Posted by Iain Litchfield on 11th September, 2018 in Chassis Setup, Dyno Tuning, ECU Remap, GT-R, Nissan, Nurburgring, Paint Protection, Suspension
Our 2018 Nurburgring trip marked the second time that Anthony Gaylard’s LM1 RS has been to this famous circuit. To give a bit of background on this project the freshly built car was first driven at Spa and the ‘Ring in autumn 2017. This epic 5 day test came after a successful shakedown at Silverstone where we were lucky enough to get the feedback from touring car driver Jake Hill. Not only that, but the GT-R designer Tamara San and Nismo boss Bob Laishley, were there to give us their valuable insight!
The car was near faultless over that 2017 trip and we were delighted with the lap times even in that early state of development. Anthony’s original goal for us was to build him a car capable of posting a Sub 7 minute time. Reviewing the data showed that we had already surpassed this target. We left the ‘Ring very satisfied with where the performance was, but with a nice list of upgrades to work on over the winter. The main improvements we wanted to see were more pedal feel from the brakes and to increase the front aero balance, but most importantly we needed to revise the gearbox cooling. There were other small changes here and there, but nothing too dramatic you would think…..
This is the type of project where we’re all dreaming big and so the inevitable happens. New products emerge that might be of an advantage so are fitted. Small changes on one part of the car result in much larger changes elsewhere and before you know it the whole project has moved onwards (and upwards) so that a lot more needs to be tested than originally planned. This is all part of the fun of development for Anthony and myself, but perhaps less so for our engineers who have to make it all work! 😉
After many late nights and a lot of custom fabrication the car was ready for this year’s Nurburgring trip. You would be forgiven for thinking it’s not the same car at all, but in fact the engine, transmission and suspension remained unchanged.
Outwardly the car was now wearing the wider GT3 body work, plus a complete PPS respray in Nissan ‘Storm Grey’ courtesy of our in-house body shop. The bespoke side ducts that feed the rear coolers have now been integrated into the wider rear wings with an R8 style rear blade to guide the airflow.
Following conversations with tyre manufacturers about their best road legal track tyres, Anthony decided to switch to a larger and wider tyre size all round with a view to testing the Pirelli Trofeo R and Michelin Cup 2 tyres back to back. This meant a very attractive set of custom made lightweight Magnesium 21” alloy wheels were produced and flown in from the USA. With just 4 days to go, 3 of the wheels turned up! Fortunately the FedEx man delivered the remaining one the next day after some panicked phone calls. Then we could get into the next challenge.
The car originally used Alcon GT-R brakes, but the change to a bespoke pedal box meant their usually excellent brakes didn’t feel quite right. Speaking to Alcon about our options system creep went into overdrive! They had just released a new pedal box and braking system for a number of manufacturer GT teams like Aston Martin, and before long we were swapping out the whole braking system for these incredible new components. There was just the small matter of making them fit a GT-R, which we couldn’t commit to until the wheels had arrived. Steve and Scott spent over 3 hours per caliper modifying and machining each hub to allow the new brakes to be installed.
The new body work features a revised front lip spoiler and larger canards for improvements to the aero at the front of the car. The front intercooler and radiator were tilted forward with improved ducting made before and after to help steer the hot air through the larger bonnet ducts. Measurements from our wind tunnel visit had shown that this would be a positive move with plenty of spare capacity available from the rear spoiler. These bodywork changes were handled in the main by Elliot from Elweld who once again created some stunning work.
However his real triumph was to move our original exhaust setup, which exited on one side, to a twin exit exhaust system: larger than even the Nissan GT3 team thought was possible. Complete with larger silencers and 90mm downpipes the engine would be able to breathe even easier than before and a huge impact in dropping the in-car temperatures. Where once the foot well would become too hot to touch, now the cabin was a much nicer place to sit. The space available through the centre of the car now made the ideal place to re-route many of the cooling hoses and dry sump lines. The flat floor was remade and along with the inclusion of the larger GT3 rear diffuser we expected to see an overall improvements in the way the car controlled the aero under and through it.
With the brakes and wheels arriving just before we left we didn’t have a chance to fully test the car so it was with both excitement and a little trepidation that we loaded the car up and headed over to the ‘Ring.
Friday 17th August was the first chance to get the testing ball rolling with Anthony taking the car to the track briefing and having his first outing on the road in the new specification. Once this was complete we needed to get our professional driver, Moritz Kranz, and Anthony sat comfortably in the car. Following on from his feedback the year before, the entire pedal box mounting was now adjustable (thanks to the new Alcon setup) and the steering column was moved closer to the driver, so the driving position was able to be optimised to his and Anthony’s liking.
