Stock 128i Weighed
In the autocross world, weight is
king. Especially in a class like STX where we are all limited to the same size tire, a car that is substantially lighter that can use the same tires is typically at an advantage. BMW claims the 128i weighs 3197lbs, or 223lbs lighter than a 135i.
I wanted to weigh the car exactly as I am likely to race it. It is still a street car and as such, I weighed it with washer fluid, an owner's manual, etc. still in the car to get a realistic starting point. I purposely ran the tank down to about 1/8 of a tank to get an approximate race weight, and then went straight to the gas station to fill the tank so I could figure out precisely how much gas was in it (8 litres or just over 2 US gallons).
3,049lbs bone stock - not a bad start! I expected closer to 3,100lbs and was very happy to see that.
In general, I am going to make an effort to stay away from guesses and stick to measured facts. However, just for the fun of it, let us do a little back of the envelope weight calculations based on Kyle's measurements:
1) Replace wheels/tires with race wheels/tires (-25lbs verified 06/20/15)
2) Add rear swaybar (+10lbs)
3) Replace battery with lightweight (-35lbs)
4) Replace manual seats with Recaros (-50lbs)
5) Aftermarket header and lightweight exhaust (-25lbs)
6) Lightweight brake setup (-15lbs)
=2,909lbs
Of course these are just the big ticket items but I think these are all attainable and conservative, but we will see along the way just how we do. If this car can get down to sub 2,900lbs (and that's a big if), it should be a real force to be reckoned with!
With a little luck this weekend should bring swaybars and wheels/tires. There is a set of M bushings on the shelf for the rear subframe as well, just have to wait for the swaybars as the rear swaybar installation requires the rear subframe to come down so it makes sense to do them together. Until next time...
Mark