Trackday
After not riding my S1000RR since Snetterton last November, Friday's outing marked my first UK trackday of 2016. I thought I would start the season differently this year by riding on an unfamiliar circuit that I've never visited before. Fortunately No Limits had a few spaces left on their Rockingham National Circuit trackday. After adding a plethora of parts, including a HP Race Power Kit, over the winter this trackday provided an excellent opportunity to do a proper shakedown.
I've not visited Rockingham before as I've always been a bit sceptical about going there given its four-wheeled focus and that it was dropped from the BSB calendar several years ago. That said I was pleasantly surprised and I would definitely recommend a trackday on the National Circuit. Due to the last minute booking I was told there were no places left in the Fast Group so I had to settle for the Intermediate Group. All well and good but frustrating at times given the abundance of incidents requiring red flags due to the inability of many to stay upright on cold tyres. That said it was easy enough to find space if you timed it right when leaving the paddock. Whilst short, at only 1.7 miles long, the track has some impressively fast corners and several elevation changes. However, the best part of the circuit for me is the rapid right/left/right section prior to Turn 4 which is immensely enjoyable given the speed you can carry through it.
I spent the first few sessions learning the track and finding the quickest lines through the bumpier corners and my lap times averaged in the 1:22s. The inconsistent track surface did necessitate some minor DDC suspension changes and I made adjustments to both front compression and rebound. Changes to compression were made first to allow the suspension to compress more over the bumps before rebound was altered to control the rate at which the front forks extended again. The 2D potentiometer certainly helped in this respect and the resulting changes just allowed the bike to cope better with the bumps at several points around circuit; particularly those found at the apex of Turn 7.
The combined 7 Kg weight saving from the Akrapovič HP Race System and BST wheels was certainly noticeable as the bike simply felt lighter and sharper. After previously only managing three wets laps with the BST carbon fibre wheels fitted it was good to finally get out on them properly. They do make a noticeable and positive difference to the BMW's handling. Steering is even more responsive than before and if anything direction changes are easier and require less physical effort. They are certainly a hugely worthwhile investment as a second set of wheels to compliment the HP offering that came fitted to my BMW. Whilst marginally better, what the BST wheels do highlight is just how good the HP Forged wheels actually are.
The HP Race Power Kit is a bit of a revelation. With it fitted the bike is now much more akin to a race bike and is no longer hampered by emission controls and such like and overall it just revs much more freely. With the HP Racing Data Release BMW claim increases in terms of both power and torque across the entire rev range espicially between 5,000-9,000 rpm. This increase in midrange is instantly noticeable and throttle response is now even smoother having experimented with the bike in Race, Slick and User modes. Engine braking certainly feels reduced and this is definitely beneficial for smoother and faster corner entry. As for any significant difference in top end I couldn't tell as I never needed to use anything more than 4th gear due to the short nature of the circuit. This aspect will have to wait until I get the bike back to Snetterton and subsequently on a Dyno.
Traction control is also different and the bike has a much more aggressive feel to it. With the HP Racing Data Release I now have fully adjustable traction control available in all modes via the toggle switch on the bars. The DTC feels less intrusive than before with the DTC set at '0' but in the higher '+' figures the traction control light was almost constantly flashing when accelerating hard whilst exiting corners. With negative DTC values inputted the harder compound K3 tyres would slide predictably but forward momentum was never sacrificed. The DTC was good before but it now feels even better on track.
The Metzeler Racetec RR K3 tyres I had fitted are very good. Running hot pressures towards the lower threshold of Metzeler's recommended pressure ranges they offer good feedback and are very stable especially under braking and over Rockingham's bumps. Mid-corner at 51? lean they feel planted even when the surface changes. If these are anything to go by the softer K1 compound front tyre should be epic. Exit grip is also very good and any slides induced by lowering the DTC value are predictable. Even though I was using tyre warmers between sessions the numerous red flags did mean that I spent a fair bit of time waiting in pit lane. Whilst this certainly isn't a good thing in terms of time on track, a point worth noting is that after going straight back out on the circuit they retain heat well and warm-up again particularly quickly and inspire confidence. Furthermore, after 7 sessions and 47 laps their wear rates are impressive.
The only small negative point is the front tyre is pressure-sensitive. Therefore they do require a bit of experimentation with Metzeler's recommended hot pressures ranges; especially when ambient temperatures are quite low. I ended up settling for 30 psi front and 26 psi rear, which I found worked well in the dry 12?C conditions. Overall the Metzeler Racetec RRs are extremely good and I can't wait to get a set of the K1 and K2 race compound tyres fitted.
Finally, the Akrapovič HP full race exhaust system also passed Rockingham's static noise testing without issue. For reference it recorded 102.1 dB at 5,500 rpm without the baffle fitted and 98.4 dB with it inserted. Akrapovič exhausts have thankfully never been that loud but fitting a full system can sometimes lead to noise test problems. These results are quite reassuring for when it comes to passing the stricter noise test limits found at MSV circuits and Donington Park.
All in all a very good start to my trackday season.