Notices
991
Sponsored by:

991.2 Carrera - Track Journal!

 
Old 07-17-2018, 03:23 PM
  #31  
JAhmed
Addict
Rennlist Member
Thread Starter
 
JAhmed's Avatar
 
Join Date: Jan 2012
Location: CHICAGOLAND!!!
Posts: 1,067
Default

Originally Posted by arter View Post
Brake fluid best first step as no negatives there.
If your getting some fade and using OEM pads, then suggest limiting sessions to 25 minutes to keep them cooler.
Also, remember, pads will heat up faster as they get thinner.
JAhmed is online now  
Old 07-17-2018, 04:14 PM
  #32  
PCA1983
Addict
Rennlist Member
 
PCA1983's Avatar
 
Join Date: Apr 2014
Location: Orlando (winter), Chicago (Summer)
Posts: 1,744
Default

John Mclane: "Fluid fade -
If there is too much energy being transferred to the caliper and fluid, it can boil the fluid. These gas bubbles being compressible, the pedal travel increases and becomes "spongy" with poor modulation. (This is a gradual process with advanced warning). Solutions include: Changing brake fluid to one with a higher boiling point, using a different pad compound with better heat transfer properties, or improving the cooling to prevent the fluid from boiling."

One thing you forgot to mention that is sometimes a factor at track events. The pad is the only thermal insulation between the fluid and the red hot brake rotor. At 50% pad thickness, 50% of thermal insulation is worn away. So, running the pads down thin for economy is a no-no. Our Chicago Region recognizes that, and does not allow a car to run a track event with pads less than 50% of new pad thickness. A wise rule!
PCA1983 is offline  
Old 07-17-2018, 05:09 PM
  #33  
JAhmed
Addict
Rennlist Member
Thread Starter
 
JAhmed's Avatar
 
Join Date: Jan 2012
Location: CHICAGOLAND!!!
Posts: 1,067
Default

Originally Posted by 09RedGTS View Post
John Mclane: "Fluid fade -
If there is too much energy being transferred to the caliper and fluid, it can boil the fluid. These gas bubbles being compressible, the pedal travel increases and becomes "spongy" with poor modulation. (This is a gradual process with advanced warning). Solutions include: Changing brake fluid to one with a higher boiling point, using a different pad compound with better heat transfer properties, or improving the cooling to prevent the fluid from boiling."

One thing you forgot to mention that is sometimes a factor at track events. The pad is the only thermal insulation between the fluid and the red hot brake rotor. At 50% pad thickness, 50% of thermal insulation is worn away. So, running the pads down thin for economy is a no-no. Our Chicago Region recognizes that, and does not allow a car to run a track event with pads less than 50% of new pad thickness. A wise rule!
Good point! Definitely watching my pad thickness.
JAhmed is online now  
Old 07-17-2018, 05:11 PM
  #34  
JAhmed
Addict
Rennlist Member
Thread Starter
 
JAhmed's Avatar
 
Join Date: Jan 2012
Location: CHICAGOLAND!!!
Posts: 1,067
Default

Found some non-potato phone pics, courtesy of the event organizers!!!





JAhmed is online now  
Old 07-19-2018, 02:48 PM
  #35  
PCA1983
Addict
Rennlist Member
 
PCA1983's Avatar
 
Join Date: Apr 2014
Location: Orlando (winter), Chicago (Summer)
Posts: 1,744
Default

What are the best DE event tire pressures for a C2S?
PCA1983 is offline  
Old 07-19-2018, 03:42 PM
  #36  
JAhmed
Addict
Rennlist Member
Thread Starter
 
JAhmed's Avatar
 
Join Date: Jan 2012
Location: CHICAGOLAND!!!
Posts: 1,067
Default

Originally Posted by 09RedGTS View Post
What are the best DE event tire pressures for a C2S?
I have a C2, but I run them at 30 hot up front and 32 hot in the rear. I am sure those who are more experienced than me can chime in also though!
JAhmed is online now  
Old 07-19-2018, 03:54 PM
  #37  
Jon D
Addict
Rennlist Member
 
Jon D's Avatar
 
Join Date: May 2016
Location: Smokies
Posts: 209
Default

Originally Posted by 09RedGTS View Post
What are the best DE event tire pressures for a C2S?
what kind of tires?
Jon D is offline  
Old 07-19-2018, 04:33 PM
  #38  
awrryan
Addict
Rennlist Member
 
awrryan's Avatar
 
Join Date: Jun 2010
Location: Boca Raton, FL
Posts: 1,489
Default

Originally Posted by JAhmed View Post
Thanks for your input!!! I have some obligations that will keep me off track for the next month or so, but am planning to be back at Autobahn on 6/18.

