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Discussion Starter #1 (Edited)
These are available now at bohnman customs! www.bohnmancustoms.com





Hey guys, I've been wanting to create a bracket to fit v2 calipers onto a gto for some time now and finally got around to doing so. If you have seen any of my other bracket threads (http://www.ls1gto.com/forums/showthread.php?p=8747353#post8747353 & http://www.ls1gto.com/forums/showthread.php?t=437821&highlight= ) you'll notice that I have a set set of requirements & will make them happen if they are not available to me. Same goes for this.

Evenso that the CTSV2 front rotors are 370mm (14.56") and originally ride on vehicle equipped with 19"+ wheels I've been wanting to fit a cts-v caliper in an 18" wheel. I figured out that the gen 5 Camaro SS/Pontiac G8 GXP rotors should do the job, they were smaller in diameter (355mm - 14") and utilize the oem brembo 32mm grasp thickness since they come from a car equipped with them from the factory already, also the 5x120 bolt pattern is retained as well, so it was pretty much a win in almost every category for me. The challenges to be dealt with were the Hub diameter & wheel stud differences between the gto & GXP/SS rotors.
The G8/SS rotors have a smaller hub diameter/circle on them than the gto; the gto seems to be a unique case as most cars aside from larger saloons/sedans or even trucks only trump it in hub diameter clearance.

Being as the gto hub clearance is 71.4mm and the GXP/SS is 67.4mm, I had to do some work to open it up to gto specs, which can be even done with regular demurring bit attachments or fanciers ways via a lathe. After the clearance was dealt with, the wheel stud holes were adressed.

As you can see the G8/SS have larger wheel stud bolt holes, this is due to them using an m14 stud opposed to the Gto m12 studs. I didn't like the looser fit of the rotor around the studs so I went ahead and designed small sleeves that slip/press into the G8/SS stud clearance holes. These sleeves replicate the gto stud clearance and sit below the rotor surface in order to not cause any clearance issues. They make the rotor feel as if it was meant to be on there in the first place.

The bracket is pretty much bolt on, with no compromise at all, the calipers go on without issue over the rotor/bracket setup. I even test fitted an oem gto 18" wheel and it cleared, minimal clearance but it clears. And those 6 Piston V2 Brembos do look menacing behind the stock wheels!
I do not wanna blow my own horn but I think I really did outdo myself on this one, I knew wheel clearance with the stock +48 offset 18's would be tight or even close where I would have to use a spacer but it all bolts in!
Rotor clearance is held with oem spec as well:


Bolted in pre wheel test:

Spinning free (bolted in pre wheel test):

Spacer in pics cause lugs were too short lol.

The GM part #'s for the 6 Piston CTS-v2 Brembo Calipers are 25912967 & 25912477

They can be had thru many retailers, in ranges of 700-900$ per set, amazon for example has them roughly 340$ a piece:

[ame]http://www.amazon.com/ACDelco-172-2488-Service-Front-Caliper/dp/B00559OB7E/ref=sr_1_1?ie=UTF8&qid=1354730755&sr=8-1&keywords=25912967[/ame]
[ame]http://www.amazon.com/ACDelco-172-2487-Service-Front-Caliper/dp/B00559O9A8/ref=sr_1_1?ie=UTF8&qid=1354730729&sr=8-1&keywords=25912477[/ame]

GM# 25912477 (AC Delco# 172-2487) - Silver 6 Piston Front Brembo Caliper LH
GM# 25912967 (AC Delco# 172-2488) - Silver 6 Piston Front Brembo Caliper RH
GM# 20982719 (ACDelco #172-2521) - Yellow 6 Piston Front Brembo Caliper LH
GM #20982734 (ACDelco #172-2522) -Yellow 6 Piston Front Brembo Caliper RH

Remanufactured CARDONE 18-5200 & 18-5201 units can be had for 160-200$ each.
 

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Discussion Starter #2 (Edited)
On the hub prior wheel fitment:




Assembled with stock 18" gto wheel:








LET ME KNOW WHAT YOU GUYS THINK!!111
 

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Yes, I'm a Registered User...
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Sahweet!
 

