Calm down, I pushed every vehicle I own to its limits. Every time the back end walked out on me I expected it because I was pushing the car to its limits and I was in an area where it was safe if I lost control. The corner I was talking about I never touched the brakes but slowly applied throttle. I only added my comments because I feel Mazda added to much brake bias to the rear brakes allowing the rear brakes to lock up under extreme conditions. I have hit the brakes hard in every vehicle I have driven and this was the first one that back end want to walk around on me (only with traction control/DSC turned off). Everything is in check with the car, the car only had 100-200 miles and nothing has changed at 3000 miles. Mazda chose a certain percent of force front to back brake force on this car and in my opinion it has too much rear bias.
Speed 3 brakes - I'm wondering.....
- Thread starter tripledigits
- Start date
Calm down, I pushed every vehicle I own to its limits. Every time the back end walked out on me I expected it because I was pushing the car to its limits and I was in an area where it was safe if I lost control. The corner I was talking about I never touched the brakes but slowly applied throttle. I only added my comments because I feel Mazda added to much brake bias to the rear brakes allowing the rear brakes to lock up under extreme conditions. I have hit the brakes hard in every vehicle I have driven and this was the first one that back end want to walk around on me (only with traction control/DSC turned off). Everything is in check with the car, the car only had 100-200 miles and nothing has changed at 3000 miles. Mazda chose a certain percent of force front to back brake force on this car and in my opinion it has too much rear bias.
I disagree, I think it is wonderful that mazda thought about those of us who like a car that can be trailbraked, even A little more rear bias would be awesome. Must be tough for oem engineers to try to make us all happy.
happy and angry
Member
How does a story about you not even using the brakes apply to a discussion about front/rear brake balance, exactly? I guess I just assumed that if you were going to be talking about handling characteristics in a corner in a thread about how braking affects handling characteristics you'd have actually touched the brakes, but since you didn't even use the brakes in that situation, what relevance does it even have to this thread and how does it refute anything I said and how does it back up your opinion?
You made a comment
"In your story you say you pushed into a corner and tried to recover - if you hit the brakes too hot in a corner, no wonder your ass got out of shape. Next time slow down before the turn, and take a driver course to learn some vehicle dynamics)."
I have had the exact same thing happen to me as well....the brakes get nailed and the rear end wants to come around. I didn't do it on purpose, this was a panic stop.
I was thinking that because of how heavy the front is and how possibly light the rear is along with the stiffness of the chassis that this is causing a rear swing issue. I guess it could be considered normal but I have owned 13 cars and never experienced this. Then again, I have never had a car this fast before either so eh.
Either way, I still freaking love this car.
I was thinking that because of how heavy the front is and how possibly light the rear is along with the stiffness of the chassis that this is causing a rear swing issue. I guess it could be considered normal but I have owned 13 cars and never experienced this. Then again, I have never had a car this fast before either so eh.
Either way, I still freaking love this car.
happy and angry
Member
Here's your first quote:
I'm not sure what it is you're trying to get at, but the first story you told and the subsequent correction do not make sense told back to back. Either you took a corner hot and you didn't touch your brakes and your story and anecdotal evidence to support your opinion about the brakes in this car are irrelevant because there was no braking, OR you took a corner too hot and hit the brakes, subsequently de-stabilized your car and are attributing typical vehicle handling characteristics to vehicle problems as opposed to driver error. Currently you are arguing both, and they are mutually exclusive positions. Pick one.
Here's your second:
So, first you tell a story about your back end getting loose in a corner and your rear end locking up, in a thread about braking balance. When someone tells you not to brake mid corner and upset the balance of your car, you say you didn't hit the brakes.
I'm not sure what it is you're trying to get at, but the first story you told and the subsequent correction do not make sense told back to back. Either you took a corner hot and you didn't touch your brakes and your story and anecdotal evidence to support your opinion about the brakes in this car are irrelevant because there was no braking, OR you took a corner too hot and hit the brakes, subsequently de-stabilized your car and are attributing typical vehicle handling characteristics to vehicle problems as opposed to driver error. Currently you are arguing both, and they are mutually exclusive positions. Pick one.
You also say you are new to cars and get defensive when someone points out an apparently mistake made by you based on your own description of an event and the context of which it was told.
tripledigits
Member
Perhaps I wasn't clear when referring to rear brake bias - to make it more accurate, I was saying the car feels like there is less front brake bias than what I've experienced in passenger cars. Of course there wouldn't be more total braking force in the rear than the front. I have enough race car experience to feel when there is too much front or rear brake. I'm not saying my car has too much rear bias. I was just surprised that I actually had to stay awake under hard braking in my abovementioned experience. Most passenger cars err on the side of too much front bias - that's why you replace your rear pads much less frequently than your fronts. The front end on any car will be doing most of the stopping because of the weight transfer under braking.
drledford93
Member
- :
- Mazdaspeed 3
On any nose-heavy car when one applies the brakes liberally and quickly, the rears are unloaded and would logically lock up first, regardless of bias.
