Porsche Cayman S Brake update: DIY rebuilding Girodisc brake rotors

I'm writing this post because I couldn't find anywhere on the web that had a step-by-step discussion of doing this task...hopefully someone finds this helpful.

A few years ago, I performed an upgrade to the stock brake set-up on my 2007 Porsche Cayman S, utilizing aftermarket rotors from Girodisc and race-oriented pads from Pagid.  I wrote about it in this prior blog post:

brake-upgrade-for-cayman-s

I have been extremely happy with the amazing performance of the brake set-up and also with the longevity of the rotors, which have lasted my several seasons of track days (about 10-12 track days per year). So when the rotors got down to minimum width specs and it was time to replace them, I had no doubt I would again use Girodisc rotors which are slightly larger than the stock rotors, seem to dissipate heat more readily, and don't have cracking problems when used in high-temperature, hard-braking track conditions.

When I went to purchase new rotors, I was pleasantly surprised to realize that Girodisc developed their rotors so that the ring, or disc portion of the rotor can be replaced separately from the "hat" portion which attaches to the axle assembly and ultimately the wheel. What this meant was that instead of purchasing $2200 worth of new rotors ($1100 for each set of two), I could purchase only the ring/discs for $700 for a set of two, for $1400 total. That $800 difference was a nice surprise and represents almost the cost of a new set of tires!  So, I ordered the rings and started taking apart the old brakes to prepare to re-assemble the new ones. That is when I discovered that I couldn't find any online resources that showed me exactly how to complete the job, so I started taking some photos along the way to share with anyone else who might do this.

First steps were to get the car up on jack stands and remove the old brakes, then I set out the new front and rear rotor parts where they need to go (fronts and rear are different sizes and left and right are labeled from the vendor). Note that left and right are different to ensure the proper rotation of the rotor and the cooling grooves cut into the disc. See the Girodisc site for more info on that here:
girodisc.com/Technical-Info

If you have never removed your Cayman brakes, it is pretty simple (at least on the 987 version of the car in 2007). With wheels off, use pliers to remove the cotter pin that holds in the retaining pin in place over the brake pads, then tap the retaining pin out from the holes at the top of the brake pads, releasing them from the small tensioner plate and remove the pads with pliers.  You then remove to large bolts that hold the calipers to the axle using a T55 Torx drive socket. You then remove two small phillips head screws that hold the rotor to the axle and you can pull the rotors fully away from the axle and out of the caliper assembly. There are lots of web posts on this subject so I won't go into it any farther here. I always use some wire to then keep the calipers from dangling on their brake lines while the brakes are disassembled. It'll look something like this:

Now it was time to take the rotor "hats" off the rotor discs. This requires a 5/32 allen head wrench which will also need to be used with a  torque wrench for reassembly, so it is best to just find a ratchet-driven one now for taking it apart.

I started taking them part and found a few things to note.  First, the fronts were much tighter than the rears.  I can only assume this is because the fronts got much hotter during their life on the track and the bolts had gone through more expansion and contraction. I was surprised at how hard it was to get the bolts off the from the hat because I knew the torque settings to reassemble were only 5 ft-lbs (60 inch-pounds).

Once the 10 bolts have been removed from the inside of the hat, the hat should separate from the ring. But on the fronts, again, it didn't come away easily. The heat had them somewhat bonded, but by holding the hat I could smack the disc with a hammer to separate them. The next thing to get out were the drive bushings, which are the threaded "sleeves" that the bolts go into, the heads of which you see on the outside-facing part of the rotor.

Again, the front ones had a harder time coming out, so I used an old screwdriver as a center-punch to get them out. The rear ones came out just with with finger-power.

With the hats now removed, I used a wire brush on a drill to clean up any corrosion, and finished off with some brake-clean to make sure the hats would seat perfectly on the new rings and that the assembly would seat nicely to the axle. The people at Girodisc make sure to tell you that any burrs or inconsistencies on the contact surfaces can lead to vibration or diminished performance. The clean hats were now ready to go onto the new rings.

When I had previously read the specs for assembly, I had realized I needed a smaller torque wrench and could find one only online.  For settings as small as 5 ft-lbs, the wrench is a 1/4" drive.  So since the allen-head socket is a 3/8" drive, I also needed an adapter to allow a 3/8" socket to go on my new 1/4" drive torque wrench. the Girodisc ring set comes with all new hardware, so with shiny new stuff, I was ready to go.

The hardware kit includes 10 bolts and drive bushings for each rotor, with 5 of one type of bolt assembly and 5 of another. You assemble them using these two bolts in an alternating pattern around the hat. One type has an expansion piece/spacer that looks like "shoulders" on the bolt.  This sits against the hat surface and (I assume) allows for some expansion when the brakes get hot.

