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Discussion Starter · #1 ·
Anyone foresee problems for my GT with running the CTS-V 6 piston Brembos on the front of my car while still running stock calipers on the rear - until my mod funds recouperate?? Will the braking be messed up or ABS go nuts??

This is not about wheels and clearance, I have that covered.

Thx!

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Should not be an issue
 

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If the new calipers/rotors now apply more braking force than the stock oem units, there will be a problem. Especially if the force is signfically greater. The brake bias will be altered and you will end up with front brake lock/abs activation and more nose dive.

I ran upgraded front brakes on my maxima. It was exactly like above until I upgraded the rears
 

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Should be fine.
 

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Should be fine for a couple reasons.. The total piston area isn't changing too much between the two setups and Per the FSM our cars have a computer controlled brake bias system. It monitors the braking effectiveness between the front and rear and can make its own adjustments.
 

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Discussion Starter · #7 ·
Good feedback guys, thank you!
 

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Slight hijack, but I was thinking about this setup as well and have the clearance covered with my CTS-V wheels, but my winter setup is the stock 18s. What would it take for the stock wheels to clear those big 6-pots? 20mm spacer? Longer studs?
 

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Slight hijack, but I was thinking about this setup as well and have the clearance covered with my CTS-V wheels, but my winter setup is the stock 18s. What would it take for the stock wheels to clear those big 6-pots? 20mm spacer? Longer studs?
Might be easier to change to the TSW Nuerinbergring wheels in 18 for your winter setup. They fit without spacers or longer studs. My 18 x 9.5 +40 TSWs have more clearance than the stock GXP wheels.
 

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i will plus one the tsw nurburgrings. been DD the 18s with the complete 2009 ctsv brakes for a while now. love the setup. more tire for the bumps. i drive dirt roads some. and lots of bad beatup roads. the only downside to them is there low load rating of like 1300lbs. but i drive mine pretty hard and havent bent one, so i feel confedent in them


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Should be fine for a couple reasons.. The total piston area isn't changing too much between the two setups and Per the FSM our cars have a computer controlled brake bias system. It monitors the braking effectiveness between the front and rear and can make its own adjustments.
Another major factor is braking torque force is how far the caliper is from the center of the rotor. ie.. rotor diameter. That makes a bigger diff in brake torque than piston area imho.

If it's true that we have brake bias adjusters then that would indicate that your braking wouldn't be improved as the force of the front brakes is going to be limited to the amount of force the rears are going to be able to provide. You'd only be gaining fade resistance
 

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Another major factor is braking torque force is how far the caliper is from the center of the rotor. ie.. rotor diameter. That makes a bigger diff in brake torque than piston area imho.

If it's true that we have brake bias adjusters then that would indicate that your braking wouldn't be improved as the force of the front brakes is going to be limited to the amount of force the rears are going to be able to provide. You'd only be gaining fade resistance
Piston area being close means fluid volume should be good using the standard master cylinder.

The brake preportioning valve tries to maintain effective braking by distributing your applied brake pressure front to rear. If the system senses your front brakes are more effective than the rear it will shift additional pressure to the rear. It draws it's info from the wheel speed sensors used by the ABS.

So if your front brakes lock first it shifts some of the new greater total braking force to the rear. While your front brakes might not be working as hard as they did when first installed your total braking remains with your rear brakes now doing more work.

For example and clarity say the new front brakes increase braking force by 20 lbs while the rears are the same. The proportioning valve will increase pressure to the rear after your first ABS stop. But it will only be trying to balance the total force between the front and rear systems. At lets say 80% front 20% rear.

Old system -
front 80lbs braking force / rear 20lbs total force = 100lbs

New system before proportioning valve adjustment-
front 100lbs / rear 20lbs new total force = 120 lbs

Proportioning valve returning system to 80%/20% but now of 120lbs-
Front 96lbs / rear 24lbs

Of course the brakes can only stop as good as the tires on the car allow. So bigger stronger brakes need tires with more traction to be effective. ABS only kicks in when braking force exceeds the tires ability to transfer the brake force to the ground.
 

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Discussion Starter · #13 ·
Piston area being close means fluid volume should be good using the standard master cylinder.

The brake preportioning valve tries to maintain effective braking by distributing your applied brake pressure front to rear. If the system senses your front brakes are more effective than the rear it will shift additional pressure to the rear. It draws it's info from the wheel speed sensors used by the ABS.

So if your front brakes lock first it shifts some of the new greater total braking force to the rear. While your front brakes might not be working as hard as they did when first installed your total braking remains with your rear brakes now doing more work.

For example and clarity say the new front brakes increase braking force by 20 lbs while the rears are the same. The proportioning valve will increase pressure to the rear after your first ABS stop. But it will only be trying to balance the total force between the front and rear systems. At lets say 80% front 20% rear.

Old system -
front 80lbs braking force / rear 20lbs total force = 100lbs

New system before proportioning valve adjustment-
front 100lbs / rear 20lbs new total force = 120 lbs

Proportioning valve returning system to 80%/20% but now of 120lbs-
Front 96lbs / rear 24lbs

Of course the brakes can only stop as good as the tires on the car allow. So bigger stronger brakes need tires with more traction to be effective. ABS only kicks in when braking force exceeds the tires ability to transfer the brake force to the ground.
Fantastic post! Thx.
 

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The only thing that you might want to consider is the bleeding process. In order to FULLY bleed the system you gotta get the Tech II tool used to activate the ABS to do the full brake flush. That's the only thing I would consider since you are gonna end up doing the fluid twice. I guess the 2nd go around do the full bleed.

I had mine put on for me, so I'm just speaking from what I remember being told.
 

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The only thing that you might want to consider is the bleeding process. In order to FULLY bleed the system you gotta get the Tech II tool used to activate the ABS to do the full brake flush. That's the only thing I would consider since you are gonna end up doing the fluid twice. I guess the 2nd go around do the full bleed.

I had mine put on for me, so I'm just speaking from what I remember being told.
The Factory Service Manual States this is only required if you induce air into the system upstream of the hydraulic modulator assembly.

If you don't introduce air into the system by letting the reservoir empty during the bleed process you will only be retaining a very small amount of old fluid in areas of the modulator that are normally closed unless the ABS system is active.
 
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