Everyone knows when building any sort of performance car you need to do shakedown tests along the way. In the case of our Project E36 M3, our first proper testing was a track day at Buttonwillow Raceway Park, configuration CW13 of course, with the car pretty much stock aside from a new set of Yokohama S. Drive tires. During what would turn out to be the only session of the day, I had fun for about a lap or two but quickly encountered a couple areas of concern.
After the first warm-up lap, I noticed the oil light flickering during hard cornering. This is typically an indication that the stock oil pick up tube is being starved during lateral acceleration; the oil is getting pushed to the side of the pan. The standard E36 M3 does not come from the factory with an adequately baffled oil pan and/or a dual pickup setup like the E36 M3 Lightweight, European E36 M3 or E46 M3, so this issue was not entirely surprising.
After entering the pits, I discovered there was also very nasty valve lifter ticking sound coming from the top of the engine. There was also a knocking sound which could be heard mostly under load, not so much at idle. Not rod knock, thankfully, but an issue relating to the VANOS system being worn out. This is a common issue with BMW cars of this era, and luckily there is a relatively straightforward fix. The timing chain tensioner was also making a bit of noise, as were the belt tensioners. The oil light was also flickering at idle, which it had done a couple of times around town in the past. All in all, the motor was crying out for me to "please stop," so I called it a day and headed back into town.
The next day at Garagerz Automotive in Burbank, Calif., Robbie and I began to come up with a plan of attack. After we had fixed the oiling and noisy ticking and tensioner related problems, we would add a bit of power from a small selection of 50-state legal bolt-on parts. First things first, we checked the valve lifter clearances and everything appeared to be fine. They were clean, too. We chalked up the lifter ticking to the motor being slightly under filled and having too light of an oil weight.
The VANOS system is a known weak point of these engines; failures can cause a loss in power and fuel economy, as well as a really nasty ticking/knocking sound. Luckily the experts at Dr. VANOS were ready to jump in and help us out. Dr. VANOS has built a reputation over the past decade as the go-to for performance VANOS rebuilds. We opted to go with the Stage 1 VANOS kit, consisting of a fully rebuilt VANOS unit including upgraded O-rings and seals to restore lost power and torque, and Dr. VANOS' own modified bearings, designed to have less play than the OE and therefore reduce the awful rattling sound. The Dr. VANOS Stage 1 solution is ideal because it's a direct replacement, meaning you don't need to tear into the unit yourself. It just comes off as a whole part, and yes, simpler is better on something like this. Replacing the VANOS is a fairly straightforward affair, but you might not want to undertake this in your driveway unless you are fully confident and have the proper tools. We went ahead and replaced the two timing chain tensioners at this point, as well as all the belts, belt tensioners and rollers.
To address the low oil pressure under cornering load, I turned to Achilles Motorsports of Fresno for their upgraded oil pump, reinforced pick-up tube, and extremely well engineered pan baffle. Achilles Motorsports founder Mino Iorgoveanu and his guys offer a full core service for oil pump rebuilds; Achilles replaces the internals and seals with factory BMW parts, upgrades the standard pump shaft with a hardened chromoly center-less ground shaft, a double-d type key which threads into the shaft itself, and a reverse threaded nut with included safety wire. These three features address the common failures of the E36 oil pump, which are the nut coming loose and falling off the gear, the shaft shearing completely, or gear shearing off the thinly splined OE shaft.
The reinforced pick-up tube is essentially a stock tube with welded reinforcement plates, improving upon the weak OE design, which can crack over time. The oil pan baffle from Achilles is another well-designed piece, which welds in place of the inefficient stock baffle. You must cut or drill out the stock baffle, clean the pan thoroughly, and spot weld the Achilles Motorsports baffle in place. The way the Achilles baffle is designed allows for oil to pass through a pair of one-way doors to create an oil reserve around the pickup tube, while still allowing oil to flow freely around the sides of the baffle. Basically it does everything the OE baffle does, but also creates a pocket of extra oil for situations where the stock setup would be starved under hard cornering, braking or acceleration.
At this point I probably should have gone ahead and checked the rod bearings while we had the oil pan off and everything was right in front of us. Rod bearing wear can cause an internal pressure loss and is fairly common on BMW engines of this age. It was my call to not do the bearings, and in hindsight I regret my decision. I recommend doing your bearings if you are in the engine this far anyway, as preventative maintenance if nothing else.
After we put everything back together underneath, we filled up with 15W-40 Liqui Moly, which is a good choice for the warm LA-area weather. We noticed the engine mounts were a bit worn and the power steering pump appeared to be leaking out of the main line, so we replaced those items as well. Since we had the car up on the rack already, I thought it would be the perfect time to install the Dinan cat-back exhaust I had been hoarding. This 50 state-legal cat-back exhaust looks great and the muffler itself is actually slightly smaller than the factory muffler — definitely not flashy, just straight up classy. Installation of this exhaust is easy with a lift and air tools; Dinan provides clear instructions, but in a nutshell you just remove the old exhaust and attach the new one with fresh gaskets and new hardware. Lining up the tips with the bumper is the only tricky part. I recommend not trying to do this in your driveway on jack stands by yourself unless you have some sort of self-loathing complex.
The next day, I installed the Dinan cold-air intake in my own driveway with simple hand tools. This piece is also 50-state legal, which is a big deal here in California. I rented a grinder from the hardware store but otherwise everything is very straightforward. You have to cut one horn bracket out of the way, easily relocate the horns, and do some drilling to mount the plate that holds the filter in place, but it's roughly a two- to three-hour job depending on how fast you work. Dinan provides excellent instructions for the installation; the only thing I can point out is that it would have been easier if the front of the car was raised up and the wheel and fender liner had been removed for easy access to the area where the filter is located.
With the exhaust and intake installed, I quickly installed the front upper strut tower brace from Dinan as well (extremely simple job, 20 minutes) and then headed to one of Dinan's preferred installers for a Stage 2 software upgrade (about a two-hour turnaround). These four items together make the car a real pleasure to drive! The strut brace actually helps a lot; coming from a stock car with no upper support I immediately noticed it tightened things up around corners. I can't comment on dyno gains from the software, intake and exhaust; breathing mods and a software upgrade are not going to give a massive increase in power (according to Dinan the package will net you anywhere between 10-20 whp depending on the individual car) but it certainly sounds better and pulls harder. The quality of all the Dinan parts is top notch, designed and built right here in California; Dinan makes some of the very best performance parts available for BMW and Mini, old or new. I wonder if they have any of the E36 M3 supercharger kits lurking around in the back of their warehouse...
Everything is working well with the car now; the area we hope to focus on next will be the braking and suspension, and likely a wider and stickier tire. Stock brakes are fine for around town but these babies did not hold up as expected, even to a single session on track. Then we will tackle the big issue of the suspension and alignment; all stock, and by and large, original 17-year-old suspension parts have seen better days, to put it mildly. Stay tuned!