Orthojoe's track build journal
05-11-2015, 10:55 PM
#931
Intermediate
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Alignment is not something you want to DIY unless you you have a laser alignment rack readily available that you know how to use.
You want more negative camber to account for increased wear on the outer edge of the tire from hard cornering. Increased camber should actually IMPROVE tire wear and life, not decrease it. If you're outer edges are wearing, in general you want more negative camber.
There is no set rule on what camber works for everyone. It is different for everyone based on track, skill level, driving style, and type of tire. In the past, most setups like less negative camber in the rear, not more. I'm setting the car up with -2.9 on all 4 corners running trofeo R next.
You want more negative camber to account for increased wear on the outer edge of the tire from hard cornering. Increased camber should actually IMPROVE tire wear and life, not decrease it. If you're outer edges are wearing, in general you want more negative camber.
There is no set rule on what camber works for everyone. It is different for everyone based on track, skill level, driving style, and type of tire. In the past, most setups like less negative camber in the rear, not more. I'm setting the car up with -2.9 on all 4 corners running trofeo R next.
05-11-2015, 11:07 PM
#932
Burning Brakes
Guys-
I'm new to all of this, but i have a 991 GT3 that i,ve tracked 2400 miles out of 3,000 on car and an RS SEPT build. I have learned a LOT by reading this particular forum by OrthoJoe - thanks and great job. I think i'd like to go more negative on the camber b/c from what i read and from what y'all are telling me - it can improve handling and traction but at the cost of faster tire wear (which i can live with). That said, i am a finance guy and know very little about mechanical engineering - except i like DIY stuff (satisfying). I didn't think the CL wheel change was a problem - and thats the extent of my 'experience' (lol). That said, can someone explain to me how exactly to change it (without shims) and just as importantly WHY it helps - meaning what is the engineering behind the degrees/angle - what's it adjusting on the car? and therefore why do you guys have more negative on front versus back? I've read that stock is -1.4 to -1.5 all four corners...and i was thinking of starting slowly (changing to -2.0 on all 4) to see if i can actually feel a difference on track. I know this is a basic question, but figured that was one of the reasons behind the forum and no doubt you guys know more than me! Don't know if it matters, but my home track is HEAVY right turns (Road ATL). My knowledge base on Toe and Caster is ZERO too, but i'll tackle that later....what i do know is that i like to go fast. Thx in advance, Richard
I'm new to all of this, but i have a 991 GT3 that i,ve tracked 2400 miles out of 3,000 on car and an RS SEPT build. I have learned a LOT by reading this particular forum by OrthoJoe - thanks and great job. I think i'd like to go more negative on the camber b/c from what i read and from what y'all are telling me - it can improve handling and traction but at the cost of faster tire wear (which i can live with). That said, i am a finance guy and know very little about mechanical engineering - except i like DIY stuff (satisfying). I didn't think the CL wheel change was a problem - and thats the extent of my 'experience' (lol). That said, can someone explain to me how exactly to change it (without shims) and just as importantly WHY it helps - meaning what is the engineering behind the degrees/angle - what's it adjusting on the car? and therefore why do you guys have more negative on front versus back? I've read that stock is -1.4 to -1.5 all four corners...and i was thinking of starting slowly (changing to -2.0 on all 4) to see if i can actually feel a difference on track. I know this is a basic question, but figured that was one of the reasons behind the forum and no doubt you guys know more than me! Don't know if it matters, but my home track is HEAVY right turns (Road ATL). My knowledge base on Toe and Caster is ZERO too, but i'll tackle that later....what i do know is that i like to go fast. Thx in advance, Richard
Just to clarify one point in case it wasn't clear: increasing negative camber will generally increase grip and promote even wear when driving on track, but will result in accelerated wear when driving on the street. On the street, lots of negative camber will wear the inside edges of the tires. -3 degrees is a lot of camber for a car that gets any significant street driving, but it doesn't sound as if that's the case for your car.
