Cliff
Drag Racing Champion
- Location
- San Francisco Bay Area
- Car(s)
- 2015 Cayman GTS
Since I have a lot of modifications coming up in the next month or so, I figure I ought to start a thread to detail those rather than cluttering up unrelated threads with my plans. As for my driving CV: I have been autocrossing, mostly with the Golden Gate chapter of the BMWCCA, actively since 2010 and occasionally since 2003. I started doing HPDE events with my BMW 330Ci in 2013 and that bug bit hard. As of August 2019 I have done 67 HPDE days, 50 of them in the R, and well over 100 autocross events. I have yet to hit a drag strip.
Let me start with a bit of background on the car. I bought my 2015 Limestone Grey with DSG, DCC & Nav on March 25, 2015. I immediately replaced the 19" Cadiz wheels with 18x8" Neuspeed RSe07 wheels and 235/40R18 Dunlop ZII Star Spec tires. I did my first autocross in the car the next month, followed by HPDE events at Thunderhill and Laguna Seca in May, and on the Roval at Fastivus in June. After 5 days on track with the car in stock form I had a pretty good idea of the weak points that could be addressed with products available in the aftermarket. There wasn't much available for the car in the aftermarket in the early days. I had Porterfield do some custom cut brake pads with R4S compound in the summer of 2015, added a Superpro 24mm rear sway, and installed an APR stage 1 ECU tune and TCU tune.
At the suggestion of the Sacramento-based APR dealer I contacted Ground Control Suspension Systems about doing suspension for the car in August 2015, and the results of that contact are discussed in this thread over on Vortex: link to thread. TLDR: they fit me into their production schedule in February 2016 and used my car to develop prototype camber plates and springs on adjustable perches. My current alignment can be found in the first post in that thread.
Over the next couple of years I battled heat-related brake problems by trying different pads, ducting, ti shims and so on,. I gave up on trying to make the stock brakes work in February 2019 and installed a Stoptech ST-40 kit. As the car sits right now, these are the performance mods:
I haven't done much to the car cosmetically. I had Suntek paint protection film installed a couple weeks after buying the car, installed e-code tailights from Germany, a spacesaver spare tire, the VW sunshade kit, and Homelink rear view mirror.
Edit: current mod list as of Oct 2020 for the TL;DR folks

Let me start with a bit of background on the car. I bought my 2015 Limestone Grey with DSG, DCC & Nav on March 25, 2015. I immediately replaced the 19" Cadiz wheels with 18x8" Neuspeed RSe07 wheels and 235/40R18 Dunlop ZII Star Spec tires. I did my first autocross in the car the next month, followed by HPDE events at Thunderhill and Laguna Seca in May, and on the Roval at Fastivus in June. After 5 days on track with the car in stock form I had a pretty good idea of the weak points that could be addressed with products available in the aftermarket. There wasn't much available for the car in the aftermarket in the early days. I had Porterfield do some custom cut brake pads with R4S compound in the summer of 2015, added a Superpro 24mm rear sway, and installed an APR stage 1 ECU tune and TCU tune.
At the suggestion of the Sacramento-based APR dealer I contacted Ground Control Suspension Systems about doing suspension for the car in August 2015, and the results of that contact are discussed in this thread over on Vortex: link to thread. TLDR: they fit me into their production schedule in February 2016 and used my car to develop prototype camber plates and springs on adjustable perches. My current alignment can be found in the first post in that thread.
Over the next couple of years I battled heat-related brake problems by trying different pads, ducting, ti shims and so on,. I gave up on trying to make the stock brakes work in February 2019 and installed a Stoptech ST-40 kit. As the car sits right now, these are the performance mods:
APR Stage 1 High Torque ECU tune - 91 octane (CARB legal)
APR TCU tune - upshifts disabled, 3k/3.5k/4k launch rpm
United Motorsport Haldex tune
Neuspeed intake (CARB legal)
Ground Control camber plates
Ground Control coilover conversion kit
475 pound front, 650 pound rear springs
Car is lowered about 0.5"
Superpro 24mm rear sway
Stoptech ST-40 BBK with Pagid RSL29 pads
8J TTRS air deflectors attached to the control arms
Ferodo DS2500 rear pads with stock rotors
Motul RBF600 fluid
Neuspeed RSe11R 18x9" et45 wheels in gunmetal with 255/35R18 Dunlop ZIII tires
Neuspeed RSe10 18x9" et45 wheels in satin black with 235/40R18 Nitto NT01 tires
I haven't done much to the car cosmetically. I had Suntek paint protection film installed a couple weeks after buying the car, installed e-code tailights from Germany, a spacesaver spare tire, the VW sunshade kit, and Homelink rear view mirror.
Edit: current mod list as of Oct 2020 for the TL;DR folks
- Driveline
- APR Stage 1 High Torque ECU tune - 91 octane (CARB legal)
- APR TCU tune - upshifts disabled, 3k/3.5k/4k launch rpm
- United Motorsport Haldex tune
- Neuspeed intake (CARB legal)
- Wavetrac LSD
- APR Intercooler
- VWR RacingLine PCV plate and catch can (removed Oct 2020)
- PCV Valve (06K103495BL)
- Forge catch can
- Suspension
- Ground Control camber plates
- Ohlins R&T Coilovers - MT21
- Ohlins DCC Cancellation Kit
- 80 N/mm front, 110 N/mm rear (approx. 450#/625#) 7" Swift 65mm ID main springs paired with Swift helper springs to keep the main springs located under negative load
- Front - Z65-178-080
- Rear - Z65-178-110
- Helper - H65-0135-0008
- SuperPro 24mm rear sway with EuroCode adjustable end links
- SuperPro lower control arm and rear trailing arm bushings - no added caster angle
- SPF4195K RTAB
- SPF4175K LCAB
- SPF4176K LCAB
- TyrolSport front subframe deadset kit
- Current alignment: link to document
- Car is lowered about 0.5" and corner balanced
- Braking
- Stoptech ST-40 BBK with Pagid RSL29 pads
- 8J TTRS air deflectors attached to the control arms
- Ferodo DS2500 rear pads with stock rotors
- Motul RBF600 fluid
- Wheels & Tires
- Neuspeed RSe11R 18x9" et45 wheels in gunmetal with 265/35R18 Michelin PS4S tires (Daily & HPDE rain)
- Neuspeed RSe10 18x9" et45 wheels in satin black with 265/35R18 Bridgestone RE71R tires (HPDE/Autocross)
- Other
- Schroth QuickFit Pro harnesses
- CAN bus cable for AiM SoloDL
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