The E30 M3 has evolved into one of the most popular dual purpose street/track cars available today. Performance, durability, and the ability to drive it to and from the track are just some of the attributes which have made the cars appealing to their second and third owners.

Despite a solid chassis and driveline, at average yearly mileage most E30 M3's are in need of "freshening up" before being pressed into regular track service. It is always less expensive to make needed repairs before you have a failure, plus you get the added benefits safety and reliability.

The bulk of our M3 work today involves preparing cars in our shop for their next decade of high performance use.  Our lengthy experience and continued involvement with these cars means we have the unique ability to translate your expectations into the M3 you've always wanted.  Our approach is to address the entire car to achieve a complete, balanced and reliable package.  We invite you to call one of our salespeople to discuss your project, enthusiast to enthusiast.  

Below are a few technical tips to help in the meantime... 

 

Quick Notes on Racing the E30 M3

Oil Pan Baffle - Absolutely essential!!! Don’t go on the track without it. (see additional info below)

Oil Level - Never more than a sixteenth of an inch over the full mark. Over-filling brings the oil level above the windage tray where it is picked up and splattered by the crankshaft. The drag on the crank will cause a 4 to 5 H.P. loss and the crank will drive the oil through the rear main seal (onto the clutch). High oil levels will also be atomized and sucked into the intake manifold in sufficient quantity to dampen combustion (power loss) and in extreme cases, oil foul the spark plugs. Never allow the oil level to go more than a half quart below the fill mark. Even with the extended oil baffle, the low level can permit pick-up of air into the oil pump and immediately damage the rod bearings. Always watch for a flickering oil pressure light as you exit long right hand corners. Known "M3 bearing eating tracks" include Sebring, Road Atlanta, Riverside (turn 9) and the carousel at Road America. I’m sure there are others.

Spark Plugs - Go one step colder. Use Bosch XR4CS Silver Tip plug for high performance/on-track running.

Differential - The stock 25% limited slip will run hot enough to turn the bearing races a blue/black color. You must use the very best Limited Slip Differential Lubricant. We strongly recommend RED LINE 75/90 Differential Lube. In our testing, nothing else came close. If rules allow, convert your 25% to 75%. This will give you more traction and substantially lower differential operating temperatures.

Brakes - Brakes are the Achilles Heel of the E30 M3. On the track, street - performances pads have actually melted and stuck to the rotors so that the brakes dragged all the way around the track. The drag was so great, the engine couldn’t pull over 5000 rpm in 4th gear! The heat build-up ruptured the caliper seals resulting in total brake failure. If you value your car (and your good looks) use only the very best racing brake pads available. Some racing pads are made for sprint racing. They slow the car rapidly with surprisingly light pedal pressure. They feel great, but make so much heat they destroy rotors and the pad gets so hot the backing plate gets soft and bends. When the backing plate bends, the brake material fractures and departs suddenly, leaving you metal against metal to slow for the next corner. That won’t last long because when you get down to metal to metal (backing plate to rotor) the piston comes so far out of the caliper bore that the seal comes out, followed by most of the brake fluid. By this time the rotor is usually hot enough to ignite the brake fluid. Recommendation: when you leave the road, try to crash near a corner station where a fire extinguisher is available. Or better yet, use an endurance type racing pad that can handle the demands of the M3. None of the above are hypothetical or ‘what if’ speculations. They are all actual E30 M3 on-track experiences!

Air Plenum Housing - There is a 90 degree air breather fitting pressed into the lower inside front corner of the air plenum housing. These fittings work loose. We have seen it happen ten years ago, developed a simple fix for it, but still see club members racing without this protective measure. As recently as the 1997 Oktoberfest Club Race, a racer lost an engine in practice when this fitting came loose. It creates such a large air leak that the engine goes lean, not always enough to hear the detonation above the racing exhaust, but enough to break the pistons, piston rings, and blow the head gasket. Drill, tap, and install a 6mm set screw and avoid a catastrophic engine loss. Not to mention the loss of the trophy you would have won that day.

Front Control Arm Ball Joints - These vital joints fatigue under racing conditions and break. That front corner drops suddenly to the ground and leads the car into whatever is off the side of the road. More than one M3 has been totaled from this failure, others heavily damaged. A guide would be to change the lower control arms and joints every two years for short club races, annually for endurance racing.

