I love my spyder, but I have been very disappointed with the soft and long pedal travel on the brake pedal. Add in the fact that I have 8k PCCBs on the car to boot, and it turns into a embarrassment. The feedback is no good, and the long pedal travel makes it difficult for me to heel-toe. This is a chronic problem with caymans/boxsters. At first I thought it was my PCCBs, but I was at the porsche world road show event and had the opportunity to try out multiple variations of the 987, including the cayman R, and they ALL had the same mushy pedal with the standard brakes as well. Luckily, Savyboy had the same gripe on his spyder as well and suggested I try to swap the master cylinder for a GT3 master cylinder.

I installed SS brake lines and swapped out my PCCB master cylinder for a GT3 master cylinder. Install was very straight forward:
Use a torx screwdriver to remove the screws holding the plastic cover over the master cylinder. Detach the lines going to the master cylinder and fluid reservoir. I used an o2 sensor socket to remove the large nut holding the master cylinder to the brake booster. The blue colored torx bolts can be left alone. Here's a picture:



I did a bench bleed of the master cylinder and reassembled everything. Here is a picture of the PCCB master cylinder (left) and the GT3 master cylinder (right). They look identical, although the stampings suggest they are different.



Install was easy, but bleeding all of the air out of the lines was a PAIN. I had to bleed everything twice before I got all the air out. I used my durametric 6.0 cable to actuate the ABS, and I think that helped to get out all the air as well. I did not end up bleeding my clutch because it did not seem to be affected and feels the same. Results?

Much better. The pedal travel has been shortened noticeably. Braking power is just a strong as before. I can heel-toe MUCH more easily now. The initial pedal feedback is still somewhat soft, and I think this is due to the brake booster. However, even though the initial feedback is soft, the pedal travel to get good bite is shorter, and feed back at this point is better as result. I still like the pedal feel of my Evo X better, but the GT3 master cylinder swap has made the spyder brakes now acceptable to me. Before, they were a mushy mess that had no business being in a sports car. They used to feel like the brakes on my wife's Infiniti FX35, which was particularly disappointing, having PCCBs. That is no longer the case. I would recommend doing this modification to anyone who tracks their car or is looking for a shorter pedal travel to allow for easier heel-toe. Credit goes to savyboy, who tried this on his PCCB spyder and suggested I do the same. The brakes still aren't perfect, and I would agree with savyboy's assessment that if fixes 80% of the problem. The other 20% probably lies with the brake booster, but it's too big of a job to make it worth it...
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orthojoe
2011 Boxster Spyder
2008 Evolution X

 

Thanks for the great write up. I'll probably do the same in the future even though I have steel brakes and PDK. My car suffers from the same issue of long pedal travel and iffy feel. Which GT3 master cylinder did you use? 996 or 997 or is there even a difference?

 

Ben,

I installed a 997 GT3 master cylinder, but I'm not sure if there's a difference between a 996/997. From my understanding, since those with steel brakes have smaller calipers, they have had good success with a PCCB master cylinder. If you're interested in going that route, I'll sell you mine. It might give us a good excuse to meet up too.

Joe

 

Thanks orthojoe! And thanks to savyboy too. The brake feel is my only gripe about the car and this mod has now moved to the top of the list. I'm going to second ben's question and which GT3 master cylinder is best? Thanks again, guys.

 

Part number on the GT3 master cylinder I used is: 99735591030

 

Joe,

Thanks for the offer but I'll probably go the same route as you to hopefully get as much brake improvement as possible but that will be further down the road. I just installed GT3 LCA along with track alignment. Also switched out the OEM brake pads for Pagid Yellows, I should probably slow down on the mods. Have you decided when you'll hit the track next?

Ben

 

CCB's on a GT-3 have a very high engagement point for H&T on the street. More suited to the track where brake pressure is stronger, near perfect for that in fact (at least for me)

I've been thinking about the swap, but to tell you the truth I've been having fun with this car as a momentum racer and use the brakes very little. The turn-in and catch is so good that brakes seem fine when used that way. I'd have to push it at the track to know if I felt it needed it, but sure doesn't seem to on the street.

Of course, how it "feels" to you is very important.

Has anyone "cooked" redheads at the track yet with stockers?

FWIW, I have PDK as well so playing brakes with my left foot is kind of fun

 

GT3 LCAs? Nice. You are getting hardcore pretty fast, man. What kind of camber are you running? How much tread is left on your stock tires? Great idea swapping pads for the track. More cost efficient and one of the best things you can do to drop lap times. My next track day still won't be until Aug 19th, with HOD. I've got a group of 12-13 friends/co-workers going. Should be blast. I'm bringing my Evo X though, since HOD doesn't allow convertibles in C-class. I'm in the process of doing a turbo upgrade for the Evo, so coupled with an Ohlins suspension I'm lookin' to make some GT-Rs and GT3s sweat that day.

That was my problem. It was very easy to H/T on the street on the stock setup, but at the track when you hit the brakes hard, the pedal would drop way too far to the floor with no endpoint for feed back. With the brake waaay below the throttle, I had a real tough time with H/T. The brakes performed perfectly, but the 'feel' was just not right for me.