Some initial laps on Friday showed that Moritz was struggling to get heat into the wider front Pirelli tyres and the brakes also needed more work. More troubling was a random misfire had begun to develop and was effecting the driving experience. After going through the data logs back at base it was showing multiple intermittent faults on one of the electrical circuits. We traced these back to the cam sensor, which when removed and cleaned appeared to resolve the issue. A quick bleed of the brakes and road test showed that the car was working better, but after another few laps on track the misfire had returned only this time it was reporting an issue with the throttle. This was very frustrating as nothing obvious had changed from our engine or ECU side and because the fault was intermittent, it made it difficult to replicate. The good thing though is that we had plenty of time to work on it.
The Saturday began with an early start as we spent time with the guys from the Öhlins Distribution & Test Center – ODTC. Emerson and Magnus kindly gave up their Saturday to further help us with the cars set up after we had increased the width of the car since our 2017 visit. Their TTX race dampers were dyno tested and adjusted to suit the stiffer springs that James selected to work with the increased width. They modified the damper stroke to better control the clearance with the wider front wheels.
Dan and James were then able to calculate the motion ratios so we can correctly monitor the suspension movement through the Motec Datalogs. Now we can check ride height, rake and aerodynamic loads on the car. A massive thank you once again to the Öhlins guys for their input and for giving up their time off!
That evening the car was taken out for another test and the suspension felt great. The brakes were much improved although still a little down on feel, but overall we were happy with the progress made. Saturday night the guys worked until 1am (powered by Pizza) as we looked to modify the front arches to give extra clearance for the 21” wheels under extreme compression.
Whilst we tried fault finding the root cause of the misfire, we also hatched a backup plan. We had Lee, our Parts Manager, pick up a spare Motec ECU from our UK workshop at 10pm before boarding the 3am Le Shuttle from London, so that we would have a spare ECU should it be needed. It wasn’t, but thanks anyway Lee!
Sunday was a day of rest for Anthony’s LM1 RS so we continued to search for the fault causing the misfire. With the newly delivered ECU proving that the original ECU was working correctly, attention turned to the throttle on the new pedal box. Some more out-of-the-box thinking by our team led to an afternoon visit to a scrapyard (open on a Sunday!) and the purchase of an electronic throttle pedal from a BMW. With this throttle installed we seemed to have fixed the fault, but once we put the car under proper load again the fault would reappear.
Realising all of the affected sensors ran on Motec’s 5v system, Dan was finally able to trace the fault back to a bad earth through the crank sensor that was close to the re-routed metal dry sump lines. This had the knock on effect throughout the whole 5v network and why the Motec ECU was randomly reporting faults, which of course included the throttle pedal potentiometer and cam position sensor to name a few. Scott also changed the master cylinder with a different size alternative and then re-bled the brakes using the options within Bosch Motorsport ABS ECU with a hope of improving the new brakes further.
Those not working on the car spent time having VERY fast Tourist Fahrten rides in the newly christened ‘Litchfield Ring Taxi’ otherwise known as Anthony’s tuned F80 M3.
Monday morning came and we headed back to the track in force with all our cars and drivers signed up for the Destination Nurburgring Prime track day. For those that don’t know Darren and the DN team, quite simply they put on the best track days at the Nurburgring! A relaxed open pit lane event with low numbers of great cars and sensible drivers – we highly recommended it.
Moritz was straight out on track in the LM1 RS and clearly it was working much better. The brakes, whilst not perfect, were much improved and now we could concentrate on the setup and balance of the car.
The new suspension setup was enabling him to attack the corners at a much quicker rate, but he still thought the front tyres were not getting enough heat into them to work properly. James quickly made changes to the suspension, which Moritz approved of and we began getting some miles on the car and some good data. He was very impressed with the pace and each small change James and the team made seem to have a positive effect. Dan was sat in our van watching the data stream back from the car as it pounded around the track. The changes to the suspension had “switched on” the front tyres and Moritz was beginning to press on. On some of the crests and drops that the ‘Ring is so famous for the front felt a little light, so after a small change to the rear wing gurney we had a happy German to go with our excited Aussie! 🙂
Moritz explained that despite some traffic he was some 40 km/h faster through the Foxhole than he would be in his own Porsche race car! We were still on our lowest power setting, but pace was clearly there and we were starting to get excited about what Tuesday might bring. After lunch we continued to work on the car and get miles on the clock with Dan working on the calibration and setup of the Motec systems. With everyone happy with how the car was working we planned to switch tyres and see how it performed on a fresh set of Michelin Cup 2s.
This was timely as we noticed the front passenger tyre was starting to lose pressure and presumably had picked up a puncture. However back at the workshop the guys found the problem and unfortunately it was game over for this test. The front magnesium wheel had cracked and with spare set still being built in the US, we didn’t have a replacement in Germany.
Once the frustration of not making it to the last day had passed we were able to reflect on what was a really valuable test for this car. Clearly it’s going to be very quick, but even if the wheel had not failed we had plenty of improvements that we wanted to make once the car was back at base.