This old BMW E46 shows just how much weight you can remove from your race carby Dim Angelov, on LISTEN 04:28
Building a budget-friendly project car for racing purposes is a goal for many car and motorsport enthusiasts. Luckily, even if you’re not officially versed in the art of wrenching, it is possible to achieve this. This is, in no small part, thanks to channels like ChrisFix. Despite his age, Chris has already proven quite a capable mechanic and his videos are highly informative. This time, it’s all about weight reduction on his BMW 330ix project race car and we’ll see just how much you can remove and how it affects performance.
In every comparison, there is a “before” and “after", which is why we start by gathering some measurable data. We first get the 0 to 60 mph (97 km/h) times.
The BMW consistently achieves around 6.8 seconds, with the best being 6.79 seconds.
Next, Chris utilizes a set of racing scales in order to determine the car’s weight. As it turns out, the all-wheel-drive BMW weighs 3,370 pounds (1,529 kg) with all required fluids and a quarter of a tank of gas. The goal is to get below 3,000 pounds (1,360 kg). The weight reduction will consist of removing all the seats, trunk liners, plastic bits, carpets, headlining and sunroof, and dashboard.
Removing the seats saves 180 pounds (82 kg), while the rear-mounted battery alone weighs 45 pounds (20 kg). That has been replaced by a lightweight battery, weighing just 25 pounds (11.3 kg). Getting “all the junk from the trunk” saved another 75 pounds (34 kg) plus 50 pounds (22.7 kg) worth of a spare tire, tools, and some top-up fluids.
Next up are the interior trim pieces, like the A and B-pillar covers, and door sills. The trick about removing these plastics is using a “hard jerking motion”. The center console is in good shape and worth reselling to recuperate some of the car’s value, so Chris is extra careful with it.
Removing all this saves 50 pounds (22.7 kg), bringing the weight down to 3,043 pounds (1,380 kg).
Next to go are the carpets, which require the throttle pedal to be removed – a surprisingly easy procedure. Removing the carpet requires some careful cutting along the center console, as there are wires behind it. The rear carpet can simply be pulled up and removed. The result is a curb weight of 2,998 pounds (1,360 kg). Goal achieved, but it’s not over yet.
The next step is removing the sound deadening that’s bonded to the metal. The reason is that the roll cage cannot be welded on top of it, since it’s flammable. The solution is dry ice. Simply pour it over, cover it, and in 15 minutes start hammering it out with a rubber mallet. The end result is 2,972 pounds (1,348 kg). The headliner and sunroof drop another 40 pounds (18 kg). A lightweight sunroof delete kit is used to fill the hole on the roof – it only adds 2 pounds (0.9 kg). Another 15 pounds (6.8 kg) were lost from the dashboard and still, there’s more weight to be shed. For now, Chris is happy with the 2,940-pound (1,333 kg) figure.
A total of 430 pounds (195 kg) were lost from the “diet”. What does this mean performance-wise?
On the third run after the “diet”, Chris managed 5.97 seconds to 60 mph (97 km/h) – almost a full second quicker than before.
More importantly, cornering speeds and handling have also improved. Less weight means better braking times. A significant improvement of 138 feet, compared to the 170-figure from before. More power is always good, provided you can put it to the ground, but this video just goes to show how much difference weight reduction can make.