Anti-Sway Bar Link - While you are checking your control arm joints, have a look at the steel connecting links connecting the anti-sway bar to the front strut housing. We found it necessary to weld a gusset plate to reinforce the mounting bracket on the strut. And we changed the long ball joint connecting links about three times a season when we ran the long races. Annually should keep you out of trouble for sprint races.

Rear Sway-Bar Mounts - Under track usage, these brackets will pull out of the sheet metal bulkhead, leaving your rear sway-bar suddenly and completely ineffective. You can make your own reinforcement or buy a bolt-in reinforcement mount.

Coil Mount - The mount is spot welded to the side engine bay wall. Under racing vibrations the weight of the coil will crack the mount loose. Drill through the mount, install a 6mm bolt with large flat washer on the tire well side and it will hold forever.

We have pages and pages of parts to make you go faster. This list is what you need to prevent D.N.F.’s .

 

Update-8/99-E30 M3 Oil Sump Problems

We have seen an increase in BMW E30 M3 motors losing rod bearings in driving school and club racing conditions here on the East coast, plus reports from the West coast and tuning firms and customers overseas.

The newest "spec" tires now coming into increased use, BFG G-Force, Goodyear GS-CS, Hoosiers, etc, along with improved suspension systems, generate cornering forces previously experienced only with racing slicks. In hard braking and cornering, oil surging in the pan can cause oil pickup problems. The BMW Motorsport type oil baffle added to the stock pan that has worked so well for the past 10-12 years may not provide sufficient protection under these new conditions. Modified engines carrying higher RPM through corners add to the problem. At high RPM, oil is pumped to the head faster than it can drain back to the pan, further lowering the oil level around the pick up.

In marginal conditions, two identical M3's may run through a long corner at the same speed. The one in third gear and 7600 RPM may lose his rod bearings. The other, in fourth gear at 5500 may have no trouble at all.

There are several options!

The old rule in racing was, if you go to racing slicks, you need a dry sump system. A good dry sump system will absolutely cure the problem, but at greater expense than most of us want to contemplate.

  1. Accusump System

    2. Good back-up. Short surges and transient oil pressure drops are exactly what this system is designed to handle. If oil pressure drops, the Accusump immediately dumps two or three quarts of oil under pressure into the oil galley.

  2. Competition Oil Pan

    3. Provides increased oil capacity and designed to control oil surging. Not inexpensive but costs much less than a blown engine. A really good oil pan design may be better than an Accusump. It seems better to prevent a surge and drop in oil pressure than to fit a device that restores pressure when a loss is experienced.

  3. If rules or budget do not allow any of the above, the following tips may provide a sufficient margin of safety.
  1. Never let the oil level get below the full mark when on the track! Note: Under track conditions, the oil surging in the pan will get beat up by the crank, some vaporized and pushed out the breather system. In our IMSA Firehawk M3 race cars we would lose a half a pint every 90 minutes, and we were on 205/55/ZR15 shaved street spec tires. Check oil level before every on-track session!
  2. Start out your on-track session with the oil level 1/8-3/16 inches above the full line. Don't over-fill above this level. If you add more, the oil level will rise above the windage tray, the crank will really stir it up, you will blow even more oil out the breather, and if too full, the turbulence will blow oil through the rear main seal onto the clutch.
  3. If the oil light flickers occasionally, back off through that corner! Try a larger gear (carefully, we don't want you sliding into the armco!). Or just give up a little speed in that spot. Long right hand curves are the E30 M3 rod bearing killers. Uphill is worse, like the toe of the boot at Watkins Glen. Other notorious turns, the carousel at Road Atlanta, and the turn 7&8 combination as well. And again, monitor your oil level. If it's low, almost any long right hander can get you.
  4. Add an oil temperature gauge and keep an eye on it. An atypical rise in oil temp will often provide warning long before an oil pressure drop is seen. If you see a significant increase in oil temp and a pressure drop, back off and come on in. M3 pistons have such minimum piston to head clearance that if a rod bearing is lost, the piston will hit the head. The shock then breaks the rod. You don't want to hear more, and your buddy following close behind will have his hands full driving through that hot oil and large chunks of sharp metal.

If you want to run fast, you've got to follow the rules; Control oil surging and monitor your oil temp, pressure and level! Get it all right and the weekend is all fun. And don't forget to watch your rear view mirror, watch your RPM, water temp and fuel level too. And don't follow that other M3 too close through that long right hander unless you know he has his oil surging under control. You don't want to drive over his piston pieces.

 Ray Korman