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Original Owners Club
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What size rotor?
 

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Are those the 14" camaro rotors?
 

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Discussion Starter #6

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How about them 'Canes
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That is definitely cool. The brakes on the V2 are superb.

That said, I don't get why people don't just get a BBK designed for the car. For just a bit more you can get a Stoptech kit.

Is the price the incentive here?
 

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Ecotec tech
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2,133 Posts
$810 for the calipers, ~$160 rotors, $200? adapters, and $50 for pads. $1220. We're up in the aftermarket BBK price range now, though still a couple hundred cheaper, but that's using OEM quality rotors/pads too
i still want em :p

See if you can find a 6pot caliper made for an 18" rim on rockauto that has re-manufactured options, like the 17Z Brembos Bohman tried. Re-manufactured calipers will be the biggest selling point, since they're usually half the cost of new calipers. That's what makes the 17Z caliper so attractive: it costs more for one of these calipers new than a pair of reman. 17Zs.

Awesome work in the world of GTO brakes though! Keep it up!
 

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06 Cyclone GTO
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Awesome! This is much cheaper than the factory Aussie bbk.
Just out of curiosity, what is the specs for the Aussie factory bbl? I assume that they are 4 or 6 pistons?
 

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Ecotec tech
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2,133 Posts
Awesome! This is much cheaper than the factory Aussie bbk.
Just out of curiosity, what is the specs for the Aussie factory bbl? I assume that they are 4 or 6 pistons?
well, which setup are you referring?
Harrop's 6pot is for 15" rotors/19" rims whereas their 4pot is for 13.5" rotors, both of which are more expensive than the OEM stuff

StopTech has 332mm and 355mm (13" and 14") rotor setups, both using the same 4pot caliper for $2200 and $2700 respectively

Wilwood has 13" and 14" setups, both using a 6pot caliper, for $1500 and $1700. This is the closest any aftermarket solution matches the OP brake setup, but still costs you $500 more, or even more than that if you compare them with one of the other retrofit solutions out there (be it CTS-V V1 /w 17" rim, 18" rim, or 17Z brembos)

OEM equip is a 4pot 13" rotor setup($2100), a 4pot 13.5" rotor setup($4000), or a 6pot 14.25" ($5000) (optional DBA rotors available in same size), but I can't find who makes the calipers. I would assume Brembo or Harrop.
Note: OEM prices are in AUD, not USD
 

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06 Cyclone GTO
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3,526 Posts
well, which setup are you referring?
Harrop's 6pot is for 15" rotors/19" rims whereas their 4pot is for 13.5" rotors, both of which are more expensive than the OEM stuff

StopTech has 332mm and 355mm (13" and 14") rotor setups, both using the same 4pot caliper for $2200 and $2700 respectively

Wilwood has 13" and 14" setups, both using a 6pot caliper, for $1500 and $1700. This is the closest any aftermarket solution matches the OP brake setup, but still costs you $500 more, or even more than that if you compare them with one of the other retrofit solutions out there (be it CTS-V V1 /w 17" rim, 18" rim, or 17Z brembos)

OEM equip is a 4pot 13" rotor setup($2100), a 4pot 13.5" rotor setup($4000), or a 6pot 14.25" ($5000) (optional DBA rotors available in same size), but I can't find who makes the calipers. I would assume Brembo or Harrop.
Note: OEM prices are in AUD, not USD
Wow! Thank you for clarifying that for me. I was thinking about the Harrop kit. Which isn't cheap.
 

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Discussion Starter #14 (Edited)
Oem aussie brakes are made by AP, which is a subsidiary of Brembo.

I wasn't concerned with cost here, but more with form/function, which I wasn't going to sacrafice over cost. Ending result is a totally bolt on bracket & I replicated oem spec grasp thickness, which for ctv1/2 (and most others) brembos are 32mm. The camaro/g8-gxp utilize rotors with such a thickness since they are basically a 5x120 version of the ctsv-1 front rotor.

The great thing about this for me is that I can piece everything together and have a plethora of rotor/pad choices.

