# stopping distances



## sethwas (Apr 30, 2002)

So I read this in my search for info

http://www.se-r.net/about/sentra_se-r/scc/oct98/

and it only helped slightly. 
Here's what I want to know:
I was looking for the stock stopping distance of a 1993 NX2000 w/AD22VF and the stock stopping distance of any B14 sentra GXE.
I also wanted to know their respective weights.
From reading the article they show what a stock B14 SE-R can do, and what NX rotors and calipers with Metal Masters pads and SS lines will do. (Also they had Nitto NT555's on 16" rims)
Not too shabby.
However I want to know (obviously the best way is to do it myself but I don't have the equipment) what my stopping distance is now with my KVR pads with the rest of the NX parts for brakes, SS lines, and 14" NX rims with Pirelli HP's. I know my stopping distances are 'way' shorter than before and pedal feel (once the pads are warm) has improved, but I have more weight (slightly) than the SE-R and don't have rear discs and my pads are allegedly grippier than the Axxis ones. Plus I have a soft suspension so their's lots of lean.
I figured if I had the weights and stock stopping distances I could do some math to find out, but if anyone knows offhand let me know.
Thanks.

Seth

P.S. The article said:
169 stock
148 with add-ons
I'm guessing in the mid 150's since my rims/tires are lighter with grippier pads, noting the loss in contact area and massive weight shift. I believe I am at an advantage with rear drums as opposed to discs (this is straight line dry not racing wet where drums are 'worse').


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## sethwas (Apr 30, 2002)

Oh,
For comparison:
C43 AMG - 112
Mini - 125
'90 ZR-1 - 109
Z06 - 123
Saturn SC2 - 136
NSX - 125
F40 - 122
Enzo - 95!!
911 GT2 - 116
Civic - 148
350Z - 115
'93 supra - 125
Viper - 135
RX7 - 127
TT - 122
M3 - 112
M5 - 129
Murcielago - 122
300ZX - 129
R34 - 121
S15 - 113
WRX - 128



Mind you all these numbers are from going about 80 mph and slamming on the brakes and only recording the 60-0 part. My above numbers are from going 60 mph and then hitting the brakes from there so it includes transition and suspension settleing time.

Seth

http://www.fast-autos.net/makes.html


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## sethwas (Apr 30, 2002)

Ok,
I finally found a statistic from a B15. Apparently with the 'sport' brakes (the 11" ones since it was an SE) a 4 door B15 (cuz there's a 2 door...) will stop in:
130 ft.


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## sethwas (Apr 30, 2002)

More stats (weight):
B15 sentra - 2674
B14 sentra - 2592
B13 NX - 2509

Given this info since 11 inch rotors on the heavier B15 stop the car in 130 ft, one would think that the 10 inch rotors on the less weighing B13/B14 would stop shorter.

But is all this crap? I mean I've looked at tons of websites and they all give way off numbers for similar cars. I know there are testing discrepancies but how is it a Stock 2000 Sentra SE can outstop a Viper (2700 lbs) in a straight line?

Seth


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## niky (Jul 20, 2002)

explanation? you've got too much time on your hands! j/k 

i was going to say weight... but that doesn't explain it... a lot of factors could affect the distances shown in the tests, ranging from pads used to brake wear and fade... but still, those are the 'sport brakes', i'm assuming, off the B15 SE-R ? maybe they had the new one with the big ass brembos. 

i think the only discrepancy is with the viper's numbers.


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## ReVerm (Jan 13, 2003)

> _Originally posted by sethwas _*
> But is all this crap? I mean I've looked at tons of websites and they all give way off numbers for similar cars. I know there are testing discrepancies but how is it a Stock 2000 Sentra SE can outstop a Viper (2700 lbs) in a straight line?
> Seth *


I don't remember the Dodge Viper being that light. A stock 03 Viper weighs 3380 lbs, and even the older convertible (which was for some strange reason lighter than the coupe version) weighed 3319 lbs.