 

Hmm... I wonder, what pads were you using on the PCCB rotors? What mileage, and percentage road/track did they have on them? Prior to the replacement, were your brakes feeling exactly as they did when you picked up the car new? Did you attempt to flush the fluid before replacing the master? What fluid did you use?

I have never driven a Porsche whose brakes could be described as "mushy" unless a) the stock pads were overheated under a heavy brake foot on the track, or b) the brake fluid needed replacement. I haven't driven the latest Boxster and Cayman, so maybe I'm missing out.

There was a debate about heel-and-toe awhile back; some people actually use their heel on the pedal, others "roll" the side and ball of their foot onto the throttle. I have pretty wide feet so the latter technique works best for me. Street or track, the side of my foot never has a problem reaching the throttle under threshold braking.

 

Great points. I'll try to answer each one.

I'm currently using stock pads still. The pads have 6000 miles on them, but only 1500 were in my hands. I bought the car at 4500 miles. The car is mostly driven on the weekends and it has been driven to 2 track events so far. Prior to the MC replacement, the brakes felt the same as the day when I first received it: mushy. Prior to each track event I did a full bleed of the system with motul RBF 600 brake fluid. To my disappointment, the brake bleed each time did NOT improve the pedal feel. Since I did a full flush twice I was confident that air in the system was not an issue. If you pump the brakes with the car off, the brakes will end up with a very solid stop, with no give to suggest air in the line. The brakes had NO issues with fade at the track, and stopped the car VERY well. I consider myself a fairly late/aggressive braker, since this is usually how I catch up with GTRs and GT3s after a straightaway. Great stopping power on stock pads, nonetheless.

Fortunately for you, I think you're missing out. I'm just as shocked as you that a Porsche would come with mushy brakes, but I drove multiple caymans/boxsters at the porsche world road show event in candlestick park a few weeks ago and confirmed they are ALL like this. The 911s were not. There are multiple 987 owners on the forums who complain of the same problem, and craig@rennstore has confirmed to me it is a ubiquitous issue as well.

I prefer the 'roll' method myself for H/T. On the street this is not a problem, but on the track it is impossible with the stock setup. The brake pedal is so far past the throttle, you can't possibly grab the throttle without letting up on the brake pedal. Even after the MC swap, it's going to be tough to pull off a 'roll' H/T because the brake still goes past the throttle (just not as crazy far). However, it has made stabbing at the throttle with my heel much easier.

One confounding factor is the addition of the SS brake lines. However, I would be surprised if just SS lines would make just a big difference, if any at all since they were essentially new rubber lines that were replaced...

 

I'm running -2.0 in the front and -1.8 in the back to start, I don't want to get too aggressive because I want to be able to enjoy it on the street. Incidentally, the back was at -1.8 and -2.0 from the factory and the rears have been wearing pretty evenly. My tires have plenty of tread, probably below 1/2 tread depth in the back and 3/4 in the front but the outer edge of the fronts are getting hammered especially the drivers side because my last two track days were in clockwise direction (Buttonwillow and Infineon). The tires may actually get heat cycled out before all the tread is gone. Somehow the dynamic cornering function of my headlights got disabled with the install, hope the shop gets it sorted out the next time I'm in. I'll try to make the Aug 19th event and check out your Evo, sounds like it's going to be a beast. It's unfortunate that we can't run our Spyders in C group with HOD but apparently it was mandated by their liability insurance company.

 

another fix is to contact Ultimate Pedals and get the wider gas. Install a brake pedal with spacers to build it up

the best way is to just teach yourself a classic H&T, but if the height disparity is too great, even this is not easy

 

Is the GT3 master cylinder the same part for both iron and PCCBs?

 

That's the same camber setup I use on my Evo X, which I also drive on the street. I agree it's a fair compromise for street/track. What amount of camber is the spyder running in stock form? Did you end up running at Infineon with TMR? NCRC and TMR will be my groups of choice for the spyder. HOD needs to change their liability insurance company... I needed to do something to the Evo anyway to make it valid. The spyder currently outperforms it in all categories: Looks, handling, power/weight, and braking. With the turbo upgrade I can at tip the power/weight scale in favor of the Evo. There's also something cool about keeping up with expensive cars using a 'cheap' car... It would be great to meet you on Aug 19th!

I have the rennline pedals with the throttle extension plates, but a putting some spacers behind the brake pedal might not be a bad idea if I really want to do the 'roll' H/T. Although I'm doing 'classic' H/T now with the new master cylinder fairly easily now.

Good question. I don't know. I have these master cylinder part numbers:
Boxster Spyder with PCCB - 997-355-910-10
997 GT3 (all use the same version) - 997-355-910-30

 

My Spyder's stock camber setting for the left rear was -1.8 and right rear was -2.0. I don't know what the fronts were stock because they didn't measure it before installing the LCAs. Yes, I ended up going to Infineon with TMR, there was a local Ferrari group in attendance. I've never seen so many Ferraris in one place, there were a handful of Gallardos as well. I'm doing Thunderhill with HOD this weekend and Laguna Seca with Speed Ventures later this month. If you decide to go to the track before the 19th, let me know, otherwise i'll see you on the 19th.