My 2019 718 Cayman GTS PDK

[AndrewT]

Another great report Brian, you really ought to be a regular contributor to Porsche Post. I hope that the weather is kind to you for the Knockhill track day next weekend, I look forward to reading your report and hope that you manage to dip below 60 seconds!

 

[Jedimaster65]

Fascinating report, Brian!

I agree about the value of race instructors, because we all develop bad driving habits, or forget odd skills we may have once had and there is nothing like a refresher to add the best skills back in.

I was at Silverstone PEC in April (GT RS day) and was reminded of the value of trail-braking.

Also: It would be interesting to see just how much Cup 2 tyres would knock off the laptime?

Cheers

Peter

 

[Brian_Innes]

Peter,

Cup 2 tyres are worth at least 2 seconds per lap at Knockhill due to the challenging nature of the corners and cambers.

Brian

 

[Wollemi]

Great write up again Brian, really enjoyed reading it.

Would it be possible for you to share you geo settings again. I have got the Porsche Centre in Leeds to set my 987.2 S to have the maximum negative camber on the front wheels, which has certainly improved the turn in, but I still have got a significant amount of scrubbing of the outside edges (more on the N/S wheel) after the PCGB Silverstone track day.

Very interesting regarding your observations of the MPS4S tyres going of so quickly. I am still using PS2N2s on my car and found that it took 20-25 minutes of track time at a pretty hot Silverstone before these tyres started to go off. I was getting tired before the tyres! Related but probably unrelated is that I have found over the last two years that length of time on track before tyres go off has been significantly improved since Porsche started using nitrogen inflation as a matter of policy. Nothing to do with the lack of oxygen, but the nitrogen is dry rather than compressed air which contains a fair amount of water vapour and it is the water vapour expanding with increased temperature that leads to heat related over inflation.

 

[Sunder81]

Brian,

Very entertaining post.

During your track days, have you come across the ECU holding the car around 6000 rpm for a few seconds when turning into a sharp bend . It sounds like hitting the limiter ( but way before before the redline ) and the yellow 'traction' signal comes up on the dashboard momentarily. Presumably to prevent the car from losing balance ?

 

[Sunder81]

Brian,

Very entertaining post.

During your track days, have you come across the ECU holding the car around 6000 rpm for a few seconds when turning into a sharp bend . It sounds like hitting the limiter ( but way before before the redline ) and the yellow 'traction' signal comes up on the dashboard momentarily. Presumably to prevent the car from losing balance ?

 

[Brian_Innes]

Graham,

My current geo settings are shown below. Bear in mind my GTS has 20mm lower PASM which factors in a few extra minutes of negative camber on the front.

The Michelin PS2 N2 tyre has a harder compound than the PS4S N0 tyres. They are also a single compound tyre, unlike the PS4S N0 which is dual compound, with different compounds on the outer and centre sections of the tread. This accounts for the longer durability of the PS2 N2, but remember the Silverstone track has long straights which allow the tyres to cool down because the sidewalls are not working so hard as they do when cornering. The same would apply at Goodwood for example. Knockhill is a very demanding track on both chassis and tyres. I would guess that's why Porsche Germany decided to ship so many cars across to Knockhill for the 982 GT4 press launch. I'm pleased Porsche Germany have discovered Knockhill. Perhaps they'll use it again.

In my experience of Caymans, the 718 Cayman GTS chassis is so well developed that it works the tyres extremely hard, especially on a track such as Knockhill. If I continue to be fit enough for track days next year, I am very tempted to buy a spare set of wheels with Cup 2 tyres for my GTS. As I experienced with my Cayman R, a set of Cup 2's on a 718 CGTS PDK would make a very formidable track car at Oulton Park and Knockhill.

Geo settings below as requested.

Brian

 

[Brian_Innes]

Brian,

Very entertaining post.

During your track days, have you come across the ECU holding the car around 6000 rpm for a few seconds when turning into a sharp bend . It sounds like hitting the limiter ( but way before before the redline ) and the yellow 'traction' signal comes up on the dashboard momentarily. Presumably to prevent the car from losing balance ?