In terms of rotation, more weight up front (vs rear) = quick ability to rotate. Ex: Honda CRX.
Daniel
In terms of rotation, more weight up front (vs rear) = quick ability to rotate. Ex: Honda CRX.
Daniel
I am talking about 2 different corners, I have gone around corners in the car many times sometimes applying the brakes and other times throttle. When I said I am new to cars, I meant I am new to driving cars in track like conditions. You should try to calm down, I am only giving my opinion.
I agree an disagree
You are wrong in regards rear lockup. This is a critical design feature that was implemented long ago in the automotive industry. The fronts should lock first even during turning creating push. and all my 'modern cars' have driven this way. As mentioned earlier, woudn't oversteer in a front wheel drive car be good for xcross! Well thats a pretty honest point. If you could steer the car with rear braking ala rally style well that would be fun. But the National Highway regulatory agencies could not allow it. again very unsafe unless you are a qualified experienced driver. That said, I do understand a bit about chassis balance and driving technique. And I completely agree that modding suspension, chassis bracing, tires wheels alignment, weight can dramatically affect the car. But I actually tried to reproduce the effects in my dodge 'modded suspension+' and in the Mazda I can bring the ass out under hard turns but not with the brakes. I did come around to hard trying to kick it out, went too far and hit brakes and slid sideways for a bit. I still think see Mazda about this. imo. sorry so long
You are wrong in regards rear lockup. This is a critical design feature that was implemented long ago in the automotive industry. The fronts should lock first even during turning creating push. and all my 'modern cars' have driven this way. As mentioned earlier, woudn't oversteer in a front wheel drive car be good for xcross! Well thats a pretty honest point. If you could steer the car with rear braking ala rally style well that would be fun. But the National Highway regulatory agencies could not allow it. again very unsafe unless you are a qualified experienced driver. That said, I do understand a bit about chassis balance and driving technique. And I completely agree that modding suspension, chassis bracing, tires wheels alignment, weight can dramatically affect the car. But I actually tried to reproduce the effects in my dodge 'modded suspension+' and in the Mazda I can bring the ass out under hard turns but not with the brakes. I did come around to hard trying to kick it out, went too far and hit brakes and slid sideways for a bit. I still think see Mazda about this. imo. sorry so long
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happy and angry
Member
This isn't your regular passenger car. It's stiffer all around with much more aggressive braking characteristics. When you stop, you front load the vehicle, the ass unweights and swings out more easily. Because of chassis and suspension stiffness, you get oversteer under many circumstances. Slight, controlled oversteer. That's actually a good thing for aggressive drivers and enthusiasts like us. We just need to control it.
Keep in mind I'm only talking about oversteer for this vehicle under aggressive braking. In most cases, going into a corner at normal speed or trail braking you'll get slight understeer, but this thread is about emergency full-on pedal to the floor stops, and that changes the scenario a bit.
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happy and angry
Member
You have said nothing about two different corners until now. I am calm, I just think your opinion is largely baseless and your anecdotes irrelevant given the scope of this discussion. I also think you're backpedaling.
happy and angry
Member
How has anything you've said refuted what I've said regarding rear lockup? You think anecdotal evidence somehow supports a position?
Front wheels will almost never lock up before rears. It's physics. Weight distribution under braking almost guarantees this. And, uh, you CAN steer the car with rear braking, it's called "hand brake."
This car is generally described as having slight understeer, but you have to keep in mind that you can very easily cause it to oversteer through various means. Under braking is a good way to do it, given the weight distribution.
No one has described anything surprising in this thread. I largely doubt brake balance is an issue in this car.
This dialogue has been rewarding as I have had to look at dynamics again Thanks All. But my Mazda and then my dodge: that is very much stiff and nicely weight balanced. They both attempt to lock up front first with stock proportional valving in a straight line. I believe that something is faulty ? no?
happy and angry
Member
I don't think anything is "faulty." Braking force is always applied more on the front than the rear. Because of weight transfer, most of the traction on a stopping car is in the front, so brake bias is front loaded. Under extreme braking you can unload the rear enough to compromise rear lateral grip in any car. It's really just a matter of how vehicles behave.
