'78 with S4 brakes
08-07-2016, 08:50 PM
#1
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'78 with S4 brakes
Extensive search has allowed me to get the caliper bolt adapters and S4 rotors (front and rear) for my installed onto my '78 5-spd. I also read in an opinion that I would need 993TT rotors instead to clear the lower ball joints.
A couple of quick questions before my install:
1. Can I use S4 rotors with my '78? -->answered, thank you. 993 rotors are ordered
2. Would 993TT rotors (same as GTS brake brakes, right?) be too big? -->answered, thank you
3. Can I use the stainless brake lines that I purchased for my OB brakes? (same thread sizes and diameter) -->answered, new stainless brake lines are being ordered
4. Do I need new brake dust shields or can I reuse the old ones (probably too small) or just leave them off? -->they will be left off
New questions:
-5 mm spacers for rear S4 calipers sounds about right?
-can I use these S4 front calipers with 16" phone dials?
Thanks for any and all advice,
Hoi
A couple of quick questions before my install:
1. Can I use S4 rotors with my '78? -->answered, thank you. 993 rotors are ordered
2. Would 993TT rotors (same as GTS brake brakes, right?) be too big? -->answered, thank you
3. Can I use the stainless brake lines that I purchased for my OB brakes? (same thread sizes and diameter) -->answered, new stainless brake lines are being ordered
4. Do I need new brake dust shields or can I reuse the old ones (probably too small) or just leave them off? -->they will be left off
New questions:
-5 mm spacers for rear S4 calipers sounds about right?
-can I use these S4 front calipers with 16" phone dials?
Thanks for any and all advice,
Hoi
Last edited by hlee96; 08-09-2016 at 11:19 AM.
08-08-2016, 12:22 AM
#2
Rennlist Member
Alright, to answer your questions:
S4 rotors have the wrong offset for the OB hubs and wont fit.
The rotors you need are normal 993 rotors. Not the larger turbo ones unless you have big black/reds.
Get a set of new brake lines for an S4. OB lines are different.
The dust shields wont fit around the rotors so you can just leave them off.
I did all of this last year and it has been a great upgrade for daily driving. I no longer need to stand on the brake pedal to get the car to stop which has made the car safer and easier to DD.
S4 rotors have the wrong offset for the OB hubs and wont fit.
The rotors you need are normal 993 rotors. Not the larger turbo ones unless you have big black/reds.
Get a set of new brake lines for an S4. OB lines are different.
The dust shields wont fit around the rotors so you can just leave them off.
I did all of this last year and it has been a great upgrade for daily driving. I no longer need to stand on the brake pedal to get the car to stop which has made the car safer and easier to DD.
08-08-2016, 01:58 PM
#4
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08-08-2016, 03:51 PM
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08-08-2016, 05:45 PM
#7
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if you have the proper adapters that allow for the 993 rotors, then you can 993TT rotors and use a .3" washer to space out the calipers to fit the rotor. however, you need grind the s4 caliper to have the radius to accomodate the larger rotor. I have an entire thread on the mod. OR, if you find a 964T caliper, its just like a S4, but has the radius built in for the GTS or 993 diameter. (no washers are needed with that caliper)
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08-08-2016, 10:04 PM
#8
Rennlist Member
You can use 993 calipers, they are even better than S4 (pistons are about 20% bigger) You just need to use S4/GTS rear rotors with some washers like Mark said regardless if they are S4 or 993 rear calipers.
I use 993 calipers front and rear because I could get them cheaper than S4 calipers at the time.
They also have the later style pistons, dust boots, and scrapers that are easier to get ahold of if you need to ever rebuild them.
I use 993 calipers front and rear because I could get them cheaper than S4 calipers at the time.
They also have the later style pistons, dust boots, and scrapers that are easier to get ahold of if you need to ever rebuild them.
08-09-2016, 03:50 PM
#10
Drifting
What diameter is the rotor? 330mm will barely clear a few 16" wheels. Generally 323 is safe with a 16". 345mm barely fits under 17" wheels.
I'd guess you need 17" wheels.
I'd guess you need 17" wheels.
08-09-2016, 04:01 PM
#11
Rennlist Member
You can use 993 calipers, they are even better than S4 (pistons are about 20% bigger) You just need to use S4/GTS rear rotors with some washers like Mark said regardless if they are S4 or 993 rear calipers.
I use 993 calipers front and rear because I could get them cheaper than S4 calipers at the time.
They also have the later style pistons, dust boots, and scrapers that are easier to get ahold of if you need to ever rebuild them.
I use 993 calipers front and rear because I could get them cheaper than S4 calipers at the time.
They also have the later style pistons, dust boots, and scrapers that are easier to get ahold of if you need to ever rebuild them.
08-09-2016, 09:14 PM
#12
Rennlist Member
The front pistons are the same as a 928 but the rear pistons are a lot larger (~20%) due to the 911's weight distribution.
They bolt right on no problem, you might have even noticed them at Sharks in the Park on my beat up 81.
08-09-2016, 10:23 PM
#13
Rennlist Member
The only difference is the internal caliper size along with having a smooth face needing a sticker instead of the cast PORSCHE logo.
The front pistons are the same as a 928 but the rear pistons are a lot larger (~20%) due to the 911's weight distribution.
They bolt right on no problem, you might have even noticed them at Sharks in the Park on my beat up 81.
The front pistons are the same as a 928 but the rear pistons are a lot larger (~20%) due to the 911's weight distribution.
They bolt right on no problem, you might have even noticed them at Sharks in the Park on my beat up 81.
wow, i never knew this... so , same pads and calipers. not like a C2turbo caliper which uses the GTS rotor, but the S4 pads and "similar" caliper, right?
point is, i wonder if the calipers on the 993 is identical to S4 or is more radiused . sounds like it is the same, but newer!
08-10-2016, 02:12 AM
#14
Rennlist Member
I'm not sure if the pads are the same. I just use 993 pads instead so I know they fit. It wouldn't hurt to cross reference them though.
I usually find them to be cheaper with a larger variety than 928 pads only because they are marketed for a 911.
Albeit the Ferodo DS2500 pads I have on front and rear aren't exactly cheap or easy to find here in the states.
I usually find them to be cheaper with a larger variety than 928 pads only because they are marketed for a 911.
Albeit the Ferodo DS2500 pads I have on front and rear aren't exactly cheap or easy to find here in the states.