First off, whoever posted about the wheel shaking... that's most likely warped rotors. When brakes fade, it doesn't cause the wheel to shake, the car just doesn't stop as fast.

As for adding lighter wheels and rotors, I doubt it would help braking at all. Most cars are already able to stop harder than the tires can hold, so the weak link is not the stopping capacity of the brakes, it's grip of the tires. Making the car lighter reduces the friction force the tire is capable of creating, and thus, it would probably end up hurting total braking force. Granted, the amount of weight lost by changing wheels and rotors would have a minimal impact in the car's overall weight. That is not to say that the minute amount of braking force lost wouldn't be offset by a performance increase due to a drop in unsprung weight.

 

Btw, wouldnt the steering wheel shake everytime I brake if the rotors were warped? It dosent shake if I drive calm, its only after a heavy break like 120-40 that it starts, but then I can fell it in low speeds too.

Can overheating do this?

 

First, your discs are not really "warped." That's a bit of an urban legend. I would highly recommend you go to Stoptech's Tech section and read the "White Papers." http://www.stoptech.com/tech_info/te...e_papers.shtml

You'll note the article "The "Warped" Brake Disc and Other Myths of the Braking System" This is authored by Carroll Smith (one of Stoptech's technical advisers). Enough said.

As for the rest, I can only speculate. Overheating should have no effect on the feel of the steering wheel. The two suspects that are effected by heat (in a manner you would feel at all) are the pads and the fluids. The first would feel like you are pushing on a hard pedal, but the car isn't slowing as fast. The second would feel like the pedal is sinking deeper than it should or did (and the car is likely not stopping as fast).

Roy, the reason I suggested deposits being left on your rotors (effectively what most folks call "warped rotors"), was the temporary nature of your experience. If the deposits are "light" (such a technical term!) they may be scrubbed off on subsequent normal braking efforts. So rather than continuing to build up the deposits by poor braking technique (dragging the brakes, continued longer-than-necessary braking, etc.) you may be removing the little that was deposited on that first bonzai run. Again, pure guess here.

And for wheel diameter, the general rule of thumb is that increasing the rotational mass of any component makes you accelerate or decelerate less effectively. So a lighter wheel/tire combo (esp. where the lightness is at the end of the diameter) is going to be easier to pull down from speed. Of course, this is just theory. In the real world there are a huge host of other factors that will come into play (as Texotic began to explain), so I don't think it's a yes/no answer for anyone considering going to a lighter rotor. They should help, but getting it all together may come at the cost of other sacrifices. At any rate, I doubt it would be a substantial benefit. I'm pretty sure there are 2-piece OEM size rotors available, but they are very expensive. So shelling out $500 or so for a front pair alone just to save 3' of 60-0mph stopping sounds a bit eccentric.

Now my parting thought on the matter comes from Stoptech again. This is a company that makes its living selling big-brake systems for real race car teams and performance enthusiasts. And yet in one of their White Paper articles ("Brake Systems and Upgrade Selections") they state as their first conclusion, "In order to brake effectively, the tires must comply with and grip on the road. Your braking system is no better than your tires and suspension. The best money that you can spend is on really good tires and really good shocks."

Best,
-j

 

I would agree with the best money spent on braking is in the tires if you're talking about total braking capacity, but if someone is tracking their car, the best money spent, IMO, would be in pads and fluid. If someone upgrades to a stickier tire and doesn't also upgrade the pads and fluid, the brakes will fade even faster. I speak from personal experience: I did a track day at Texas World Speedway on a 100% stock brake system, but with wider, stickier tires than stock and boiled my fluid coming off the front straight. Let me tell you, it is scary to realize you have no brakes when you're trying to come down from 130 to enter a turn.

I think he said he wasn't tracking his car, so that is a moot point. Just thought I would throw that in for anybody else reading with track day intentions.

And, yes, a "warped" rotor just has uneven pad material deposits that make it feel warped. That doesn't actually mean your rotor is bent or something.

 

Stop Quoting white papers like a robot especially when you're going to go and do it wrong, this has more to do with the second article. First of all though like you said warping does exist, if you read the article it points out that while it may have absolutely nothing to do with the disc being "physically" warped the common method of warping a brake disc still causes it to feel warped. Interesting stuff.

I've warped the brake discs on several cars in only one driving session. It's a very specific result you want to avoid.

Upgrading tires and shocks only is a complete missquote actually. It says "If the braking system is only marginal" to upgrade it first. If it's already good, going from a good braking system to a great one won't do much and I agree with that. Only if it's great they say to focus on suspension. However both the GT500 braking system and the GT braking system are a POS. I've watched two GT500's crash and get totaled respectively at Mid Ohio because their brakes suck and became cooked.