I use manual shifting on the track, not the full auto D mode. I select Sport Plus on the steering wheel dial, and if the track is dry I switch off the PSM. This illuminates the symbol on the dash permanently with "OFF" shown below. If it's damp I select the Sport PSM mode by pressing the button on the console for less than 2 seconds to back off the intervention of PSM. If you see the PSM light flashing, this backs-off the engine power and applies braking to individual wheels. I don't like this.

On the gear shifting, I have tried full auto mode with Sport Plus and it works quite well. Especially if I have done a number of laps in manual mode beforehand. The ECU seems to "remember" the gear shift points. The only reservation I have about using full auto mode with Sport Plus on the track, is that it consistently revs to the 7500rpm red line before upshifting. Due to the power/torque profiles of the 718 GTS, 7500rpm is way past the optimum. I use manual shifting and usually rev to 7000-7200rpm for upshifts. Sometimes sooner for some tracks like Knockhill and Oulton Park. This seems to work best in my experience.

Brian

 

[Steve Brookes]

Brian, don't forget that in full auto sports plus mode, you can still pull the upshift paddle to overide the auto for a few seconds. So, if say there are two places on the track that you don't want to go to the limiter, you could manually shift at the time you would like in those sections. Doing that might give you the ultimate lap time?

 

[Brian_Innes]

Good point Steve. I've been so engrossed on my cornering lines lately, I've forgotten about the manual override facility in auto.

Preferring manual shifting, I seldom use full auto on the track, but perhaps I'll give it a go this weekend at Knockhill. As you say it may result in a full line of cherries!

It would be a PB for me if I break the one minute barrier at Knockhill.

Brian

 

[Brian_Innes]

Thanks to all for your supportive comments on my Knockhill Supercar scribblings. I am always grateful for feedback comments whether supportive or otherwise.

My GTS is all cleaned, checked, and prepped ready for the PCGB Knockhill track day on Saturday. To those on this forum who are intending coming along, please introduce yourselves to me. Track days are very much about social contact as well as the driving experience. To those Porsche owners who are participating at Knockhill for the first time, I would strongly recommend you make use of the excellent tuition available. All Official Knockhill driving instructors are from a motorsport background, some of whom are current championship competitors. In my experience the coaching at Knockhill provides consistently high standards. It's a tricky circuit. Knockhill may only be 1.4 miles long, but the challenges to the drivers and cars make each lap a busy one. Brakes, suspension geometry, and tyres, are key factors on any track day. At Knockhill, all of these components are subjected to intense scrutiny.

I am very much looking forward to the event, with Knockhill being my "local" track. I shall be reporting back on how my day unfolded in due course.

Brian

 

[Sunder81]

Hi Brian, im a novice to track days. What will be your advice regarding preparation / consumables for track days. In particular;

-oil change

- brakes

- tyres

- paint protection

if i just do one or 2 per year ( assuming i im not fully thrashing the car ) will I need to address any of the above or i can just use the setup as it is on road and track.

 

[Silversword]

Not wanting to interrupt the flow, I have just read through the whole 24-page thread today and wanted to thank in particular Brian for such an honest and entertaining read, but also everyone else who has contributed to the discussion. I look forward to seeing the next updates and more gorgeous photographs - please carry on.

 

[Brian_Innes]

Hi Brian, im a novice to track days. What will be your advice regarding preparation / consumables for track days. In particular;

-oil change

- brakes

- tyres

- paint protection

if i just do one or 2 per year ( assuming i im not fully thrashing the car ) will I need to address any of the above or i can just use the setup as it is on road and track.

The important thing to remember about participating in track days is that your car will be subjected to higher levels of stress and general wear and tear. Most Porsches are robust machines, and particularly in the case of the newer models, Porsche as a motorsport orientated manufacturer have embraced the concept that some owners will use their cars on the race track. References in the Driver's handbook confirm this. Mechanical components, such as brakes, and tyres, will be exposed to above normal operating temperatures compared to the regulated constraints of the public roads. The PCGB Track Day Event section on this website provides excellent guidance on vehicle preparation and mechanical checks before you embark on a track day.

