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Old 04-25-2003, 11:52 PM   #1
Siper2
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Default So how *can* you decrease stopping distance?

After just reading AWDBOY's thread (http://forums.nasioc.com/forums/show...hreadid=351407), and replying to it myself, I find myself a bit stumped.

I've learned a lot by paying attention to some of the brake gurus here, but one thing baffles me... A lot of people, including me, came to this forum at one time to learn how to "stop better." Our theories got laundered and hung out to dry, mostly, and we walked away with a cleaner view on braking dynamics. In plain English, a lot of us now realize that bigger can be better, but not always. Sometimes, it's worse, especially when utilizing otherwise stock brake system components.

Lots of mathematics and physics involved. It's more complicated than even slapping on a front BBK. Recently the hot topic's been front and rear brake bias, and leaving some of the duty to the rears. All very interesting stuff, a lot of which isn't divulged to the public...


But for those who TRULY want, or need, to have a comprehensive, kick-butt brake upgrade, how do you do it?
If a BBK is potentially LESS effective because of the OEM master cylinder, etc., would a new cylinder (and anti-flex bracket, etc.) cure that, and effectively make a better brake setup?

Then would brake distance decrease?

My point is this: I know BBKs are often a fashion statement, but they DO help in more than just fast/heavy repetetive braking, as in racing................... Don't they?

-S2-
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Old 04-26-2003, 12:10 AM   #2
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Default Re: So how *can* you decrease stopping distance?

Quote:
Originally posted by Siper2
My point is this: I know BBKs are often a fashion statement, but they DO help in more than just fast/heavy repetetive braking, as in racing................... Don't they?

-S2-
i would think that the tires are the biggest contributing factor to braking. now after saying this, when you're on the track you've got your race tires and your BBK. when you're on the street, i doubt you still have your race tires on still so you're back to your typical azenis or s-03. i think that's where the difference is. i'm still convinced that the main purpose of a BBK is for cooling.

there's other stuff to consider like pad selection (initial bite, operating temps, etc), front/rear bias - brake torque. most of the BBKs reduce front brake torque because stock is so heavily biased towards the front, that's also a contributing factor. some people try to do the H6 rear upgrade to try to use the bigger rotor for increase brake torque in the rear. i'm not quite sure if that works or not, i've read some stuff debating both sides of that one, not sure who's more right.
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Old 04-26-2003, 12:27 AM   #3
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Siper2 - there's many different aspects to your question. The biggest being in which situation do you want to increase your braking performance.

BBK's are designed to increase thermal capacity. Hence after repeated stops, it's not suppose to fade.

A BBK designed for street use and track use operate on the same principle, however the actual effectiveness will be different.
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Old 04-26-2003, 03:35 AM   #4
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The ways to actually decrease braking distances are few and are generally tied to fundamental design of the cars.

Note that the traditionally best braking cars are Porsches.

(Most) Porsches have the engine in the rear, meaning the rears carry more braking load and the fronts less. Since when you brake the weight transfer is forward, fronts do more work than rears. Any amount you can distribute to the rears will decrease your braking distances

Porsches also use flat engines, with a very low CG, this means that on braking there will be less weight shift to the front (because of the low CG of the large mass in the rear)

As I understand it, things that will improve stopping distances are things like:
moving weight distribution more rearward
lowering the local CG of the rear of the car. Lowering the CG of the entire car will help as well (reduces weight transfer)
Properly balancing front and rear brake torque for a given situation.
(Obviously) stickier tires help
Making the entire car lighter will help, as it requires less energy to stop.

One thing to note about weight transfer, stiffer springs give the impression of minimized weight transfer, but really do not change the weight transfer much, as pretty much the same amount of weight is transferred, just the springs compress less with that amount of weight on them.

Traditional brake upgrades are items that increase the FEEL of the brakes and give better control to the driver. The initial reaction to learning this is often that these are not worthwhile mods because what does it matter how the brakes feel. Experience with the brakes in 7/10 to 10/10 applications will change that initial reaction. Brake feel and feedback to the driver is absolutely important in reducing stopping distances in a lapping situation. Though on the street, emergency type application of these mods may be questionable.
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Old 04-26-2003, 03:25 PM   #5
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Quote:
Originally posted by Concillian
Note that the traditionally best braking cars are Porsches.

