84 911 brake upgrade
#1
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Ok, please be patient with me. I am a newbie, have read alot of posts here and other places, and am feeling a bit overwhelmed........
I would like to upgrade the braking performance of my '84 911, while maintaining the 16" Fuchs wheels. I am looking for a bolt-on caliper or caliper/replacement rotor that will be popular enough to have performance pad choices. Hopefully without m/c replacement, with good availability and reasonably priced. I have read a wide spectrum of ways to go, 930's etc, but some seem dated, others like the 930 are based on parts that are too hard to find and be reasonably priced. I would like to have good balance under heavy application.
Thank you.
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Thank you.
#2
RL Technical Advisor
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Brake solution choices are based on two things:
1) Wheel diameters
2) How the car is used; street and/or track
With 16" wheels, the choices are more limited but the real question here is about what you use the car for. If you are strictly on the street, one can install good pads, good fluid and with the right choices, this makes a very nice improvement in pedal feel and grip. Light track use can be accomodated with the installation of a brake cooling kit. In some cases, a front caliper change is very effective for the street.
If you intend to do a lot of Driver Ed events, you may eventually require a brake upgrade commensurate with such activities and thats not inexpensive to do properly. The use of DOT-spec race tires require real brakes on the track and the only solution for heavy DE use are the 930 brakes which fit inside your existing wheels.
My best advice would be to sit down & evaluate how you will use the car and budget realistically.
1) Wheel diameters
2) How the car is used; street and/or track
With 16" wheels, the choices are more limited but the real question here is about what you use the car for. If you are strictly on the street, one can install good pads, good fluid and with the right choices, this makes a very nice improvement in pedal feel and grip. Light track use can be accomodated with the installation of a brake cooling kit. In some cases, a front caliper change is very effective for the street.
If you intend to do a lot of Driver Ed events, you may eventually require a brake upgrade commensurate with such activities and thats not inexpensive to do properly. The use of DOT-spec race tires require real brakes on the track and the only solution for heavy DE use are the 930 brakes which fit inside your existing wheels.
My best advice would be to sit down & evaluate how you will use the car and budget realistically.
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Thank you Steve. PFC pads, Blue fluid, Control arm mounted scoop with hose to center of disk are all in use, would like more stopping power from higher speeds at track events. Looking for a lighter caliper with more pad area, like many 4 pots offer. Any ideas on what would bolt up inside the 16" wheels?
Thanks!
Thanks!
#4
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The caliper and rotor must be matched. If you are exceeding the capability of the stock brake system, it's because it's getting overheated. A larger caliper with the same rotor will give you more pad area, clamping force and may provide better feel but that will only last until the rotors overheat, which with no increase in rotor size (the heat dissipator) will very likely be even sooner than when the car had a stone stock system.
I did a ton of research on this a couple of years ago. I considered going aftermarket but went with the 930 system for several reasons. Keeping the Fuchs was one but concern over the future availability of replacement parts helped me make my decision. One of the systems I was considering had become NLA while I stewed over my options, which made me wonder if I would have to buy another complete system in a few years if something failed on whatever flavor of the day I had chosen. I reasoned the 930 parts although expensive would be available for a long time to come.
About that master cylinder, if you are going to increase the volume/area of the pistons in the calipers, you must also match the master cylinder so it can move enough fluid for those larger capacity pistons. Truth is, even if you decide to live with the increased travel of the stock M/C (some do), odds are that you will wipe it out shortly due to moving the piston into a part of the bore that it has never been and likely full of gunk which will rapidly wear out the seal. Of course then you can install the bigger M/C since you'll be in there anyway.
Yes, I bought my 930 upgrade from Steve W
I did a ton of research on this a couple of years ago. I considered going aftermarket but went with the 930 system for several reasons. Keeping the Fuchs was one but concern over the future availability of replacement parts helped me make my decision. One of the systems I was considering had become NLA while I stewed over my options, which made me wonder if I would have to buy another complete system in a few years if something failed on whatever flavor of the day I had chosen. I reasoned the 930 parts although expensive would be available for a long time to come.
About that master cylinder, if you are going to increase the volume/area of the pistons in the calipers, you must also match the master cylinder so it can move enough fluid for those larger capacity pistons. Truth is, even if you decide to live with the increased travel of the stock M/C (some do), odds are that you will wipe it out shortly due to moving the piston into a part of the bore that it has never been and likely full of gunk which will rapidly wear out the seal. Of course then you can install the bigger M/C since you'll be in there anyway.
Yes, I bought my 930 upgrade from Steve W
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#5
RL Technical Advisor
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Thank you Steve. PFC pads, Blue fluid, Control arm mounted scoop with hose to center of disk are all in use, would like more stopping power from higher speeds at track events. Looking for a lighter caliper with more pad area, like many 4 pots offer. Any ideas on what would bolt up inside the 16" wheels?
Thanks!
Thanks!
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What you need is more thermal dissipation capacity and thats not possible unless the rotor size is increased. Naturally, that allows one to employ calipers with larger pads and more grip, but the key principle here is a larger "heat sink".
Simply installing larger calipers/pads on existing or similarly sized rotors accomplishes nothing at all and in fact, accelerates the demise of your braking capacity.
The biggest rotors and calipers that fit your wheels are the 930 brakes. Not cheap by any means, but truly bulletproof and effective. You get what you pay for,...
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#6
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and you can't just do one end w/ good results'
The 930 brakes that Steve mentions are a very good choice. An interesting alternative is GTP-L brakes and recently introduced 917 brakes
The 930 brakes that Steve mentions are a very good choice. An interesting alternative is GTP-L brakes and recently introduced 917 brakes
#7
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There is a thread on Pelican - http://forums.pelicanparts.com/showt...=930%2A+brakes - about new 917/930 brake set replicas from Zuffenhaus (very respected resto/mod folk).
These are bolt-on for your car and about $4,000.00 including rotors. Not cheap, but when you price locating, buying and refrubishing 930 brakes, together with adapting them, it seems pretty reasonable. Oh, and they clear 15" wheels.
As far as the effectiveness of 930 brakes - I took my car to Streets of Willow for the first time a couple of months ago. The 930 brakes on my car took it from 100+mph to maybe 40 twice a lap (CCW) for 8-10 laps at a time with no sign of fade or heating issues and no drama. I have OEM pads, stainless lines and 993 air deflectors. I think it will be a long time before I worry about bigger brakes than these.
These are bolt-on for your car and about $4,000.00 including rotors. Not cheap, but when you price locating, buying and refrubishing 930 brakes, together with adapting them, it seems pretty reasonable. Oh, and they clear 15" wheels.
As far as the effectiveness of 930 brakes - I took my car to Streets of Willow for the first time a couple of months ago. The 930 brakes on my car took it from 100+mph to maybe 40 twice a lap (CCW) for 8-10 laps at a time with no sign of fade or heating issues and no drama. I have OEM pads, stainless lines and 993 air deflectors. I think it will be a long time before I worry about bigger brakes than these.