Hell, we have it pretty easy, all things considered. Less weight in the rear means less lateral grip in the rear under braking, but it also means less weight to deal with. In a truck, weight is so low over the rear that under extreme braking it's very easy to lock up the rear. A rear wheel drive vehicle (BMW, for example) with a longitudinal tranny and a rear diff has a much better weight distribution, but when the front is loaded under braking the heavier rear end has more momentum which can cause the front end to more easily behave as a pivot. Taken to extremes, like in an ass-engined Porsche, weight balance is so rear biased that braking mid corner (and in fact anything other than a straight line, and even then you need to be careful, especially at speed) becomes an exercise in insanity because while the rear is less likely to lock up, there is so much weight that can be thrown laterally that it quickly exceeds rear lateral grip.
Vehicle dynamics are complicated. Ultimately a tendency to oversteer will be created when lateral grip in the rear is exceeded. You can cause this in a lot of different ways: lateral weight shift in the rear, rear lock up which compromises lateral grip, power oversteer, or various combinations of these. There's a lot to it, too. A Dodge Shadow has such weak braking and so much body roll you may never be able to get it sideways, where the powerful braking and stiffness in our car actually makes it somewhat easier to do.
Under normal circumstances, under throttle, off throttle or trail braking in a corner, our vehicle will understeer slightly, although it's still possible to create controlled oversteer in a number of ways. To tie this back to braking, and extreme emergency stops as discussed in this thread, weight transfer will so severely front load the vehicle that rear lockup becomes much more likely, which in turn compromises rear lateral grip even more than the weight transfer alone did. Having the ass end start to walk out a bit in this situation isn't surprising, just as the rear end approaching lock up isn't surprising. In a straight line under extreme braking, lots of little things can get the rear end moving a bit sideways with lateral grip as compromised as that.
Hell, we have it pretty easy, all things considered. Less weight in the rear means less lateral grip in the rear under braking, but it also means less weight to deal with. In a truck, weight is so low over the rear that under extreme braking it's very easy to lock up the rear. A rear wheel drive vehicle (BMW, for example) with a longitudinal tranny and a rear diff has a much better weight distribution, but when the front is loaded under braking the heavier rear end has more momentum which can cause the front end to more easily behave as a pivot. Taken to extremes, like in an ass-engined Porsche, weight balance is so rear biased that braking mid corner (and in fact anything other than a straight line, and even then you need to be careful, especially at speed) becomes an exercise in insanity because while the rear is less likely to lock up, there is so much weight that can be thrown laterally that it quickly exceeds rear lateral grip.
Vehicle dynamics are complicated. Ultimately a tendency to oversteer will be created when lateral grip in the rear is exceeded. You can cause this in a lot of different ways: lateral weight shift in the rear, rear lock up which compromises lateral grip, power oversteer, or various combinations of these. There's a lot to it, too. A Dodge Shadow has such weak braking and so much body roll you may never be able to get it sideways, where the powerful braking and stiffness in our car actually makes it somewhat easier to do.
Under normal circumstances, under throttle, off throttle or trail braking in a corner, our vehicle will understeer slightly, although it's still possible to create controlled oversteer in a number of ways. To tie this back to braking, and extreme emergency stops as discussed in this thread, weight transfer will so severely front load the vehicle that rear lockup becomes much more likely, which in turn compromises rear lateral grip even more than the weight transfer alone did. Having the ass end start to walk out a bit in this situation isn't surprising, just as the rear end approaching lock up isn't surprising. In a straight line under extreme braking, lots of little things can get the rear end moving a bit sideways with lateral grip as compromised as that.
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My 2 pennies.. If you think the car is not right, get it checked out. It's under warranty right? Nobody else here on this forum has driven it to know for sure if there really is a problem or not. They may be right, and there's no problem. But fact is, sometimes something in the braking system of a car may go wrong. My buddy has a POS cavalier and the back brakes started locking up on him when he'd try to stop. There was obviously a problem with it. I say for your own piece of mind, just get it checked out.
I enjoy theory very much and in detail all the more. I spent A good bit of time trying do anything to get rear lockup or rear end to even try to come around on braking and sunday morning the roads were wet, again no luck. stock very worn tires and stock suspension bits. But I do like how with weight transfer she can do a little fwd drift. so tripledigits. What do you think?
pointysticks
Member
let me start by saying this is the FIRST front engine sports car i have ever owned. so i may be pulling this from my butt. but i think this guy is right. all the load is up front, and when you brake it even gets worse. i think the rears chirping on hard braking can me attributed to some minor unloading of the rear wheels? sorry, i am in the break in period, so i havent gotten on or off of it hard yet.
thanks.
whitey4311
Member
- :
- MS3 GT Black Mica w/nav
I suppose the fact there is a ton more brake dust on the front wheels then the rears refutes the theory of more brake bias to the rears?