(Most) Porsches have the engine in the rear, meaning the rears carry more braking load and the fronts less. Since when you brake the weight transfer is forward, fronts do more work than rears. Any amount you can distribute to the rears will decrease your braking distances.
All in all an excellent post Concillian. I am gonna tweak it just a bit if I may. The AWD nature of the car tends toward the use of four equally sized tires on subarus. That coupled with a front engine leads to a highly front biased braking condition in Subarus. So this places essentially all the braking responsibility on half of 4 equally sized and rather small tires, this yields a less than ideal situation. Contrast this to the Porsche GT2, rear engine AND much larger rear tires. This unequal inherent rear traction helps balance out the unloading of the rear tires under braking = good braking of the chassis.

Concillian makes a very important point about weight transfer, even while employing a stiff or even solid suspension, the weight transfer still occurs in a nearly identical amount.

Reaching into some of Subarus excessive front bias by increasing rear brake torque(or decreasing front relative to rear as StopTech does) theoretically should increase overall performance slightly. Insuring you have a competent suspension that keeps the tires in contact with the road is also a key component to good braking.

But in closing the biggest factor in improving braking is gonna be improving the net tire traction itself.

ss
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Old 04-26-2003, 04:00 PM   #6
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so in laymens terms

"bigger stickier tires"

?
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Old 04-26-2003, 04:13 PM   #7
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Quote:
Originally posted by Jaxx
so in laymens terms

"bigger stickier tires"

?
If you're talking about realistic things you can do, sticky tires, lighter, and lower the CG. Not much else is practical for changing how fast you actually stop.

In tracking situations, mods like SS lines, master cylinder brackets and opposing piston calipers will help modulation. This will allow more confident braking which should result in braking later going into a corner.

There is (much) more to brakes than 60-0 distance.
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Old 04-27-2003, 02:26 AM   #8
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Tires are probably the biggest factor but also larger rotors can help alot too. Why do you think companies like porsche, ferrari, and lamborgini offer 18" and 19" wheels? So they can fit 15" to 16" rotors in there with beefy calipers.

Good brake info
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Old 04-27-2003, 04:41 AM   #9
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Quote:
Originally posted by nate49509
Tires are probably the biggest factor but also larger rotors can help alot too. Why do you think companies like porsche, ferrari, and lamborgini offer 18" and 19" wheels? So they can fit 15" to 16" rotors in there with beefy calipers.

Good brake info
yeah they use big wheels to fit the calipers, but i'm still not convinced. also porsche runs different size tires front and rear, the rears are much wider than the front - which would help emphasize subysouth's point. also those cars you listed aren't exactly all street cars so you can't quite make a fair comparison. an exotic car with cloth seats would look too ordinary. not saying that the huge rotors don't help, but those 18" and 19" wheels are also really wide and have a lot of rubber. if they really wanted to they could make 19 x 6.5" wheels and run 225 width tires, but instead they choose to go really wide.
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Old 04-27-2003, 10:35 AM   #10
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Quote:
Originally posted by nate49509
Tires are probably the biggest factor but also larger rotors can help alot too. Why do you think companies like porsche, ferrari, and lamborgini offer 18" and 19" wheels? So they can fit 15" to 16" rotors in there with beefy calipers.

Good brake info
Big rotors increase heat consumption capability. They could increase brake torque, but do not inherently do so. Again Stoptech's kit uses a significantly larger rotor than stock, but puts out an overall 10% less brake torque(at any given point) than the stock 2pots.

ss
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Old 04-27-2003, 12:31 PM   #11
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Just the kind of good answers I thought I'd get.

The tires I do know about, and I've got that end covered with my Dunlop SP9000s (on OEM wheels, OEM size). I like them a lot--not as grippy as many other summer tires, but man these things are like miracles in the rain. I'd buy them again in a heartbeat just for that practicality!

