The Quest for the Perfect "Do It All" Car - 981 Cayman S

Did some tire mounting this weekend. One of these days I'll just give in and by a truck (if it's not obvious the car is totally full as well, including a loose wheel in the passenger seat)

This was the trailer's first real trip after I finally got around to registering it last week. Trip was about 40miles each way, the vast majority at 70mph. No tire or bearing blowouts and it towed just fine, so that's good.

Looks like I never posted about it, but back in january I semi-impulse bought a nice set of OZ wheels for the road tires. I wasn't totally sure I'd like the slightly darker color, but now finally seeing them on the car in sunlight, it was absolutely the right choice.

On top of just looking better, the wheels are 1/2" wider with lower offsets which makes the tires look less balloon-y and does away with the wheel spacers I was running before, which will make swapping to the track wheels less involved.

Also mounted up the front autocross/track tires, so now everything should be ready for the season to start at the end of the month.

Maximum versatility achieved!

Okay, realistically the bike rack is going to spend most of its time on the fiesta, but it's nice to have the option and I was bored and wanted a quick project. This is about as much weight as I would trust the hitch with. The bike rack uses a bolt as the hitch pin and because of the tight packaging to the bumper beam some custom hardware was needed to make it all work.

The two main issues were 1) the pin location is close enough to the bumper beam that the head wouldn't clear to thread in and 2) because I relocated the pin hole as close to the end of the receiver as possible it's up against the reinforced end and so there's no flat surface to tighten down on. For reference:

So, the solution. 1) the bolt becomes a stud and a lock nut, with a hex cut into the end of the stud to make it easier to thread in and 2) an "offset" washer. I didn't have easy access to a welder so I just jb welded the stack together. Not pretty but plenty functional.

Also I registered for SCCA time trials nationals. Looking at the entry list and the names and cars in my class I've probably missed my chance at actually being competitive, but it should still be a fun time. I figured if I'm going to the effort of going I should get some actual track pads since the R4S were just barely up to the task of last year's track day and I really wasn't pushing them all that hard. Got a caliper stud conversion kit for the front too since I'll now be semi-regularly swapping pads between track and street.

Your new wheels look great. This thread kills me. I really want a 981 S and Blue is the best color they came in. 

CAinCA said:

Your new wheels look great. This thread kills me. I really want a 981 S and Blue is the best color they came in. 

I too have that want

CAinCA said:

Your new wheels look great. This thread kills me. I really want a 981 S and Blue is the best color they came in. 

My sentiments across the board

The three of you just should. Really.

So I really like the porterfield R4S for street and autocross use, but I found last year that they're not quite up to the task of real track use. Since I'm doing at least one TT event this year, I figured it was time to step up to some real track pads. I'm lazy, so the easy option was the porterfield R4 since that means I won't need to worry about cleaning the rotors and fully re-bedding brakes every time I swap pads. More frequent pad swaps meant it felt like a good idea to do the caliper stud conversion on the front brakes. For some reason the front calipers aren't quick change like most porsche calipers are, so the caliper has to fully unbolt from the car to swap pads. The caliper bolts directly to the aluminum steering knuckle and is known for having issues with stripping threads with repeated bolting and unbolting. The added bonus of the studs is having a place to hang the caliper while swapping pads, rather than it just falling off the car once the bolts are removed.

Stud kit, complete with vibratite, ARP lube, and a thread chaser that turned out to be very necessary:

Installation ended up being kind of a pain, the aluminum threads are very sensitive and the studs thread in further than the stock bolts did, so it took a couple of passes and a lot of blowing out with air to get the threads cleaned up enough for the studs to thread in nicely.

It's hard to get good lighting under the car/in the fender well, so these photos are extra crappy. Here's the studs installed, with the caliper for scale I guess.

And installed. The pads have provisions for the wear sensors, but they seemed to be unhappy about getting hot, so I just zip tied them out of the way (visible just to the left of the caliper).