Don't let Texotic disagree with you though let me.

Also for anyone considering upgrading the pads lines discs fluids etc, if you do it completely it commes to about $900. I've had six braking systems on the car since 2006 if you count the front setups only and stock system and I don't just track my car but do serious long sessions with it.

Considering that the brake bite, consistency thought the application, caliper flex and brake control are important to the ABS system and being able to stop quicker aftermarket brake systems will make a difference of around 3 mph based on telemetry data when I have no traction, primarily because they are much smoother. And if you don't know about brake feel, consistency and control now you do.

If you look at the actual price of upgradings pads lines etc to getting a big brake kit which already comes with lines then the money spent starts to make some sense. While it won't make complete sense unless you start fading your brakes, it could offer you lots of feel and improve your driving experience in addition to the overall deceleration too. The big 15" systems are mostly for looks or track use but the cheaper 14" ones are nominally priced.

Also I'm very good friends with StopTech's VP Mark Cornwall. If anyone wants a slight discount on their products I can order them for you to help you out.

 

Usually whenever someone suggests that someone upgrade pads, fluid, and lines, the person is a beginner and those upgrades will be more than enough for them for a while. If it gets to a point that someone is considering swapping discs, they might as well go with a BBK, IMO. However, I feel that the pads/fluid/lines upgrade should be the first step for most and that the BBKs should only be used after the person starts getting serious about tracking their car.

 

Response to Legion5

First, I’m not sure exactly what your criticism is aimed at here. You seem to take issue with ghosts, for I haven’t said anything that disagrees with what you or Texotic have said with regard to braking (in fact I was going to second his last two posts until I saw yours). Context is important, so let me lay this out clearly.
1. I make a distinction between street and track use. If you don’t, we can stop here. However others do (I think reasonably), so to them I am speaking.
2. Across that distinction a tire upgrade will always yield the best bang for the buck with respect to stopping distance. So you start there to the extent you can (money, use, etc.).
3. Within that distinction different problem present themselves, thus the need for different attempts to resolve the problems. I’ve tried to focus my recommendations (here and elsewhere) with this distinction in mind.

Second, I have no doubt that with your track experience you have found need for seriously upgraded braking equipment. To this I can only ask, what should you or anyone else doing this expect? Hell even with my limited track experience I’m inching up on the point where I am considering upgrading soon (nasty pad taper after a couple of weekends last year, and it seems to me that this is coming from caliper flex). So I may take you up on your discount offer. My point is that nothing like this kind of abuse is witnessed on the street. Nothing.

Now with respect to suggesting the White Papers, you’ll note that I recommended people read them. I gave source, author, and article title. That wasn’t done for my personal record keeping. That was done to give folks the resources they need to go and make up their own mind about such matters. If you’ve read them and disagree with my conclusions, then that’s great, after all that’s the real point to giving resources in the first place (to give people common ground).

As far as quoting out of context, you should heed your own advice. I never said someone should only upgrade tires and shocks, nor did I offer the quote to suggest it for me. So how is it you make such a claim? If you misread my words, that is your problem. The point of the quote was to show that even a company in the business has enough knowledge to establish priorities and (perhaps even more importantly) the integrity to say it outright even though it may cost them sales. Having priorities in no way suggests ruling out options, quite the contrary. What priorities imply is that you take the time to evaluate those options. I’ve insisting the same as Texotic, namely that pad, fluid, and line upgrades are a good starting point for someone who begins to track their car and then upgrade as needed, and these upgrades (esp. pads) will pay strong dividends for someone seeking to upgrade street braking performance. In saying this we are both expressing our evaluation of the relative worth of the returns on one’s investment.

Finally, with respect to GT500 incidents, I’ve personally seen three totaled at the tracks. I can’t claim to have “seen” their brakes get cooked. What I’ve witnessed are guys with little experience (self-professed in conversation) jumping into very powerful cars getting in over their heads. Not by accident their mishaps were coming out of corners, not losing it going in. At any rate, if you have more direct experience on the matter, then this is good to share, especially since many folks who are looking to upgrade their brake systems look to the GT500 Brembo set ups as a cheaper alternative to something like Stoptech. If what you are saying is correct, they should again perhaps reconsider their priorities.

Best,
-j

 

yeah there's a common quote in racing. "You give me your X and I'll destroy it's X in X laps".

The thing about brakes is that in almost all street cars they are so unbelievably bad. They are the worst X in any car. If you think of brakes as the inverse of an engine, to generate maximum braking force, they have to generate -400 horsepower each continuously on any car, even a honda civic. Now judging by looks alone those tiny pieces of metal don't look like being 400 horsepower generating systems for any length of time.

