PFC users. Tried any different F to R PFC pad combos?
07-29-2010, 02:00 PM
#31
car isnt that much lower from factory ride height... i had the shop corner balance her so they played with ride height a bit here and there but i dont think its much lower than factory... maybe set to the "euro spec" ride height but thats about it.
07-29-2010, 07:02 PM
#33
getting back on topic with the original post...
here's what my shop had to say about the "dancing" after I explained to him i was running 01's front/rear:
"I have had some instances of rear instability when running the PFC 01’s front and rear. The rears don’t get much cooling and ramp up in friction at the end of the brake zones. It might be worth trying a set of 06 rear pads with the 01’s in the front and see if that cures it. You could also add 997 GT3 rear cooling ducts and see if that makes it better"
interesting explanation....
here's what my shop had to say about the "dancing" after I explained to him i was running 01's front/rear:
"I have had some instances of rear instability when running the PFC 01’s front and rear. The rears don’t get much cooling and ramp up in friction at the end of the brake zones. It might be worth trying a set of 06 rear pads with the 01’s in the front and see if that cures it. You could also add 997 GT3 rear cooling ducts and see if that makes it better"
interesting explanation....
07-29-2010, 08:41 PM
#34
Nordschleife Master
Thread Starter
I find it VERY HARD to believe that you are overheating your rear brakes. Running the 01F 06R might actually overheat your fronts and never give your rears a chance to get really moving.
One thing I would suggest at your next track day is to experiment with a few different setups if you ahve the time and patience to change pads at the end of the day. Maybe 01F&R on 1 day and then 01F 06R or 06F 01R on day 2. When doing this I would highly rec'd running this test with brake temp paint to see what temps you are REALLY running. This will allow you to match your pad to your temps rather than guessing. This is how we did it in my GT3 and were able to find the perfect mix of pads. Obviously those days are behind me so the next test will be on my Turbo.
REMEMBER.....THE NAME OF THE GAME IS EMPIRICAL DATA!!!!! Guessing and the butt meter are fun but are not the answer
One thing I would suggest at your next track day is to experiment with a few different setups if you ahve the time and patience to change pads at the end of the day. Maybe 01F&R on 1 day and then 01F 06R or 06F 01R on day 2. When doing this I would highly rec'd running this test with brake temp paint to see what temps you are REALLY running. This will allow you to match your pad to your temps rather than guessing. This is how we did it in my GT3 and were able to find the perfect mix of pads. Obviously those days are behind me so the next test will be on my Turbo.
REMEMBER.....THE NAME OF THE GAME IS EMPIRICAL DATA!!!!! Guessing and the butt meter are fun but are not the answer
07-30-2010, 01:24 AM
#35
Rennlist Member
Join Date: Sep 2006
Location: Vancouver, BC, Canada
Posts: 1,968
Likes: 0
Received 0 Likes
on
0 Posts
Drop your rear tire pressures a couple lbs. Your tire pressures under hard braking will be a bit higher than after your cool down lap and by the time you get out to check pressures. So your 39-40 hot might really be 42. Aim for 38 hot max. Other folks I know actually get better performance several lbs lower. I've been playing with 33-38 hot. Haven't decided what is best for me yet.
Cheers,
Cheers,
07-30-2010, 08:02 AM
#36
Nordschleife Master
Thread Starter
I found through multiple iterations that 38-40 hot is the best for these tires. Increasing the spring rate a touch, reduces the tire roll, and gives the best grip. The only downside is if you go over 40, things start to get VERY slick quickly
07-30-2010, 12:52 PM
#37
Rennlist Member
Join Date: Sep 2006
Location: Vancouver, BC, Canada
Posts: 1,968
Likes: 0
Received 0 Likes
on
0 Posts
Thx Dell.
Last week the rear was sliding a bit so I dropped the psi by 2lbs and the car became stable again. All was good (pressures in upper 30's to help reduce driving on the sidewall)
Yesterday at my home track the tires were sliding around. Heat cycle count was in the mid 30's so I expected that. Constant chirping under braking, etc that wasn't around when the tires were fresher. I dropped 2 more lbs (now around 35f/36r hot) and grip came back. At heat cycle #40 looking at the data, I'm pulling over 1.2g's in a couple corners. Nice....
Once my driving becomes more consistent I'll do some proper testing with my alignment and driving style.
Cheers,
Last week the rear was sliding a bit so I dropped the psi by 2lbs and the car became stable again. All was good (pressures in upper 30's to help reduce driving on the sidewall)
Yesterday at my home track the tires were sliding around. Heat cycle count was in the mid 30's so I expected that. Constant chirping under braking, etc that wasn't around when the tires were fresher. I dropped 2 more lbs (now around 35f/36r hot) and grip came back. At heat cycle #40 looking at the data, I'm pulling over 1.2g's in a couple corners. Nice....
Once my driving becomes more consistent I'll do some proper testing with my alignment and driving style.
