4-piston brake conversion questions

[carrman]

Guys, there are 2 different calipers which can be used, depends if you want to run stock rotors, or vented ones. Calipers from the 4 cylinder trucks have a casting mark of "S12" and they are used with stock rotors. Calipers from V6 trucks, and the heavier 4-runners are marked "S12W" and are used with vented rotors. These take more work to set everything up.

[Z-point]

correct but to make to story complete

the S12 is for NON vented rotors

and the S12W is for Vented rotors

have a nice day

[Z-point]

Michael,

I did some research into those callipers.

The callipers are made by the same manufacture as the Datsun callipers.

They’ve got the same set-up. The only thing that could be a problem is the rim you’ve got at your car!! If you use vented disks you could have a space problem between the rim and the calliper. It dispenses what rim you use!

My Z has the first generation 280ZX rim (the cross) and there is no problem with the space between them. With the normal disk you don’t have to bather at all. It fits!

Many guys did it before you; please read http://www.geocities.com/row4navy/brake.html

[hf240z]

Originally posted by 2ManyZs

These are the numbers I got from an ex-buddy who worked at Auto Zone for the 79-84 4x4 calipers.

FWIW anyways....

7142 L/H 7141 R/H

$69.94 each plus 30 core

D137 Carbon metallic pads to fit were $11.99 back then

hi,

by any chance do you know if only the s12 stamped toyota 4x4 caliper will work on 240z 72. i try calling autosone and the number i got are the following 039j and 2337 (79)

thanks

[zrl]

Vented rotor conversion

You may find that you need to shim the calipers a bit.

you should not need any shim/spacer for the caliper.

I bet the spacer thickness of 0.5" is not correct. you should compare the thickness of the rotors to calculate the right spacer thickness, not the "hat height". assume the thickness of the rotors are the same at the hub mounting area (not the braking surf; the area where four holes are), the thickness of the spacer now should be ="the new rotor thickness" - "the old rotor thickness", and then divide the result by 2.

if this still can't get your new rotor center inside the caliper, you should mount the caliper (without pads) and the new rotor in place, then measure the offset. the offset should be the distance betwteen the center line of the rotor (the center between the two disc surfaces) to the center line of the caliper. this should be the spacer thickness that is needed.

hope this is not too confusing. i think you should be able to figure it out anyway when you are installing. I want to do it, but it will cost me around $150 to get the remanufactured ones from Kragen for both sides.

[Doehring]

A question to those who have done the conversion: Did someone of you measure the improvement in feet or meters when fully braking from 60mph to 0 before and after the conversion or in comparison to another, but stock 240 Z?

For already some time I think about that conversion. Because changing something at the brakes is not in line with the law here

I need an expensive extra test by our authorities. In case of an accident the insurance will not pay without that official agree. This only makes sense if there is a real improvement.

Thanks

Rolf

[Daniel]

Doehring,I certainly understand the insurance concerns.In the U.S. the first thing the insurance companies try to do is find a way NOT to pay.It's not hard to believe yours is any different.I sure would want to be sure that "official agreement "was as solid an agreement as you had before you made the brake change.Loopholes can bite !!

[hf240z]

hi,

what u just mention is something we all need to consider before any mod's. i never thought about this before i read ur comment.

thank u so much. after i switch to s12 brake i will take the car to the insurance co, and see what they say or what should i do? or did i understand ur quote correctly?

ty,

hf

Originally posted by Daniel

Doehring,I certainly understand the insurance concerns.In the U.S. the first thing the insurance companies try to do is find a way NOT to pay.It's not hard to believe yours is any different.I sure would want to be sure that "official agreement "was as solid an agreement as you had before you made the brake change.Loopholes can bite !!

[carguyinok]

after i switch to s12 brake i will take the car to the insurance co, and see what they say or what should i do?

That may not be the best thing for you to do. You may just be opening a can of worms with your insurance company. If you are just doing a upgrade with nissan parts keep your mouth shut IMO. The reasons I say this.

#1 the insurance company is NOT your buddy thats going to say "ahh dont worry looks good:D " They are going to make money off this:devious:. Here you are asking if you need to pay more for doing this.

#2 If you are going with stock looking nissan parts. The chance that you are in a wreck is slim anyway. But then the odds that the person inspecting your car will even see it or know better must be outa this world.

The only thing that would change that is when you start painting or powder coating calipers and other things. For that (Race) look :stupid:

Just looking to help. I have a background with finance and car dealers. I know how the insurance boys work here in the states.