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Cliff's Grey Hare

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:

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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Cliff

Drag Racing Champion
Location
San Francisco Bay Area
Car(s)
2015 Cayman GTS
In December 2018 while at Willow Springs International Raceway I began to experience more intrusive DCC faults. We raised the front ride height, but this didn't solve the problem as I continued to see ride height sensor errors at track events in January and April. The DCC system failed again at Laguna Seca at the end of July, so I decided it was time to replace my DCC/Ground Control suspension with coilovers. I also experienced an issue with oil starvation under heavy braking for which the installation of a RacingLine oil catch can system is the right solution.

I decided it was time to cut to the chase and install the remaining items on my modification wish list: a Wavetrac limited slip diff, Integrated Engineering intercooler, and replace various suspension bushings since the shop will need to drop the subframe and transmission to install the diff.

I had 2 coilover systems on my short list, both of which came recommended by friends: Ohlins R&T and KW Clubsport. While researching the Ohlins, it came to light that they are redesigning the product in response to customer concerns and could not offer a timeframe for delivery of the redesigned product. So KW Clubsports it is.

I am currently working with Griffin Motorwerke in Berkeley to finish up the plan for the car. Availability of the KW Clubsports will primarily drive the date the work can start. The goal for completion is 9/20. The list of items going on the car currently looks like this:

RacingLine catch can and remote fill kit
Integrated Engineering intercooler
Wavetrac diff
Superpro SPF4195K RTAB
Superpro SPF4175K LCAB
Superpro SPF4176K LCAB
Tyrolsport deadset kit
KW Clubsports w/DCC Cancellation Kit

The coilovers come with 100n front and 80n rear springs. I want to continue with the spring rate balance I currently have in the so we will probably go with H&R I.D. Race Springs with an 80n front and 110n rear spring rate. We still need to confirm this plan with KW.

We are being fairly tame with the bushing plans as this car is primarily a daily driver and I don't want to destroy the qualities that make it a great daily driver. So no spherical bearings (other than those in the camber plates) and no hard core motor mounts or anything.

Edit: I will be replacing the nearly toasted NT01 tires with 265/35R18 Bridgestone RE71R tires and using those to set the ride height on the suspension. These tires will be for autocross and keep the car in STU class. They wear out too quickly for track days so I will continue to run the Dunlop ZIII tires for daily and HPDE use. Once I wear out the 255's currently on the car I will replace them with 265's.
 
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Jedimk7

Drag Race Newbie
Wow nice build! Great footage from Laguna seca [emoji41][emoji106]

Sent from my Gavin Belson black box signature edition
 

bfury5

Autocross Champion
Location
CT
I was reading an Ohlins thread that led me here, interesting that you're going with the KW over the Ohlins. I know the RS3/TTRS crew are having issues with them, but I thought the geometry for the Golf platform was pretty well settled, no?

Also, how do the 255s fit currently? I see you're only down .5" from stock on the coil conversion, any other mods to support the 255s?

For context: I have a '17 GTI and am debating full STH build next year. Ohlins are on my short list for suspension, and I'm trying to squeeze the full 265s onto the car per rules.
 

Cliff

Drag Racing Champion
Location
San Francisco Bay Area
Car(s)
2015 Cayman GTS
I was reading an Ohlins thread that led me here, interesting that you're going with the KW over the Ohlins. I know the RS3/TTRS crew are having issues with them, but I thought the geometry for the Golf platform was pretty well settled, no?

Also, how do the 255s fit currently? I see you're only down .5" from stock on the coil conversion, any other mods to support the 255s?

For context: I have a '17 GTI and am debating full STH build next year. Ohlins are on my short list for suspension, and I'm trying to squeeze the full 265s onto the car per rules.

Your questions suggest that you didn't read my posts that started this thread.
 

Mini7

Autocross Champion
Location
Charlotte, NC
Car(s)
2017 GTi Sport PP
Subscribed!

Cliff, what are your cold starting pressures for your NT01’s?
What are your target hot PSI’s when you come off the track?

I did not get my pressures dialed in and ran 2-seconds off my best time at VIR when running 235 MPS4S vs. 255 NT01’s. I know that I’m not getting the best from the NT01’s
 

Cliff

Drag Racing Champion
Location
San Francisco Bay Area
Car(s)
2015 Cayman GTS
Subscribed, 9/20 completion date is just around the corner!

We'll see how the date works out. KW is now telling Griffin that the Clubsports have a 6 week ship date. That would push the start of this project out to October as I have an autocross on 9/21, then I will be at Oregon Raceway Park the following weekend.

I have asked Griffin to clarify with Ohlins the suitability of the current version of their product for my intended use. They originally discouraged Griffin from ordering them making the comment that they cannot accommodate the sort of ride heights the track users are running. Since I am planning on running 265/35R18 tires and want to set the ride height to minimize rubbing, I am probably not going to be all that low. So we'll see what they come back with.

Subscribed!

Cliff, what are your cold starting pressures for your NT01’s?
What are your target hot PSI’s when you come off the track?

I did not get my pressures dialed in and ran 2-seconds off my best time at VIR when running 235 MPS4S vs. 255 NT01’s. I know that I’m not getting the best from the NT01’s

31 front, 33 rear. The fronts gain 8 pounds and the rears gain 6 pounds in the first session. I bleed them back to 38 hot, then keep bleeding them after each session until the pressures stabilize.
 

Cliff

Drag Racing Champion
Location
San Francisco Bay Area
Car(s)
2015 Cayman GTS
We got a fairly quick response from Ohlins, and they indicated that if lowering is kept to a half inch or less, then the current version of the product is fine. They indicated that they do not have any notes corroborating the RS3/TTRS concerns that have been expressed on this and other forums.

They will provide 80n front/110n rear springs and revalve the shocks for a $500 surcharge. There is a 2-3 week lead time on these. So I am proceeding with the Ohlins.
 

Mini7

Autocross Champion
Location
Charlotte, NC
Car(s)
2017 GTi Sport PP
We got a fairly quick response from Ohlins, and they indicated that if lowering is kept to a half inch or less, then the current version of the product is fine. They indicated that they do not have any notes corroborating the RS3/TTRS concerns that have been expressed on this and other forums.

They will provide 80n front/110n rear springs and revalve the shocks for a $500 surcharge. There is a 2-3 week lead time on these. So I am proceeding with the Ohlins.

That’s good news. 9/20 is still doable.

I’ve gotten feedback from a Miata and BMW owners that the Ohlins R&Ts suit a dual purpose track/daily car. The dual flow piston/valving working well to soak up bumps.
 
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