Cheers,
07-30-2010, 01:58 PM
#38
Nordschleife Master
Thread Starter
I'd be interested to get the temp data on the different psi ratings we run. Next time at VIR I will take tire temps at 36, 38, and 40. I have a tire probe pyrometer that I can have my "pit crew" do for me (and I for them....thanks Scott ).
).
07-30-2010, 03:31 PM
#39
Rennlist Member
Join Date: Sep 2006
Location: Vancouver, BC, Canada
Posts: 1,968
Likes: 0
Received 0 Likes
on
0 Posts
I have a dual mode (IR and probe) pyrometer too. Haven't tried it this season (so much other stuff to work on) but when I used it last year running at 36f/38r I wasn't getting anywhere near 180F with the probe. Now my driving is at a higher level compared to then so I'll look into it again when I'm at the track next. Good thing you have Scott A pit crew is mandatory when checking tire temps.
Cheers,
A pit crew is mandatory when checking tire temps.Cheers,
08-24-2010, 03:03 AM
#41
forgot to post back on here my experiences after a track weekend outing using pfc 06 or 01 (front) and pfc 01 (rear) scenarios.
first of all, i reported that i had some "dancing" in the rear under hard braking... thought maybe it had something to do with brake bias but the real problem was my rear toe was off measuring only .04" per side! i had the rear toe reset to .08" and the dancing went away. regardless of pads (f/r 01/01 or 06/01 front/rear).
in fact, i couldnt tell any difference in brake bias between 01/01 or 06/01. and i actually prefer the 01/01 combo. i like the stronger initial bite, feels as tho the 01's just brake harder and stop the car faster. i think the 06's were easier to modulate tho? but not a big deal honestly... had to adjust my braking technique a bit but not a big deal at all. again, bias felt the same with either combination.
i'll likely go back to 01/01 on my next set
first of all, i reported that i had some "dancing" in the rear under hard braking... thought maybe it had something to do with brake bias but the real problem was my rear toe was off measuring only .04" per side! i had the rear toe reset to .08" and the dancing went away. regardless of pads (f/r 01/01 or 06/01 front/rear).
in fact, i couldnt tell any difference in brake bias between 01/01 or 06/01. and i actually prefer the 01/01 combo. i like the stronger initial bite, feels as tho the 01's just brake harder and stop the car faster. i think the 06's were easier to modulate tho? but not a big deal honestly... had to adjust my braking technique a bit but not a big deal at all. again, bias felt the same with either combination.
i'll likely go back to 01/01 on my next set
08-24-2010, 12:42 PM
#43
A little something different to report:
1) I tried P90 (F) and RS14 (R) for 1 event. No issues once the fronts got up to temp - about 1.5 laps on 2 mile track. [Deman rotors F, OEM rotors R]
2) I tried PFC06 (F) and RS14 (R) for 1 event. About the same result, but the 06s got to temp a little faster than the P90. [ATE rotors F, OEM rotors R]
[Next event I'm going back to 06 square, which has been my favorite setup]
Neither setup [1 or 2 above] had any real issues WRT shimmying, shaking, or general bad behavior. Just gotta be careful for the first lap or so until sure F/R pads were both up to temp. FWIW, I don't drive a lot of straight_line_brake_to_turn-in_and_go. I like to trail fairly deep most places, and for my driving style, I get better results/feedback with PFC pads [vs Pagids] based on how they react in the braking zone. I suppose one way to say this is that amount of torque variation through the braking zone and pedal release feel is more suited for my foot than Pagids. I really had no "stopping power" issue with Pagids [in any configuration] - it was mostly release "issues." I also prefer a square setup vs a biased setup.
For really bleeding speed in a straight line I found adjusting bias backwards worked fine. But for me, it never felt as good under trailing as a square setup. YMMV.
-td
1) I tried P90 (F) and RS14 (R) for 1 event. No issues once the fronts got up to temp - about 1.5 laps on 2 mile track. [Deman rotors F, OEM rotors R]
2) I tried PFC06 (F) and RS14 (R) for 1 event. About the same result, but the 06s got to temp a little faster than the P90. [ATE rotors F, OEM rotors R]
[Next event I'm going back to 06 square, which has been my favorite setup]
Neither setup [1 or 2 above] had any real issues WRT shimmying, shaking, or general bad behavior. Just gotta be careful for the first lap or so until sure F/R pads were both up to temp. FWIW, I don't drive a lot of straight_line_brake_to_turn-in_and_go. I like to trail fairly deep most places, and for my driving style, I get better results/feedback with PFC pads [vs Pagids] based on how they react in the braking zone. I suppose one way to say this is that amount of torque variation through the braking zone and pedal release feel is more suited for my foot than Pagids. I really had no "stopping power" issue with Pagids [in any configuration] - it was mostly release "issues." I also prefer a square setup vs a biased setup.
For really bleeding speed in a straight line I found adjusting bias backwards worked fine. But for me, it never felt as good under trailing as a square setup. YMMV.
-td