Taking your list of questions in chronological order I can only give you my personal opinion based upon my track day experiences.

Oil Change:

Engine oil and filter is best changed annually if you are participating in track days. Two year old engine oil may be perfectly fine for public road speeds, but for the consistently high revving conditions on the track I choose change the oil and filter within a 12 month period. Assuming and annual mileage of up to 10,000 miles per annum. Always check your oil level before a track day. It should be at the correct maximum level for the car. Don't forget to check coolant levels also.

Brakes:

Absolutely essential to check the brake pad thickness before a track day. Pads with an excess of 50% wear, particularly on the front brakes, are best replaced before a brake heavy track day. Some tracks are light on brakes, but any track with +100mph stops will cause a huge heat build-up resulting in brake fade and boiling brake fluid. Remember, that public road braking is generally gentler and at much lower speeds compared that attained on the track. An annual brake fluid change is also recommended if you are doing more than four track days a year where heavy braking is involved. Always check your brake fluid level before and after each track day.

Tyres:

Tyres should be in good condition with sufficient tread depth across the width of the contact area for the number of laps you are intending doing. You have to drive home afterwards ensuring your tyres are still within the legal tread depth. Tyre pressures are an individual choice. I start my track laps with pressures at the recommended levels for the car. I choose to set mine at the "Comfort" pressures of 2.1 Bar (30psi). Porsche recommend 2.3 Bar (33psi) for general high speed use on my car. This higher setting would cause my tyres to over-inflate on the track. Your tyre pressures will increase by approximately 0.4 Bar (6psi) with consistent hard cornering. You don't want either under-inflated nor over-inflated tyres when driving at high speed on the track. Excessive tyre wear, overheating, and/or sidewall stresses will result in either case. Everyone has their own plan regarding preferred tyre pressures. Often this depends on driving style as much as anything else.

Paint Protection:

I have Expel PPF protective film on the frontal areas, side sills, and rear wheel arch surrounds on my car. In my experience this provides adequate protection against stone chips both on the road and the track. Some Porsche owners cover the front of their car with tape or clingfilm material for track days. It's up to you really. I always pack a roll of duct tape, just in case of any unforeseen circumstances.

Finally, I purchased an additional towing eye from my OPC so that I have both the front and the rear of the car prepared for any recovery situation. I also take a variety of robust suction mountings for my GoPro camera and phone. If you are doing a couple of track days or more every year, best to purchase your own safety helmet and balaclava. Gloves are an optional extra. Some drivers wear them some don't. I use fingerless cycling mitts. I find them excellent for grip on the Alcantara steering wheel, and also leaves your fingers bared for easier pushing of the PSM buttons and such like on the steering wheel and console.

My car is set up with geometry settings attuned for optimum performance on the track. These settings have proved entirely satisfactory for general road use also.

Brian

 

[ChrisW]

Hi Brian,

I will be there with Steve (my Brother in Law) and we are staying at the Premier Inn at Dunfermline on the Friday evening.

It looks like rain to me, so I've fitted my M. Pilot Supersports which are a safe choice ... my M. PSC2's are half worn and not worth taking a chance on with rain and a round trip of 500 miles in addition to the track day !

I did as you suggested and took tuition first thing in the day last time I was there ... very good advice !

I'm looking forward to your showing me the way around your turf

 

[Brian_Innes]

Chris,

A wise choice fitting the MP Supersports for Knockhill. Especially with the weather forecast being iffy for Saturday. If we are lucky, there should be some dry laps on the cards at some point during the day.

Interesting to learn that you are faced with a 500 mile round trip to Knockhill. From my Highland location it's a round trip of 400 miles all in. I still call it my "local" circuit.

See you there.

