Random Technical Info BS Thread
Drifting
Joined: Dec 2015
Posts: 2,201
Likes: 516
From: Bellevue, WA
I know upgrading to the 997 GT3 brake master is a popular mod for people with the 6-pot front calipers. I still have the factory 4-piston calipers on my car and I intend to keep them, but I'd like to upgrade to the 997 GT3 master simply for better brake feel. I know some people with the 6-piston fronts need a brake proportioning valve to keep the ABS from freaking out with that master, but is it needed if you are keeping the standard calipers all around?
Drifting
Joined: Dec 2015
Posts: 2,201
Likes: 516
From: Bellevue, WA
If we were to move the MAP sensor to get readings post-throttle body could we theoretically get better tunability, or was the ECU designed assuming the MAP would never see a vacuum reading anyway so it would do nothing? I'm guessing the latter since if it were useful more people would have relocated MAP sensors...
Rennlist Member
Joined: Dec 2011
Posts: 4,416
Likes: 1,804
From: Gig Harbor, WA
The need for the proportioning valve seems to be hit or miss. Some people need it, some people don't. It's easy enough to add after the fact so I think I'll do just the master cylinder for now and see if I need the extra parts.
Thread Starter
Drifting
Joined: Jul 2021
Posts: 2,986
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From: New Jersey
Is this the GT3 master cylinder part #?
997-355-910-30
I don't like the spongey feeling in my brakes either. I hate comparing this cars braking to my DC2 because the car is so much lighter on its feet lol
997-355-910-30
I don't like the spongey feeling in my brakes either. I hate comparing this cars braking to my DC2 because the car is so much lighter on its feet lol
Race Car
Joined: Aug 2017
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From: Central MA
I am making a wild assumption that the 996 Cup ABS won't care about the master cylinder so I can get rid of the proprtioning valve.
Just a little note, the stock 996TT ABS with the 997TT master cylinder - even with the psm pump unplugged - is very susceptible to "ice mode" on track. I never ran into ice mode with the 996TT master cylinder, now it happens with alarming regularity. It's so bad I have been unplugging the ABS the last few track days.
Just a little note, the stock 996TT ABS with the 997TT master cylinder - even with the psm pump unplugged - is very susceptible to "ice mode" on track. I never ran into ice mode with the 996TT master cylinder, now it happens with alarming regularity. It's so bad I have been unplugging the ABS the last few track days.
Last edited by theprf; May 24, 2024 at 10:25 AM. Reason: Clarify
Drifting
Joined: Dec 2015
Posts: 2,201
Likes: 516
From: Bellevue, WA
I am making a wild assumption that the 996 Cup ABS won't care about the master cylinder so I can get rid of the proprtioning valve.
Just a little note, the stock 996TT ABS with the 996TT master cylinder - even with the psm pump unplugged - is very susceptible to "ice mode" on track. I never ran into ice mode with the 996TT master cylinder, now it happens with alarming regularity. It's so bad I have been unplugging the ABS the last few track days.
Just a little note, the stock 996TT ABS with the 996TT master cylinder - even with the psm pump unplugged - is very susceptible to "ice mode" on track. I never ran into ice mode with the 996TT master cylinder, now it happens with alarming regularity. It's so bad I have been unplugging the ABS the last few track days.
Rennlist Member
Joined: Dec 2011
Posts: 4,416
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From: Gig Harbor, WA
Drifting
Joined: Dec 2015
Posts: 2,201
Likes: 516
From: Bellevue, WA
Correct. Ice mode is inherent to the road car ABS unit. My PSM pump has taken up residence in a garbage dump somewhere for at least 7-8 years now but ice mode was an issue until the stock ABS unit came out.
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