Anyway.. I do understand and appreciate the low CG and flat engine, but I think Subaru's got that pretty well-covered, having a boxer-style engine just two cylinders short of what Porsche themselves use. Of course there's a great FRONT weight bias, so that's likely what screws it up...

I'm not looking to cut my stopping distance in half or anything, it just seems to me that the distances should improve more than they do, in most brake tests I read, here and in magazines. The June '03 Sport Compact Car, for instance, tests the Tommykaira M20b 2.2-stroked WRX, using STi 7 brakes. They report that the brakes aren't much better than the stock ones, meaning the US-market brakes. So yes, while there's an obvious help in having much larger rotors in racing, one would think that'd transfer to the street more than it does.

In my mind, larger rotors = greater heat dissipation. Since brakes generate heat, and the point is to dissipate that heat in order to stop, than larger rotors should improve braking distance.
But what you guys are saying is that this only truly happens with heavy, repeated braking, right?


Like I said... I'm not looking for my car to stop in 100 ft. from 90mph, I guess it just seems like big brake kits should help more in the single-brake department (street), instead of just repeated hot laps.

-S2-
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Old 04-27-2003, 02:47 PM   #12
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Well youre kinda gettin it. The friction necessary to stop the car generates heat. Only when this heat exceeds the effective temps of the pads or fluid will your braking performance diminish.

If A system can lock the tires and B system can lock the tires. Essentially their braking performance is equal. Brake systems are judged on their ability to repeat this at elevated temps without damaging other components in the process.

You can entirely eliminate fade in the stock system by upgrading pads and fluid. However in racing circumstances that additional heat not dissipated in the stock rotors will soak into surrounding components and damage them.

There are cars that came from the factory with inherently undersized brake systems even for street use, my 76 Trans Am was such an example. The WRX IMO is not such a system. The stock brake system can maximize the braking ability of the chassis with a few tweaks. Upgrading the rear brakes can improve bias distribution as previously posted.

ss
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Old 04-27-2003, 04:12 PM   #13
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Quote:
Originally posted by Siper2
...Like I said... I'm not looking for my car to stop in 100 ft. from 90mph, I guess it just seems like big brake kits should help more in the single-brake department (street), instead of just repeated hot laps.
-S2-
If you're talking about the braking distance of a single stop, and the calipers already have the potential of locking the rotors, then there's no more you can do to stop the car faster, other than stickier tires. Period.
The only way it would matter how big the calipers and rotors, how little air, how high a tempurature the fluid can withstand, how little expansion in the lines, how little flex in the firewall would be if all those things help you detect the optimum amount of pedal force necessary to maintain the friction of the tires against the road surface at impending lockup.

And after all that, a new set of stickier tires will decrease the distance more.

Edit: In fact, I believe that stock pads are better for a single stop than race pads because they're optimized for better bite at lower tempuratures. Race pads take more time to bite because they have to reach a higher tempurature before they're effective.

Last edited by ITWRX4ME; 04-27-2003 at 04:19 PM.
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Old 04-27-2003, 04:34 PM   #14
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Well I'm no brake/physics pro, but I must point out a couple things.

Whenever brake topics come up, there are always posts saying how all brakes (stock/BBK/etc) that can lock-up the wheels will stop you in the same amount of time/distance.
Great. That is a given, assuming lock-up.
This leads people to think that since *any* brake setup can *lock-up* the wheels when you panic-stomp the pedal, then they must all be equal (repeated use, heat dissipation, fade not being a factor for non-track use or that one time stop to zero mph).
So why ever have this discussion again?

Maybe it is because 99% of your stopping is not locking up the wheels.
Most of your braking is slowing the car.
Not slowing to a stop, but slowing to a lower speed.

So do all brake setups slow the car equally? Well they must if all brake setups can stop the car in the same distance(lock-up), ya?
That is what everyone is going to think.
So can some brake/physics pro explain the real difference between slowing and sliding(lock-up), because I know they aren't the same.