And then there's the rear, which are quick change calipers and like a ten minute job altogether. These pads don't have wear sensor slots (or the fancy noise damper things that the street pads have) so no choice but to zip tie the sensors out of the way. Actually, with the quick change calipers the sensors can just stay attached to the pads, so I left the ones on the street pads and dug out the old original sensors to toss on. If only both ends of the car were this easy.

Did a test drive and quick bedding session and...holy initial bite. And stopping power. And dust, of course. So far they've been reasonably quiet, but I expect them to be pretty noisy when cold. The real test will be tomorrow night's track night event at pitt race. Also basically the first event of any kind on the new wheels/tires/suspension.

I run the R4 on the front of my GTI for track days. They will get progressively noisier the more you run them on the street. I just swapped back to my AutoX/street pads (PFC 10) and they are soooo much quieter. 
 

I run the R4S on the rear year round. I haven't had any issues with them. 

I went back and forth on what to do with the brakes a lot and had seriously considered doing something like that. Since the front calipers have to come off anyway it would have been pretty trivial to just get a second pair of rotors and swap them over as well for no bedding needed at all and then I could run cheaper pads (ST43s for the front are arguably better are actually cheaper than the R4 as well). But while the fronts seemed to take most of the heat, the rears appeared to have left more rotor deposits (which was the only real indication of any issue) so I wasn't confident that swapping only the fronts would be enough. Also I couldn't really find anyone's experience running staggered pads on these cars and I didn't want to go messing with brake balance without no idea what I was in for, especially with the other changes I've made. On a fwd car it's a no brainer though. It could still be an option in the future once I have a better sense of what the brake bias and operating temp range are like; I wouldn't mind getting away from the relatively quick wearing porterfield pads but I haven't found anything else I like as much for street/autocross use.

I think mono block brake calipers for street cars are incredibly stupid.  Having to completely remove the caliper to do a brake pad switch is such a PITA for really little to no benefit.

docwyte said:

I think mono block brake calipers for street cars are incredibly stupid.  Having to completely remove the caliper to do a brake pad switch is such a PITA for really little to no benefit.

It's not specifically that they're monoblock. The rears are also monoblock, but the center area is open and you just yank out a retaining pin and out pop the pads. I reconciled it to myself with "the front calipers must be too big and need the rib across the middle for strength". Then I looked at my friend's 997 GT3. The rear brakes are about the same as my fronts, complete with very similar looking calipers. And then there's the fronts, which are even bigger, with bigger calipers which.....are quick change? ...Okay, so there's just no logic to it I guess.

Anyway, with that ranting over...I drove it a few miles today to the gas station. The brakes are still surprisingly quiet when cold, though more than I would tolerate long term for street pads.

dps214 said:

I went back and forth on what to do with the brakes a lot and had seriously considered doing something like that. Since the front calipers have to come off anyway it would have been pretty trivial to just get a second pair of rotors and swap them over as well for no bedding needed at all and then I could run cheaper pads (ST43s for the front are arguably better are actually cheaper than the R4 as well). But while the fronts seemed to take most of the heat, the rears appeared to have left more rotor deposits (which was the only real indication of any issue) so I wasn't confident that swapping only the fronts would be enough. Also I couldn't really find anyone's experience running staggered pads on these cars and I didn't want to go messing with brake balance without no idea what I was in for, especially with the other changes I've made. On a fwd car it's a no brainer though. It could still be an option in the future once I have a better sense of what the brake bias and operating temp range are like; I wouldn't mind getting away from the relatively quick wearing porterfield pads but I haven't found anything else I like as much for street/autocross use.

I bought the PFCs in desperation. I couldn't find anything else locally that would fit and they were $90 a set. Then I called Porterfield and the guy I talked to said that not only are they great pads they are 100% compatible with Porterfield pads. No swapping of rotors needed. There was much rejoicing. 

It turns out that a LOT of guys that track GTIs use staggered pads and PF recommended the R4/R4S combination to me. I don't think I'd want a more aggressive pad in the rear. It already gets pretty light under hard braking as it is.