Brian

 

[Brian_Innes]

Whilst on the topic of track day prepping and participation, one thing I forgot to mention was checking the wheel bolts. Before I leave for a track day I always check the tightness of my wheel bolts with a torque wrench. The Driver's Handbook gives the correct torque setting for your car, in my case it's 160Nm (118lbs/ft). With high speed heavy braking, heat transfer to the hubs can loosen the wheel bolts slightly. It is not an unknown occurrence for wheels to become loose on a track day. I always check the wheel bolt torques during the lunch break. Better safe than sorry. For those owners of Porsches sporting centre-lock wheels who do not have the necessary torque bar kit, I guess you can only hope for the best.

One final word on track day etiquette. Overtaking rules are always covered in the driver's briefing, and in most cases overtaking is only allowed on the straights, and usually on the left side of the car in front. The car being overtaken should back off the throttle, indicate right, and move over to the infield side of the track to allow the faster car free passage on the racing line. On twisty, handling orientated circuits such as Knockhill and Oulton Park, it is a common occurrence for faster, experienced drivers to catch up other cars which may be of a far superior performance in terms of engine power. As a general rule on track days, if a following car comes up behind and fills your mirrors, this car and driver combo is faster than you. You are then expected to give way to the faster car at the earliest opportunity.

PCGB track days are generally very well behaved and the vast majority of participants behave in a respectful manner. Occasionally however, some drivers who are caught up by a faster pilot are reluctant to give way. In my experience, this often applies to drivers of high-end 911's who take a strong dislike to being caught and overtaken by a mere Cayman, especially one with a cylinder count deficiency. Such cases are referred to as the mobile roadblock. They dawdle through the corners and power along the straights, frustrating the rapidly forming queue of faster drivers behind. When confronted with such a situation, I choose to peel off into the pit lane at the earliest opportunity for a drive-through to reposition myself on the track and rejoin with some free space. Flashing your lights at a blocking driver is not the thing to do. This is not the M25. Drivers who persistently refuse to give way to faster cars may risk being shown the black and white Driving Standards flag by the trackside marshalls. Never a good thing. So, enjoy your track time, respect other drivers, and most of all have fun improving your driving skills.

Brian

 

[Ray]

I know I am not comparing like for like vehicles but it does show how subjective the tyre issue is:

Michelin Pilot Super Sport Given 76% while driving a Porsche 996 911 Carrera 2 (225/45 R17) on for 3,000 miles I can compare these with PS2 and Potenza S02A on the same car. Compared to PS2 the PSS feels more rubbery. It lives more sideways and IMO is a bit sluggish in turn in compared to PS2. However, I feel the PSS might have a bit more ulitmate grip. However, it is a bit vague at the limit and thus I prefer both PS2 and S02A over the PSS. The PSS is definitely a more quiet tyre than the PS2 ... about the same as S02A. Given 70% while driving a Nissan 370Z (275/35 R19 W) on a combination of roads for 9,500 spirited miles Assuming this tyre to be the pinnacle for grip, I am disappointed. The dealer placed the 'star rated' (BMW) tyres on my 370z &there is little grip when cold and or mildly warm. When only properly hot do I start to get grip but that means a lot of wheel spin &sliding prior. Not ideal in public on the street. No issues normal driving or rain. Recently at CONSTANT throttle on a reasonable curving road the rear stepped out and was saved by the electronics. Unacceptable when I can drive that corner faster in a standard NA Ford Focus with no drama, in any other car either? Seems the Star rated is very different from the standard version, more a track tyre & terrible on the street Ray

 

[Motorhead]

Brian,

I endorse all the suggestions you've make regarding vehicle track day preparation and especially the recommendation to check the tightness of the wheel bolts, something often overlooked.

Good call on the fingerless cycling gloves.!

Jeff

 

[AndrewT]

Whilst on the topic of track day prepping and participation, one thing I forgot to mention was checking the wheel bolts. Before I leave for a track day I always check the tightness of my wheel bolts with a torque wrench. The Driver's Handbook gives the correct torque setting for your car, in my case it's 130Nm (118lbs/ft). With high speed heavy braking, heat transfer to the hubs can loosen the wheel bolts slightly. It is not an unknown occurrence for wheels to become loose on a track day.

Brian

Would you vary from the Driver’s Handbook torque setting if you had wheel spacers fitted (with longer wheel bolts)?