Sunday, 15 July 2012

Going on a diet

Before our next race at the Rockingham International Speedway in August we  are looking  seriously at weight savings.  All of the front running cars are below the minimum weight and carry ballast.  At Brands Hatch we were still weighing in at 1360Kg's including driver at the end of the race (although we did overfill with fuel for one race which didn't help).  This was 60Kg's over the minimum weight and is costing 1-2 seconds per lap based on our track day experiences with 1 vs 2 people in the car.

In order to level the performance across the different Boxster 3.2S model years / engines (250-280 BHP) the regulations have also recently been adjusted and we now need to target 1280Kg's as the minimum weight for our 2001 250 BHP model. So now even more stuff needs removing!

Hardtop and Trim
The hardtop roof still had the full head lining and plastic trim pieces in so these were removed. We also removed more plastic trim from inside the car, including the centre console plastic and the heater blower motor.

Air-con
The original air conditioning compressor was next to be removed. This required changing the ancillary drive belt for a shorter non-air-con model one.  The belt change was straightforward but removing the compressor itself took several hours.  The bolts holding the compressor in place are easy to remove, but the metal pipework connections are obstructed by the intake manifold and were extremely tight.  There is some pipework running under the car still to be removed when time permits.
Battery
The heavy duty Bosch S5 battery weighs 17KG's and is high up under the windscreen.  A light weight replacement (Odyssey 30 Racing @9Kg's) has been purchased and relocated lower down on the floor of the front boot.
Windows
With the door glass in the "door-open" position (it drops by 1" to clear the rubber seals) the electric window motors and and mechanism have been disconnected and removed along with the associated wiring. 
The glass itself is being replaced with light weight Polycarbonate (plastic) with sliding vents.