 7:46 PM
Looking forward to seeing this one progress. I believe the later E36 M3s also received subframe reinforcements that didn't appear on the non-M. I owned a 1997 328is for a few years, and that motor had a decent amount of torque down low.
Thursday, May 02, 2013 7:33 AM
my 4dr M3 i got brand new in '97
car saw redline every time it warmed up.
crashed more than enough to not be perfectly straight anymore..
complete underpinning overhaul twice
(2 brand new trailing arms are expensive!!)
but not nearly as expensive as the 6-7 sets of LTW front spitters i've been thru..
car has a pretty rare OEM 4dr LTW wing + extension..
OEM GT3 class parts right from the dealership parts dept
(BMW quotes negative Cd/L @ 80mph)
i've put well over 60k miles before i left the diff sensor out.. prolly another 25k after that?
i'd say i got at least 10k just at the track lapping..
thats not counting the stacks of 1/4 mile drag slips i had..
our Sweeper is a "left" in 3rd gear..
(i had no baffle nor LTW dual pickup)
totally pegged the tach on a mechanical over-rev once.
from street racing to Touge drifting to track driving
all that and i aint never had ANY of the problem like what people encounter with these cars..
the only problem i had was a tear right down the sheetmetal under the rear seat..
prolly where all the stress loads eventually ended up in the chassis?
i did the Subframe reinforcement & swaybar reinforcement..
never sheared the diff bolt tho??
i drove the car VERY hard, but always tried to be smooth.
i have a feeling people drive/push the car like jerks and THAT is what causes MOST of the problems with these cars..
for a daily driver...
if the 4dr had the turning radius of the 2door..
THAT woulda been awesome!!
Thursday, May 02, 2013 2:20 PM
Wear and tear on the E36 chassis is definitely going to be different from one car to another depending on how it was cared for and/or driven, but climate and road conditions will play a role as well.
As for the comment about the turning radius, as far as I can remember, coupes and sedans had the same steering ratios (and same wheel base), so there's no difference in turning radius between the two. I believe the ratio changed in the M3s at some point around 1996, but it stayed the same for both the sedan and it's 2-doored counterpart.
Monday, May 06, 2013 4:45 PM
maybe you should try check the sales literature/brochure when memory Fails..
E36 coupe's are 1" wider & 1" lower VS the sedan
turning radius(curb to curb) was 10ft smaller
just cause the "same Parts" are used doesn't mean the mounting points & geometry are the same..
sedan's don't get/have the castor a coupe can achieve easily
Monday, May 06, 2013 5:02 PM
Unfortunately I threw out my original brochures 12 years ago. Luckily we do have Google now, though. With the M3s, the coupes were slightly shorter (1.1" difference) and wider (0.4" difference), but they had an identical wheelbase (106.3 in) and identical turning radius (38.1 ft), at least according the information that Edmunds pulls from the manufacturer.
What mounting points were different?
Thursday, May 09, 2013 4:10 PM
i'd guess either the towers or where the lower control arm bushing is mounted..
like i said, go check for an original sales brochure.
it's clearly stated the circle is like 10ft smaller
the limits of castor adjustment range is different between the two..
fenders are different between 2&4dr models, as is the hood..
front bumper is the same tho iirc
you can use E30 M3 aluminum lower control arms as well in the E36 to reduce weight.. but they recommend changes/servicing at a much closer interval..
i only got a few track sessions outta them before the ball-joint busted..
switched back to the steel version after.
MotoIQ Proudly Presents Our Partners: