2009 CTS-V Six Piston upgrade

[Greg@PacePerformance]

I did some test fitting this weekend.
The 2009 CTS-V with 6-piston Brembo calipers do fit the G8 front knuckle and hub.

I test fit a brand new rotor, caliper and pads to a G8 GT front end. Everything fit like factory except you will need to drill the two caliper mounting holes 2mm larger to fit the 14mm bolt needed. This would be a great upgrade for a GXP since the caliper is the same width from the mounting flange. I have yet to verify the brake line or banjo bolt size but I am pretty sure it will all work.

The only issue is brand new the parts are expensive but I did see a set on E-bay last week go for under 700. That was front and rears with rotors.

CTS-V Upgrade Link (http://PacePerformance.com/index.asp?PageAction=VIEWPROD&ProdID=264804)

My next project is to check the Z06 caliper and rotor since they are slightly cheaper.
Oh and the 6-Piston Brembo caliper is lighter than the GXP 4 piston.

-Greg

[J Wikoff]

Do they fit under GT 19's?

[MGMG8GT]

I would have bought the CTS-V set for 700 bucks if I had seen it, geez.

[Greg@PacePerformance]

No I can tell you they will not fit under the stock 19's unless they are the GXP stock 19's.

[Ktlplxm]

So we still effectively have the same problem as before, non GT fitment unless you have CTSV or GXP wheels (or on of the few wheels that fit)?

[Greg@PacePerformance]

Yes. Same fitment issues.

[Ktlplxm]

oh,thanks for the diagram you faxed me the other day, it had all the info we needed

[Greg@PacePerformance]

I would have sent it sooner but I forgot to but the "1" in front of the number and none went through.

[G8Stagger]

do you know if the back brake will also fit

[GTPprix]

Damn you got me all excited I was like woot finally an upgrade for my GT... DOH!

[Greg@PacePerformance]

Sorry Chris.

G8Stagger - Yes the rears will fit. They are the exact same as the Camaro SS. You will just need to swap all E-Brake parts over to the Camaro/CTS-V style.

[GTPprix]

Its ok :) If I keep the GXP maybe I'll do this :)

[whiterp199]

Greg, Thanks for all of your help with theses brake ideas. I have not upgraded my brakes yet, I am waiting for cash and my originals to wear down a little bit. Keep us updated on the z06 brakes. You sure do make this easy for those of us who do not have acess or time to look everywhere for this kind of info.

[fiveoh]

I'm guessing there is no chance the ZO6 brakes clear the 19s either?

[Greg@PacePerformance]

I doubt it but I will let everyone know.

[Ktlplxm]

I'm guessing there is no chance the ZO6 brakes clear the 19s either?

It would be cool if they did

[fiveoh]

It would be cool if they did

Very.

I will end up with the front baer kit when my brakes need to be changed if nothing else is proven to work with the 19s by then. Would be nice to have a few more choices thou.

[DHmotorsports08]

Greg what are the parts numbers for the cts-v calipers, rotors, bolts. I looked at gmpartsdirect and they say $222 for each front caliper, $48 each rotor did not get prices on bolts. pads are like $230 but its probably cheaper to buy aftermarket pads. What would your cost be for just the front set-up?
So the camaro SS brakes will fit front and rear?

[Greg@PacePerformance]

GM Parts direct can suck it ;)
CTS-V calipers - 25912477 , 25912967
rotors - 25851237 x2
caliper pin kit - 25940448 x2
pads - 25940447

The Camaro fronts are exactly the same as the GXP except for the fact it uses a 14mm bolt like the CTS-V so you will have to drill the knuckle to accept the larger bolt.
The rears bolt right on and fit under the stock 19" wheels. You just need to change the E-Brake parts over to the Camaro style.

[Greg@PacePerformance]

Just got my ZO6 rotor and caliper in. The caliper is the same depth from the mounting flange (4.5") so you still could not use the stock wheels.

The caliper offset is slightly different so you would have to use the Corvette rotor but then you run into the issure that the corvette uses smaller wheel studs, so the G8 studs will not pass through the Corvette rotor. Also the Corvette center hub is larger than the G8. So in my opinion you can not use the Corvette parts on the G8.

[fiveoh]

Just got my ZO6 rotor and caliper in. The caliper is the same depth from the mounting flange (4.5") so you still could not use the stock wheels.

The caliper offset is slightly different so you would have to use the Corvette rotor but then you run into the issure that the corvette uses smaller wheel studs, so the G8 studs will not pass through the Corvette rotor. Also the Corvette center hub is larger than the G8. So in my opinion you can not use the Corvette parts on the G8.

Thanks for trying.

[Ktlplxm]

Could the Corvette rotor be drilled to accept the 14mm studs? If so, that would in fact center it and the hub bore wouldn't be as crucial. What size are the Z06 rotors and calipers? All that work may be counter productive.

[Greg@PacePerformance]

I would guess the rotors could be drilled to accept the larger studs.
The rotors are slightly smaller than the GXP/ CTS-v rotors but they come cross drilled with directional vents. They also cost about $100 less each than the CTS-V rotors.

The calipers are six piston also.

[twenty2indubz]

GM Parts direct can suck it ;)
CTS-V calipers - 25912477 , 25912967
rotors - 25851237 x2
caliper pin kit - 25940448 x2
pads - 25940447

The Camaro fronts are exactly the same as the GXP except for the fact it uses a 14mm bolt like the CTS-V so you will have to drill the knuckle to accept the larger bolt.
The rears bolt right on and fit under the stock 19" wheels. You just need to change the E-Brake parts over to the Camaro style.

Greg, can you provide all the part numbers for the rear conversion including the e-brakes #'s.

[Greg@PacePerformance]

The GXP and Camaro SS front rotors are 14"
The CTS-V rotors are 14.5"

twenty2indubz:
As requested all parts to do the rear swap.
92233177 - Caliper
92233176 - Caliper
89047728 - Pin kit x 2
89047744 - rear pads
25851166 - rotors x 2

Ebrake parts
92227529 - backing plate
92227530 - backing plate
92234842 - ebrake shoes x 2
92234840 - actuator lever
92234841 - actuator lever
25867414 - adjuster x 2
25814679 - spring kit x 2
I am 99% sure that is everything needed but I won't be sure until someone steps up and does the swap.

[WhiteDeathLSX]

This would probably be a marginal upgrade for a GXP brake system, but very cool nonetheless. Do we know the total cost for jsut the front CTS V rotors + calipers?

[Greg@PacePerformance]

I updated my first post the other day with the link.
6 Piston conversion (http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=264804) - 1400.00 w/o pads

[DHmotorsports08]

not bad. it would be cool if you could make a rear conversion kit together too.

[Greg@PacePerformance]

not bad. it would be cool if you could make a rear conversion kit together too.

Who said I didn't put a kit together yet ;)
4 piston rear upgrade kit (http://PacePerformance.com/index.asp?PageAction=VIEWPROD&ProdID=265055)
I haven't got pictures taken of the parts yet.

[grandmacpubah]

you're killing me greg...

[r33pwrd]

HOw much of a spacer whould be needed to run the GT 19's? a small spacer should not be a big issue whould it?

[Ktlplxm]

A small spacer won't cut it. You have to put a good bit more than a 3/8 because of the curve on the back of the wheels. I had to sale my entire kit because of that.

[m_0ney_pit]

How large are the pistons in the cts-v 6-pistons?

The CTS-V calipers have 36mm and 40mm pistons
The EVO/STi brakes have 40mm and 46mm pistons

Does anyone know what the diameter of the GXP and camaro pistons are?

Greg do have still have the part numbers for the corvette 6-pistons? Was the offset shifted more towards the inside of the wheelwell or away from the wheel well?

[DHmotorsports08]

thanks greg thats great. so it looks like u have the option of the camaro or ctsv rear brakes. so they are going to be the 4 pistons. and this kit comes with everything for the ebrake?

[MIEngineer]

GM already beat everyone to it a while ago...not sure if anyone paid attention?

The old GXP Street Edition show vehicle has CTS-V brakes including a 4 piston rear brembo [this is not the orange GXP show vehicle].

Great upgrade, but overkill...and overkill can be fun. I already pulled the PNs for it earlier this year.

Great thread! I just joined here not long ago...and late to this party :)

[Greg@PacePerformance]

Greg do have still have the part numbers for the corvette 6-pistons? Was the offset shifted more towards the inside of the wheelwell or away from the wheel well?

The Corvette calipers - 19121788 & 19121789
The offset is pushed more to the wheel away from the wheel well.


thanks greg thats great. so it looks like u have the option of the camaro or ctsv rear brakes. so they are going to be the 4 pistons. and this kit comes with everything for the ebrake?

Yes both are the 4 piston. Yes includes everything needed as far as I know. I haven't had any one test this yet since changeing the backing plate and E-brake parts is the hard part, and you need a press to push the rear hub out of the knuckle.


GM already beat everyone to it a while ago...not sure if anyone paid attention?

The old GXP Street Edition show vehicle has CTS-V brakes including a 4 piston rear brembo [this is not the orange GXP show vehicle].

I have known it would work since spring but I haven't found any one to do the test fitting to make sure I have 100% of the parts in the kit.

[Markszz4]

I have known it would work since spring but I haven't found any one to do the test fitting to make sure I have 100% of the parts in the kit.

