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Discussion Starter #1
When I brake HARD from 70mph or so at this place in the sticks(sp?) the front wheels lock some and I have to compression brake a little. What I don't understand is how bigger brakes like AD22VFs can slow me down faster as it would seem it would just make the tires lock up easier. Can someone explain how it works? I'm sure it makes sense somehow, just don't see the logic yet
 

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I think more control just means it is easier to keep from locking the brakes, which would yeild a shorter stopping distance. I think the issue is not how much traction your tires HAVE, but how much of that traction you can USE. I'm still waiting for a second opinion though :)
 

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Discussion Starter #3
I'm waiting too... c'mon folks, whaddya do, work for a living? :) I do and I'm posting! :) heh
 

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Scary monkey windmill
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I'll give it a shot too, here. I think you have to separate the issue into two categories: racing and street (daily commute or whatever) driving. First let's talk about regular old street driving.

Scarpa was right on about control, that's exactly what it does for you. The bigger rotors help prevent fade my dispersing the heat across a bigger area, and the larger calipers cover a wider clamping area. So you get better clamping with less force, and your pads don't fade as quickly.

This is all about control, and if you only have to push the pedal down 1/2 as far with bigger brakes, then that gives you much more control over your own destiny. :) The tire lock-up problem is just a traction issue. The idea behind bigger brakes, at least in the context of daily driving, is more control. Sometimes just having a better pedal feel is worth it.

Now to talk about racing a bit... the BABK was designed by SMC for racing purposes. It's overkill for the street, plain and simple. Most people like the added control of the AD22 brakes on the street, but I never needed any more than that with my NX, at least on the street.

But on the track, you need all the braking power you can possibly get. If you drive hard and brake late, your AD22s will fade, and you won't be able to lock them up. BTW I'm talking about road racing, not autox. The AD22s are actually probably fine for AutoX.

The BABK has 4 piston calipers and almost 12" slotted rotors. There is enough there to keep most SE-Rs happy on any track. Last time I went to the track I had Hawk Blue pads for my BABK, and I found that I could not even heat the pads up hot enough to get them into their comfort zone. As a result they ate my rotors all to hell. And believe me, I was late braking as hard as I could. I even got fluid fade, but I could still lock up the tires (sticky race tires) at 95 MPH.

So that means that the brakes are good enough that I don't even need full-out race pads, even driving as fast as I can.

With race tires especially, the stock brakes won't cut it. The AD22s are OK to a certain point, but generally the tires can out-grip the AD22s. Rob Cadle uses Hawk Blues with his AD22s, and he says that's just about right, he likes that combo. But he also has some fade issues, and he's right at the top of his brakes' capacity. The BABK affords more control because it dissipates more heat and has a lot more clamping force over a wider area.

In my case I bought the BABK because I knew I was going turbo and would actually need it. I expect to tax my brakes at the track quite a bit more when the turbo is done. As it is right now I can't even use their full capacity.

And to answer your question about locking the brakes at 70 MPH... how many times in a row can you do that before the brakes heat up past usability? A lot of that has to do with the pads you're using, but bigger brakes will definitely allow you to do that more times in a row... if that's something you like to do a lot. ;)

Hope some of that made sense. :)
 

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Discussion Starter #5
Thanks for the very complete comment.

When I stop from ~70 it's simply once. Not even twice in a row. That's the only time where I feel that my brakes aren't up to snuff (and lapping at the convention with stock brake fluid and brakes I just braked very early all the time and never allowed them to fade). Normal driving the stockers are GREAT, but lapping they just feel scary like I would need to use 95% or more of the brakes capacity to stop from high speed and it would just eat them up, pads, rotors, fluid boiling, everything. So I guess it is a "feel" issue as well as a repeated braking issue. The AD22VFs are so cheap I will get them soon after my turbo upgrade even though I don't plan on doing much lapping. Just that full-on 70-0 stop once a week (or less) is not satisfactory is all. