Portim?o (Part 2)
I don't normally look at the data captured during a trackday until after the event but given I had three full days at the circuit it made sense to review it each night to make the most of my time on track the next day.
To make sense of all the graphs, you have to sort through a large amount of data, starting with the basics: throttle position, speed, braking points and lean angles. Because the system is tied in with GPS data, you can easily see each input and data stream as it relates to a specific corner on track. By comparing laps, you can immediately see where and how your inputs contributed to a faster lap. For example, you?ll quickly see where you are getting on the brakes too early, or applying the throttle too late, or too slowly.
From there, you can then determine if the traction control is helping your lap times or hurting them. By examining how and where the DTC is intervening and comparing it to data such as wheel speeds and lean angle, you can then see where the DTC system is working to prevent slides. You can then compare it to a segment where a change in riding technique could put more power to the ground instead of wasting energy by spinning up the rear tyre. You can also see, thanks again to the GPS overlay how changes in racing lines affect the usage of DTC directly. Learning these relationships does take time as you have to experiment with the 2D software. I'm still learning despite having the HP Race Datalogger fitted to my bike since May 2015.
The GPS circuit overlay is also hugely useful in working on consistent lap times, especially as Portim?o has some quite difficult and immensely fast corners. It is also a very undulating circuit with many blind crests and corner entries. Comparing various laps on screen, and looking at GPS traces of each, allows you to quickly understand where you are making progress. In contrast it also allows to you to see where you are making mistakes and costing losing time. Where it really helped around Portim?o was in Turn 12 as after analysing the data, and considering where the bike was on the track I could quickly determine that if I altered my line and push further right across the track I could go through the corner flat out as opposed to backing off the throttle. I also struggled with Turn 15 on the first day and I couldn't quite work out why. Looking at the data helped as I was frequently triggering the DTC and when looking at the spikes in traction control intervention and the rapid increase in slip rate it was abundantly clear that I was asking for way too much power, causing significant tyre slip over the bumps. I backed off the throttle during Day 2 and adopted a slow in, fast out approach and as soon as I was over the crest I could then feed in the throttle as hard as possible to get good drive onto the start/finish straight.
Compared to simply riding around guessing where I could improve the datalogging certainly helped me quantitatively improve each day and get more from my time on track. The progression in best lap times over the three days clearly illustrate this. That said whilst my times are reasonably quick, for perspective, the quickest time at the official WSBK test last year was an unbelievable 1:42.34.
Best lap time on Day 1 - 2:05.89
Best lap time on Day 2 - 2:01.42
Best lap time on Day 3 - 1:59.88
Whilst datalogging is a great tool for helping you go quicker my reduction in lap times can also be directly attributed to following the instructors around the track for a full session each day. Circuit knowledge is absolutely key to a good lap time around Portim?o and sometimes you just can't beat a bit of one-to-one coaching and feedback.
I normally just use superstock race tyres on track and don't generally bother with slicks but for the three days at Portim?o I thought I would treat the BMW to some. I took a couple of sets of Metzeler Racetec RR slicks with out with me including K1 (Soft) and K2 (Medium) compound fronts and K1 and K2 compound rears.
Having been massively impressed with the treaded Racetec RRs this season the slick variant of the Racetec RRs is quite simply outstanding. The grip offered by the treaded version is excellent but these are fantastic. If you were thinking these were just the same tyres but without the grooves cut into the surface you couldn't be further from the truth. Whilst they feel similar, they are in fact completely different and offer even more grip and feel through the bars. The rear profile is also different to the superstock RR tyres as it has a slightly taller 60 height which helps the bike turn in quicker.
Weather conditions throughout were dry and sunny with temperatures over the three days varying between 30-33?C and track temperature peaking at 48?C. Furthermore the track surface is not as abrasive as I first thought. Tyre pressure ranges are identical to the RR version and I settled on 32F and 26R hot pressures which seemed to cope well with the temperature and surface.
I started off using a K1 front and a K2 rear as that is what I had fitted prior to the bike leaving the UK. After a day and a half both front and rear needed to be changed. Whilst wear was consistent across the entire profile of the tyre the wear markers had completely disappeared.
I then changed tyres and reversed the compound combination to a K2 front and K1 rear. Looking at the Metzeler data sheets, and after discussion with the tyre fitter, this combination was definitely more appropriate for the hot conditions. The K2 front has a stronger sidewall wall and is less susceptible to high track temperatures than the softer K1 tyre. You can feel the difference on track as the front just feels more composed especially under heavy braking due to the firmer construction. With regards to the softer rear tyre, grip felt similar but tyre wear was marginally better. I would certainly use this combination again in hot conditions but revert back to a K1 front and K2 rear for colder UK trackdays. After completing seven full sessions each day, equating to well over 400 miles on track, I would certainly use the Racetec RR slicks again.
With regards to rider aids and electronics I started off Day 1 in RACE mode as I was learning the circuit but by the end of the first day I then reverted back to SLICK mode. My settings are a little different to the standard riding modes as I have the HP racing data release and mapping installed within the ECU. This makes RACE mode a lot more aggressive and SLICK mode even more so than standard. By the middle of Day 2 I had placed the bike in USER mode with all options in SLICK except the engine which I placed in RACE. I found the extra engine braking really helped slow the bike allowing me to get off the brakes earlier in order to settle the suspension, especially over the bumps, before entering the faster corners. Other than that I didn't really feel the need to experiment with the electronic settings within USER mode any further.
Portim?o really does illustrate just how good the onboard electronics and DTC actually are. You know the DTC is working as you see a flashing orange light on the dash but it doesn't feel intrusive especially when you start selecting negative values. There were also no issues with the DTC despite having a taller 200/60 rear profile tyre fitted which has a very different centre diameter to the 55 tyre. For reference I've now used 200/55, 200/60 and 190/60 race tyres without issue.
Finally, the only suspension change made was a very small adjustment to rear preload to take into account the taller profile of the 200/60 K2 Metzeler Racetec RR slick. Other than that there was very little to be gained from adjusting front/rear rebound or compression as tyre wear looked fine and the bike wasn't preventing me from holding a line or doing anything untoward which required adjustment.
Overall this has got to be simply the best track event I've done in years and I'm already planning to return to Portim?o next season along with a visit to another European MotoGP or WSBK circuit.