I had a similar experience as you with tire pressures...also started out around 30 psi front, 32 rear...had to bleed them 3 times as I drove the car harder and harder and the ambient temp rose.

Castrol SRF is more out of habit than anything else...have used Motul RBF660 in past cars with great success, but have been buying Castrol lately. Will see what the best value is when I swap fluid now, but the easy button is Castrol for me. Thanks for the tips on the rear pads though...will keep an eye on them!!! Will be excited to try new pads after using these for a while.
No Complaints with Castrol SRF. I've been using it since January 2017 and love it. I had a little fade at one point, but it wasn't the fluid: I'm 99% sure it was my hardware (low pads, hot weather and a really fast and aggressive run at Sebring).
awrryan is offline  
Old 07-19-2018, 09:17 PM
  #39  
The Fat Kid
User
 
The Fat Kid's Avatar
 
Join Date: Mar 2016
Location: New England
Posts: 512
Default

The addiction is real...

I upgraded to Pagid RS29s and Motul 600 last year, and upgraded to SRF this year. SRF is more expensive, but also lasts longer than 600, so the prices are actually closer than just doing an ounce-to-ounce comparison. I have heard good things about Pagid RSL29s, which seem to be the new RS.

I have been starting out at 26 PSI with a hot temp of 34 PSI for PZeroes. I do not think they can handle a full 20-min session on a hot, hilly track. They completely fell off in the last three laps of the last two sessions at my last day at Palmer. They did not feel over inflated, just as though the tires were trying, and failing to grip. I will probably aim for 32 or 33PSI tomorrow, though it is a far less demanding track.

I just replaced my rears this week, and probably jumping to PS4S next year when all four corners are shot. Otherwise, I might just buy a dedicated set of 19"s wheels and track tires.

Edit to add: I am in a .1 C2S
The Fat Kid is offline  
Old 07-20-2018, 04:43 PM
  #40  
Jon D
Addict
Rennlist Member
 
Jon D's Avatar
 
Join Date: May 2016
Location: Smokies
Posts: 209
Default

Originally Posted by The Fat Kid View Post
The addiction is real...

I upgraded to Pagid RS29s and Motul 600 last year, and upgraded to SRF this year. SRF is more expensive, but also lasts longer than 600, so the prices are actually closer than just doing an ounce-to-ounce comparison. I have heard good things about Pagid RSL29s, which seem to be the new RS.

I have been starting out at 26 PSI with a hot temp of 34 PSI for PZeroes. I do not think they can handle a full 20-min session on a hot, hilly track. They completely fell off in the last three laps of the last two sessions at my last day at Palmer. They did not feel over inflated, just as though the tires were trying, and failing to grip. I will probably aim for 32 or 33PSI tomorrow, though it is a far less demanding track.

I just replaced my rears this week, and probably jumping to PS4S next year when all four corners are shot. Otherwise, I might just buy a dedicated set of 19"s wheels and track tires.

Edit to add: I am in a .1 C2S
FWIW I was running Pzeros slight higher pressure. 34/38 hot. Switched to 19” wheels and Sport Cups cause I got addicted. Also using SRF and Pagid 29s
Jon D is offline  
Old 07-20-2018, 11:52 PM
  #41  
PCA1983
Addict
Rennlist Member
 
PCA1983's Avatar
 
Join Date: Apr 2014
Location: Orlando (winter), Chicago (Summer)
Posts: 1,744
Default

Originally Posted by Jon D View Post
what kind of tires?
New OEM Pirellis...
PCA1983 is offline  
Old 07-21-2018, 09:34 AM
  #42  
The Fat Kid
User
 
The Fat Kid's Avatar
 
Join Date: Mar 2016
Location: New England
Posts: 512
Default

Originally Posted by Jon D View Post


FWIW I was running Pzeros slight higher pressure. 34/38 hot. Switched to 19ö wheels and Sport Cups cause I got addicted. Also using SRF and Pagid 29s
38 hot? Were the center treads wearing out prematurely? That is way too hot for tracks I have run in summer temps; my center treads were wearing a bit faster than the rest of the tire running 37 - 34 hot at the track, and 38 PSI on the street.