So how then do you really get better braking?
Reducing the lag time between you hitting the brakes and braking actually occurring is a popular one.
SS lines, better fluid, and MS brace all help your pedal push do something sooner(better feel).
More friction.
Stickier tires, better pads, better calipers increase the friction between pad/rotor and tire/ground. More friction, faster stopping(more bite).
Bigger calipers/pads/rotors.
You would think more friction(larger pads/calipers) on a larger surface area (larger rotors) would enable you to slow the wheels quicker than the stock brakes, but everyone seems to say that isn't the case.
I'll let the pros address the why of that one.
If you do those mods and your reaction time stays the same, you'll be slowing the car sooner.

Less weight.
A lighter object will stop faster with the same friction forces as a heavier one.
Wait, a lighter car has less friction with the ground. Hmm, does this ever become a factor in the real world?

Better reaction time?
Increase your scanning distance, awareness of your surroundings, the ability to predict the actions of others..
I'm not sure how you would just go about those things, but they certainly help.
This is the biggest difference between drivers that leads to problems.
Most folks just drive like they sit and daydream, it isn't a full time activity, their concentration isn't there. This leads to the same quotes after collisions; "I didn't see the other car", "It came out of nowhere", "I don't know what the hell happened", "One minute I was driving, the next I woke up in the hospital".
They all mean the same thing, the driver didn't know what was going on.

So how do I stop faster?
I don't, I slow faster.
I have SS lines, fluid, upgraded street pads, and the StopTech BBK.
Is it better than stock? For my driving style yes.
Do I notice a difference? Yes.
Does the car stop faster?
At lower speeds it certainly appears to.
Maybe the gurus will point out whether or not it really does.

What is the fastest way to stop from say 120mph to zero?
I don't know.
Slowing the car to the threshold of lock-up?
Locking-up the wheels immediately?
Turning the car slightly one direction to get the tires sliding through their longest diagonal tire patch and locking-up the wheels?
Downshifting to a lower gear to let the spinning of the engine absorb more energy from the wheels while braking?
I think it is pretty rare that people encounter this situation.
It is not very often you are going 120mph and see something far enough ahead of time to know you have to come to a complete stop.
Now from 60mph, sure, happens all the time, but the difference in stopping distance using any of the above techniques is probably negligible.
Now in the rain, it becomes even harder to say since your tire's tread shape and depth, standing water depth, oil content in the water, wind, incline and type of pavement all play a roll.

Hopefully, we can get some of these unknowns answered.
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Old 04-27-2003, 05:23 PM   #15
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Quote:
Originally posted by mikkyo
Well I'm no brake/physics pro, but I must point out a couple things.

Whenever brake topics come up, there are always posts saying how all brakes (stock/BBK/etc) that can lock-up the wheels will stop you in the same amount of time/distance.
Great. That is a given, assuming lock-up.
This leads people to think that since *any* brake setup can *lock-up* the wheels when you panic-stomp the pedal, then they must all be equal (repeated use, heat dissipation, fade not being a factor for non-track use or that one time stop to zero mph).
So why ever have this discussion again?
The shortest stopping distances are usually achieved at the impending lockup stage. The comment of whether the stock setup CAN lock the tires merely means the stock brakes are sufficient to explore ALL the available braking power of the chassis.


Quote:
Maybe it is because 99% of your stopping is not locking up the wheels.
Most of your braking is slowing the car.
Not slowing to a stop, but slowing to a lower speed.

So do all brake setups slow the car equally? Well they must if all brake setups can stop the car in the same distance(lock-up), ya?
That is what everyone is going to think.
So can some brake/physics pro explain the real difference between slowing and sliding(lock-up), because I know they aren't the same.
Essentially slowing and locking the wheels are in exactly the same category. One imparts enough friction to slow the wheel, the other has imparted so much friction that it has exceeded the friction of the tires on the road(if the the tire is in contact with the road.)