I first placed the brass-colored drive bushings into the hat, and found that I needed to clean up the inside circumference of the old front hats with a round file, just so the bushing went in smoothly.  Just a few filings and the hat holes were ready to accept the bushings.

I then placed the hat onto the new ring, lining up the bushings into the holes on the ring and then installed the ten bolts in alternating pattern.  I placed a couple drops of high-temperature thread locking fluid on each bolt. I don't have a photo there, because I didn't have three hands and I was holding the rotor assembly vertically.  I then placed the rotor down flat on the bench and torqued the bolts to 60 in-lbs.

With the rotors now each re-assembled, I just reversed the process and re-installed the rotors onto the car. Of course, now you have a slightly thicker rotor disc than the old used one so you may have to push the caliper piston-pots back to a more flat position against the inside of the caliper. I use the handle portion of a large 1/2' ratchet to lay against the inside surface and control slowly how much pressure to apply to make the pistons go back into the caliper. With the rotors back on the car, note the proper orientation of the rotor grooves relative to the direction of the car.

Now the "Gator" is ready to get the wheels back on and get to the track.  Thunderhill Raceway this week, Sonoma raceway two weeks later and Laguna Seca in about a month ! Ya gotta love Northern California track availability!

Good luck with your brake upgrade!!

The value of a 1967 Corvette Roadster vs a 2011 Corvette ZR1 Coupe in 25 years. Which one wins?

I have posed this question to a number of my car friends, so I am putting it here for everyone's consideration.

I currently own a 1967 ("C2") Corvette convertible with the 350HP 327cid small-block, a 4-speed manual transmission, Marina Blue exterior and White/Blue interior with White top. It is in excellent condition, with a complete nuts-and-bolts restoration having been completed in 2008 (I bought the car after that, in 2009).  In today's market, I'd say the car is worth approximately $60,000 - $65,000.

Meanwhile, a used 2009-2013 era ("C6") Corvette ZR1 goes for about the same price or a bit more, around $70,000. Keep in mind, this was a car that sold for over $110,000 new and was the flagship supercar for GM during the period before the newer C7 Corvette Z06 came into being. This was a no-holds-barred shot by Corvette at all the world's top performance brands and it was a pivotal point in Chevrolet's strategy to really bring the best of automotive technology to the Corvette, which was seen as a bit "plastic" and cheap compared to some rival supercars. It ushered in the next wave of upgrades which became more standard on the redesigned "C7" Corvette Stingray in 2014.

I have considered selling my 1967 and purchasing a C6 ZR1, possibly a 2011 model, assuming it would be close to an even trade in value. I could keep both, but space becomes a little tighter if I do.

So the question is this: in 25 years, which will be worth more?

Arguments for the 1967: the 1967 Vette is a classic sports car, the best in the U.S. in it's time. It may always be seen as a hallmark of design and performance for that era. Muscle cars from the 60's will always have a strong following because they are of an iconic age that will always be important and because they are easy to maintain, relative to the complex machinery of today. The design if the 1967, as the last of the mid-year Corvette C2s, remains as beautiful today as it was then.  Everyone who sees the car loves it, just as they do iconic cars like a 1961 Jaguar E-type convertible.

Arguments against the 1967: The buyers for those cars have typically been men who lived in that era and who have the disposable income in their 50's and 60's today to go back and collect that dream car from their youth. In 30 more years, those buyers are dead or out of their car buying period. The most collectable cars will always be the big-block 427s, and this car I have is a nicely optioned small-block, but there are too many of them that have now been restored relative to the number of buyers.  Every car auction seems to have an endless supply of C2 Corvettes for sale, and eventually the market will have been satisfied. If we look at the market for cars from the 1940's and 1950's, maybe there is a lesson there for the 1960's cars. Just a couple examples would be the 1953 Packard Caribbean or the 1955 Chevry Bel Air.  Both were considered highly desirable as collector cars, but in the last 5 years values have been flat to down. The people who lusted after them are just no longer driving the market.  About all they seem to benefit from now is general inflation. This is just my opinion and I would love to be proven wrong here. Highly specialized cars from the 1950's still do well (Ferrari, Aston Martin, Continental Mark II, early Corvettes), but I can't necessarily claim that my 1967 327 convertible fits that description.

Arguments for the 2011 ZR1: In 25 years, this car will likely be desired by those in their 50's that lusted after this car as a 20-year-old today when it came out in 2011. Note that there were just over 4600 ZR1s built during the 5-year production run, with about 400 built each of the last two years 2012 and 2013, so those are the more rare years.  People in 25 years may pay a premium for a nice example that hasn't been thrashed or tracked, something that will likely happen to many ZR1s today, because they have been pushed aside by the newer, shinier C7 Z06. The ZR1 is a limited production car, and although GM probably over-produced them for the current market, there will probably be more buyers than sellers in 25 years. Also by then, cars may be dominated by EV drivetrains, hybrids, or other alternates. Manual transmissions will be a thing of the past. Everything will be turbocharged for better fuel efficiency. And the next ZR1 in 2017 is rumored to be (gasp!) a mid-engined car!  So the 2011 ZR1 could represent the "pinnacle" of this second muscle era of the early 21st century. This type of naturally-aspirated V-8 with 638HP from an internal combustion engine will be like a long-forgotten dinosaur that may be worth much more money due to their place in auto history. 

