E46 Track Car: Update #3
In my last post the BMW proved that it could endure a day-long thrashing at the hands of the ham fisted AutoInstruct staff – an excellent start. Once the day was over, we got talking about where this car was going and unanimously decided on our first goal: to lap Sandown in under 1:28.00.
Now 1:28.00 around Sandown is not a blazingly fast time, but its faster than any of us had been even in faster cars than the E46. Getting the car to lap a track 6+ seconds faster would require us to improve our driver skills and knowledge of Sandown, but it would also require more from the car which is why it was time to up the ante on the modifications….
Well it didn’t take long to decide stiffer suspension was required. While the car can certainly handle its weight without an issue, less side-to-side motion would give us more confidence to find the car’s limits. Having fully adjustable suspension on all four corners also allows us to get a proper alignment. Now the BMW is a budget track-car, we weren’t about to go and source a beautiful set of Öhlins shocks that cost more than the car, as much as we would all love to do this – K-Sport coilovers were our go-to (and they only cost 25% of the value of the car!).
With Front and Rear spring rates of 18kg & 16kg respectively, there is no doubt that these coilovers would be just a little bit stiffer than the factory BMW suspension.
Its always nice to introduce a bit of colour, even if you never see it
As mentioned last time the brake rotors were still factory spec and badly worn. While the factory spec rotors did perform admirably at the track, we want to go faster and going faster means braking harder which means the factory rotors had to go. Each end of the car was treated to a set of DBA T2, slotted and vented rotors that we all had positive experiences with in the past.
While we had the brakes off the car got a set of new Winmax W7 pads, the previous pads had only been through 2 days of Sandown and could definitely last a third however, we had the wheels off anyway and we wanted to compare the performance of the Winmax.
Probably won't be long before we're back in here replacing those pads...
Lower Control Arms
With enough play in the rubber bushings to provide the front-end feel of a well sorted Camry, we decided it was time to replace them. Seriously though, we knew the bushings were shot but once removed the difference between the new and the old were unmeasurable (well actually we measured about +/- 30mm of slop versus 0mm). The front of the car was treated to a pair of SuperPro cast aluminium arms, identical to the factory design.
The LCA changeover became significantly more complicated when it became apparent that we had to unbolt the engine/transmission and remove the subframe. Taking the subframe out became the perfect opportunity to swap the motor mounts – also significantly worn after 18 years.
In the rear of the car, you would think that changing the arms over would be simple – you would be wrong. The bolt holding the passenger arm to the subframe is tucked so far up behind the exhaust that it becomes a headache to remove and reinstall. With the help of a trusty hammer, the bolt was freed and replaced. We opted for a pair of adjustable K-Sport LCAs in the rear of the car, letting us adjust camber easily.
Not sure that these control arms will look this clean for very long!
The BMW is well and truly on its way to becoming the track-destroying weapon we’ve all envisioned. Before the car’s next run at Sandown we’re going to get it a proper track focussed alignment, now that it has fully adjustable suspension front and rear it will definitely benefit. Plus after removing every major suspension component its likely we would struggle to perform another ghetto alignment (hint: it involves rope and tape measures). Chopping the rear muffler out of the exhaust is also on the menu, the glorious inline-6 needs to be able to stretch its lungs!