Are 928 calipers useful for track cars and/or very high horsepower cars ?
The calipers are alloy and very big ('83 era) but are they adaptable ? For 914 6 and 911s ?
Of course alloy 911 and 930 (big red ) calipers are well known and widely used.
928s' too ?

Interesting question as I happen to have a full set

928 s calipers have a 3.75 bolt spacing and can be modified to fit 3.5 inch 911 front struts. They can also be modified to work with block adapters to work with other bolt patterns. I don't remember if you gave to use 20 or 24 mm thick rotors.

More details in reference to modifying the bolt spacing for the 3.5' 911 strut (anyone)?

Elongate the holes to accept the 3.5" pattern. Best done on a mill.
Requires about .100" material from the inside edge of the hole.

I wonder what performance we could expect over 911 calipers...

The 911 and 914 6 vented rotors are 19mm so 24 mm seems more likely than 20 mm for the 928.
OK, you can mount the caliper.
What 24 mm rotors is adaptable ? front ? rear ?
I'm asking because I'm doing a conversion 6 GT and can get the 928 calipers from a local wreck.
Will a 23 mm master be compatible ?
I guess 911 hand brake parts are part of the deal too

None. Remember, brakes only stop the wheels. The tires stop the car.

If you can lock up your brakes, they're doing all they can at that moment. The only things larger brakes do for you are:
- More unsprung rotating mass, which hurts performance all around
- They handle heat better

Stock 914 brakes are plenty good when in good working order for any street-driven 914 with stock fenders.

--DD

Ah...mines a v-8 with a Sheridan standard kit

Seems to me the 928 did not get alloy calipers until the 1985 S$ came out. Earlier were steel calipers.

Jim

Hi Rory,

How is my old car coming along? Post a few pics of it.
Are you looking to put the calipers on the front or rear of the 914?

I was looking at doing the S4 caliper f/r swap on my 6 but went with a Boxster
f/r setup instead. It was an easy bolt on setup once I had all the parts on hand.
I don't recall if I showed you that Boxster setup when you where here last?

My old 71 914 had a setup like the one you are looking at. I used the 928 S4 rear calipers (which take the same pads size as the 930 calipers) with 84-89 911 Carrera 24 mm front rotors with standard 911 hubs. On the rear I used the 911 sc calipers/rotors. The S4 calipers mounting holes had to be machined a little like Bruce stated. You need to make sure the larger sized piston is on top so you may need to swap the lines around too.
I was taking a machine shop class at the time so I asked my instructor if I could do it on one of the presses.. It was fairly easy to do just have the struts with the hub/rotor mounted and handy to make sure things line up properly.
I used a Mercedes 23 mm master as well. I had to make the push rod longer to fit the master or you could replace it with the longer 911 type. The brakes worked great minus the rear e-brake. I drove the car with this setup for several years on the road and track. I never had a problem with the setup that is until I stopped too quick once but the car behind me didn't. I liked the brake setup and it all fits under 15 '' wheels.

I'll hit you up the next time I'm in your area.

Here's a pic of the caliper mod needed.. not mine I found it online.

Bingo !!!
jcd 914 had it right, early 928s had steel calipers.
I was hoping to score some big ass calipers but it ain't happenin"

Here's a question:

Do 914's need 24mm rotors (heavier rotating mass/flywheels) to stop effectively?



Rory... you could use these:

https://www.facebook.com/media/set/?set=a.1...mp;notif_t=like

To Eric's question. On the track it sure is nice having that thermal capacity. I am still pretty new at the track in my 6, but am becoming a fast driver. I am running stock 86 Carrera rotors and calipers with Hawk pads and Motul fliud. In September, on a 100* day at the 5 mile Thunderhill track I was within a 1.5 seconds of the fastest cars in the advanced group. So my speeds were up there, but because of a front spoiler issue I had to make a choice that ending up with me having ZERO brake ducting and ZERO brake fade lap after lap for several sessions. In the future I would like to replace the heavy calipers with lighter ones, but I would keep the wider rotors. Hopefully with the same performance results if need be.

You can use the "rear" 928 brakes. They will fit under a 14" wheel with a small spacer. You also need to use the 23mm to get the correct pedal. Click to view attachment

Those 917 calipers are obscene, ooooooooh..............
I asked the original question before actually seeing the 928 or even knowing what year it was. Turned out to have steel calipers.
Of course unsprung weight, tire patch, wheel size, master cyl. diam., vehicle weight etc. are all big factors in choosing brakes.
Not just adapting the biggest calipers you can find.