With the build taking a lot longer than anticipated I’d lost count of the number of plans I’d had for a shakedown trackday. Early in the summer I was optimistic that I’d make the Destination Nurburgring track day (DN16) at the end of September but driving all the way to Germany just to shake the car down was probably a bit much. The next plan was to attend a Lotus 7 ownersclub day at Hethel but that got cancelled when Lotus fell foul of the local noise police.
Eventually with the car finished and having run on the dyno I ended up at Snetterton at the end of September. I’ve driven at Snetterton a number of times and I really enjoy the 300 layout, it has a good selection of fast challenging corners, some slower more techincal sections and two long straights. Ideal for making sure the car was running well!
The first minor issue I came up against was not realising the launch control was being enabled if I sat with the clutch on the floor for more than 4 seconds. Normally this wouldn’t be an issue because the car pulls away happily from tick over, it does become a problem however when you need to noise test the car and can’t reach 5200rpm because the launch control limit is 4000rpm! The pops, bangs and flames caused by the ignition cut isn’t exactly the desired outcome when you are trying to convince MSV to allow you out on track. Finally I did manage to complete the noise test and the car produced it’s lowest reading to date, a nice by product of the turbo conversion.
With the very busy briefing out of the way (strangely this didn’t actually translate into a lot of traffic on circuitI it was time to head out for some sighting laps. Even if I know the layout of the cicuit pretty well I always head out on sighting laps just to make sure the car feels ok after I’ve swapped the wheels over and to get an idea of the track conditions.
I’d already decided that I’d do a quick 10 minute warm up session with the car in low boost mode just to make sure there were no problems. Despite the car having driven 70 odd miles to the circuit there is never a chance to really lean on the car like you can on track so it was important to make sure everything was working as expected under heavier load. It also showed me that coming out of the hairpins at Wilson, Agostini and Oggies I’d need to resort to a lower gear if I wanted to keep the engine on boost.
Heading back out onto the track again I did few warm up laps and then flicked the switch to activate the boost control solenoid. Without the solenoid the boost pressure is controlled by the wastegate spring and provided about 12psi of boost, with the solenoid running boost pressure could rise as high as 20psi. With the switch engage there was an immediately noticable increase in acceleration out of the slower corners. Once I got to the back straight for the first time I started to notice a slight hesitation in acceleration as the boost pressure built to 20psi and then bled off to about 18psi. The car was still able to accelerate but didn’t feel like it was pulling cleanly, it did seem to be marginally improved by only using about 90-95% throttle. To be honest this didn’t really impact the day and apart from this small issue the car ran strongly all day. It certainly has a lot more pace than it did and was certainly amoung the faster of the “track tool” cars present, it’s also much faster down the straights than a R56 Mini Challenge car although not match for the race car through the corners (they are running slicks).
I had a visit to 1320 MINI scheduled before my next track day so we hoped to get to the bottom of the funny boost control problem.
Below is a short video of one of the cleaner series of laps from the day.