Hmm....... were's G8V8 ;)

[Greg@PacePerformance]

Hmm....... were's G8V8 ;)

He was my tester for the front GXP kit and at the time he didn't want to test the rears just yet.

[m_0ney_pit]

Do you guys know what the piston diamters are for the 6-pot it might not be worth it to upgrade if it has roughly the same piston surface area as the 4-pot GXP.

Are the GXP pistons 36mm and 40mm?

[m_0ney_pit]

one more quick thing, is the rotor offset of the GXP 14" rotor and CTS-V 14.5" the same?

[StockG8]

Why are you so hard up on the piston's diameter anyways? Do you plan on adapting these to another vehicle? If so you're better off going with the Z06 setup since they are a lot cheaper for front and rears.

[Greg@PacePerformance]

one more quick thing, is the rotor offset of the GXP 14" rotor and CTS-V 14.5" the same?

Sorry don't know piston diameters
Yes the offset is very close with the two. The CTS-V rotor is slightly thicker.

The red "competition" CTS-V calipers and two piece rotors are not available yet just an FYI for anyone interested.

[r33pwrd]

Greg in your opinion what is better the CTSv or the GXP kit? Also how does one make sure either will fit behind their wheels before ordering?

Thanks

[Greg@PacePerformance]

Just by looking at the specs on the CTS-V I would say they are better.
The caliper is lighter, rotor is larger, and the pads have more surface area. The only downside is the rotors weigh more than the GXP rotors.

Sorry they only way I know to see if a wheel fits is to check a wheel site and make sure it fits the GXP.
Nobody has made a template yet.

[r33pwrd]

Sorry they only way I know to see if a wheel fits is to check a wheel site and make sure it fits the GXP.
Nobody has made a template yet.

So if they fit a GXP they will fit a GT with the CTSV brakes?

[Greg@PacePerformance]

Yes. The calipers are the same depth. I would only suggest 19's even though some 18's fit the GXP since the CTS-V rotors are larger.

[r33pwrd]

Yes. The calipers are the same depth. I would only suggest 19's even though some 18's fit the GXP since the CTS-V rotors are larger.

Im going to order 20" wheels... so I guess I should be OK.

[G8V8]

Nobody has made a template yet.

Have you seen this? (http://www.g8board.com/forums/showthread.php?t=24032&highlight=template)

[r33pwrd]

Why are you so hard up on the piston's diameter anyways? Do you plan on adapting these to another vehicle? If so you're better off going with the Z06 setup since they are a lot cheaper for front and rears.

but do they bolt up to the G8 spindle?

[StockG8]

http://forum.grrrr8.net/showpost.php?p=151745&postcount=20


but do they bolt up to the G8 spindle?

[r33pwrd]

http://forum.grrrr8.net/showpost.php?p=151745&postcount=20


Quote from Greg:
Just got my ZO6 rotor and caliper in. The caliper is the same depth from the mounting flange (4.5") so you still could not use the stock wheels.

The caliper offset is slightly different so you would have to use the Corvette rotor but then you run into the issure that the corvette uses smaller wheel studs, so the G8 studs will not pass through the Corvette rotor. Also the Corvette center hub is larger than the G8. So in my opinion you can not use the Corvette parts on the G8.

But it does not say it the bolt pattern is the same on both calipers...

[Radrace19]

Yes the bolt pattern is the same.

[Tjay74]

I wish I knew someone that could mill the brackets, the answer is easy. It is the liability side of that scares people.

Making a bracket to adapt the caliper is not the problem, it is the worry of if that bracket breaks.

[StockG8]

Nevermind I found some pics of it.

The 2 piece rotors look like they are floating design and made by Performance Friction.

http://static.howstuffworks.com/gif/2009-cadillac-cts-v-08.jpg



The red "competition" CTS-V calipers and two piece rotors are not available yet just an FYI for anyone interested.

[Greg@PacePerformance]

The stock CTS-V rotors are a new dual cast design. Iron friction area with a cast aluminum hub. More info on Brembo's site. (http://www.brembo.com/US/Cars/Dual-Cast/)

[r33pwrd]

I wish I knew someone that could mill the brackets, the answer is easy. It is the liability side of that scares people.

Making a bracket to adapt the caliper is not the problem, it is the worry of if that bracket breaks.

Im confused? It sounds like the GXP, CTSV, and Vette calipers all bolt up to the G8 so where would brackets be needed?

[grandmacpubah]

i'm confused too...I want to put the CTS-V brakes on my car.

[StockG8]

Good info Greg, the floating design look similar to that of Performance Friction. I would put some type of warning or disclaimer that floating rotors tend to make noise regardless what pads you are using. They usually make a whirling noise when applied and I'm sure a lot of people will bitch and cry about the noise the rotors make.