Quote:
So how then do you really get better braking?
Reducing the lag time between you hitting the brakes and braking actually occurring is a popular one.
SS lines, better fluid, and MS brace all help your pedal push do something sooner(better feel).
More friction.
The SS lines and bracket may slightly decrease reaction of the brakes to pressure on the pedal but they they do not increase friction, just reaction time. The ultimate pressure and therefore friction is identical. Fluid just increases the temp at which said pressure can be maintained.


Quote:
Stickier tires, better pads, better calipers increase the friction between pad/rotor and tire/ground. More friction, faster stopping(more bite).
As several of us have stated stickier tires will improve braking performance.

More bite on the pad is more of an esoteric thing, up to the user to decide if they prefer it. You can vary the pad material to increase or decrease temp range and uptake range.


Quote:
Bigger calipers/pads/rotors.
You would think more friction(larger pads/calipers) on a larger surface area (larger rotors) would enable you to slow the wheels quicker than the stock brakes, but everyone seems to say that isn't the case.
The fundamental error you are operating under here is that the larger rotors and calipers in BBKs apply MORE torque than the stockers. In most cases they dont. The Stoptech kit specifically does not. Inclusive of all factors- caliper size, rotor size and pad coefficient of friction, the Stoptech kit is down ~10% in brake torque applied vs the stock brakes. AND this is a good thing, because it allows the rears to contribute more to the overall braking effort.


Quote:
Less weight.
A lighter object will stop faster with the same friction forces as a heavier one.
Wait, a lighter car has less friction with the ground. Hmm, does this ever become a factor in the real world?
Lighter weight GENERALLY means shorter stopping distances, but you have hit on an important point that less weight means less contact on equal tires. Its a fine line to walk on street tires, with WIDER still being generally better. This is why race cars use very soft and wide tires(and amazing downforce technology) to sort of force the contact patch issue. But these principles are kinda useless on street cars


Quote:
So how do I stop faster?
I don't, I slow faster.
I have SS lines, fluid, upgraded street pads, and the StopTech BBK.
Is it better than stock? For my driving style yes.
Do I notice a difference? Yes.
Does the car stop faster?
At lower speeds it certainly appears to.
Maybe the gurus will point out whether or not it really does.
I dont really know what your driving style is but C&D found the stock system hung together with many BBKs until repititon caught up with it. The Stoptech kit again also improves bias and feel as well as heat consumption. I would imagine it does make you a better braker and is a requirement IMO in a track driven WRX.


Quote:
What is the fastest way to stop from say 120mph to zero?
I don't know.
Slowing the car to the threshold of lock-up?
yes, in most cases


Quote:
Locking-up the wheels immediately?
No


Quote:
Downshifting to a lower gear to let the spinning of the engine absorb more energy from the wheels while braking?
Placebo effect, braking is still limited by total tire traction. This is just another way to slightly slow the car, not superior or additive to braking.


ss

Last edited by subysouth; 04-28-2003 at 12:34 AM.
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Old 04-27-2003, 08:43 PM   #16
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Very informative thread gentleman,, nice job by all!

Rudy,,<<proving the point that "you CAN teach an old dog new tricks"


and subysouth,,i had a 79 trans am that i used to race,,your right !the brakes sucked
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Old 04-27-2003, 10:03 PM   #17
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SubySouth, all good info.
And I agree that total stopping is limited by tire friction. But doesn't downshifting while braking keep your car better balanced (less inertial weight transferred to the front) allowing the rear tires to do more work as they are supporting more weight? With the large weight transfer under braking, it is the front tires that are determining the maximum traction, not the rears, as they hit their adhesion threshold first.
(Then, using my logic a car with different size front/rear tires [ie Porsches] should have larger front tires than rear, if all it was intended to do was brake. Just rambling)

So, do you agree with my logic, or am I about to get shot down by a ME.
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Old 04-28-2003, 12:12 AM   #18
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Quote:
Originally posted by MSG
SubySouth, all good info.
And I agree that total stopping is limited by tire friction. But doesn't downshifting while braking keep your car better balanced (less inertial weight transferred to the front) allowing the rear tires to do more work as they are supporting more weight? With the large weight transfer under braking, it is the front tires that are determining the maximum traction, not the rears, as they hit their adhesion threshold first.
(Then, using my logic a car with different size front/rear tires [ie Porsches] should have larger front tires than rear, if all it was intended to do was brake. Just rambling)

So, do you agree with my logic, or am I about to get shot down by a ME.
Lets see.