Arguments against the 2011 ZR1: The 2011 car is a complex piece of technology that is not as easy to maintain as the 1967 and parts availability is unknown today. Repair and parts may become more expensive than the older car. The design was not considered revolutionary, although the car's overall performance was. 

Of course, with inflation over 25 years, if an average sedan will cost you more than double today's prices (say, $100,000), then it will be easy for both these cars to increase in value.

So, which one will be worth more in 25 years?  I'm actually starting to believe the answer will be the 2011 ZR1, if for no other reason that my arguments for and against above seemed to weigh in that direction.  But maybe one single argument is just looking at the cars... I mean, who doesn't love the 1967? 

So, there are 5 possible scenarios.

A. The 1967 will be worth more than the 2011 ZR1
B. The 2011 ZR1 will be worth more than the 1967
C. They will both be worth less than they are today, so either one is a bad "investment"
D. They will both be worth more than today, but will be close in value to each other
E. Impossible to tell, it depends on inflation

That is the multiple choice question to which I can't quite figure out the answer.  Maybe I just need to go for a drive to clear my head...

Dave's Drives: Cayman S, a couple laps at Sonoma Raceway vs Mustangs

Here is a video from in-car at a recent track day with Trackmasters Racing at Sonoma (Sears Point) Raceway. The Cayman S was running well, and I was doing OK on the lines (only slightly better than the Mustangs I was chase and passing). I think my braking points and turn-ins still need work here.  Can't blame the car, just the driver - but I ran a few 1:56 range laps that weren't bad.  I need to drop another 5 seconds off that time, though.  For some reason, my sound is not synched well in this video...

Dave's Drives: Northern California Coast in the McLaren 12C

McLaren Automotive did everything right, in my opinion, when creating the MP4-12C.  It really is a superb road car that can keep you comfortable on longer trips, while being able to tear up the track when you find yourself in need of some serious speed.

So, in the spirit of its great-road-trip-car capabilities, my wife and I set out one beautiful weekend this summer to see some of our favorite spots up on the Northern California coast near Mendocino.  I'm just getting around to posting this after a short delay, but I'm already prepping to go back for another go at it. The McLaren was flawless on this trip. It makes short work of any passes necessary, feels planted at all times, and is smooth enough so your passenger doesn't feel like you should have taken a different vehicle.  And in this part of the country still untouched by time, it is almost as rare a sighting as a Starbucks cup (actually, you won't find any of those on this trip).

Here's the basic drive itinerary:

Destination / Route
Sonoma via Hwy 29 and Hwy 121
Santa Rosa via Hwy 116 and Hwy 101
Cloverdale via Hwy 101
Boonville via Hwy 128
Navarro via Hwy 128
Little River and Mendocino via Hwy 128 and Hwy 1
Elk, Gualala, Point Arena, and Bodega Bay via Hwy 1
Petaluma via Hwy 1 and Valley Ford Rd

Along the way, some terrific places to stop in Sonoma and in Anderson Valley and many amazing spots along Hwy 1:

Sonoma Square for wine tasting, breakfast or lunch.
Along Hwy 128 through the Anderson Valley:
  Boonville for the Anderson Valley Brewing Company and the Boonville Hotel
  Goldeneye (Duckhorn's Pinot Noir) wine tasting
  Navarro Vineyards (try the Chardonnay)
  Roederer Estate for sparkling wine and Chardonnay
The Little River Inn is a great place to stay on the Coast
Glass Beach in Mendocino
Point Arena feels like it probably did 50 years ago
Lighthouses (including one made famous in the movie "The Need for Speed")

And for car people: some of the most beautiful, although twisty, roads you will ever lay your tires on.  I recommend you take this trip over 2 days with about 3 hours of driving each day.  Stay overnight in Little River, Mendocino, Elk, or Gualala.  Here's why...

Cloverdale and Hwy 128, gateway to the Anderson Valley

Boonville!!

Navarro Vineyards

GOLDENEYE Pinot Noir.  Fantastic spot.

Roederer Estates

Simple curiosity.... and a great photo op.

Curvy roads and redwoods.  Good stuff.

LITTLE RIVER INN, LITTLE RIVER CA 

Glass beach, Mendocino

Headed down Hwy 1 South to Gualala

You might recognize this as the final chase scene location in "Need for Speed"

What more to say.  The pictures tell the story.  Go.