Pulling a couple pins and swapping pads is great. Popping a couple nuts loose to swap pads is a little less great. Swapping rotors sounds like a PITA. I'd use pads that are compatible. 

If I bought a Cayman S that stud kit would be on my short list of things to buy.

dps214 said:

The brakes are still surprisingly quiet when cold, though more than I would tolerate long term for street pads.

My experience is that once you track them they will be noisier and the more you drive them on the street the worse it will get. I put a couple hundred street miles on them after the last track day. By the time I  took them off it sounded like metal on metal at parking lot speeds. They need pressure and heat to work effectively. 

CAinCA said:

Pulling a couple pins and swapping pads is great. Popping a couple nuts loose to swap pads is a little less great. Swapping rotors sounds like a PITA. I'd use pads that are compatible. 

The thing is the calipers have to come off anyway. Once they're out of the way the only thing holding the rotor to the car is the two little retainer screws. I agree that it's not ideal and I'd like to keep it as simple as possible, but realistically it's an extra like two minutes per side.

In reply to dps214 :

The rears are two piece.  They look like mono block but they aren't.  The calipers on my 996 turbo (gt3 calipers up front) have easy access to the pads.  the calipers on my wifes cayenne diesel require you to remove them to change the pads.  So stupid. 

Nobody can tell any difference in performance between the two designs, just one is much harder to deal with maintenance wise.

PittRace track night yesterday. First real event of the season; new wheels, tires, swaybars, and brakes; a track I've driven once before three years ago in a completely different car. And the first real trip with the trailer...what could possibly go wrong?

Loaded up and ready to go monday night, whole thing stuffed into the garage:

Accidentally got a late start, but otherwise the trip was uneventful. Trailer is noisy as it bounces around but otherwise no real indication it was there. Not wanting to flip it over or grenade the wheel bearings forced me to drive responsibly which meant no making up for lost time but also meant that I averaged almost 27mpg at 73-75mph.

And arrived:

Registered, teched, then got to tearing the car apart to swap tires. As I said I haven't driven this track in forever, so I hopped out for a few paced laps with the novices to try to remember the track and feel out the car a little. Between still working on remembering what I was doing and missing on tire pressures, both the car any myself were kind of a mess in the first session, which then got cut short by a car breaking and dumping some oil in the last corner. By the second session I had gotten myself close enough to knowing what I was doing and the tire pressures close enough to right to get a sense of what was happening. I actually ended up softening the already soft-ish rear bar to calm the rear down. It honestly probably could have been faster as it was but was much more confidence inspiring with the rear more planted, even if it was getting a bit of on throttle understeer in a couple of places. With the stiff front bar the car really likes to be trail braked, which is a skill I've been working on as well. That probably also explains why the rear bar wanted to be softer, especially since this track is full of corners with apexes at the crst of a hill. I learned that the low fuel warning seems to come with a slight reduction in redline, so I know now not to start a session with less than a half tank of fuel. By the last session both the car and myself were feeling pretty good. The brakes had been a little weird early on and I was concerned that I was working on boiling the fluid but I think they just needed more break-in than I had given them and they felt good and consistent. The front tires still hadn't stabilized on pressure and ended up a bit higher than I wanted and the front end started to struggle some towards the end.

Here's the video of my best laps:

First lap I let a slightly faster mustang past and then used that as motivation to keep up with him. That trip through the first section of esses was my best of the night by half a second before we caught up to traffic. Lap two had traffic at the start and a missed apex coming onto the back straight but was otherwise basically identical to lap 3, my fastest at a 2:00.3. By the third lap either I was pushing too hard or the front tires were just unhappy and the esses suffered for it. Seems like there should be at least a few seconds in it between being more familiar with the track, a bit more setup tweaking, and generally having some more confidence in the car (...and not having to shift at 7k rpm) which would put me more or less in line with the pace of the S2 winner from the '19 TT event which I feel pretty good about.