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## sethwas (Apr 30, 2002)

OK,
I mean even so, with all the extra weight, I understand our cars are more racetrack worthy 
(thats with AD22VF brakes, SS lines and non OEM pads)
since they aren't prone fade and weight less
at least mine don't (I hope) since the hotter they get the grippier they get).
Even if the viper weighs 3319 lbs. or so its brakes are like the size of my rims. I can't think that I'm eating Z06's for lunch (aside from the gas pedal anyway  )

Seth


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## ReVerm (Jan 13, 2003)

Remember, rotor size doesn't say much as goes initial stopping distances. The advantage of bigger rotors is that they dissipate heat more quickly so your stopping distances remain relatively constant as you continue to use them on the track.

I don't know how big the contact areas on the Viper's brakes are or how powerful their calipers are, but 800 lbs is a LOT to compensate for, especially when it comes to braking.

Another thing to keep in mind is weight distribution. The details of this topic are really beyond the scope of my knowledge so I won't elaborate on it, but the total weight distribution of the car (F/R in this case) make a significant difference in both braking distance and stability.


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## Wont Be Beat (Sep 20, 2002)

Please listen to me very carefully. If you can already lock up your brakes at will with your stock setup or whatever else you may have, getting more powerfull brakes will do NOTHING for stopping distances no matter what any retarded magazine says. Since you can already lockup at will, what will bigger brakes do for you? Lock them up harder? Hehe.

The best way to reduce stopping distances is to get stickier tires. TIRES STOP YOUR CAR, NOT YOUR BRAKES. After that, you can play aroud with weight reduction and distribution. All the while making sure tire pressures and alignement settings are ideal.


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## niky (Jul 20, 2002)

uhh... bigger brakes also give you more stopping power before locking up, if only because the contact patch is bigger... with smaller brakes, lockup can occur with lesser braking force, because you're trying to apply braking beyound your rotors 'abilities...

smaller brakes heat and fade faster... bigger brakes give more consistent stopping times and allow you to exert much more force without locking... although really big ones might make you feel like you're sticking your feet through the floor and straight on the pavement... they're that hard.


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## sethwas (Apr 30, 2002)

Yeah,
My problem before was that for a given amount of pedal travel my brakes had a higher propensity to lock because they were trying too hard. With that much pressure the lightest slip of the tires would lock the brakes. Now with my new brakes I get better stopping power or ability for less pedal travel and I haven't locked a tire yet (unless of course you count intentionally trying to lock themn which I have and did.)

Seth

P.S. I've never run stock tires with the car. I got rid of the OEM ones the week I got the car 4 years ago.


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## Mervic (May 1, 2002)

Wont Be Beat said:


> *Please listen to me very carefully. If you can already lock up your brakes at will with your stock setup or whatever else you may have, getting more powerfull brakes will do NOTHING for stopping distances no matter what any retarded magazine says. Since you can already lockup at will, what will bigger brakes do for you? Lock them up harder? Hehe.
> 
> The best way to reduce stopping distances is to get stickier tires. TIRES STOP YOUR CAR, NOT YOUR BRAKES. After that, you can play aroud with weight reduction and distribution. All the while making sure tire pressures and alignement settings are ideal. *


 I agree. And tuning your suspension will also improve your stopping power just like it will improve your acceleration. I am not saying dont get better (bigger)brakes but I think it should be combine with better tires and suspension which will give you its full potential. Better traction(grip) means better overall car performance not just acceleration. Oh and sethwas, those curb weights are good info. Those B15's are porky compare with my Pulsar.


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## ReVerm (Jan 13, 2003)

Wont Be Beat said:


> *Please listen to me very carefully. If you can already lock up your brakes at will with your stock setup or whatever else you may have, getting more powerfull brakes will do NOTHING for stopping distances no matter what any retarded magazine says. Since you can already lockup at will, what will bigger brakes do for you? Lock them up harder? Hehe.
> 
> The best way to reduce stopping distances is to get stickier tires. TIRES STOP YOUR CAR, NOT YOUR BRAKES. After that, you can play aroud with weight reduction and distribution. All the while making sure tire pressures and alignement settings are ideal. *


You are confusing "big" and "powerful". They are not the same thing. Larger brake rotors will help your brakes cool faster and help stave off pedal fade as Niky said. Larger brake calipers will give you a larger contact patch between the pad and the brakes, so you will stop quicker. More powerful brake calipers will make braking easier, because it will reduce pedal effort.

Now, you are correct in saying that more powerful calipers alone will not help your stopping distances. However, you are completely incorrect in saying that bigger brakes will not help you stop at all. Going to a FastBrakes front brakes kit on a B14 Sentra will make a bigger difference than suspension adjustments, R compound tires, and a moderate weight drop (not gutting the interior entirely) combined. This is not to say that you should disregard these elements, because they will shorten your stopping distances and improve braking stability noticably. If you are also bad enough a driver that you think locking your brakes every time you need to stop suddenly will help you stop quicker, sticky tyres and suspension adjustments will help you significantly (although your braking distances will consistantly be longer than the driver who does not lock his brakes). 

However, if you are looking solely to improve your car's deceleration and do all of these without upgrading your brakes, you are wasting your money and our time.


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## Wont Be Beat (Sep 20, 2002)

Ok, its time for everyone to throw out all the bullshit they have heard from others or just assumed on their own and listen to the experts. Because simply put, you guys are wrong.

Listen, read, and understand...

http://www.accordinglydone.com/tech.php?ID=12

After you have read, understood, and agreed with this (because you have no other choice but to believe the truth), I will be happy to entertain any questions you may have and/or disprove any misconceptions as well.


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## ReVerm (Jan 13, 2003)

Wont Be Beat said:


> *Ok, its time for everyone to throw out all the bullshit they have heard from others or just assumed on their own and listen to the experts. Because simply put, you guys are wrong.
> 
> Listen, read, and understand...
> 
> ...


There is nothing wrong with that article. It's very detailed, and well written, and to tell you the truth, I like it. However, you seem to have misinterpreted it.

People get pissed off when we do this, but let me go through the sections of your post to which I am disagreeing (and clarify my response in the process).



> *If you can already lock up your brakes at will with your stock setup or whatever else you may have, getting more powerfull brakes will do NOTHING for stopping distances no matter what any retarded magazine says. *


You are assuming that hard braking inovlves locking the brakes for a significant period of time. If this were true, your statements would be correct. The stopping distance of the vehicle would be completely dependant on the tires, the suspension, and chassis balance. The brakes would have nothing to do with it, because they are quite literally locked in place. However, most testers will not lock the brakes on the test cars, because on many (most in fact) street cars, locking the brakes will result in longer stopping distances than if they did not (most OE street tires and suspension systems just aren't that good). 

This is not to say that they will not activate the ABS on the cars during testing. Modern ABS will prevent you from locking your brakes for a significant amount of time.



> *The best way to reduce stopping distances is to get stickier tires.*


Nowhere in the above mentioned article does it say that the best way to reduce stopping distances is to get stickier tires. I know from observing hours on end of tire testing for a (damned) student project that this is not true. It is mentioned near the end of the article that you should look at the tires and suspension system before the brakes, but this statement does not necessarily imply what you stated.

Just like with continuously increasing the size of your rotors, suspension, tires, and chassis upgrades on your car will only take you so far on a quest for shorter stopping distances. And with the undersized, underpowered brakes of most B13s and B14s (the vehicles in question in this particular thread), that isn't very far at all.


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## Wont Be Beat (Sep 20, 2002)

> *You are assuming that hard braking inovlves locking the brakes for a significant period of time.*


 No I'm not. Jesus, I'm not dumb. Though I can see why you may think this is what I meant, it indeed isnt. Let me clarify: If the mue of your stock brake pad to your stock rotors is enough to instantly lock up the tire, then threshold braking, which is the maximum possible amount of stopping force your brakes are applying TO YOUR TIRES before lockup, will do nothing but let you lockup or threshold brake easier, with less effort, and better modulation. Those three factors are the only benefits bigger brakes will give you for a daily driving application. However, all three are attainable without the use of bigger brakes, rather better brake pads and ss lines, which is generally much cheaper than a BBK.



> *Nowhere in the above mentioned article does it say that the best way to reduce stopping distances is to get stickier tires.*


 Whether that article stated it or not, is irrelevant. I can post up a mirriad of others that will state that using better tires will show a direct correlation with shorter stopping distances on a car with adequate (thats not to say upgraded) brakes. You must understand that the article is written by people working for the manufacturer that sells brake upgrade performance, and their word is in no way unquestionable. So let me say this, and try to put it simply, if you spend $5000 on 6-piston baer calipers, 15" ceramic rotors, F1-compound brake pads, SS lines, ATE SuperBlue, upgraded master cylinder, tuned proportioning valve, upgraded brake booster, brake cooling ducts, hydro-cooled rotors, and any other trick brake product you can find, spending $600 on some Maximum Performance or R-compound tires will always yeild better stopping results on a car with adequate stock brakes.



> *Just like with continuously increasing the size of your rotors, suspension, tires, and chassis upgrades on your car will only take you so far on a quest for shorter stopping distances. And with the undersized, underpowered brakes of most B13s and B14s (the vehicles in question in this particular thread), that isn't very far at all. *


 You would be surprised at how far good brakes pads and good brake fluid will get you. Take my word on that.


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## BadAhab (Apr 30, 2002)

I dont really know the math behind brake systems, but I know that my friends ad22 b14 sentra will out stop my stock 200sx se-r any day of the week. The brakes just feel a lot easier to control. I wish I had some big ass brake setup on my old pulsar nx. When I threw on a used set of bfg r1's, which is an r type compunds, you could not lock up the brakes. I went through a set of pads in one auto-x (got my lifetime warrenty on those pads insert 3vil laugh here)

-sean


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## ReVerm (Jan 13, 2003)

Wont Be Beat said:


> *If the mue of your stock brake pad to your stock rotors is enough to instantly lock up the tire, then threshold braking, which is the maximum possible amount of stopping force your brakes are applying TO YOUR TIRES before lockup, will do nothing but let you lockup or threshold brake easier, with less effort, and better modulation.*


Wait, wait. If you can threshold brake easier with less effort and better modulation, you won't get better braking/shorter stopping distances?



> *Whether that article stated it or not, is irrelevant. I can post up a mirriad of others that will state that using better tires will show a direct correlation with shorter stopping distances on a car with adequate (thats not to say upgraded) brakes.*


You're forgetting one thing though. We're talking about B13/B14 Sentras. Quite honestly, they _don't_ have adequate brakes, especially not for track use. The OE pads are pretty good (I can vouch for that), and you can stick Motul 5.1 into your system, but the baseline for braking performance is too low for better tires alone to make as much a difference as say, a FastBrakes kit.

Pads and fluids will take you a fair distance, but not nearly as far as they would in many other cars becuase of the above reason.


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## Wont Be Beat (Sep 20, 2002)

> *Wait, wait. If you can threshold brake easier with less effort and better modulation, you won't get better braking/shorter stopping distances?*


 No, not at all. Easier threshold braking with less effort and better modulation have nothing to do with the friction exchange between the tire and the ground.



> *You're forgetting one thing though. We're talking about B13/B14 Sentras. Quite honestly, they don't have adequate brakes, especially not for track use. The OE pads are pretty good (I can vouch for that), and you can stick Motul 5.1 into your system, but the baseline for braking performance is too low for better tires alone to make as much a difference as say, a FastBrakes kit.
> 
> Pads and fluids will take you a fair distance, but not nearly as far as they would in many other cars becuase of the above reason. *


 Wake up and open your eyes and take into consideration (instead of just letting it go in one ear and out the other) what I'm saying. Go out and buy some GOOD brake pads such as Axxis Ultimates, Hawk HP+ or Cobalt GT-Sport pads and use some high temp fluid as well. Try it. You will be happy for a FRACTION of the cost of a BBK.

Wont Be Beat, who has a custom OEM BBK on his Prelude.


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## Wont Be Beat (Sep 20, 2002)

> *I dont really know the math behind brake systems, but I know that my friends ad22 b14 sentra will out stop my stock 200sx se-r any day of the week. The brakes just feel a lot easier to control. I wish I had some big ass brake setup on my old pulsar nx. When I threw on a used set of bfg r1's, which is an r type compunds, you could not lock up the brakes. I went through a set of pads in one auto-x (got my lifetime warrenty on those pads insert 3vil laugh here)*


 It is precisly statements such as this that I am taking the time to help everyone understand not to make. I will repeat: YOUR BRAKES DO NOT STOP YOUR. YOUR TIRES DO. And you said it yourself, your pads had enough after 1 autox event (mine have 5 events on them and they are just breaking in). So what does that say about the brake compounds you are using? They suck! Go out and spend a little more money on something good, and come back with an experience review.


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## ReVerm (Jan 13, 2003)

Wont Be Beat said:


> *No, not at all. Easier threshold braking with less effort and better modulation have nothing to do with the friction exchange between the tire and the ground.*


That second sentence I agree with completely. 

However, you're forgetting something else. Brake testing isn't done in a closed lab with the brake system taken off the car. Stopping distances are calculated with results obtained from human subjects pressing down on the brake pedals. If you can find the limit more accurately with less effort, you will reduce your stopping distance. It's one of those things that really can't be helped, and is one of the bigger reasons that different reviewers will get different results, even when using the same cars and the same procedures. The differences don't look that big on paper, but even on the same 96 Corolla (no ABS, I THINK. I don't remember seeing or hearing one) three different people had differences of a little less than 8 feet between their average stopping distances in a "hard - no lock - cold start" test on dry pavement.

You can't just focus completely on one aspect of the subject and forget about everything else. Vehicle dynamics isn't that simple (or forgiving on the track).



> *Wake up and open your eyes and take into consideration (instead of just letting it go in one ear and out the other) what I'm saying. Go out and buy some GOOD brake pads such as Axxis Ultimates, Hawk HP+ or Cobalt GT-Sport pads and use some high temp fluid as well. Try it. You will be happy for a FRACTION of the cost of a BBK.*


I think it'd be better to ask the opinion of some of the more experienced road racers about those brake pads on B14s. I only do HPDE (i don't have the kind of money for competition. Hell, i'm borrowing eqipment from friends every two minutes just so I can do HPDE), and compared to some of the guys on this forum, I've barely driven on a track at all. From what I've seen on my friend's cars though Nissan OE pads hold up pretty well on the track, even when compared to the Ultimates that one of them runs now (bastard and his damned sponsorship). Personally, I don't think I'd be happy with them. I can't afford to replace my rotors that often... But that's a different story.

As for taking into consideration what you're saying... Well... (Save the fact that I'd have to do that anyway to respond to your arguments) you haven't really said much besides repeat what was said in that article, make claims about the results of comparison tests that you've never conducted or seen conducted, and make arrogant, condescending comments about the people on this forum and the equipment they use. If I didn't know better, I'd assume you were just another 20 year old kid who hops between forums and tech sites amassing resources, forming (untested) theories and presenting them as facts to others who just don't know better (or aren't as outspoken). But that really doesn't have much to do with the topic of discussion, so I'll leave it at that.


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## Wont Be Beat (Sep 20, 2002)

> *However, you're forgetting something else. Brake testing isn't done in a closed lab with the brake system taken off the car. Stopping distances are calculated with results obtained from human subjects pressing down on the brake pedals. If you can find the limit more accurately with less effort, you will reduce your stopping distance. It's one of those things that really can't be helped, and is one of the bigger reasons that different reviewers will get different results, even when using the same cars and the same procedures. The differences don't look that big on paper, but even on the same 96 Corolla (no ABS, I THINK. I don't remember seeing or hearing one) three different people had differences of a little less than 8 feet between their average stopping distances in a "hard - no lock - cold start" test on dry pavement.*


 I see your point but I dont see how a high dollar upgrade will help any if you can already put the maximum amount of friction to the ground. Beyond that, I cannot explain it any better.



> *I think it'd be better to ask the opinion of some of the more experienced road racers about those brake pads on B14s.*


 Those pads I listed are by no means track pads. Those pads would get owned at the track really quickly. Track pads are Hawk Black, Hawk Blue, Cobalt IT-R spec, Ferado DS3000, and Porterfield R4 among many others.



> *As for taking into consideration what you're saying... Well... (Save the fact that I'd have to do that anyway to respond to your arguments) you haven't really said much besides repeat what was said in that article*


 Honestly, I'm not really a huge fan of that article. I've got others if you'd like to read. Or better yet, just click on the link in my signature if you want to learn more.



> *make claims about the results of comparison tests that you've never conducted or seen conducted*


 Comparison tests in magazines can lick donkey nuts. I go by PERSONAL experience at the track, at the autox, building and upgrading cars and working as pit crew for an ECHC team.



> *arrogant*


 Yup.



> *condescending*


 Thats me.



> *I'd assume you were just another 20 year old kid*


 21 in 2 weeks.  



> *who hops between forums and tech sites amassing resources*


 Just a few forums. And whats wrong with amassing resources? To me, thats part of learning.



> *forming (untested) theories*


 I dont form my own theories. I listen to experts and then try out what I learned for myself.



> *presenting them as facts to others who just don't know better (or aren't as outspoken).*


 Would you rather me sit back and let kids think that cross drilled rotors help stop better, and cutting your springs or buying APC springs and using stock shocks is a good idea? Or should I let companies that makes brake kits and rotors with deformations on them continue to use sly marketing schemes to fool and educate people about falacies while charging ridiculous amounts for something they claim will happen, but only gives the impression of happening? I was in that boat once and good people helped me. Now I feel I can help others. And if you cant understand that my arrogant and condesending remarks are all just a guise, then I'm sorry that you dont know any better-but maybe now you do, and if you do, I have succeeded and helping someone and that makes me feel better.


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## ReVerm (Jan 13, 2003)

Haha. I've never seen so little text take up so much space in one day's worth of posts. I should never do that line by line thing again.

As for whether the fastbrakes kit or soft tires make a better upgrade choice for us Sentra drivers, that'll have to be solved with a controlled lab-style experiment somewhere. Beyond this point, speculation or theororizing about it is most likely just going to waste space. I'll see if I can't organize one with the people I work with (have to find out what they can get). I'll get back to you guys on that one.

I know the Ultimates aren't really full track pads. I wouldn't dare run track pads on my street car, and my friend is as cheap as hell (plus he drives his car a fair distance to the track). I know he isn't the only one that uses Ultimates in semi-race or race-prepped cars though.

I don't like magazine comparison tests either (not ones besides the ones in NissanPerformanceMag, where I know I can ask about the fine details through a quick email). I do like it when people make in-house comparisons like what Seth did (waaaaay back before we hijacked this thread ), or when people do their own private testing and make judgements based on their experience. But when people present any of these beforementioned as facts, it pisses me off for some reason (probably because my field of expertise is systems analysis, and so many people who are IT or system engineers it do just that).

As for who you are: Who knows? I'm not about to make judgements based on posts on some internet forum.


