CTS-V Calipers, anyone tried to use them?

[R.O.B.]

I was wandering about the '05+ Caddy CTS-V calipers to be used on a stang. These are Brembo 4 piston calipers, and are available new from gmpartsdirect.com for around $150.00 ea. This is dirt cheap. I figure, if there are adapters made to use the Cobra rotors and calipers for our classics, why not make one for Cobra rotors and these calipers. This would be even better right? and at a good price too.

Part numbers are:
89047726 left
89047727 right

Any thoughts?

 

[mrmustangman357]

hell yea thats a good price, but then you would also have to sort out your rotor to work for it. Adaptors can be custom made to work with the spindles too.

The mustangsteve 2008 kit works fairly well at a good price too I have heard

 

[R.O.B.]

More info:
The above part numbers are for calipers w/o pads, these are the part numbers for loaded.
25750249 left
25750250 right

And some pics:

 

[R.O.B.]

And more pics:

 

[4tun8]

Nice looking calipers there.

 

[bnickel]

those look like the same calipers used on the hummer h3 also. www.vintagevenom.com makes adapters to use the mustang cobra brembo brakes so maybe they would work with these calipers too. it's worth a look.

 

[bnickel]

these calipers would also work great with the vintage style T/A mustang 12" brakes using the 71 LTD rotors. a custom caliper brake would be needed but those can be machined easily enough. sweet!!!!! thanks for point these out.

 

[hsr]

these calipers would also work great with the vintage style T/A mustang 12" brakes using the 71 LTD rotors. a custom caliper brake would be needed but those can be machined easily enough. sweet!!!!! thanks for point these out.

The problem with trying to fit those calipers over 12" rotors is that although they will sit closer to the (rotors rotation) centerline, the ends of the caliper will sit much further away, as they were designed to fit on a 14". It will cause interference with your wheel (think you're trying to stick with a 15" wheel like me).

Can you check something for me please? What is the dimension on your LTD rotor from the inboard friction surface (closest to the engine) to the wheel mounting face? Napa online shows 4.525", but I want to make sure that isn't measured from where the dust cap fits to the friction surface.

Thanks,

 

[R.O.B.]

Another thing to keep in mind would be the rotor thickness. The Caddy one is 1.263" thick, which is what these calipers are ment to handle. I think these would work with the 13" Cobra rotors, as they are 1.105" thick.

FYI, the LTD rotors are 1.185" thick, so if possible to adapt the caliper, it would work too.

 

[C0V3R]

Whats the bolt spacing and bolt hole size?

 

[R.O.B.]

Whats the bolt spacing and bolt hole size?

Sorry, I do not know this. Anyone?

 

[bnickel]

The problem with trying to fit those calipers over 12" rotors is that although they will sit closer to the (rotors rotation) centerline, the ends of the caliper will sit much further away, as they were designed to fit on a 14". It will cause interference with your wheel (think you're trying to stick with a 15" wheel like me).

Can you check something for me please? What is the dimension on your LTD rotor from the inboard friction surface (closest to the engine) to the wheel mounting face? Napa online shows 4.525", but I want to make sure that isn't measured from where the dust cap fits to the friction surface.

Thanks,

i don't have a set of the LTD rotors but i do know they are fairly close to the same height as a stock mustang rotor. i had already figured the LTD rotor thickness in, BTW. if i'm right that these calipers are fairly similar to the Cobra Brembo's then they will work just fine with the 12" LTD rotor, they wil be really close to the center hub but that's not a problem. i am concerned that they will fit in a 15" wheel though, i guess the only way to know for sure would be to buy a pair and try them, if they don't work i could either return them or sell them on ebay.

 

[hsr]

i don't have a set of the LTD rotors but i do know they are fairly close to the same height as a stock mustang rotor. i had already figured the LTD rotor thickness in, BTW. if i'm right that these calipers are fairly similar to the Cobra Brembo's then they will work just fine with the 12" LTD rotor, they wil be really close to the center hub but that's not a problem. i am concerned that they will fit in a 15" wheel though, i guess the only way to know for sure would be to buy a pair and try them, if they don't work i could either return them or sell them on ebay.

B,

I think you're missing my point. The thickness of the rotor may work fine with that Brembo or other 6 pot caliper, but the caliper is too long (or tall) to work with the smaller diameter rotor.

In my crude picture below, the heavy black line represents a 12" rotor. The green line represents a 14" rotor. The light black line would be the inside of a wheel (15" for this example). The blue is the larger caliper designed for the 14" rotor. When placed over the 12" rotor, its ends are too far away from the spin center of the wheel/rotor and this causes clearance problems to a smaller diameter wheel and also puts a portion of the pads/pistons off the rotors friction surface.