05-11-2015, 11:10 PM
#933
Nordschleife Master
First - congrats to you for enjoying your car to the fullest and using it in its natural habitat - the track.
Just to clarify one point in case it wasn't clear: increasing negative camber will generally increase grip and promote even wear when driving on track, but will result in accelerated wear when driving on the street. On the street, lots of negative camber will wear the inside edges of the tires. -3 degrees is a lot of camber for a car that gets any significant street driving, but it doesn't sound as if that's the case for your car.
Just to clarify one point in case it wasn't clear: increasing negative camber will generally increase grip and promote even wear when driving on track, but will result in accelerated wear when driving on the street. On the street, lots of negative camber will wear the inside edges of the tires. -3 degrees is a lot of camber for a car that gets any significant street driving, but it doesn't sound as if that's the case for your car.
05-11-2015, 11:27 PM
#934
Burning Brakes
05-11-2015, 11:41 PM
#935
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^ Also keep in mind that substantial negative camber will also mean less braking capability due to less contact patch.
05-12-2015, 12:33 AM
#936
Instructor
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Maybe I should be asking this question over on one of the Performance & Competition threads, but I like this thread, so I'll give it a go here.
Most of us here agree that the R-Compound Cup2's heat cycle out before the tread wears out. Question is, what constitutes a heat cycle? I get the concept of the tires heating up and cooling down. But if you have two drivers with back to back runs at a DE event, I assume that would be one heat cycle because the tires wouldn't have time to cool down.
But how much or how long does it take for a cool down to constitute a heat cycle? 10 minutes, 20 minutes, or one hour, etc.? Or what temperature drop? I have a tire pyrometer to measure temperature if someone can tell me what constitutes a cool down.
Most of us here agree that the R-Compound Cup2's heat cycle out before the tread wears out. Question is, what constitutes a heat cycle? I get the concept of the tires heating up and cooling down. But if you have two drivers with back to back runs at a DE event, I assume that would be one heat cycle because the tires wouldn't have time to cool down.
But how much or how long does it take for a cool down to constitute a heat cycle? 10 minutes, 20 minutes, or one hour, etc.? Or what temperature drop? I have a tire pyrometer to measure temperature if someone can tell me what constitutes a cool down.
05-12-2015, 12:51 AM
#937
Nordschleife Master
Thread Starter
Maybe I should be asking this question over on one of the Performance & Competition threads, but I like this thread, so I'll give it a go here.
Most of us here agree that the R-Compound Cup2's heat cycle out before the tread wears out. Question is, what constitutes a heat cycle? I get the concept of the tires heating up and cooling down. But if you have two drivers with back to back runs at a DE event, I assume that would be one heat cycle because the tires wouldn't have time to cool down.
But how much or how long does it take for a cool down to constitute a heat cycle? 10 minutes, 20 minutes, or one hour, etc.? Or what temperature drop? I have a tire pyrometer to measure temperature if someone can tell me what constitutes a cool down.
Most of us here agree that the R-Compound Cup2's heat cycle out before the tread wears out. Question is, what constitutes a heat cycle? I get the concept of the tires heating up and cooling down. But if you have two drivers with back to back runs at a DE event, I assume that would be one heat cycle because the tires wouldn't have time to cool down.
But how much or how long does it take for a cool down to constitute a heat cycle? 10 minutes, 20 minutes, or one hour, etc.? Or what temperature drop? I have a tire pyrometer to measure temperature if someone can tell me what constitutes a cool down.
When my buddy and I were running back to back sessions, we found that the tires needed 1/2 hour of rest before full grip would return. Based on that, I think 1/2 hour of rest would equal one heat cycle.
05-12-2015, 01:39 AM
#938
Dear Joe and the rest of the Wise TrackMasters,
I've noted that after several hot lapping sessions I get some leakage of brake fluid from the bleeder nipples. I had the same problem on my 997.2 despite checking bleeder nipple torque and having had the dealer replace all four.