On the downshifting while braking. Again its mostly a placebo effect, it barely slows the car. [What you are looking for in competitive driving is speed lost quickly, not dragged off.] In a strictly RWD car with inherent excessive front bias it might be slightly helpful. Thats the only way less weight would be transferred to the fronts. Essentially "dragging" the rears slightly. However in our AWD cars its really not helpful. A well biased braking system would be a lot more helpful. The main reason for this practice is gear selection to exit a corner. Heel-toeing is a better idea tho, as you dont get the drag. [Press clutch + brake hard, shift, blip the revs, drop the clutch, accelerate.]

The front tires do indeed do more work under braking. But an even more front biased car than a Porsche like a WRX, would need even LARGER rear tires to increase friction on the even MORE unloaded rear during braking. But the larger rear tires on the rear engined Porsches are also there to balance high lateral loads under cornering from the rear-engined RWD car as well. The excellent braking is by-product of this.

Try to think about it backwards and it might be clearer. Imagine you wanted to put equal pressure to equal braking sytsems on a WRX. 294x24mm 2pots front and rear, perfect 50-50 f to r brake torque bias. As probably 80% of the weight of the vehicle ends up on the front tires under heavy braking, you would need tires on the rear wide enough to generate equal friction with only 25% of the weight on them compared to the front. They would need to be really wide and really sticky. Say 15" wide r-compound tires vs stock RE92s on the front.

Now look again at the Porsche GT2. Rear engine, rear tires about 40% wider than fronts and STILL lower brake torque to the rears under braking. The Porsche setup is about as close as you are going to get in front to rear cooperative braking in a street car. I think the front to rear bias in the Porsche GT2 is probably something like 60-40. The stock WRX is closer to 90-10(its excessively front-biased for safety reasons.)

On your last point if all it was intended to do was brake, you still want to put the most sticky tire on the ground possible. Again because of the weight transfer, the rears need to be bigger. Only in reverse would it be better to have larger front tires, this is one of the reasons braking is so squirely in reverse at speed, the brakes are operating opposite to what they are intended. Makes bootleggers easy tho .

Hope thats not too confusing.

ss

Last edited by subysouth; 04-28-2003 at 12:20 AM.
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Old 04-28-2003, 12:30 AM   #19
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Quote:
Originally posted by jagcars26

and subysouth,,i had a 79 trans am that i used to race,,your right !the brakes sucked
I had mine while I was in high school. If I knew then.... the brakes would have been my first upgrade. I cant tell you how many times I swapped padsand had my rotors turned to de-glaze them. My last resort was cop car semi-metallics which only slowed the glazing. They were downright dangerous.

Of course I drove like I was in high school too, so that didnt help much. I had a 400 Pontiac(not the 403 Olds) in mine and I had it balanced and blueprinted by a local racing engine builder. It was putting a conservative 325 to the ground at a 9.5:1 CR.

The engine was too strong for the chassis. Good drag car tho.

ss
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Old 04-28-2003, 09:16 AM   #20
Chuck H
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I'm fairly new to the Subaru scene, and this stuff is all pretty interesting and informative.

My experience may not be normal, but my impression is that my 03 WRX has one of the worst factory braking systems I've encountered in a "performance" car. Maybe it's mostly a matter of a fairly heavy car on crappy tires, but most of the other compact cars I've driven stop much shorter than my WRX and have a much firmer feeling brake pedal. Mine just feels like mush, even though the car only has 11,000 miles on it. The brake pedal has been spongy from day one, and the dealer tells me that "they all feel like that". I even forced them to bleed the brakes for me, and it didn't help at all.

