DIY 330mm to 350mm rotor upgrade install
12-23-2017, 12:12 AM
#16
Three Wheelin'
The 350 6-piston calipers have the exact same piston area as the 4 pots. As such, they both create identical torque when using same size rotors. Larger pads will not create greater leverage either as the amount of pressure created by the pistons pressing on the pads is the same. The larger pads will have the same amount of pressure acting on them as the smaller pads but that pressure is simply distributed over a larger area at a lower per square inch force. It’s plain and simple physics. The larger pads will however last longer and will absorb slightly more heat which will keep the pedal feeling better longer. Nothing more, nothing else. Providing cooling air to the rotors/calipers is paramount no matter what size brakes you have. People go way too Gaga over large calipers and rotors but unless you are tracking the car all you are doing is adding unsprung mass. Not trying to burst anyone’s bubble but the stock brakes are more than adequate for 99% of Street users. For track use, the upsizing is nice but if you are looking to improve brake feel a larger master cylinder and an engine driven vacuum pump and greater brake cooling will provide a much greater and noticeable benefit.. No, I did not stay at a Holiday Inn last night, but I have tried just about every conceivable permutation of brakes on these cars...
12-23-2017, 01:08 PM
#17
Yes the same piston area but displaced over a larger pad and rotors is a noticeable difference in braking forces. Gives a feel of leverage meaning for me less effort to brake and modulate. With oem 4 piston more than one occasion the “ice” syndrome for me had me look into the 6 piston upgrade. I originally posted about the ice pedal long before anyone else had mentioned the syndrome. Since the switch haven’t had any issues.
12-23-2017, 02:14 PM
#18
Three Wheelin'
The 350 6-piston calipers have the exact same piston area as the 4 pots. As such, they both create identical torque when using same size rotors. Larger pads will not create greater leverage either as the amount of pressure created by the pistons pressing on the pads is the same. The larger pads will have the same amount of pressure acting on them as the smaller pads but that pressure is simply distributed over a larger area at a lower per square inch force. It’s plain and simple physics. The larger pads will however last longer and will absorb slightly more heat which will keep the pedal feeling better longer. Nothing more, nothing else. Providing cooling air to the rotors/calipers is paramount no matter what size brakes you have. People go way too Gaga over large calipers and rotors but unless you are tracking the car all you are doing is adding unsprung mass. Not trying to burst anyone’s bubble but the stock brakes are more than adequate for 99% of Street users. For track use, the upsizing is nice but if you are looking to improve brake feel a larger master cylinder and an engine driven vacuum pump and greater brake cooling will provide a much greater and noticeable benefit.. No, I did not stay at a Holiday Inn last night, but I have tried just about every conceivable permutation of brakes on these cars...
Sorry to OP I just made a side comment didn’t mean to hi jack your post. Thanks for posting.
Last edited by Oak; 12-23-2017 at 03:16 PM.
12-23-2017, 06:05 PM
#19
RL Community Team
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Yes the same piston area but displaced over a larger pad and rotors is a noticeable difference in braking forces. Gives a feel of leverage meaning for me less effort to brake and modulate. With oem 4 piston more than one occasion the “ice” syndrome for me had me look into the 6 piston upgrade. I originally posted about the ice pedal long before anyone else had mentioned the syndrome. Since the switch haven’t had any issues.
12-23-2017, 07:01 PM
#20
Three Wheelin'
that’s a good question. I have not been on this board for many years due to back injuries and my turbo was on ice since til just recently. I have been inspired to get back in the saddle and back on track. I think back in 03-04 I posted about the ice issue and it was all crickets. Not til it seemed like second and third owners posted about the issue years later. since the upgrade not had any issues but I only had a few track days post upgrade. Funny how in every brake upgrade post there’s always someone that has to post all the physics ad nauseum.
12-23-2017, 08:44 PM
#21
RL Community Team
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that’s a good question. I have not been on this board for many years due to back injuries and my turbo was on ice since til just recently. I have been inspired to get back in the saddle and back on track. I think back in 03-04 I posted about the ice issue and it was all crickets. Not til it seemed like second and third owners posted about the issue years later. since the upgrade not had any issues but I only had a few track days post upgrade. Funny how in every brake upgrade post there’s always someone that has to post all the physics ad nauseum.
