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Anyone want performance rotors for the GS??

synolimit

Full Member
387
1
0
Akron OH
Buick Ownership
2012 GS
When I had my WRX's the OEM brakes were horrible!! Very small with lots of fade. They were 11.6" rotors with under an inch in thickness with single piston one sided calipers. The STI had Brembos 4 pistons with 12"+ rotors (not the real deal like a race kit, what we have that are good but not the best). So I wanted to upgrade. There were some nice street kits out there but nothing what I wanted for the track. They had decent calipers, 4 piston or 6, ok sized rotors, 12" I believe etc. But just not what I really wanted. Then I came across a guy that made custom brackets to use 14" x 1.25" Wilwood rotors and their race HUGE 4 piston or 6 calipers!! It was the best thing I ever seen.

The point of all that is Wilwood makes some nice rotors. In my research to save money on the kit I thought about not buying their rotors but using solid rotors from a factory car like ours (14" x 1"+ rotor). The problem though was gaining weight. Solid rotors like ours are 20 or even 30 lbs (I can't remember). Wilwood uses aluminium top hats then a slotted, drilled, slotted/drilled rotor. If I remember the weight was only 17lbs. It was a good 5-10lbs lighter! That's a huge amount off unsprung weight vs like removing 100lbs from the trunk.

I know this isn't a race car but who would add these to there car for the look, lighter weight, better performance on the street??




 

RevJohnnyVegas

Full Member
248
1
0
DFW, Texas
Buick Ownership
2012 Buick Regal GS
Depending on the price, I'd be in. Can't break the bank too badly on car parts because I'm trying to keep money aside for an engagement ring.
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synolimit

Full Member
387
1
0
Akron OH
Buick Ownership
2012 GS
Ok i just took off the OEM rotors and got as many measurements as i could. i am blown away at what size these things are!!! the rear GS rotors are bigger than my WRX's front rotors! thats crazy and there as big as a STI's front with brembo calipers!! with these sizes you could track this car no problem and not have to worry about fade since the heat has so much room to disapate (of course you'd want new fluid, pads, and SS brake lines to go with).

ok i called up Wilwood and we got as close to OEM size as we could. my way of measure the offset and back spacing is not 100% on. the things i know that are 100% are we need a top hat with a 5x4.5" bolt patter (thats a 5x120). we also need a rotor that is 14x1.25" for the front and the only thing they have is the GT72 in that size and thats fine because its the most bad ass rotor they have.

now where it gets tricky with my measurements. i measured from where my rotor was sitting on a table to the back of the rotor where it sits against the hub. im sure i was a little off because i had to use a bolt and write on it with a pen because my caliper couldnt measure that like that. i got "1.62 inch". now if you subtract the thickness of the rotor you sould get the offset, 0.37". now Wilwood doesnt make a 0.37" offset. its either a 0.35" or a 0.41" in a 5x4.5" hat. we can rule out the 0.35" hat because that hat will not bolt to a rotor big enough in our size (14x1.25"). so we have to go with the 0.41" offset hat. lets just hope my writing with a pen and then measuring is a little off. however 0.04" is only 1.016mm so it should bolt in and be fine being that small.

now the other numbers that are not an issue and are 100% correct are the OEM hub hole and hat thickness from the back to the front where the wheel bolts to. our hub hole is 2.65". the 0.41" offset hat has a 2.8" hole. but since the hat sits in the studs the hub hole sould not be an issue. if is was smaller then yes that would be an issue but bigger should be ok. as for the hat thickness the 0.41" offset hat is only 0.27" thick. our OEM rotor is 0.33" thick. what that means is our wheels will be pulled into the car an extra 0.06" or 1.524mm. i know most people want spacers to kick the wheels out and someone on here has installed a 20mm spacer so you could do that. again it shouldnt be a problem only coming in 1.5mm. no one can really see that with the naked eye.

as for weight. the OEM rotor is 24.96lbs. getting the GT72 rotor and aluminium 0.41" hat the weight savings should be 5.46lbs. thats a good amount off the drive train having to spin that up times 2! add some lighter wheels and tires and she should start to take off a little faster and free up some power.

im still working on the rear rotors. its not looking to good at the moment. heres the part numbers so far.

