The whole cooling system was at about 75k miles and was right at the known failure range. I pulled all the old parts and replaced them with new ones.
The stock water pump is junk so I opted for a pump with a metal impeller; this would save the internals from pieces of impeller later.
While monitoring my temps with INPA I noticed the coolant temps would continue to climb during idle. I quickly ordered a 80/88 white temperature switch to replace my 91/ 99 black switch.
I added a bottle of water wetter, removed the fan clutch to prevent an explosion ruining the radiator, and as mentioned in the last blog; I removed the condenser to let more air into the radiator. I then took black BBQ grill paint and painted the radiator, as it has been proven countless times that black reduced heat.
My Z3 came with an electric pull fan used by the A/C system so the fan clutch was never needed, especially after the lower temp switch was installed. The results are it comes on super early and keeps the engine right where I want it.
Now, this clearly isn't enough; So in the future I will be:
Let's strip this thing!
I began by pulling out the interior, I left in the dash and under panels; as well as, the center console. Then I moved onto the carpet, I pulled it all out and removed the heavy water soaked foam underneath.
The official Removal List:
Once the interior was stripped, I noticed a lot of water in the bottom of the car. The foam was soaked and weighed about 15 lbs; I drilled holes and removed the body plugs in the floor to let the water out.
I Plastidipped all exposed metal inside of the now empty shell, added black mat to the door panels to protect from the sharp edges and to give that racing look, and then added a block off plate to the radio.
Straps were added to the doors as a handle, I welded in roll hoops and the mounting brackets, and put in a single racing seat with a 5-point harness.
I then moved onto relocating my battery to the trunk; I pulled all of the metal tray parts out and only kept the one that mounts the battery. I ordered a stock positive cable from a 97 and later Z3, and a fuse breaker from a 00-04 E46 and spliced them together. I welded the battery tray to the trunk floor, and Mounted the ground cable directly to the body.
This is my list of priorities; every build needs a template:
Here is a list of explanations for the order of priorities and needs for the build:
Weight reduction is a free mod for the most part and can increase acceleration and stopping times.
Better cooling is needed considering the small 2 gallon system on these cars coupled with a radiator that is positioned higher than the engine. With the higher RPM range used and constant acceleration in a race heat soaking is a big fear.
Suspension is next because slowing down around turns will dramatically increase your lap times. The rear semi-trailing arm and lack of camber is a big down point. The stock 16 inch wheels are too narrow and the sway bars are too small.
Stopping is the biggest necessity if you are going to go faster. The front disks are non-vented, the brake hoses aren't sturdy enough, and the calipers aren't anything to write home about.
Power gets you moving and you will need to get moving out of corners and on the straights. The intake is restrictive, the RPM range is poor, the clutch sucks, and the differential is very tame.