So I went to bolt my FD calipers on today, and there is no way they will work without a different rotor/adapter. The pad is around a cm or so too far past the rotor, and the rotor sits... unevenly. 2/3rds of the space on one side of the rotor, 1/3rd on the other.

Vehicle in question is a jdm 1987 5 lug turbo vert. Nothing mod-ed on the spindles at all. I cant say for certain what FD the calipers came off though.

 

So went and took some pictures today of what Im talking about. Really curious if anyone else has ever had these issues.

 

subscribed - I'm curious for any suggestions also.

 

I think you need a spacer because the FD rotor is thicker. I thought everyone wanted the FD rotor because the calipers are basically the same.

 

This is with an FC rotor attached. The FD rotor would just make it worse. The top-hat depth on an FC rotor is 42mm and an FD is 45mm, so it would just push the rotor even further towards the caliper. The issue I have here is that the rotor seems to be too small in diameter, and also not even spaced in the caliper.

Again, its just the stock s4 jdm rotor on this, with what I can only assume is a typical FD caliper.

 

Spacer at the caliper bracket, not wheel spacer, I should have been clearer.

 

Everything Ive read has said that the FD caliper just straight bolts on though, am I missing something here?

 

maybe you bolted something together wrong, dont know what to tell you?

 

i needed a couple of washers on one side for mine, the spindle might have been tweaked.

 

When people say the FD and FC calipers are identical, I think they mostly mean "functionally identical" as the pistons are the same (they take the same rebuild kits) and the pads interchange.
The FD does have a larger diameter and wider rotor and the rotor offset is obviously different.

At this point Poison, what you "thought" or what the internet says is irrelevant...you have the parts in hand and it's obvious what has to happen to make them work...backspace the caliper on the mounts.
The time for conjecture and theory ended when you bolted the pieces together and confronted reality.

 

I searched around yesterday for you, I also came across "they bolt right up", but sometimes the person who posted that wasnt the guy who actually "bolted them right up"

as j9 said- he shimmed his, and as clokker said the FD has larger rotors so you will get some overhang

Im running FD rotors in the rear and they were same thickness as FC I didnt have to modify caliper in that regard but did have to relocate it- but im also still using FC calipers

good luck with your project

 

i only shimmed mine on one side so something was bent

 

good thing I didn't buy fd rotors!

Well, At least you can have some spacers machined to center it. How is the height of the caliper? Is the fc rotor diameter the right height, or will the brake pad be overhung?

 

Almost 45% of the pad would be overhung. Im thinking maybe the knuckle is different on the s4 here in Japan. I have some S5 knuckles to swap out and try though.