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## sethwas (Apr 30, 2002)

Wont Be Beat said:


> *getting more powerfull brakes will do NOTHING for stopping distances no matter what any retarded magazine says. *


I think this is part of the line that started this whole cavalcade of info. I don't mind a hijacked thread. When people see a thread has a lot of responces and views they tend to visit them more than another. 
Anyway, I hope that line wasn't directed at me. All I was trying to do is find out quantitatively (different from qualitative which I have already done) the increase in what is being argued about 'stopping ability' and actual reduction in feet from 60-0.
Since no sentra has been tested with out stock everything it is only possible to guess. I used info from an SE-R which has similar weight, and then the same SE-R with similar upgrades to my own. I balanced that against a newer B15 which is heavier, but has similar proportions (4 doors) and slightly larger brakes than my own now.
Finally I looked at factory stopping info from a B13 with AD22VF.
From all these I came to an educated guess of my own cars stopping ability. 
Its a shame that no one else has KVR pads except the autoX crowd. Otherwise I could probably find more numbers to compare to.
One thing is for sure is that tires do make all the difference. It is tires that cause lock. If they didn't slip or be overpowered by the pad mashing the rotor, it would not suddenly stop rotating. Of course tire weight and rim weight not to mention the diameter of both considering rotational inertia play a role.
Anyway as for track vs. street aside from grippier materials and eating rotors, it is my understanding that the main difference is temperature range. Track pads are designed to run hot during normal use. Regular street pads can't really run hot.


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## Wont Be Beat (Sep 20, 2002)

> *As for whether the fastbrakes kit or soft tires make a better upgrade choice for us Sentra drivers, that'll have to be solved with a controlled lab-style experiment somewhere. Beyond this point, speculation or theororizing about it is most likely just going to waste space. I'll see if I can't organize one with the people I work with (have to find out what they can get). I'll get back to you guys on that one.*


 Cars have been raced for over 100 years now and if to this point, the concept I'm putting forward is foreign or "unproven" to you, you have no business doing HPDE. Next time your at an HPDE school, ask your instructor.

Other than that, I really see no point in arguing because once a debate becomes an issue of credibility, I'm just wasting my time, and have no need to prove myself to anyone. Those that know me will believe me and take my words as facts, and those that dont, I really dont care.

I have nothing against NissanPerformanceMag. Its probebly a credible and tech based media--especially since it got covered in SCC this month.


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## ReVerm (Jan 13, 2003)

Wont Be Beat said:


> *Cars have been raced for over 100 years now and if to this point, the concept I'm putting forward is foreign or "unproven" to you, you have no business doing HPDE. Next time your at an HPDE school, ask your instructor.*


Who said anything about the concept of softer tires equalling better stopping distances being foreign to anybody? The debate here is whether softer tires or a big brakes kit like the Fastbrakes kit will lead to better stopping distances on our cars (or at least it was before things got heated and started going astray).


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## Wont Be Beat (Sep 20, 2002)

Like I said: If with soft tires, you have the ability to lock up the brakes at will, then threshold braking with stock brakes and threshold braking with big pimpy brakes, the stopping distance will not differ by more than a couple of % either way. I'm done with this thread.


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## ReVerm (Jan 13, 2003)

Theory is one thing. Results from actual testing is another. Until someone tests out what any of us have said about whether tires or BABKs improving stopping distances more on our cars, nothing either of us can say will prove that.

Christ, I hope no one takes what anyone says here as fact. I mean, people can take in facts that others present, but I sure to hell hope no one takes anyone's word as fact. That's stupid to the point that it's scary.


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## James (Apr 29, 2002)

I understand what WBB is saying and I agree to some extent but a majority of my own braking is done without locking the brakes, because frankly I CAN'T (my brakes suck), I think what is TRYING to be said is that the larger rotors can stop the car faster without having ever locked up the brakes. 

ie if two of the same car, same weight, everything except one has larger rotors, were braking from a 60 mph stop without locking up the brake, the one with larger rotor would stop faster since the tire is still rolling and no matter how sticky it is, as it's rolling the friction is not that much different as when it is moving... it'd be different if you said both cars HAD to lock up their tires to stop, then stickier tires would be advantageous.



