Printable Version of Topic

Posted by: jmargush Apr 3 2024, 07:14 AM

I'm in the process of putting 911 brakes up front.
I have 2 sets of calipers and noticed one at has a wider space between the 2 caliper halves than the other set.

Are there different thicknesses of rotors or what is the purpose and how do I know which one to use?
Just test fit and use prices of elimination I suppose?


Attached thumbnail(s)

Posted by: r_towle Apr 3 2024, 10:53 AM

What rotors are you using? vented or not?

Easiest way is to ask Eric at PMBPerformance.

OR
Stick pads in there, use clamps to push the pads all the way open...measure between pads.
Do both calipers
do both rotor types.

Rich

Posted by: jmargush Apr 3 2024, 11:33 AM

I'll be using vented rotors.

Guess I will mock up the assembly

Posted by: Freezin 914 Apr 3 2024, 02:46 PM

No expert here, but I believe, pre 78 are 24mm and post 77 26mm, but not exactly sure. But I am sure the earlier rotors were a bit thinner.

Posted by: Freezin 914 Apr 3 2024, 02:52 PM

I am pretty sure your set up is a 74’ Bilstein, with A calipers. Then the other set is a wide A. Again, hopefully some more people chime in.

Posted by: mepstein Apr 3 2024, 03:02 PM

Early is 20mm, Carrera is 24mm

Posted by: Freezin 914 Apr 3 2024, 03:17 PM

I knew someone knew the deal!! Ha!

Posted by: mepstein Apr 3 2024, 03:25 PM

Do those calipers have the same spacing - 3” or 3.5”
What front hubs are you using?
Eric is the one to ask regarding all the compatibility.

Posted by: Freezin 914 Apr 3 2024, 03:38 PM

All 3.5”
Maybe Jeff will chime in…..not sure if he has different parts from what I had sold him.

Posted by: jmargush Apr 3 2024, 05:19 PM

Nope still same parts you sold me!
Getting closer to putting out all together!

Posted by: jmargush Apr 3 2024, 05:24 PM

So 7.2mm spacer = 24mm gap in caliper for rotor
11.2mm spacer= 27.5mm gap in caliper for rotor

My rotor thickness measures just over 20mm.

There aren't different hat heights on the rotor are there?

Posted by: jmargush Apr 3 2024, 05:29 PM

Next question
Should this inner bearing slide on or does it need to be driven on slightly?



Attached thumbnail(s)

Posted by: jmargush Apr 3 2024, 05:48 PM

another question
the spacers between the caliper halves, should those stay matched to the calipers or can they switched?

If caliper #1 was a wide and caliper #2 is normal is it ok to swap the spacers and make caliper #2 the wide one?

Posted by: mepstein Apr 3 2024, 06:09 PM

Bearings just drop into the hub.

Posted by: mepstein Apr 3 2024, 06:14 PM

Spacers can be switched to at least some extent. For example, I gave Eric a rear M caliper and a 914-6 caliper. He used the spacer and hardware from the M caliper to remake the six caliper into a 914-6GT caliper. But again, I would go to Eric for exact specs.

Posted by: jmargush Apr 12 2024, 03:19 PM

One more 911 caliper question.

Are there rights and lefts on the front Wide A calipers?or are they interchangeable?

I would assume in order to get the bleeder on the top when mounted.