I've mocked this up in CAD using the GT500 caliper on a 12" and 13" rotor. It just doesn't fit. Guessing the GM, Brembo or other caliper designed for a 14" rotor will have the same issue.

On another note, I have a set of '65 TBird calipers that are usable but could probably use a piston seal kit or would make excellent cores if anyone is interested. Will sell for $75 shipped in the US.

I've decided to go another route. 12" off the shelf Ford rotors and Cobra calipers that fit inside my 15" Torque Thrusts without modification or spacers.

 

[bnickel]

B,

I think you're missing my point. The thickness of the rotor may work fine with that Brembo or other 6 pot caliper, but the caliper is too long (or tall) to work with the smaller diameter rotor.

In my crude picture below, the heavy black line represents a 12" rotor. The green line represents a 14" rotor. The light black line would be the inside of a wheel (15" for this example). The blue is the larger caliper designed for the 14" rotor. When placed over the 12" rotor, its ends are too far away from the spin center of the wheel/rotor and this causes clearance problems to a smaller diameter wheel and also puts a portion of the pads/pistons off the rotors friction surface.

I've mocked this up in CAD using the GT500 caliper on a 12" and 13" rotor. It just doesn't fit. Guessing the GM, Brembo or other caliper designed for a 14" rotor will have the same issue.

On another note, I have a set of '65 TBird calipers that are usable but could probably use a piston seal kit or would make excellent cores if anyone is interested. Will sell for $75 shipped in the US.

I've decided to go another route. 12" off the shelf Ford rotors and Cobra calipers that fit inside my 15" Torque Thrusts without modification or spacers.

I'm not so sure about that myself. it would seem that this 4 pot Brembo would work absolutely perfectly on the 12" rotor and possibly even an 11" rotor but that would really be cutting it close. there is a pic above of the rotor with a tape measure next to it and it's in perfect scale on my computer when i enlarge the pic and i can measure approximately how much rotor surface the pads and calipers will cover and it looks to me like they will work just fine on a 12" rotor, it will be tight with a 15" wheel but even if i had to grind on the calipers a bit it wouldn't be a big deal to make them work.


what 12" rotor have you found that will work if you don't mind me asking? i've also looked at the possibility of using a 12" 90's model CV rotor with a either a Cobra or standard 99-04 GT PBR caliper using the stock 69 stang disc hub, i haven't been able to fully calculate everything yet but that seems like a possible alternative.

i've also been looking awfully hard at using a C5 Vette PBR caliper with the 71 LTD rotor too but this particular Brembo caliper looks pretty promising to me as well, especially for the price. it looks as if the friction material is about 2.5-2.75" tall and there is a little over 3" of friction surface on the 12" rotor so i think it should work out fine. i will have to actually measure the friction material to know for sure and even though i know it will be close i think there is just enough wiggle room to make these calipers work

 

[hsr]

I'm not so sure about that myself. it would seem that this 4 pot Brembo would work absolutely perfectly on the 12" rotor and possibly even an 11" rotor but that would really be cutting it close. there is a pic above of the rotor with a tape measure next to it and it's in perfect scale on my computer when i enlarge the pic and i can measure approximately how much rotor surface the pads and calipers will cover and it looks to me like they will work just fine on a 12" rotor, it will be tight with a 15" wheel but even if i had to grind on the calipers a bit it wouldn't be a big deal to make them work.

It won't work behind the 15" wheel. Even a 16" is too close. I work for Ford and have CAD data of these parts and access to brake engineers. I've laid it all out (not guess work), but whatever.

what 12" rotor have you found that will work if you don't mind me asking? i've also looked at the possibility of using a 12" 90's model CV rotor with a either a Cobra or standard 99-04 GT PBR caliper using the stock 69 stang disc hub, i haven't been able to fully calculate everything yet but that seems like a possible alternative.

Not ready to give that out to the world yet. Might want to see if either of the "brake Steve's" want to do something with this first. It's not the CV rotor. Applejack on this forum (and on V-M) has Cobra calipers with '03 CV rotor's behind 15" wheels. Took a lot of work (I know because I helped his cause) and he still ended up with spacers to push the wheel out. His wheels are steel, which provide a lot more clearance than aluminum ones do.

The Cobra caliper is much smaller than the '99-04 GT PBR. I've had the GT PBR's on my car since '02 (on Granada spindles). They are huge compared to the Cobra and won't clear the 15" when put over a 12" rotor.

i've also been looking awfully hard at using a C5 Vette PBR caliper with the 71 LTD rotor too but this particular Brembo caliper looks pretty promising to me as well, especially for the price. it looks as if the friction material is about 2.5-2.75" tall and there is a little over 3" of friction surface on the 12" rotor so i think it should work out fine. i will have to actually measure the friction material to know for sure and even though i know it will be close i think there is just enough wiggle room to make these calipers work

The C5 PBR is the same caliper as the Cobra.

