964 Break Upgrade
11-05-2017, 10:24 AM
#32
Instructor
I have a full big black setup with OEM RS uprights sitting in my basement.
Nonetheless I will keep them for a later upgrade.
So here is my question:
Does Bill refer to 993C2 or C4 rear calipers?
11-05-2017, 04:24 PM
#33
I have a full big black setup with OEM RS uprights sitting in my basement.
964 RS?
964t ?
other?
Assuming you have just the front 964RS or 964 3.3t setup and are going to keep the stock rear rotors on a 964 C2 or 4 then either 993 2 or 4 rear calipers may be used for good bias. These are essentially the same as 964 RS rear calipers except for cosmetics. The difference between 993 2 & 4 is just color. Not to be confused w/ 993 RS or 993tt or 9934S rears which are much different.
11-05-2017, 05:55 PM
#34
Three Wheelin'
Maybe it's already been stated in this thread, but unless you do "track days", there is no reason to upgrade the stock 964 brakes and stock pads; of course high quality brake fluid and a flush every two years is a must.
11-06-2017, 01:56 PM
#35
Race Car
I’m in agreement with the last statement - for street there is no need to upgrade-
That said- initial bite is better with big brakes and adjusting to more rear bias makes a big difference. For a stock setup, removing the proportioning valve gives better rear brake bias, which is a big difference. The bigger brakes with better initial bite feel better, but in terms of stopping distance and performance, it’s negligible....
Big brakes look significantly better - if you have the wheel size to fit them.
As far as real track benefit- heat dispersion for long track sessions is way better...but when is that necessary when the car isn’t being raced? So in real terms...performance money is better spent elsewhere, initially, but the details cosmetically and the feeling of having them is priceless...enjoy the hunt...
With mine, I went with 89 front and rear c4 oem. Raised letter. Repaint and rebuilt. I’m not tracking the car, and I use d90 with snows sometimes in the winter. So I wouldn’t be able to use those if I had a big brake kit. I think the standard 993 c2 front and rear fit under the d90...but haven’t verified that yet, and with those, performance increase is very minimal, though the caliper size is a little bigger. Pad size and piston size is not like in the proper big red or big black brakes...heat dispersion is slightly better, but with standard 993 c2 upgrade, it can really only be seen as a cosmetic change for street use, since the performance and feel under normal driving will be largely identical to stock 964 c4.
That said- initial bite is better with big brakes and adjusting to more rear bias makes a big difference. For a stock setup, removing the proportioning valve gives better rear brake bias, which is a big difference. The bigger brakes with better initial bite feel better, but in terms of stopping distance and performance, it’s negligible....
Big brakes look significantly better - if you have the wheel size to fit them.
As far as real track benefit- heat dispersion for long track sessions is way better...but when is that necessary when the car isn’t being raced? So in real terms...performance money is better spent elsewhere, initially, but the details cosmetically and the feeling of having them is priceless...enjoy the hunt...
With mine, I went with 89 front and rear c4 oem. Raised letter. Repaint and rebuilt. I’m not tracking the car, and I use d90 with snows sometimes in the winter. So I wouldn’t be able to use those if I had a big brake kit. I think the standard 993 c2 front and rear fit under the d90...but haven’t verified that yet, and with those, performance increase is very minimal, though the caliper size is a little bigger. Pad size and piston size is not like in the proper big red or big black brakes...heat dispersion is slightly better, but with standard 993 c2 upgrade, it can really only be seen as a cosmetic change for street use, since the performance and feel under normal driving will be largely identical to stock 964 c4.
11-07-2017, 02:34 PM
#36
....
That said- initial bite is better with big brakes and adjusting to more rear bias makes a big difference. For a stock setup, removing the proportioning valve gives better rear brake bias, which is a big difference. The bigger brakes with better initial bite feel better, but in terms of stopping distance and performance, it’s negligible....
Big brakes look significantly better - if you have the wheel size to fit them.
As far as real track benefit- heat dispersion for long track sessions is way better...but when is that necessary when the car isn’t being raced? So in real terms...performance money is better spent elsewhere, initially, but the details cosmetically and the feeling of having them is priceless...enjoy the hunt...
With mine, I went with 89 front and rear c4 oem. Raised letter. Repaint and rebuilt. I’m not tracking the car, and I use d90 with snows sometimes in the winter. So I wouldn’t be able to use those if I had a big brake kit. I think the standard 993 c2 front and rear fit under the d90...but haven’t verified that yet, and with those, performance increase is very minimal, though the caliper size is a little bigger. Pad size and piston size is not like in the proper big red or big black brakes...heat dispersion is slightly better, but with standard 993 c2 upgrade, it can really only be seen as a cosmetic change for street use, since the performance and feel under normal driving will be largely identical to stock 964 c4.
That said- initial bite is better with big brakes and adjusting to more rear bias makes a big difference. For a stock setup, removing the proportioning valve gives better rear brake bias, which is a big difference. The bigger brakes with better initial bite feel better, but in terms of stopping distance and performance, it’s negligible....
Big brakes look significantly better - if you have the wheel size to fit them.
As far as real track benefit- heat dispersion for long track sessions is way better...but when is that necessary when the car isn’t being raced? So in real terms...performance money is better spent elsewhere, initially, but the details cosmetically and the feeling of having them is priceless...enjoy the hunt...
With mine, I went with 89 front and rear c4 oem. Raised letter. Repaint and rebuilt. I’m not tracking the car, and I use d90 with snows sometimes in the winter. So I wouldn’t be able to use those if I had a big brake kit. I think the standard 993 c2 front and rear fit under the d90...but haven’t verified that yet, and with those, performance increase is very minimal, though the caliper size is a little bigger. Pad size and piston size is not like in the proper big red or big black brakes...heat dispersion is slightly better, but with standard 993 c2 upgrade, it can really only be seen as a cosmetic change for street use, since the performance and feel under normal driving will be largely identical to stock 964 c4.
the 993 basic brake setup is a significant step up from 964 in terms of both torque and thermal capacity. pistons size in front is the same thought the 993 caliper is much bigger rear pistons on the 993 are bigger moving bias to the back relieving the thermal load in front which is where most of the issues arise. 964 4/2 is actually a better setup than 964 4/4 but the 993 4/4 is much better. A nice upgrade to any 964 is to put 993 calipers in back. The 993 front rotors are larger than 964 and have better internal architecture both vastly improve thermal performance.
11-07-2017, 06:21 PM
#37
Intermediate
Join Date: Nov 2016
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Bill, reading this last post of yours, can I conclude that just transferring the entire 993 setup (both calipers and rotors) to the 964 is advisable? Your last sentence mentions 993 caliper on the back, and then 993 rotor on the front (which I presume means I need the 993 caliper on the front as well?). The only thing then not mentioned is a a 993 rotor on the back also. Sorry for the question, just trying to interpret your comments. Rgds, Andrew
11-07-2017, 08:53 PM
#38
Bill, reading this last post of yours, can I conclude that just transferring the entire 993 setup (both calipers and rotors) to the 964 is advisable? Your last sentence mentions 993 caliper on the back, and then 993 rotor on the front (which I presume means I need the 993 caliper on the front as well?). The only thing then not mentioned is a a 993 rotor on the back also. Sorry for the question, just trying to interpret your comments. Rgds, Andrew
The issue is you will need to use 993 wheel carriers and also 993 power brake booster & mount. Of course most any bbk upgrade will require the latter and the 993 wheel carriers do have much to recommend them.