Is this a common issue related to heating and expansion of the calipers relative to the bleeder nipple? Anything to worry about besides rinsing off the brake fluid from the calipers to keep them purdy, then checking the brake fluid reservoir for level?
I've noted that after several hot lapping sessions I get some leakage of brake fluid from the bleeder nipples. I had the same problem on my 997.2 despite checking bleeder nipple torque and having had the dealer replace all four.
Is this a common issue related to heating and expansion of the calipers relative to the bleeder nipple? Anything to worry about besides rinsing off the brake fluid from the calipers to keep them purdy, then checking the brake fluid reservoir for level?
05-12-2015, 02:14 AM
#939
Nordschleife Master
Thread Starter
Dear Joe and the rest of the Wise TrackMasters,
I've noted that after several hot lapping sessions I get some leakage of brake fluid from the bleeder nipples. I had the same problem on my 997.2 despite checking bleeder nipple torque and having had the dealer replace all four.
Is this a common issue related to heating and expansion of the calipers relative to the bleeder nipple? Anything to worry about besides rinsing off the brake fluid from the calipers to keep them purdy, then checking the brake fluid reservoir for level?
I've noted that after several hot lapping sessions I get some leakage of brake fluid from the bleeder nipples. I had the same problem on my 997.2 despite checking bleeder nipple torque and having had the dealer replace all four.
Is this a common issue related to heating and expansion of the calipers relative to the bleeder nipple? Anything to worry about besides rinsing off the brake fluid from the calipers to keep them purdy, then checking the brake fluid reservoir for level?
3 things to consider:
1) are you cooling down your brakes last lap?
2) are you using aftermarket fluid with a higher boiling point?
3) is your track brutal on brakes?
05-12-2015, 02:20 AM
#940
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Join Date: Jan 2013
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Dear Joe and the rest of the Wise TrackMasters,
I've noted that after several hot lapping sessions I get some leakage of brake fluid from the bleeder nipples. I had the same problem on my 997.2 despite checking bleeder nipple torque and having had the dealer replace all four.
Is this a common issue related to heating and expansion of the calipers relative to the bleeder nipple? Anything to worry about besides rinsing off the brake fluid from the calipers to keep them purdy, then checking the brake fluid reservoir for level?
I've noted that after several hot lapping sessions I get some leakage of brake fluid from the bleeder nipples. I had the same problem on my 997.2 despite checking bleeder nipple torque and having had the dealer replace all four.
Is this a common issue related to heating and expansion of the calipers relative to the bleeder nipple? Anything to worry about besides rinsing off the brake fluid from the calipers to keep them purdy, then checking the brake fluid reservoir for level?
05-12-2015, 02:23 AM
#941
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It's usually a sign of fluid boiling over from excess heat. I've seen it in brake systems that aren't robust enough for the application. I haven't seen any yet in the GT3, but I'm taking it to Laguna next week, which is much harder on brakes.
3 things to consider:
1) are you cooling down your brakes last lap?
2) are you using aftermarket fluid with a higher boiling point?
3) is your track brutal on brakes?
3 things to consider:
1) are you cooling down your brakes last lap?
2) are you using aftermarket fluid with a higher boiling point?
3) is your track brutal on brakes?
Joe, what are you doing for sound at Laguna?
05-12-2015, 02:26 AM
#942
Nordschleife Master
Thread Starter
It involves a very special switch just for turn 5 combined with a simple turn away pipe. Let's hope it's enough!
05-12-2015, 03:46 AM
#943
GT3 player par excellence
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^ dude trust me. after 5 laps you will forget if the switch is on or off.
i can't remmber when i had the switch for 7.2RS.
i can't remmber when i had the switch for 7.2RS.
05-12-2015, 09:17 AM
#944
Special indeed! GPS-based direct exhaust valve control that forces valves shut just near turn 5 sound booth, then open again for the rest of the track. Testing it at Laguna on Friday... Will create a thread on it shortly so folks can duplicate if they want.
05-12-2015, 09:54 AM
#945
Nordschleife Master
Thread Starter