Event over, swapped tires, packed up and ready to leave. Surprisingly good lighting, plus a bonus matching GT4 in the background:

The drive home was equally uneventful aside from the brakes now being fully LOUD. Rolling into my neighborhood at around 1130pm I felt bad every time I had to touch the brake pedal. Ended up basically coasting into my driveway in an effort to not wake up the entire neighborhood.

Hahaha! I know how that feels. Every stop sign, stop light, and entry to the driveway is a like nails on a chalkboard.

Swapped back to street brakes yesterday. The whole process took about an hour and was pretty painless, caliper studs make it a lot easier. I did learn not to be lazy and do it one side at a time, having a front wheel on the ground keeps the suspension loaded up and puts the sway bar end link slightly in the way of the brake line/abs wire bracket that has to come off with the caliper. Also noticed, disappointingly but not surprisingly, that the track pads create enough extra heat that the front rotors are developing some cracks. Next set will definitely be either plain or slotted.

If we remember all the way back to about the fourth post in this thread, one of the first things I did to the car was pull the badges off of the trunklid. I never loved the look of the chrome lettering, and what was on the car was the wrong badges and/or installed wrong. Lately I've been thinking about replacing at least the "Cayman S" emblem. The trunklid looks like it needs *something* on it, and maybe it'll cut down on everyone's first question about the car being whether it's an S or not. At that track night in my previous post, there was a GT4 in the same color, with the black badges that are the default for all the GT cars. I thought that color combo looked good, so I dug out some black plastidip I had laying around and plastidipped the old badges black to see what it would look like. It was about as good as I had hoped, so I looked into getting actual black badges. They're...not cheap, but not awful, so I went ahead and ordered some. New badges in hand, I confirmed my suspicion that the old badges were not quite right. Then got to work figuring out how to place them on the trunklid. I took some photos and measurements of the old badges before I removed them for just this occasion, but those badges being a slightly different shape that wasn't super useful. Plus I wanted to experiment with a different vertical location. From my testing with the plastidipped old badges I was pretty sure I wanted something closer to centered vertically on the panel. I originally wanted to put it over where the old "PORSCHE" was to cover up the paint defects those letters left behind. Up close it looked good, but from a distance it was a bit too high. After some messing around it landed I think basically in the middle of where the two old badges were, a little bit below the midline of the panel.

Original placement had the bottom edge of the letters aligned with the top edge of the horizontal tape line.

Then it was time to take some measurements and attempt to make some kind of template for actually installing them. Of course the "Cayman" has a slight curve to it, so it's not quite as simple as aligning it with that tape line as I had hoped. But after some experimenting and some careful trimming I ended up with this:

And applied to the car, ready for install:

So now for the fun (incredibly nerve racking) part...actually installing the emblems. I figured out that setting them down lightly gave me a little bit of freedom to pick up and replace them, but I wanted it to be as close to a single step application as possible to not ruin the adhesive. With some serious care and a gentle touch I managed to get them both on. I ended up placing the S ever so slightly higher than I had it on the template, which I think was the right move.

And the finished product, close up and from a bit of distance out in the sun. I'm really happy with the results and think the car looks a lot better this way. Definitely worth the $120 and several hours of effort. It could have been cheaper, particularly the "S", but I wanted to get all OE stuff to be sure that everything matched in color, font, and quality.

Fixing Porsche's questionable braking system designs, part 2:

The caliper studs went a long way to making front pad swaps faster and less annoying, but there's still a hangup. For some reason the soft brake line doesn't run directly to the caliper, but to a bracket on the knuckle, with a ~6" piece of hard line that connects to the caliper. That means to get the caliper off the bracket has to be unbolted from the knuckle. Not a huge deal in itself but that also requires disconnecting some electrical connectors and, the much bigger issue, the bracket is giant and can't actually fit between the knuckle and sway bar link to move far enough to get the caliper out of the way enough to get the pads out. So you end up forcing it a bit, getting just barely enough space to squeeze the pads out, and putting a bunch of stress on the brake line in the process. Not ideal for ease of maintenance or safety. Plus having "is this the time I was too hard on the brake line and it's going to explode when I hit the brakes" in the back of my mind going into every braking zone isn't great for having confidence behind the wheel.