> Clamping force: The clamping force of a caliper is the force exerted on the disc by the caliper pistons. Measured in pounds clamping force, it is the product of brake line pressure, in psi, multiplied by the total piston area of the caliper in square inches. This is true whether the caliper is of fixed or floating design. Increasing the pad area will not increase the clamping force.


Isn't that saying that the total clamping force is = to line psi times surface area of clamping right? So larger surface area, more clamping force.


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## ReVerm (Jan 13, 2003)

*Damn*

Due to Jason (the guy who I was going to have help me with the testing)'s schedule for the rest of August, we won't be able to do a complete comparison test until Winter break rolls around (December. But even then it's iffy). Sorry guys. If anything changes, I'll let you know.


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## Wont Be Beat (Sep 20, 2002)

Ill do a test for you.

Car: 1992 Prelude Si 4WS
Weight: Approx 3100lbs.
Brake mods: 94 Legend GS 2-piston calipers, Prelude VTEC MC, Prelude VTEC 11.2" Cobalt G-3000 spec rotors, Axxis Ultimate pads.

I will do several threshold stops (allowing cooling time) from 60mph and do my best to calculate distance while using my 205-55-15 Falken Ziex 502 tires.

Then, I will do the same test with 205-50-15 Falken Azenis.

If I dont stop any better with Azenis, I will eat a ketchup sandwich and post the video here.


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## ReVerm (Jan 13, 2003)

Will you be using the modded brakes with the softer tyres or will you be switching back to the stock brakes while testing them? Because, as you probably know, if you don't switch back to the stock brakes, there's really no point in doing those tests.

Either way though, that's still kinda iffy. Especially since the Prelude does come with much better stock brakes than the stock Sentra compared to the upgraded ones for each.

PS: Sorry about the number of edits. Just don't want to waste space on another reply.


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## Wont Be Beat (Sep 20, 2002)

I wont be switching to stock brakes seeing as I no longer have them. I'm just trying to make a point about tires here. I think your smart enough to see where I'm going with it.


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## ReVerm (Jan 13, 2003)

But the discussion here wasn't about whether softer tyres will stop better than your average street tyre. Everyone with the slightest amount of knowledge of vehicle dynamics knows that stickier tyres will stop better. Like you and I both implied before, that doesn't need to be proven.

The test I was going to have conducted was a comparison between the Fastbrakes BBK and several sets of fairly streetable sticky tyres (R compounds, mostly) with average agressiveness street pads (we were thinking Metal Matrixx). The test I want to conduct is to test how true your original claim that putting big brakes on our cars is a waste of money is.


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## Wont Be Beat (Sep 20, 2002)

Now I see your point. Well, let me clarify: if the Sentra's have poor brakes (I know, I took my road test a few years back in a B13 and was barely able to stop it), then they dont stand a chance in hell of locking up R-compound tires. What I'm trying to say is if a car already has adequet brakes, and is able to lock up said R-compound tire, then more powerful brakes that are able to exert a good friction coeffiction such that lockup at will is available, then threshold braking with an expensive BBK and threshold braking with stock (yet adequet) brakes will yeild no difference in stopping distance (baring fade) because ultimately, the friction applied to the ground is dependent on the tires, and not the brakes. I hope I clarified that.


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## ReVerm (Jan 13, 2003)

Thank you.
You're absolutely right (=perfectly clear) there, and needless to say, I agree with you completely. On a side note, that's exactly the kind of post that make me want to come back to this forum so often, (and the kind we need more of here): Concise, detailed, and full of accurate information.


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## Wont Be Beat (Sep 20, 2002)

Thanks. I can be a dick at times. Dont mind me.


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## niky (Jul 20, 2002)

woohooo!!! we finally have an answer folks!!!

don't mind me, guys, i've been following this discussion with interest from the beginning.


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