Your ice mode experience is interesting. Have you driven the same tracks and roads that ice mode used to kick in?
12-23-2017, 09:16 PM
#22
I understand the physics I am not making an argument or disagree with you, thank you for the lecture. if you reread my post I just mentioned about “feel” my braking issue was with “ice” pedal feel. A couple butt puckering incidents of a stiff pedal no sign of boiled fluid or overheated rotors with out any warning it feels like the rotors have turned to ice and all pedal leverage has gone, no initial immediate bite no ability to modulate pedal didn’t make any diff how hard you pressed. I posted about this early on years before anyone had mentioned the same exact symptoms. Not sure what caused this possibly high heat off gassing from pads.
Sorry to OP I just made a side comment didn’t mean to hi jack your post. Thanks for posting.
I was simply posting in response to your post #11 on page 1 where you state "If you think larger rotors feel like it increases more leverage try the larger 6 piston calipers with larger pads. wow." Here you are saying that the 6 piston calipers will give you more leverage above and beyond the 4 piston caliper of the same piston area when used on the same 350 rotors. Since you state that you clearly understand physics, you must realize that that your statement is patently false. Not a biggie but I just didn't want guys spending thousands of dollars on fancy 6 piston calipers only to be disappointed that they get no real benefit over the spaced out 4 pots on the street. Finally, I mention this because many people don't realize it, but the last thing you want with these cars is to increase the brake leverage on the front as they are already biased too far to the front. Increasing brake bias toward the rear as was done on the 997 platform provides a quantifiable benefit and car easily be achieved with a more aggressive rear pad. Obviously all stuff you know already but maybe good info for some guys new to this platform..
Last edited by powdrhound; 12-23-2017 at 09:31 PM.
12-23-2017, 09:22 PM
#23
Three Wheelin'
Yes I have with no issues since the upgrades. this is the first time that I’ve heard ABS is the culprit. I had a few great track and canyon sessions with early og 996tt, Gt2-3 owners. Hopefully I will be able to log more seat time.
12-23-2017, 09:38 PM
#24
Three Wheelin'
No worries Oak. I know ice mode and its strictly an abs issue but can be managed once you understand the issues that cause it. Glad you got it sorted.
I was simply posting in response to your post #11 on page 1 where you state "If you think larger rotors feel like it increases more leverage try the larger 6 piston calipers with larger pads. wow." Here you are saying that the 6 piston calipers will give you more leverage above and beyond the 4 piston caliper of the same piston area when used on the same 350 rotors. Since you state that you clearly understand physics, you must realize that that your statement is patently false. Not a biggie but I just didn't want guys spending thousands of dollars on fancy 6 piston calipers only to be disappointed that they get no real benefit over the spaced out 4 pots on the street. Finally, I mention this because many people don't realize it, but the last thing you want with these cars is to increase the brake leverage on the front as they are already biased too far to the front. Increasing brake bias toward the rear as was done on the 997 platform provides a quantifiable benefit and car easily be achieved with a more aggressive rear pad. Obviously all stuff you know already but maybe good info for some guys new to this platform..
I was simply posting in response to your post #11 on page 1 where you state "If you think larger rotors feel like it increases more leverage try the larger 6 piston calipers with larger pads. wow." Here you are saying that the 6 piston calipers will give you more leverage above and beyond the 4 piston caliper of the same piston area when used on the same 350 rotors. Since you state that you clearly understand physics, you must realize that that your statement is patently false. Not a biggie but I just didn't want guys spending thousands of dollars on fancy 6 piston calipers only to be disappointed that they get no real benefit over the spaced out 4 pots on the street. Finally, I mention this because many people don't realize it, but the last thing you want with these cars is to increase the brake leverage on the front as they are already biased too far to the front. Increasing brake bias toward the rear as was done on the 997 platform provides a quantifiable benefit and car easily be achieved with a more aggressive rear pad. Obviously all stuff you know already but maybe good info for some guys new to this platform..
12-23-2017, 09:56 PM
#25
RL Community Team
Rennlist Member
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Triggering it has something to do with getting on the brakes sharply combined with uneveness of the road surface. There was a small pot hole by a stop sign at the end of my street that triggered ice mode on all my cars everytime. And there is a corner at a track I drive regularly that triggers ice mode just as I am ending my trail braking into it. Triggering it tells me I have entered that corner at the maximum.