Unsurprisingly, I'm not the only one that's encountered this problem and there's a solution in the form of a kit that replaces the hard line with a soft line, with extra length so that the bracket can stay attached to the knuckle as you pull the caliper off. It's marketed as specifically for GT cars but is definitely compatible with any 981/991 as far as I can tell. The porsche tax is real on this one especially since it only comes in a full kit that replaces all of the normal soft lines as well. But if it works it'll be well worth the money and the hoses are really really nice pieces at least.

Here's the stock stupid hard line configuration with the giant harness/brake line bracket. The larger diameter aftermarket links certainly don't help clearance but I remember this being something of an issue with the stock bar/links as well.

And the new soft line, with extra length. I added some extra protection where the line might rub against the knuckle.

And since I had the system open anyway I replace the flexible line as well. Again added rub protection, though realistically the line is only ever close to the knuckle bolt at full lock full droop, but better safe than sorry.

Tightened everything up and did a quick bleed and it all seems to work. I only had the time/energy to do one side last night so I need to do the other side, swap pads, and give everything a good bleed sometime this week. I think I'm going to leave the rear alone for now because I'm not a fan of opening up the hydraulic system any more than necessary and there's nothing wrong with the rear as it stands. I considered not even replacing the front flex line but the system was open anyway and it seemed dumb to buy the full kit and then only use a third of the parts that came with it.

This brake fluid (ATE 200) has been in the car for almost two years and I'm pretty sure I'm pushing the limit of its heat tolerance, so I'll upgrade to something better before the next track event. The stupid OE drilled rotors are starting to get pretty cracked as well. Those will eventually get replaced with either blanks or grooved rotors; I should be able to make these last through the year at least so that can be a winter project.

In reply to dps214 :

I wonder if those would fit on my 996 Turbo?  I have those same hard line extensions on my calipers and I hate them!!  Where'd you buy them from?

https://apexperformance.net/product/spiegler-stainless-brake-lines-porsche-991gt3981gt4-front-and-rear-6-line-kit/

The 996 parts are all slightly different of course but it looks like at the very least the fittings are all the same so you could probably make it work one way or another.

Just got the email that my fancy new brake fluid just shipped and should be here friday so I'll wait to finish putting everything back together and toss the fluid in now while I'm bleeding the system anyway.

Thanks, I've emailed them!

Those hard lines were the worst part of swapping pads in my 981- the soft lines would make that a lot easier. Re: rotors, the slotted Sebro ones from FCP Euro held up to track use much better than stock drilled rotors for me- and FCP will replace them for free when they wear out. One thing I noticed is that the rear pads wore about as fast as the front ones; first car I've ever owned where this was the case. I wonder if it's the electronic traction control using the rear brakes to prevent wheel spin coming out of corners, since they don't have an LSD?  Either way, I would not mismatch pads front/rear. I used DTC60's and was happy with their performance and price.

If you bleed brakes, make sure to torque the bleeder screws down to factory spec. I tightened mine hand-tight and one of them came loose, spraying brake fuid everywhere and leaving me with no brakes coming into turn 10a at Road Atlanta ar about 140mph. (!). Talk about a code brown. 

Mine seems to wear front pads at least a little faster than the rear. Unless the rear pads start substantially thicker, I've never paid attention to that. The rear pads look like they get about as hot as the fronts but the rotors aren't cracking so they must be staying at least a tiny bit cooler. Honestly it feels like if anything it could use a bit more rear brake to keep the rear end in line.

The 981 doesn't have torque vectoring by default, but mine does happen to have that option (ptv, which also includes a real lsd but either it's very weak to begin with and/or mine is toast...neither would be surprising). I've never felt like I could feel the torque vectoring doing anything, but I've also never driven a non-ptv car to compare to. It's also possible that turning off stability control kills it, who knows.

My rotor choice is going to be between the lifetime warranty slotted rotors or some cheap blanks, leaning towards the slotted ones.