160-8398 rotor, retail price $284, cheapest ive seen ebay at $250
160-8399 rotor, same above
170-6223 hat, $170 times 2, cheapest ive seen summit racing $158
 
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synolimit

Full Member
387
1
0
Akron OH
Buick Ownership
2012 GS
Depending on the price, I'd be in. Can't break the bank too badly on car parts because I'm trying to keep money aside for an engagement ring.
to bad you dont live in ohio. i know some people. im very very very picky and end up learning everything about something before i buy it. after 6 months i finally landed on a diamond my freind had at his story. its made by Tolkowsky whos 7th great grand father invented the 58 facet cut to produce the most bounce back of light and stuff using math and all that. they are pretty insane diamonds and much better than what you normally come across! his stores cost was $15,000 and his cost was only $9000! the ring we ended up getting was Ritani who is an italian designer. all hand custom made, better gold alloy, only use D E F colorless stones with VS-VVS clarity for the little side stones if she likes that stuff. should check all that out.

and remember this stuff is marked up 50-80%!!! my $400 Tungsten ring was only $38 cost!!!
 

RevJohnnyVegas

Full Member
248
1
0
DFW, Texas
Buick Ownership
2012 Buick Regal GS
That's very nice. Fortunately I've got a friend in Dallas who is extremely knowledgable about rings, stones, etc. and she's going to be helping out.

And for the rotors, that's not to bad on the pricing for the front rotors.
 

wungun

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0
Buick Ownership
Buick
Bringing this one back...
GS shares the same brakes as the Camaro ss and G8 GXP
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dmr02

Full Member
278
57
28
Toronto, Ontario
Buick Ownership
18 Regal GS
im still working on the rear rotors. its not looking to good at the moment. heres the part numbers so far.

160-8398 rotor, retail price $284, cheapest ive seen ebay at $250
160-8399 rotor, same above
170-6223 hat, $170 times 2, cheapest ive seen summit racing $158[/QUOTE]


Can anyone confirm if these part numbers will work, or has anyone tried at least? It's a bit much for me to spend on trial and error. Worst case scenario I'm going with slotted rotors and OE GS pads from a 2013, the pads on my '14 are a joke
 

dmr02

Full Member
278
57
28
Toronto, Ontario
Buick Ownership
18 Regal GS
The company I work for buys a lot of product from Wilwood. I will reach out to them and see if I can get some mock up parts.
That would be awesome, because I am happy with the calipers we have but would like to see some options for a bigger rotor, and of course a different caliper bracket, I am thinking one from the 5th Gen Camaro SS would work, thanks slow4dr
 

Walt G

Full Member
859
63
28
25 miles SW of Chicago
Buick Ownership
'12 Regal GS
I'm curious how much bigger than our stock 14" rotor were you thinking of trying to put in there? I'm not super familiar with what the 5th gen Camaro SS came with, but I thought they were also 14" like ours.
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dmr02

Full Member
278
57
28
Toronto, Ontario
Buick Ownership
18 Regal GS
I'm curious how much bigger than our stock 14" rotor were you thinking of trying to put in there? I'm not super familiar with what the 5th gen Camaro SS came with, but I thought they were also 14" like ours.
I haven't exactly figured out what I am going to do, at this point all I really need is new pads for the front but while I am spending money on those I'd like to upgrade the system a bit, I still have until April until I do anything, just trying to see if anyone has done a bigger rotor. I don't see a reason to go with a 2 Piece rotor unless it is going to be a bigger rotor, if not I will just go with a Stoptech slotted rotor and some OE '13 GS Pads. My bad on the 5th Gen Camaro SS reference, more like a ZL1 Bracket or CTS-V bracket, I seen a member on here who bolted up a CTS-V Caliper no problem, so maybe I will start there.
 

Walt G

Full Member
859
63
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25 miles SW of Chicago
Buick Ownership
'12 Regal GS
I hope I didn't come across as 'snarky'... that seems to happen to me sometimes online. I ask because I'm currently debating if I want to do some upgrades to my Regal (brakes mostly) and run more HPDE's with it this year, or if I should just buy a dedicated track car. I have been researching what could be done with the brakes. I'm thinking a good set of rotors, real race pads (leaning towards Carbotech XP-10's or XP-12's), and some cooling ducts would do the trick. Rotors and race pads are easy, of course no one will ever make a brake cooling duct kit for this car, so that would be fabrication (it would be cool to incorporate the fangs somehow).

I've tracked my car twice now. I boiled the brake fluid the first time out... probably my bad for not putting in brand new DOT 4. Second time I did put in new fluid and didn't have any problems. But I'm thinking an upgrade would be necessary once I ditch the RSAs and put on much stickier tires. I'd be carrying a lot more corner speed and therefore straight speed, and braking later.

Let us know if you find something good.
 

dmr02

Full Member
278
57
28
Toronto, Ontario
Buick Ownership
18 Regal GS
I've tracked my car twice now. I boiled the brake fluid the first time out... probably my bad for not putting in brand new DOT 4. Second time I did put in new fluid and didn't have any problems. But I'm thinking an upgrade would be necessary once I ditch the RSAs and put on much stickier tires. I'd be carrying a lot more corner speed and therefore straight speed, and braking later.

Let us know if you find something good.

Not snarky at all, I am glad to have someone chime in on this as I am interested in upgrading the brakes. I have not tracked the car like yourself, I could and probably will as we have some open track days pretty close to me, my main issue is just slowing the beast down from higher speeds, I like to have fun on the on and off ramps and sometimes feel like the brakes could use more bite. Ideally if someone came up with a 2 piece rotor or even a bigger rotor in general like off of a c6 zo6 etc, and what bracket to use I would pull the trigger, if not I am sure I will be fine with some slotted rotors and better pads
 
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wungun

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Buick
If I could just find someone in Canada that sold the 2 piece rotors for the G8 and SS, I'd be happy. $200 freight from the US and the CDN at an all time low, it's not happening for me. :S
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dmr02

Full Member
278
57
28
Toronto, Ontario
Buick Ownership
18 Regal GS
If I could just find someone in Canada that sold the 2 piece rotors for the G8 and SS, I'd be happy. $200 freight from the US and the CDN at an all time low, it's not happening for me. :S
Hahaha not the best time for us Canadians is it, hopefully things turn around a bit come spring
 

Walt G

Full Member
859
63
28
25 miles SW of Chicago
Buick Ownership
'12 Regal GS
I like to have fun on the on and off ramps and sometimes feel like the brakes could use more bite.
I think before you change rotors and calipers, you'll want to just try some different pads. From what I've been reading, the pads more than anything else determine that initial bite feel. The original, early model GS pads had a lot of bite, but they also made a lot of dust. So many people complained about the dust that GM changed them in later GS's.

So far, I have been putting back on the original '12 GS front pads when I track the car and they've worked pretty well. I'm traction limited, not brake bite limited. I'm mostly afraid they'll overheat once I start pushing harder with better tires.

Last time I tracked the car I did screw up my rotors though. I got a bad pad imprint on both front rotors (two imprints actually on one of them). I'm not sure if I came into the pits too soon and applied the brakes, or if maybe it happened when a car in front went off track and I had to come to a complete stop for a few seconds right after the front straight (so, 105mph to dead stop). But ever since that day, I've had a mild pulsation. Just yesterday I finally swapped rotors.

I'm going to try Powerstop Z23 pads this time (for daily driver pads... something else will go in for the track). I'm not even done breaking them in yet, so too early to report on initial bite.

brake_pad_imprint.jpg
 
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