 Brakes, Stopping with M, A, or S |
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| johnmhudson111 |
 Jul 28 2005, 08:11 AM
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#1
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Member  Group: Members Posts: 491 Joined: 29-November 04 From: Nesbit, MS Member No.: 3,191  |
Coupe of questions about brakes. First of all what is the difference between "M", "A", and "S" capliers? Is it the mounting bolt distance? Early vs.Late? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)
Did the 914/6 come with "M" capliers? If not what did they come with? Can these brakes be upgraded to something like the "big reds? |
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Replies(1 - 19)
| ClayPerrine |
Jul 28 2005, 08:27 AM
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#2
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Life's been good to me so far..... Group: Admin Posts: 15,512 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille 
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M caliper. Cast iron 2 piston caliper. Uses 3" bolt spacing. Used on 73 and older 911, 914 and 914/6. Used with a spacer for the vented rotors. Same piston bore, pad size, and bolt pattern as the 914/6 rear caliper.
S Caliper. Aluminum 2 piston caliper. Uses 3.5" bolt spacing. Used on 74 and later 911 S and all 911s with sportomatic. Bigger pads than the M caliper. Had problems with corrosion in the piston bores. Rebuilt ones use a stainless steel sleeve to alleviate this. A Caliper. Same as the S caliper, but made from cast iron. Bigger pad sizes than the M caliper. As for upgrading to "Big Reds", you would have to put 74 and later 911 struts on the front to get the correct bolt spacing to fit the caliper, and you have to have 17" wheels for caliper clearance. My suggestion.. Boxster (Not Boxster S) Monoblocks. There are bolt on adapters for them, and you can fit them under 16" wheels. But you still have to have the 74 and later 911 struts with the 3.5" bolt spacing. My question to you.. how much brake do you REALLY need? Can you lock the wheels up now? Do you plan on running on a track where you would heat the brakes up enough to warrant the big increase in unsprung weight? |
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| johnmhudson111 |
Jul 28 2005, 08:47 AM
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#3
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Member Group: Members Posts: 491 Joined: 29-November 04 From: Nesbit, MS Member No.: 3,191 |
I plan on taking the car to DEs and to AutoX but no club racing. The reason I was asking about the difference in the capliers and the related struts was to get insure that I didn't buy a set of struts that locked me into having to no options. It looks like I need to stick with 74 or later strut. Thanks! |
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| ClayPerrine |
Jul 28 2005, 09:03 AM
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#4
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Life's been good to me so far..... Group: Admin Posts: 15,512 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille
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Just make sure you don't get stuck with a set of Hydro-Pneumatic struts.. They were a POS right out of the factory....
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| johnmhudson111 |
Jul 28 2005, 09:05 AM
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#5
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Member Group: Members Posts: 491 Joined: 29-November 04 From: Nesbit, MS Member No.: 3,191 |
How can you tell them from regular struts? |
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| ClayPerrine |
Jul 28 2005, 09:33 AM
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#6
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Life's been good to me so far..... Group: Admin Posts: 15,512 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille
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The hydro-pneumatic struts were quite a bit bigger in diameter, and look completely different from the standard 911 strut.
Simple, If it doesn't look like a 914 strut with different bolt spacing, don't buy it. |
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| johnmhudson111 |
Jul 28 2005, 09:43 AM
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#7
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Member Group: Members Posts: 491 Joined: 29-November 04 From: Nesbit, MS Member No.: 3,191 |
I have been looking at a couple of different listings on evil-bey one for a set off a 77 911. I would think they would be a good starting point. If I can get them. |
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| Oled |
Jul 28 2005, 10:34 AM
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#8
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Newbie Group: Members Posts: 44 Joined: 5-February 03 From: San Antonio, TX Member No.: 247 |
I have Boxster calipers on the front of my 914 on '89 carerra struts. Widened 914/6 calipers on the rear and ventilated discs all around. I can lock up the front wheels to easily, even on the strack with new race tires on the car. On the street it would be dangerous for a different driver who would expect normal brake response. i am thinking about taking off the Boxster caliper and putting A's on the car. Several years ago I found a great deal on Ebay for these new in the box calipers and since my car has not run for a year and a half now, they are hardly used.
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| johnmhudson111 |
Jul 28 2005, 12:20 PM
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#9
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Member Group: Members Posts: 491 Joined: 29-November 04 From: Nesbit, MS Member No.: 3,191 |
Looks like I am going to be getting the struts from that 77 911. It has the "A" capliers, want to trade? (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif) |
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| Eric_Shea |
Jul 28 2005, 08:40 PM
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#10
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PMB Performance Group: Admin Posts: 19,278 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains  |
Ahhhhhhhhhhhh Hello, Clay...