I know that I can spend $600 for better tires which will probably help somewhat. And I can upgrade to SS brake lines and DOT 4 fluid and get the master cylinder brace and stuff. But is there anything that will really make an appreciable difference in stopping distance on a single emergency stop, or is the car just 500 lbs too heavy for its braking system and you just have to live with it?
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Old 04-28-2003, 12:02 PM   #21
ITWRX4ME
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Quote:
Originally posted by Chuck H
I'm fairly new to the Subaru scene, and this stuff is all pretty interesting and informative.

My experience may not be normal, but my impression is that my 03 WRX has one of the worst factory braking systems I've encountered in a "performance" car. Maybe it's mostly a matter of a fairly heavy car on crappy tires, but most of the other compact cars I've driven stop much shorter than my WRX and have a much firmer feeling brake pedal. Mine just feels like mush, even though the car only has 11,000 miles on it. The brake pedal has been spongy from day one, and the dealer tells me that "they all feel like that". I even forced them to bleed the brakes for me, and it didn't help at all.
Yeah, they're all like that. I, and most people, did stainless steel lines and pads at a minimum. I didn't feel any difference in pedal firmness. Some people have done the master cylinder bracket and claim it's better. Other people have fastened a block of wood to the brake pedal(helps with heel and toe and gets you past the mushy point easier).
Quote:
Originally posted by Chuck H
I know that I can spend $600 for better tires which will probably help somewhat. And I can upgrade to SS brake lines and DOT 4 fluid and get the master cylinder brace and stuff. But is there anything that will really make an appreciable difference in stopping distance on a single emergency stop, or is the car just 500 lbs too heavy for its braking system and you just have to live with it?
That's been answered in this thread. The short answers are
-- no, there's nothing beyond tires that will make an appreciable difference
-- no, the braking system is capable of locking the tires and therefore has the power to maintain them at the threshold of lockup
-- no, you don't have to live with it. Get stickier tires.
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Old 04-28-2003, 12:09 PM   #22
jagcars26
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Well IMHO the dealer is partly right,,the imprezas do have a mushy feel.But the stock brakes themselves are excellent IMHO even though i upgraded to Wilwoods,SS lines,and fluid..Interesting that the Legacy brake sysytem has a MUCH better feel along with good brakes.

Rudy
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Old 04-28-2003, 12:17 PM   #23
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Quote:
Originally posted by subysouth


I had mine while I was in high school. If I knew then.... the brakes would have been my first upgrade. I cant tell you how many times I swapped padsand had my rotors turned to de-glaze them. My last resort was cop car semi-metallics which only slowed the glazing. They were downright dangerous.

Of course I drove like I was in high school too, so that didnt help much. I had a 400 Pontiac(not the 403 Olds) in mine and I had it balanced and blueprinted by a local racing engine builder. It was putting a conservative 325 to the ground at a 9.5:1 CR.

The engine was too strong for the chassis. Good drag car tho.

ss
More OT lol
Yep that 403 olds engine was terrible,,mine had a rare factory 302/4speed. I tricked up the suspension with some Koni's and some sway bars.Sticky tires,small Holley carb,little better ignition,exhaust and went autocrossing
That car was a handfull on the course or off!!!

Rudy
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Old 04-28-2003, 12:46 PM   #24
MSG
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SubySouth,
Thanks for the reply to my brake musings. I guess I like the placebo effect of downshifting to aid slowing, even though I try to blip the throttle/heel & toe.

MSG
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Old 04-28-2003, 03:58 PM   #25
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Thanks SubySouth. You always have very valuable info.

However, I don't understand people when they say stock brakes have the potential of locking the wheels... At 40 mph, yes they do. Not at 120 mph though! This is when an upgrated brake system will be able to dissipate heat faster and allow us to run within the working temp specs of the upgrated pads/rotor combination.

A BBK the will allow me to stop from 60 mph in 121 ft instead of 126 ft does very little difference to me. However, one the will allow me to slow down from 120 mph to 60 mph in 2.5 seconds instead of 5 seconds makes a world of difference.

My 0.02 $
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