I agree with 19" wheels and Cup2s, or other track tires.

Originally Posted by 09RedGTS View Post
New OEM Pirellis...
I started at 25PSI cold and ran 32/33 hot yesterday and they felt pretty good, but Thompson is far less demanding than Palmer. They still fell off a bit toward the end of the third and fourth sessions, so they would have probably gotten killed at Palmer.

They are going to feel way too soft if you are used to running higher temps
The Fat Kid is offline  
Old 07-21-2018, 10:20 AM
  #43  
awrryan
Addict
Rennlist Member
 
awrryan's Avatar
 
Join Date: Jun 2010
Location: Boca Raton, FL
Posts: 1,489
Default

Originally Posted by 09RedGTS View Post
John Mclane: "Fluid fade -
If there is too much energy being transferred to the caliper and fluid, it can boil the fluid. These gas bubbles being compressible, the pedal travel increases and becomes "spongy" with poor modulation. (This is a gradual process with advanced warning). Solutions include: Changing brake fluid to one with a higher boiling point, using a different pad compound with better heat transfer properties, or improving the cooling to prevent the fluid from boiling."

One thing you forgot to mention that is sometimes a factor at track events. The pad is the only thermal insulation between the fluid and the red hot brake rotor. At 50% pad thickness, 50% of thermal insulation is worn away. So, running the pads down thin for economy is a no-no. Our Chicago Region recognizes that, and does not allow a car to run a track event with pads less than 50% of new pad thickness. A wise rule!
seems kind of wasteful no? I get the point, but have friends with decent hardware who can run their pads below half without fade. Part of that is know the car really well and being a good driver. They run consistent laps at Sebring within a second or two of each other.
awrryan is offline  
Old 07-21-2018, 12:17 PM
  #44  
Jon D
Addict
Rennlist Member
 
Jon D's Avatar
 
Join Date: May 2016
Location: Smokies
Posts: 209
Default

Originally Posted by The Fat Kid View Post


38 hot? Were the center treads wearing out prematurely? That is way too hot for tracks I have run in summer temps; my center treads were wearing a bit faster than the rest of the tire running 37 - 34 hot at the track, and 38 PSI on the street.

I agree with 19" wheels and Cup2s, or other track tires.



I started at 25PSI cold and ran 32/33 hot yesterday and they felt pretty good, but Thompson is far less demanding than Palmer. They still fell off a bit toward the end of the third and fourth sessions, so they would have probably gotten killed at Palmer.

They are going to feel way too soft if you are used to running higher temps
just looked back through my P Zero notes. They got a little slippery at 38 note was to drop rears to 36/7 but I upgraded wheels/tires after that session. I still was able to overheat them. Anything over 38 hot got very slippery quickly. Wear was even. That was at Homestead in Miami over the winter. March I think.
Jon D is offline  
Old 07-21-2018, 12:38 PM
  #45  
CarreraFahrer
User
 
CarreraFahrer's Avatar
 
Join Date: Dec 2017
Location: 90 Miles East of Sonoma Raceway
Posts: 319
Default

Originally Posted by stout View Post
Thanks for the writeupŚgreat to hear you had fun using your 991.2!

Another three-pedal devotee here, but PDK is very hard to beat on track. I never miss a clutch pedal on track, but I almost always miss it on the street.
I also prefer a PDK/DCT on track and a manual on the street. Unless I'm on the fwy I always use Sport or Sport Plus mode and Manual driving around town. Virtually every professional racing class has moved to paddle shifting cars as they are faster.

I'm also impressed with my Porsche C2S showroom stock on track. The suspension is surprisingly buttoned down and very predictable with the stock Pirelli's. Not sure how it will fare with stickies though.
CarreraFahrer is offline  

Thread Tools
Search this Thread
Quick Reply: 991.2 Carrera - Track Journal!


Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: