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The Big Bad Brake Thread



Looking for a slight braking improvement while keeping weight and price in check, so the F-body upgrade seems about right.

No issues with stock 16" wheels, correct?
 
I did the F body brake upgrade a few months ago and I got a big difference in stopping power. The only clearance issues I've heard of are with the 16" alloy wheels with the cross-lace. I have the torque stars and no problems at all. As Drunkie's original post said, the heavier rotors are pretty much compensated for by the much lighter F body calipers.

Now I need to find the GXP rear calipers!

Drunkie, this post has been great! Good job!
 
Heavier rotors effect rotational mass, but we really don't have to worry too much about it since 12" rotors are something these cars can take with ease.

Upsprung weight /= sprung weight.

I'm glad I could help out and I'm glad you like your new setup!
 
Ok so 90% front bias seems a bit much, even if we have a soft suspension. This would be even more evident with a stiffer suspension (coughdrunkiecough) Every time you slam on the brakes the fronts always lock up first. would it be beneficial for stopping distance to upgrade the rears to GXP only? IMO if the stock brakes can lock up the tires, why do you need stronger brakes? unless you are road racing and the heat becomes an issue.
 


JoRoW99 said:
Ok so 90% front bias seems a bit much, even if we have a soft suspension. This would be even more evident with a stiffer suspension (coughdrunkiecough) Every time you slam on the brakes the fronts always lock up first. would it be beneficial for stopping distance to upgrade the rears to GXP only? IMO if the stock brakes can lock up the tires, why do you need stronger brakes? unless you are road racing and the heat becomes an issue.
Click to expand...

Its not just about stronger, its about moving out from the center point of rotation. Its like my analogy with the door, its easier to push a door open the further you are from the center pivot point.

My brakes are overkill and I know it, but it does have a huge difference in stopping, just because you lock the brakes up doesn't mean your stopping can't improve. I think the front GXP upgrade is more then enough as is with the right pads and rotors, as for the rear GXP brakes, No...lets face it these cars are not high performance in the handling department. They tend to suck wind at it.

The stock brakes are enough to beat the maximum distance allowed by US Government regulations for stopping, so yes the stock brakes are really enough, but there are plenty of options for all of us who would like better braking cause the bare minimum just isn't acceptable sometimes.

Its all in a matter of what you really want. You can do a nice set of rotors and pads on stock brakes with SS lines and that should be enough of an improvement that you will feel.
 
drunkie so Fbody rotors are drilled for 115 and 120 mm bolt pattern? i got hawk hps pads and im wondering what i need for rotors, people so 04+ works, Fbody, monte carlo rotors all could be used.
 
04+ rotors DO NOT WORK...I did that and found out why, they do not make full contact with the pads.

So F-body rotors are the only ones you should use, they are drilled with holes large enough to fit the two patterns (saves money). And I suggest blank or slotted rotors only with some hawk pads.

So I take it you got the package? Did you like how wrapped up those calipers LOL
 
DrunkieTheBear said:
Its not just about stronger, its about moving out from the center point of rotation. Its like my analogy with the door, its easier to push a door open the further you are from the center pivot point.

My brakes are overkill and I know it, but it does have a huge difference in stopping, just because you lock the brakes up doesn't mean your stopping can't improve. I think the front GXP upgrade is more then enough as is with the right pads and rotors, as for the rear GXP brakes, No...lets face it these cars are not high performance in the handling department. They tend to suck wind at it.

The stock brakes are enough to beat the maximum distance allowed by US Government regulations for stopping, so yes the stock brakes are really enough, but there are plenty of options for all of us who would like better braking cause the bare minimum just isn't acceptable sometimes.

Its all in a matter of what you really want. You can do a nice set of rotors and pads on stock brakes with SS lines and that should be enough of an improvement that you will feel.
Click to expand...

In all due respect, I dont think you completely understood or at least commented on what I said. Basically, the best stopping distance will be when all 4 tires lock at once, although this may not be desirable for track conditions because it will be harder to control if you lock them up. By upgrading the front brakes only, you are putting even more force on the front brakes buy increasing the bias towards the front brakes which already lock up first, which means the back ones arent helping to stop the car as much, while the fronts are stopping it the same amount. I agree that bigger rotors/stronger calipers will increase the stopping force due to leverage and other physics. But since they are already capable of locking up, the benefit of larger front brakes only means that you have to apply less force on the brake pedal (ignoring the heat factor.) Thats why I think upgrading the back would put more bias on the back brakes since they DONT lock up would help stopping distance, especially on cars with stiffer suspension.


EDIT: these guys explain it well.

http://www.i-club.com/forums/suspen...what-will-decrease-my-braking-distance-45930/
 
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No comment as I dont have any proof that ABS helps/hurts braking distance. My guess would be that it increases distance on a perfectly tuned setup. It may help compensate for a bias that is too much towards the front IF out GPs can control the front and rear separately.
 
well ill just say drunkies setup is overkill. period (still awsome though)

after talking with some of racers at our local track, they like having abs on their cars. it takes away some of the understeer and stops the ***end from coming around ( refering to the car on a track)

how often do you lock up your car on the street?
 
Never. You never know when someone will pull out in front of you though. How often do you need more braking power in the front only? even less often. Also like I said, if all 4 brakes lock up at the same time, you will have the shortest stopping distance. But if the fronts lock up SLIGHTLY before the rears, you will have more control on a track (no oversteer if brakes are locked up) with minimal reduction to braking distance.
 


"The car with perfectly balanced brake bias will, however, be the last one to hit the brakes going down the back straight. By distributing the braking forces so that all four tires are simultaneously generating their maximum deceleration, stopping distance will be minimized and our hero will quickly find his way to victory lane."

"We know where most auto manufacturers tune brake bias – they like our cars to be front-biased in all conditions achievable by the tires offered on the vehicle."

"Now, if we make changes to the car that can effect brake bias and re-measure stopping distance, we can tell immediately if we have taken a step in the wrong direction. For example, it is not uncommon to install more aggressive front brake pads (which will make the car even more front biased) and see stopping distances go up 5% or more. Dedicated race pads can result in even longer stopping distances.

The most dramatic front-bias impacts are usually brought about by “big brake kits” which are not properly matched to the intended vehicle. Any time that a bigger front rotor is installed, there is a simultaneous need to decrease the effective clamping force of the caliper (installing smaller pistons is the easiest method) to offset the increased torque created by larger rotor effective radius. The objective is to maintain a constant amount of brake corner output (torque) for a given brake line pressure as Figure 6 illustrates. Unfortunately, too many upgrades do not take this factor into account, and those poor cars end up with both bigger rotors and larger pistons which serve to drastically shift the bias even more forward. While rock-solid stable under braking, stopping distances will go up dramatically."

Your point? Yes I may not realize how much weight transfer there is on these cars, but we havent exactly been throwing out weight transfer numbers at all. The simple fact is that these cars have the front wheels lock up first during hard breaking. making them lock up sooner will not help anything other than pedal feel. I have seen some brake kits for subarus increase the rotor size but purposely REDUCE stopping force on the front brakes to decrease braking distance.
 
redlinepontiac said:
hmm if you lock up all 4 wheels at the same time wouldnt that put your car into a slide, and sliding isnt stopping right?
Click to expand...

Yes you are right. I did not say (or at least didnt mean to say) that sliding on all 4 tires will be the best way to stop. Simply that there is the bias to do so.
 
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