SlideWRX

For track-day durable braking:

Bang for the buck is GT rotors (replacements at newtakeoff.com I think, cheap to replace) with pads, lines, fluid & cooling ducts. Lots of guys going to track days use this setup without brake fade. Hopefully some will chime in here with their choice of brake pad.

If you have a supercharger, you may need to upgrade, especially with the hot daytime temps you are talking about. Then the GT500 setup is great. Whatever you do, don't buy rotors assuming the drilled and/or slotted are better; They are for looks only. Solid rotors will last the longest, assuming they are of the same quality. If you want to research this, there are huge threads elsewhere that go into the stress analysis, cooling, the metallurgy and other factors.

Glengemen

The reason the big GT500 brakes work so good is their size. Big brakes add weight. 14" rotors have more leverage than your V6 brakes. Unless you want to really spend money on the Baer aluminum center rotors with the relacation brackets for the GT calipers (I am not sure if the calipers are different GT to V6) or even their 2 piston calipers.

Forget the brake perpotioning valve if you want to retain ABS, as it wont work right with it.

Being in the desert wont affect your braking temps unless you are racing, but even then 5-700 degrees disapates pretty good in 110 degrees.

clintster77

wow. I thought cross drilled was better due to cooling effect .

If I upgrade the front brakes and use a larger rotors up front and giving more stop torque earlyer in the pedal compression . Along with the rear tires being wider than stock that is more out of balance than I thought .

Here is a thought about how I could get a proportioning effect without using a proportioning valve or disconnecting the ABS.
I could put better gripping brake pads on the rear than the front .this seems to defeat the purpose of upgrading the front but it actually makes the front work less hard so it would give a overall better stopping effect as a whole.

As far as the suspension goes this is what I was thinking about the rear axle geometry . from what I understand the more anti-squat a car has in the rear the more the brake torque has a tendency to take load off the rear tires. ( just the opposite )The mustang also has fairly short Lcas and a very short UCA this also contributes to axle lift . A V6 can get away with less anti-squat than a high power 400 hp v8 car. This can also be taken into account .

Anyone?

Norm Peterson

Nope. The original reason was to give pad outgassing a place to go rather than float the pad off the rotor via high pressure gas film. Not really an issue any more, I think particularly not once you've broken the pads in and used them really hard a couple of times.


Race pads are much worse than stock for "bite" when they're cold, and they can be extremely abusive to your rotors under some conditions. Even performance street and autocross pads may not be quite as grippy on the first stop when they're dead cold in the winter (let's say maybe 20°F ambient or lower). Pad coefficient of friction varies with temperature


Two things going on here. One is brake balance and the other involves what the tires can do with it. I'm not sure that wider (by itself) always equals better stopping. Wider that permits softer, sure.

Quote:

Here is a thought about how I could get a proportioning effect without using a proportioning valve or disconnecting the ABS.

You should play around with a spreadsheet solution for brakes that considers all of the variables. Effective pad radius, piston sizes and numbers, loaded rolling radius, pad coefficient of friction (which may differ front vs rear even as OE). Proportioning valve characteristics can be modeled in, etc. etc, and I know I've left a few other things out. I'd post a screenshot except I'm out of upload space.


The length of the links themselves is only part of the story, and is related more to how rapidly the antisquat and axle steer percentages change with suspension bump/rebound travel. IOW, you could get 80% anti-squat with the OE arms, with longer ones, or shorter ones, and the initial amount of A/S would be the same in all three cases.


Norm

clintster77

Is it a safe statement to say( "The A/S percentages change with suspension bump/rebound travel is more when the UCA and Lcas have a larger difference in length when compared to each other .

For example : (the roll steer issue aside for now) in straight line test ,an equal length 4 link set up would have a lot less bump/rebound percentage change than the mustang S197 would with the short UCA comparative to the Lcas.

Is it the ''percentage change'' that would have an effect on rear axle brake lift or the initial anti squat percent ?

Texotic

If you go with drilled rotors, plan on replacing them much more often because they crack. If you must, go slotted, but I'd avoid cross-drilled.

I used completely stock brakes at a track day and I burned through probably close to a 1/4 of the stock pads. I also boiled the fluid on the second to last session of the day. I ended up machining the rotors afterwards also, but they were a bit warped beforehand and the track day just made it worse. If you need to replace the rotors, you can get all 4 from newtakeoff.com for about $80, I think. My first step as far as upgrades are concerned is better fluid, I just switched to ATE Super Blue, but haven't used it yet at the track. The reason fluid would be my first concern is because that is the only thing I had that I didn't feel was up to the task without endangering me. Boiling fluid is scary, mine boiled coming off the front straight, luckily I wasn't pushing it quite as hard as I had been earlier in the day, because the pedal dropped to the floor and I had no braking power for a few seconds. I was only doing about 100 at the time... if I had been at 130, I would have been screwed. Pads would also be smart because you'll burn through the stock pads really really fast.

Norm Peterson

At this point, all I'll say is "probably". To say for sure sounds like an exercise in differential calculus involving how the IC and CG coordinates vary with the actual chassis movement (how much is pure vertical "heave", how much is pitch).


Percentage change is going to be a secondary effect that happens once the chassis starts to move. Mostly it would matter in cases where you're very close to something that's critical, such as brake hop/no brake hop, wheelspin/no wheelspin, or maybe wheel hop/no wheel hop.


Norm

Sleeper_08

I was reading a thread on a Corvette site and they have 'standards' for how badly a cross drilled rotor can be cracked before it has to be replaced!

In this example the rotor had 18K road miles and 4 track days

http://forums.corvetteforum.com/auto...his-rotor.html

Texotic

Exactly. I wouldn't want to worry about if my rotors are cracked too much to use or if the cracks are still small enough to keep using. Solid and slotted rotors FTW. If I had the money, I'd put on a set of DBA 4000 or 5000 slotted (only) rotors.

http://www.dba.com.au/2006/products.asp

RodeoFlyer

Brembo has oem replacement rotors available now. I believe Moss Motors has them.