The mustang actually has ones that while they aren't pathetic they're still lacking. I would label them a set of "premium economy" brakes. By economy I mean that they are part of a set of brake systems that won't last for any serious length of time or work flawlessly when applied (for example flexing). The ford engineers knows what they are doing and they're making something that you can reasonably pretend to go fast in, not something that will be brutally tested by a reasonable amount of people like a Porsche or Corvette.

The problem with aiming an upgrade for the street is that based on example it really depends how you drive, not where, with police and reckless endangerment laws out there it makes a point to slow you down a bit but I have a video of a stock Mustang GT on the nurbergring (a course which mimics street driving) and the driver fades the stock brakes in 4 minutes or so, driving fairly slowly for that track. So it's possible to do a lot on the street, and the mustang's street brakes are probably one the best of their economy sort after all...

To be honest I actually don't see the benefit of doing all this expensive stuff, ie suspension pads lines fluids tire, AND sticking with basic brake upgrades in doing that.

If you are going to bother with the cost and time to put all that on the only way skipping on brakes makes sense as an "investment" is when you want to reduce weight and aren't worried about huge brake fade, or have to stick to a set of rules. What I'm trying to say is that if you're going to do "everything", then the only conceivable way that it's going to make sense is if you're doing autocross, where you have short laps on a short circuit.

The marginal benefit of a $1900 brake kit over a $900 brake upgrade is equal in terms of your bang for the buck and it's not exponential like most things with cars. When you combine added control, with added bite, and consistency and the fact that just a simple upgrade to the stock brakes of the car really won't change too much it's definitely a linear progression, again unless you are trying to exploit an unchanging specific autocross situations. If the progression is so linear the reason why I don't see the use is in doing a $900+ upgrade is you may want to go bigger at some point and then your initial upgrade is a waste.


My ideal begginer upgrade would go like this:

Enkei RPF1 18" Wheels $900
Direzza Sport Z1 Tires 245/45/18 $900
Koni Dampers $450
Vogtland GT500 Springs $550 (installed)
Adjustable Antiroll $300
Stoptech 14" front with steel lines $1800
Hawk Pads, all around $225

Total $5100


As with quality of the braking on a GT500, the GT500 brakes have more in common with the brakes that come on an E46 M3 than on a Ferrari. By this I mean very specifically that they aren't all that great. They're not a full blown setup, they're a half done setup that can barley get by at high speeds, the stock brakes on new a Z06 Corvette are much better for example. I know this because one of the crashes i've witnessed involved a GT500 that had only done a few laps trying to follow a base Corvette that had done a similar amount of laps. The GT500's brakes faded quicker and he totaled the car by flipping it 5 or 6 times. It was a brand new stang.

you think specifically like a professional race car driver or crew cheif phillostang. It's a very obvious trait. good direction.

Having an easier to or modulate drive car, or one you have better control over isn't a bad thing at all though.

 

Interesting exchange guys - I was wondering when the pro/con BBK discourse would start...it always does.

My "starter" brake kit that I began with at my first track day:
Hawk HT-10 Fronts: $179
Hawk HP+ Rears: $86
Goodridge SS lines: $145
Thats a total of $410

For a novice to intermediate driver doing typical HPDEs this set up works great. In 13 track days last year I had zero brake issues (note I did add brake ducts mid way thru last season).

In defense of Philo - he, and many others have been very consistent in their advice: go with a starter setup like this as the first upgrade. If/when you need more, you will know it without having to ask (its the newbys and inexperienced that are here looking for advice to whom this comment is directed), then upgrade to a BBK. IMO - very, very few of the folks reading these posts and looking for brake upgrade advice *need* a BBK. There are certainly reasons for a BBK (enduros or prolonged intense usage, longer pad and rotor life, your rich, you like big rotor bling, better "feel", etc), but for most drivers wanting to improve their braking, going straight to a BBK without first trying the simple and cheap starter setup are missing out on an opportunity to save $ while accomplishing the same end result (for almost all scenarios). If some folks want to disagree and state that going straight to a BBK is the smart and prudent thing to do...fine, differing opinions are what these discussions are all about. In the end, its reader who is here looking for advice and wondering what to do who must evaluate all advice and come to a conclusion that best fits his/her situation.

 

Great thread..... I like hearing what people have to say. I'm one of the new guys here looking for help and I FOUND IT and then some. Thanks for all the input it has helped me out a lot to come up with what I'm going to do for my first brake upgrade. Thanks again.