Venue: Silverstone Grand Prix Circuit
Date: 6th May 2013
Discs Tested: Performance Friction 405mm front and 381mm rear slotted discs
Brake Pads Tested: Performance Friction Carbon Metallic 08 front and rear pads
Ambient temperature: 21c
Track temperature: 29c
Humidity: 34% (low)
Drivers: Jake Hill for the analysed test and John Miskin for an amateur’s perspective
The test was carried out with the help of Paul Hayden from Performance Friction who attended the entire Track Day at Silverstone. Lap timing is forbidden and the car was equipped with a V-Box that collected the data which was downloaded later. This data did include lap times but this was coincidental and was interrogated after the event! This test is also undertaken with the view that the results were those that GTROC members would understand and relate to rather than a cold scientific and analytical one that could have been done under more controlled conditions.
The front and rear brake kit was fitted a day before the test as it would not have been practical to change the complete set of front and rear discs and pads together with new Performance Friction RH665 DOT 4 racing brake fluid. The brakes were comprehensively bedded in and checked prior to the test by Paul Hayden at their headquarters in Banbury prior to the Silverstone test.
The original brakes were Alcon 400mm front and 380mm rear with Pagid 29 pads all round. This brake set had been punished severely over the past couple of months with three track days and 16 runs at the Abersoch runway event where all runs required cold braking from speeds of up to 190mph. I am very guilty of abusing my brakes, and Iain Litchfield claims me to be more aggressive on brakes than any other R35 customer he has at the moment. The results were inevitable, with prominent cracks on the front discs and minor ones on the rear with the front pads crumbling quite badly. Litchfield’s supply both Performance Friction and Alcon brake kits so Iain can match the product to your driving style. This original set up allowed the pads to nearly fit the discs completely apart from a minor area of about 2mm on the outside edge of the disc and this blend of discs and pads never gave me any problems on the road and produced a progressive and solid pedal with little or no noise under normal road use. On track some initial vibration was evident until the temperatures had risen to a more effective level, and I never experienced any fade at all. On extreme braking, some typical loud drumming noise was apparent from the front and this dissipated immediately once the punishing episode was completed, and the next period of braking would be fine.
The new Performance Friction all round set up allows the full pad surface area to be matched to the disc correctly and optimises the maximum area for braking as PFC produce both pads and discs in house so have full control of compatibility between pad friction and disc materials. This only really becomes apparent when on track, but when used on the road, little difference is noticeable apart from a slightly firmer pedal.
Jake Hill’s comments were as follows:
“I have driven John’s car many times on track when the original discs and pads were fitted, and always felt that the car braked extremely well but with some degree of noise and initial vibration. The Alcon and Pagid set up was strong and only under very heavy braking did I experience some instability that caused the car to squirm slightly before turn in. Trail braking into some of the fast corners was nervous at times as the overall feel was insufficient to balance the car as I would have liked. I believe the last track session I drove the car a few weeks back, it had PF front pads instead of the Pagid’s but I didn’t notice a dramatic difference in performance.
During this test with the full PF set up I immediately felt a lot more confident to lean on the brakes and explore the limits of adhesion under maximum load. To be fair, these were brand new brakes all round and with new racing brake fluid, I would have been disappointed not to have been impressed.
I drove the car after a break from cold and when the new Toyo 888 tyres had been fitted, so the first three laps were bedding in the tyres and warming the brakes etc. On my next five laps after the tyre pressures had been adjusted I pushed hard and had to brake hard on several occasions due to slower cars and the odd spinner in front of me, and I found the brakes to be immensely strong with a good progressive bite. Never was there any abnormal noise, and even when I was asked to come straight into the pits at full chatter after maximum breaking from over 160mph on the Hanger straight followed by a rapid entry into the pit lane, braking at the very last minute, did I experience any brake fade or instability. When PF’s Paul Hayden measured the disc temperatures when I stopped, they were as hot as I would ever get when using a Ginetta G55 during qualifying. I then left the pits immediately and found the brakes to be right there at the first corner at Farm and continued to exploit the limits over the next four laps.
Trail braking was very progressive and with no grabbing and any squirming from high speed that I had experienced before was not apparent. The car almost felt as if they were running a ceramic set up without the problems of cold braking etc.
The test of this brake set up was in conjunction with the Toyo tyres, so some of the improvement and confidence I experienced may have been partially due to the tyres, but for any heavy track use, the PF (Performance Friction) combination is as good as the GT-R could handle. It takes some mega brakes to stop such a heavy car when doing speeds in excess of 160mph, and having driven five other GT-R’s on the same day with standard OEM brakes, AP discs with an unknown pad and an almost identical car to John’s with the 400mm Alcon’s and Pagid 29’s, I have to say that the PF kit was sublime. They were new but they just felt right”
Right, that was straight from Jake, and the V-Box showed some interesting statistics that needed some interpretation before giving the results. Even now, I think that there were some glitches in the results but we recorded a maximum of 2.2G under braking on three occasions. There was one showing 2.7G just before Brooklands corner at the end of the Wellington straight, but previous and future laps were lower and this could have been a blip. Jake was certainly using both the throttle and the brakes at the same time when going into some of the fast corners and there appears to be no fidgeting from the rear whatsoever.
There was plenty of sliding and playing with the understeer and oversteer and clearly Jake was having fun apart from when he met a Maserati that was doing 35mph around Copse and a Lotus that spun in front of him at Chapel curve where a heavy brake had to be applied to avoid contact and he had forgotten that the microphone was on!
As is normally the case when doing this kind of evaluation during a track day, there wasn’t one clear lap during this brake test so for clarity we used the optimum lap (combination of the best sectors over the laps covered) to get a clear picture and interrogate the data to ascertain the potential performance. It is difficult to explain to other drivers the sheer weight of the Nissan GT-R and the colossal amount of braking that is required to stop one of these cars from speeds approaching 200mph!
After this track day when the car was punished more than normal, the journey home was faultless with no brake noise or vibration. The pedal remained firm throughout.
The OEM brakes supplied with the car are adequate for normal road use and fast driving that the car was designed for. However, any track use will soon show that the drilled OEM discs will crack between the holes, and eventually they will need replacing before they become dangerous. There are many alternatives to the OEM discs and pads and virtually all of them are cheaper and will last longer when used aggressively either on track or fast road use. The AP grooved disc is a good replacement at a very competitive price, particularly when used with either Pagid 29’s or Ferodo pads. For more aggressive track use, the 400mm front and 380mm rear Alcon’s have been used universally with Pagid 29’s and with some excellent results and many comments and write up’s can be viewed on the GTR Register forum.
In my opinion, for extreme track use and high speed braking, the Performance Friction set that I have reported on appear to be superb and certainly suit my aggressive driving style, which I am constantly told is not the quickest or best style! There will always be a caveat when trying something new and the fact that this was only one track day under warm sunny conditions will not have the same performance as a cold damp December track day. I need to see how they perform over time and how well they last compared with the Alcon’s. I will continue to report as the track days come and go and I will run this set up until something needs replacing.