Prepared to go, with test drive!

With the necessary major initial projects at an end, only a few small things remain to be wrapped up before the first autocross event. It’s a good feeling to be at this point though a little concerning as well because I start wondering if I’ve missed anything that may fail in the first run. Plans this time are to address fluids, more worn bushings, and swapping in a lighter weight battery.


I have no proof as to when all the fluids were all previously replaced, only the word of the prior owner. Not good enough for me, so this is now a requirement because I don’t even have any clue what fluids he used. Here are the fluids that I’m using for my 325is:

  • Brake Fluid – ATE Original TYP 200 DOT 4
  • Manual Transmission Oil – Red Line 30504 D4 Automatic Transmission Fluid
  • Power Steering Oil – Mobil 1 Synthetic ATF
  • Engine Coolant – Prestone Green
  • Engine Oil – Mobile 1 Full Synthetic 10w-40
  • Rear Differential Oil – Mobil 1 LS 70w-140

I chose all these specific products based upon my research and other user experiences. Feel free to do your own digging around but these all seemed like great choices to me.


The Motive Power Bleeder is a great tool when it comes to changing brake fluid. Nice and controlled one person operation with no chance of introducing air bubbles in the lines. The old fluid didn’t look too bad so it seems it really had been replaced lately (though I have no clue what fluid was used). Once the brake fluid swap was complete I had a nice firm pedal as desired.


When I installed the Ground Control suspension, I notice that the sway bar bushings looked to be in pretty terrible shape. Most definitely original to the car and well passed their usable life. The picture on the left is the main bar bushing which has been elongated and no longer circular in internal diameter. The picture on the right is of the end link which connects the end of the sway bar to the lower control arm. I was able to change all these at the same time as the brake bleed.


Due to SCCA STX rules, losing weight in the car is not so easy. As previously stated, you’re not allowed to strip out the interior or gut the car in any real way. One of the fairly easy ways to lose weight in the BMW E36 is replacing the heavy OEM battery (43.0 lbs) with a lightweight battery (14.0lbs). A lightweight battery will work for my car since I don’t need the car to start in very low temperatures, have drain from stereo or other electronics, and I don’t use the car everyday with multiple starts per day.


I ended up using a STX20HL-BS “motorcycle battery” that I found on for only about $40. You can see the manufacturer stated specifications for the battery in the table above. I paid particular attention to the Cold Cranking Amps (CCA) and wanted the weight to be under 15 lbs. The 325is cranks very similar to how it did with the old larger battery but in the current colder temps (between 30* – 40* F) it’s just a bit more sluggish. No problem though. My friends and family can’t believe that this small of a battery starts the car as reliably as it does!


You’ll just need to be a little creative to get it to stay in place in the original battery tray area. I used some battery J-hooks that I found at the auto store and coupled them with an aluminum extrusion that I had. I also installed a master disconnect switch to the negative terminal just to make it easier to disconnect the battery. This hold-down method has held up well so far but I may need to revise it as the season progresses.


One of the keys to running a small battery in a car used infrequently is to make sure that it stays optimally charged. After researching this and looking around at the various options, I purchased the Deltran Battery Tender Junior. You can find these from various retailers for less than $30. You just have to attach the clips to the terminals on the battery and then plug the Battery Tender Jr into a wall outlet. I keep my car backed in my driveway next to the garage, so I just run the cable under the garage door and keep it plugged in whenever I’m not driving the 325is.


One final small modification that I made was the addition of a clutch pedal adjustable stop. The travel of the clutch pedal in an E36 is fairly long before engaging or disengaging the clutch. After simply screwing in the Garagistic clutch stop into the footwell, I could adjust the pedal to only have about an inch of play before the clutch actually does something. Much quicker shifting and less work on your leg.

Above is a video of the car from a test drive with everything complete. The GoPro actually fits pretty well on a mount wedged into the rear sunroof area. Should work well for taking in car videos during events.

The first autocross is coming up soon!

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