 

[bnickel]

It won't work behind the 15" wheel. Even a 16" is too close. I work for Ford and have CAD data of these parts and access to brake engineers. I've laid it all out (not guess work), but whatever.



Not ready to give that out to the world yet. Might want to see if either of the "brake Steve's" want to do something with this first. It's not the CV rotor. Applejack on this forum (and on V-M) has Cobra calipers with '03 CV rotor's behind 15" wheels. Took a lot of work (I know because I helped his cause) and he still ended up with spacers to push the wheel out. His wheels are steel, which provide a lot more clearance than aluminum ones do.

The Cobra caliper is much smaller than the '99-04 GT PBR. I've had the GT PBR's on my car since '02 (on Granada spindles). They are huge compared to the Cobra and won't clear the 15" when put over a 12" rotor.



The C5 PBR is the same caliper as the Cobra.

there are 2 C5 calipers, one for the 1.125 rotor and one for the thinner rotor.

so are you telling me that the CTS-V 4 piston Brembo (not 6 piston as you orginally said) are bigger than the Lincoln 4 piston K/H caliper?

the hummer H3 has a 4 piston aluminum caliper that was designed for a 12.4" rotor that i've been looking at as well that may be a better fit for the LTD rotor.

in the end i may just stick with a stock 67 K/H style system with SSBC aluminum calipers but i'd rather make something like the T/A Boss 12" brake system with some sort of 4 piston aluminum caliper that will work better instead.

 

[hsr]

there are 2 C5 calipers, one for the 1.125 rotor and one for the thinner rotor.

Cobra rotors are 28mm thick (1.10"). The CV's are 30mm (1.18"). Just info. The Cobra's mounting brackets only have 32mm between surfaces that go over the rotor.

so are you telling me that the CTS-V 4 piston Brembo (not 6 piston as you orginally said) are bigger than the Lincoln 4 piston K/H caliper?

Yes. My mistake on the number of pistons, but yes. I will take a picture of one of my '65 TBird calipers with the measuring tape like the OP did and post that.

the hummer H3 has a 4 piston aluminum caliper that was designed for a 12.4" rotor that i've been looking at as well that may be a better fit for the LTD rotor.

I recall reading your posts on that. Too bad there aren't any in the junkyards around here to experiment with.

in the end i may just stick with a stock 67 K/H style system with SSBC aluminum calipers but i'd rather make something like the T/A Boss 12" brake system with some sort of 4 piston aluminum caliper that will work better instead.

That would be cool. I gave up and decided to stick with the Cobra's. Between those and the Vettes that use them, there are lots of different pad compounds available. Plus, I already have a set. The 12" rotors that I'll be using are 1.03" (26mm) thick and can be had for $35 new by Raybestos.

 

[bnickel]

Cobra rotors are 28mm thick (1.10"). The CV's are 30mm (1.18"). Just info. The Cobra's mounting brackets only have 32mm between surfaces that go over the rotor.


Yes. My mistake on the number of pistons, but yes. I will take a picture of one of my '65 TBird calipers with the measuring tape like the OP did and post that.


I recall reading your posts on that. Too bad there aren't any in the junkyards around here to experiment with.


That would be cool. I gave up and decided to stick with the Cobra's. Between those and the Vettes that use them, there are lots of different pad compounds available. Plus, I already have a set. The 12" rotors that I'll be using are 1.03" (26mm) thick and can be had for $35 new by Raybestos.

i've found slotted and/or drilled and zinc washed rotors for the 71 LTD on ebay for $120 for the pair, i'll just get the slotted and zinc washed versions, i have no use for drilled rotors. i've found the H3 calipers on ebay for about $100 for the pair before but i haven't found any in wrecking yards around here either....yet.

i'm kind of on hold on doing anything big to the cougar until i can get the stang sold and then there's still the little matter of buying a house with a garage so i can work on the damn thing, i could do the cougar in the driveway at the house we are currently renting like i did the stang but i really don't want to go through that again.

when you get ready to share the cobra caliper and whatever rotor you decide on, let me know, i may be very interested if i haven't done anything yet.

 

[hsr]

I will take a picture of one of my '65 TBird calipers with the measuring tape like the OP did and post that.

Here is a shot of the '65 TBird caliper. It's about 9" long. Perspective is off from the tape measure on the floor and the portion of the caliper closest to the camera.