Any guesstimate on retail pricing on the bad puppy?

[99-LS1-SS]

i'm confused too...I want to put the CTS-V brakes on my car.

Unless you know the inside of your rims will clear them I would be concerned. Try to find someone near you with a GXP and see if your rims with clear their front calipers. That should give you an idea.

[Greg@PacePerformance]

Have you seen this? (http://www.g8board.com/forums/showthread.php?t=24032&highlight=template)

Thanks I missed that one. Using those specs I made this up.
It is to scale just like the Baer templates ;)
G8 GXP caliper Template (http://PacePerformance.com/paceperformance/pdf/gxptemplate.pdf)

[Greg@PacePerformance]

Im confused? It sounds like the GXP, CTSV, and Vette calipers all bolt up to the G8 so where would brackets be needed?

The Vette calipers will not work on the G8 unless you found a special rotor to work with the caliper offset and specific rotor size. They will bolt onto the knuckles but that is about it.

The GXP is a direct swap and the CTS-V will need the knuckles drilled to use the 14mm bolts instead of the 12mm on the G8.

Clear yet :)

[r33pwrd]

The Vette calipers will not work on the G8 unless you found a special rotor to work with the caliper offset and specific rotor size. They will bolt onto the knuckles but that is about it.

The GXP is a direct swap and the CTS-V will need the knuckles drilled to use the 14mm bolts instead of the 12mm on the G8.

Clear yet :)

Got it! Thanks

[Greg@PacePerformance]

Good info Greg, the floating design look similar to that of Performance Friction. I would put some type of warning or disclaimer that floating rotors tend to make noise regardless what pads you are using. They usually make a whirling noise when applied and I'm sure a lot of people will bitch and cry about the noise the rotors make.

Any guesstimate on retail pricing on the bad puppy?

No GM has not released pricing at all on the calipers or rotors.

Calipers
20831807 - 20831782
Rotors
20795300 - 20795302
The rotors are left and right so they must be vented or something.

[m_0ney_pit]

Why are you so hard up on the piston's diameter anyways? Do you plan on adapting these to another vehicle? If so you're better off going with the Z06 setup since they are a lot cheaper for front and rears.

Because its dumb to upgrade something just guessing that there will be an improvement.

For all we know there might be a decrease in braking torque.

The gxp with a 14" rotor has a braking torque of 52k in-lbs lets compare to that.

Is there any drawings or technical documents floating around for the caliper, maybe a casting or part number on the caliper?

[StockG8]

GXP calipers is not all that. I have 2 sets of Brembo's sitting in my garage collecting dust.

[Ktlplxm]

GXP calipers is not all that. I have 2 sets of Brembo's sitting in my garage collecting dust.

Thats completely objective. Aesthetically they are a much nicer piece. Pad changes easy and simple. Various pad compounds are easier to find. Regardless of piston diameter, the internal fluid passages and design are optimized for superior clamping force. Greater contact area, even under lesser pressures, provides a better controlled deceleration, with less chance of rotor warping. Being a "floating" design decreases drag when they aren't being applied. Are they necessarily that much greater than a Baer, Aerospace, or Wilwood; no. Are they that much better than a completely stock style set-up built for lots of miles and easier driving; yes

[Greg@PacePerformance]

Because its dumb to upgrade something just guessing that there will be an improvement.

For all we know there might be a decrease in braking torque.

The gxp with a 14" rotor has a braking torque of 52k in-lbs lets compare to that.

Is there any drawings or technical documents floating around for the caliper, maybe a casting or part number on the caliper?

I dug the 6-piston caliper out again an checked the piston sizes
The two large pistons are about 34 or 35mm and the two middle pistons are 31 or 32mm and the two small pistons are ~26mm.

It is hard to get an exact spec because the piston is down in the bore and has a taper at the edge.
I hope that helps.

[incon3037r]

I know the CTS-V fronts will fit the GT after modifying to 14mm and the Camaro rears will bolt onto the GT. I want to know do the CTS-V rears bolt onto the GT as well?

[incon3037r]

Nevermind I see the Pace website had been updated and my question has been answered.

[616 of 933]

I would not mind dropping my car off while I go to MA. But i really dont think the wife would like to drive 2 cars and in the middle Dec or Jan.

[R.Penguin]

you're killing me greg...
I ran over something on the road today. I stopped, went back to see WTF?.....and it was your wallet.

Nothing I could do tho'. It was dead before I hit it! :rofl:

[BigV8]

I'd like to know if the V rears will be that hard to due? Maybe some one that has taking apart the rear hubs can chime in. What would need to be pressed out? Oh Charlie.....