Mech33

I don't see why this can't be done with some clever bar attachment.

orthojoe

It probably has something to do with the fact that these new LWB seats are height adjustable.

Mech33

Hmm could be. I'm still not convinced until folks that have designed these for the 997 have looked at the 991 LWBs and chimed in with the reason why.

Joe, did you get any pics of the underneath of the seats when you had them out for the bar install?

Would be very nice to not have the belt length change as the seat moves.

orthojoe

I can take some the next time they are out. Probably next weekend. Hope to be done with the project finally then. Iirc, someone has tried to make the old BK brackets to work on the lwb, but it didn't work. I don't know why. We should know more soon as I know people are looking into this. The caveat with having the belts move with the seat is that they by definition are no longer mounted to the tub, but to the seat. Depends on what you are looking for. To adjust the position on the GMG setup is just a matter of moving 2 bolts.

MayorAdamWest

Finally just changed my front brake pads yesterday. Wow, that was probably the most annoying thing I have ever tried to do on a car. Joe, how did you deal with the silly bracket on the back holding the caliper lines in place? It was a pain the *** to loosen, still gave me minimal room to work, and was bent out of shape when done. I did finally get them back on, but it seems unhealthy for the part to put that much stress on it? Why did Porsche do this? Between the center lock and this, it feels like Porsche really has no idea how people use their cars...

TRAKCAR

I'm hoping someone will make the PFC CUP calipers work on these cars, if they are open bridge..
Anyone have these caliper part numbers?

Racing Brake has an alternative, they posted here with Carbon Ceramic and steel options: https://rennlist.com/forums/991-gt3/...r-991-gt3.html

orthojoe

NOW you are starting to feel the pain that I have experienced! LOL. Yes, even with the caliper studs, the process is a major PITA and not 'healthy' either because of the brake lines having to be mobilized via that bracket you mention.

RB does make an open top caliper for our cars that works with OEM rotors...

blockbuster

I know that PFC 11 compound pads have been recommended in this thread. But, my local race shop recommends PFC 08 Compound. They say the 11 is more for sprint cars and 08 is better for track days with a GT3. They say the 08 will perform very well and last longer than 11.

Any thoughts on PFC 11 vs PFC 08 would be welcome. Thanks!

orthojoe

PFC08 aren't available for the 991GT3 to my knowledge, but I have experience with both on my boxster spyder.

I much prefer the PFC11 over the PFC08. The bite and consistency of the 11 over the 8 is much better, and I haven't noticed a difference in pad or rotor wear rate between the 2. My buddy Ben has found the same on his car as well. Also, the PFC08 are MUCH louder on the street than the PFC11. PFC11 barely make any noise.

orthojoe

Forgot to mention that I flushed the OEM brake fluid out and replaced with motul RBF600. The pedal was starting to feel a bit soft after the 5th track day, so I did the flush. Pedal feels great with the motul RBF after 3 days so far.

Mech33

Any tricks to the brake fluid flush? Did you use a pressurization tool for a 1-person job, or did you do it the old fashioned way?

lordpantsington

F:
9913514278A
9913514288A
R:
9913524278A
9913524288A
Looks like they are single piece with an X brace instead of an open bridge.

the_vetman

991 Cup calipers are not open bridge...

PFC 11s are supposed to have more bite and therefore create more heat IIRC. Corollary could be Pagid Blacks (~PFC 11) vs. Yellows (~PFC 08). Lot of racers use Blacks. They stop better but create too much heat for my application (DEs in a Boxster Spyder). Yellows also last longer. I wonder if I'd need more cooling or larger rotors with PFC 11s..

GrantG

That sounds annoying. I haven't seen the GT3 with a wheel removed (and my GT4 isn't built yet), so I am not sure I understand the bracket problem. Is it something that could be fixed by having a longer custom braided brake line (to replace a hard line)? Does anyone have a photo of this bracket and brake line issue (sorry if I missed it in the thread)?

Thanks!

MayorAdamWest

Possibly, yes, though the hard brake line is 1 of many things attached, and that still wouldn't solve the bracket problem. You have to get under the car, in a tiny space, and remove two super annoying screws holding the bracket in place. Then, moving the caliper to change the pads bends the bracket, so it's a PITA to get back on. I really don;t know how anyone at porsche thought this was acceptable and how the shops aren't complaining (or maybe they are...).