S-Calipers arrived a tad before 74 Uncle Clay (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) There's no such thing as a stainless sleeve for an S-Caliper. Stainless pistons are the trick. The corrosion in the bore "generally" isn't the problem it's the corrosion on the piston where it sits in the bore and rests against the seal (picture included) A-Calipers don't look anything like an S-Caliper (it's twu, it's twu). Same pad surface area but not as deep as an S-Pad. This is such a common myth. They look like they're from different manufacturers. They look more like the BMW Calipers people are using than they do an S-Caliper. M-Calipers were never (ever) used on 914's (post 73 or whatever), they were stock on 914-6's and 911T's though. And the bore is about 5mm larger than a 914-6 (me believes... I can confirm if desired) Other than that "You're SPOT ON Clay" (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/w00t.gif) John, what engine do you have? If it's a -4, I wouldn't go with anything larger than an M-Caliper. I have my reasons which I'll go into detail if you really want to know. Many, many BTDT experiences. Attached image(s) 
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| johnmhudson111 |
Jul 29 2005, 07:43 AM
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#11
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Member Group: Members Posts: 491 Joined: 29-November 04 From: Nesbit, MS Member No.: 3,191 |
Right now I have a 1.8 4 in the car but this will be replaced at some point with a 6 in the future. The plan right now is a nice 3.0 or 3.2. I will be upgrading the suspension and the brakes with that in mind, the engine will be the LAST big upgrade. I have the 5 bolt conversion kit for the rear comming from you and I just bought a 911 front suspension off a 77 with "A" capliers. I am thinking that going with Boxster monoblocks down the road would be the best solution... (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif) |
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| Eric_Shea |
Jul 30 2005, 09:08 AM
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#12
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PMB Performance Group: Admin Posts: 19,278 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Based upon your future plans it sounds like you're on the right track. You're going to have a hard time getting the rears to work right now. Take out the P-Valve and put a T-Fitting in there for sure.
You're now into the "Rear Handbrake Black Hole". Enjoy, and sort your options. If'n I was you, I'd max out at Carrera brakes ala. Sir Andy. Proque? You go with the Monoblocks and you'll have to weld on a new ear on those shinny new control arms (that are "still" waiting for the bushings to arrive... I'm going to see if I can have them next-day air them... sorry). If you plan on big tires etc you'll still have enough stopping power to lock them up. I'll bet Andy's happy with his set-up. Ask. I'll have a 200-220hp -6 in my GT with S-Calipers up front and 911 M-Calipers in the rear (T-Fitting). I'm using the 911 handbrake assembly. Same basic setup that came on a 76 930 (with 240hp and a similar 7 & 8 x 15 wheel/tire package) |
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| johnmhudson111 |
Jul 30 2005, 01:29 PM
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#13
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Member Group: Members Posts: 491 Joined: 29-November 04 From: Nesbit, MS Member No.: 3,191 |
Eric - No rush on the rears, so just send them out normally once you get them together. Until I started looking into this upgrade I never thought you could have too much brake on a car. Would the "stock" 914/6 brakes for the rear and the boxster monoblocks for the front be a workable package? |
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| DanT |
 Jul 30 2005, 01:49 PM
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#14
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Going back to the Dark Side! Group: Members Posts: 4,300 Joined: 4-October 04 From: Auburn, CA Member No.: 2,880 Region Association: None |
I am interested in this thread since I am considering the 5 bolt set up and brake up grade.
I was thinking of a SC/Carrera front suspension with associated brakes. Is is best to use a matching SC/Carrera rears for best balance? Not to mention ventilation? Eric, Can you adapt your 5 bolt rear setups for a later style caliper and offset? Ears welded for 3.5 mounting spacing? Is it preferred to just use the 914 rears or put the fronts on the rear? I know, questions questions questions! Thanks (IMG:http://www.914world.com/bbs2/html/emoticons/hijacked.gif) |
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| ClayPerrine |
Jul 30 2005, 02:31 PM
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#15
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Life's been good to me so far..... Group: Admin Posts: 15,512 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille
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The boxster monoblocks use an adapter block available from Rich Johnson that will allow them to bolt to the existing tab on the trailing arm. |
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| Andyrew |
Jul 30 2005, 02:35 PM
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#16
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Spooling.... Please wait Group: Members Posts: 13,376 Joined: 20-January 03 From: Riverbank, Ca Member No.: 172 Region Association: Northern California
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I've got A calipers and stock rears with vented rotors all the way around and racing pads....
Stops good, but no where near the stopping ability of ABS.... lol I get one tire to lock up too soon... sucks.... |
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| michel richard |
Jul 30 2005, 02:36 PM
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#17
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Senior Member Group: Members Posts: 1,291 Joined: 22-July 03 From: Longueuil, Québec Member No.: 936 |
And the problem with the stock 914/6 rears is that they are very very difficult to find. And there's apparently a couple or Ferrari models on which they fit . . . but I dunno if that's a big fator. |
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| Aaron Cox |
Jul 30 2005, 02:38 PM
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#18
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
one more correction to uncle clay's knowledge... monoblocks from a boxster fit under 15" cookie cutters...... ive seen it (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) |
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| johnmhudson111 |
Jul 30 2005, 02:38 PM
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#19
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Member Group: Members Posts: 491 Joined: 29-November 04 From: Nesbit, MS Member No.: 3,191 |
Clay, How can I get in touch with Rich? And which rotor do you have to use on the rear with the monoblocks? |
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| Aaron Cox |
Jul 30 2005, 02:39 PM
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#20
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
paragob products has the adapter / rotor / new calipers setup for ~900 or so....
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