All I have to say regarding the 17z calipers is that the pricing for them seems to be on par with these, also their oem grasp thickness is 32mm. I see others are utilizing the bmw 745 rotor with them, which is 30mm thick, which is at the service limit of what those calipers are already meant to grab prior replacement, which means its out of its optimal squeeze/operating range. With that in mind, I can only imagine what happens to the brake pad and/or rotor when those pistons push into them, I don't want to speculate but that's why I stick with the oem rotor thickness. But, I'm not trying to make this a confrontational/comparison post/thread of any sort (it's just something I wouldn't get into myself.), but one about the ctv2 calipers bolting on. So I'd appreciate if it would be the end of that here.

Thanks for the input/interest guys!

More deets/pics comming soon.



Edit: I was looking at 18z specs and listed them as 17z specs.
 

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Ecotec tech
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2,133 Posts
Oem aussie brakes are made by AP, which is a subsidiary of Brembo.

I wasn't concerned with cost here, but more with form/function, which I wasn't going to sacrafice over cost. Ending result is a totally bolt on bracket & I replicated oem spec grasp thickness, which for ctv1/2 (and most others) brembos are 32mm. The camaro/g8-gxp utilize rotors with such a thickness since they are basically a 5x120 version of the ctsv-1 front rotor.

The great thing about this for me is that I can piece everything together and have a plethora of rotor/pad choices.

All I have to say regarding the 17z calipers is that the pricing for them seems to be on par with utuhese.

Thanks for the input/interest guys!

More deets/pics comming soon.
$350 vs $810. Again, that's why i was wondering if you had any plans to experiment with
a re manufactured caliper to help bring the cost way down. Maybe I'll check if any of the
OEM 17Z rotors are in 5x120, as i was unaware there was such a huge thickness variation. Maybe just machine a set to fit our bolt pattern/hub?

This is the most attractive BBK option available, but I can imagine the other kit selling more due to cost, despite less than ideal rotors. I'm just trying to help you out by
suggesting a way to be more competitive financially, since your already win the performance category. It just so happens that helping you helps me :D
Someone should make a database of rotors that can be sorted by diameter, bolt pattern, and thickness to make diy kits like this easier to spec. Likewise for the calipers

That's the last I'll mention of other kits..just throwing info out there for everyone
 

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Any spacers or anything required to run these brakes? Didnt you have a kit that needed a spacer added to the wheel to fit? Can you just bolt on your bracket and go with it or is there some other modifications that need to happen first (grinding the hub, the hub carrier?) Thanks!
 

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o.g.owner since 10/31/2004
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584 Posts
i would stay with factory brembo's if its a six piston design,not rebuild VW made for a truck or you might as well put a tundra front calipers on,Cts-v and Zr1 +Zl1 calipers are made for cars not trucks.His bracket made for it and at a minimal cost of calipers plus bracket and no cutting or fucking shit up that dont have too do its a plus and its bolt on,all RD done....just saying
 

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o.g.owner since 10/31/2004
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584 Posts
brembos

Any spacers or anything required to run these brakes? Didnt you have a kit that needed a spacer added to the wheel to fit? Can you just bolt on your bracket and go with it or is there some other modifications that need to happen first (grinding the hub, the hub carrier?) Thanks!
test fit on 18's on wednesday nite and im sure he will post pics
 

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FWIW, I am doing the same thing except I will be using the Brembo 2 piece rotors designed to work with this caliper on the CTSV. Got them for $685, and with very little work it was a bolt on affair. The calipers will be utilized with a custom built bracket like the OP has made. The only downfall is the much larger rotor may require a 19" wheel. I'm still waiting to hear back from Forgeline on if they can make it work or not with an 18".

The work done thusfar looks great OP.
 

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Grumpy Bastage
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I see others are utilizing the bmw 745 rotor with them, which is 30mm thick, which is 2mm below the service limit of what those calipers are already meant to grab prior replacement, which means its out of its optimal squeeze/operating range. With that in mind, I can only imagine what happens to the brake pad and/or rotor when those pistons push into them, I don't want to speculate but that's why I stick with the oem rotor thickness.
Nothing.

I thought Konnie the Goat already clarified that...
 
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