2009 Season – Build Update

During the 2009 season I forced myself to keep the M3 as stock as possible. The M3 is a great platform for the track, a very “happy” and balanced car which needs little modifications to make it ready for serious HPDE events.

My goal was to do minimal upgrades and “learn how to drive the car as it is”. 98% of going faster during your first season is DRIVER UPGRADES…those come in the form of class room instruction and seat time with an experienced instructor.

During 2009 Build Upgrades included:

Performance Friction 2Piece Rotors
These 2rotors allow you to keep the hat and simply replace the rotor when it becomes worn. Initial cost is a bit higher and buying a 1 piece rotor&hat but over the longer haul by only having to replace the rotor component and reusing the hat rotor consumable cost is lowered.

Racing pads are a must once you start going quicker on the track. Stock rotors on any production car are setup to operate with high levels of “bite” even when they are cold, but used again and again to pull a car down from high speeds stock pads overheat causing brake fade and will eventually boil your stock brake fluid.

Racing Pads operate efficiently at much higher temperatures … the kinds of temperatures you find when you are really working the brakes hard. Image the energy it takes to slow a 3000lb car down from 140Mph to 40Mph. Brakes take that energy and turn it into heat… now that’s HOT!

I have tried both the PFC01 and PFC06 compound pads. The PFC01 is a very aggressive pad with a lot of bite. The PFC06 pad is nearly aggressive but is touted as an endurance pad … The PFC06 seems to last QUITE a bit longer than the PFC01. Also with street tires I had some issues keeping enough temperature in the PFC01 to keep them in their optimal operational range, didn’t have that problem with the PFC06.

Racing Brake Fluid
With higher brake pad and rotor temperatures in a track environment upgrading your brake fluid so it won’t boil is a must. If you boil your brake fluid, air bubbles are left in your brake lines and will leave you with a soft brake pedal, or worst case a brake pedal that goes all the way to the floor w/out slowing the car at all! The reason for this, fluids don’t compress much, air compresses A LOT! The force that squeezes the pads onto the rotors requires pressure in your brake system, w/out pressure or with air that compresses in your brake lines you don’t get much squeeze on the rotors from the pads. Not a situation you want when you are headed into a low speed corner coming down the main straight on the racetrack!

I chose Castrol SRF. It’s one of the best and has one of the highest boiling points of any brake fluid. At $80 liter it better be good! 🙂

Stainless Steel Brake Lines
As you can see, keeping pressure in your brake system is critical to the operation of your brakes. Most cars come with rubber brake lines, rubber when it gets hot will stretch or bulge. Replacing the rubber brake lines with Stainless Steel lines keeps this from happening and contributes to a good performing brake system.

Square Tire Setup
The E46 M3 like most commercial cars comes from the factory setup to understeer. Manufactures do this because they believe understeer is “safer” and easier to control and correct when it occurs, it is also more predictable than overstreer.

Understeer is when the front end of the car feels like it is getting pushed to the outside of the turn. Basically the car is not turning as sharp as you have the wheel turned due to lack of traction. Understeer is easy to correct by a) slowing down a bit, or b) opening the wheel so you are turning less.

The stock setup of the E46 M3 causes the car to understeer both when entering a corner and when exiting. On the track that becomes a nuisance and a performance limiter unless something is changed.

One of the easiest ways to compensate for the undesirable and excessive understeer setup of the E46 is to replace the front wheels and tires with the same size wheels and tires you are running on the rear of the car. Trackers call this a “square setup”.

Instead of 225/45/18 sized front and 255/40/18 sized rear tire (staggered setup), you end up with a 255/40/18 sized tire setup on all four wheels. The extra grip provided by the 255 tire compared to the stock 225 does a good job of eliminating a lot of the factory understeer and really makes the car feel good on “turn in” (when turning into a corner).

Other than some minor cosmetic enhancements those upgrades above served me very well for my first season, I would recommend anyone new to HPDE with an M3 consider the same upgrades.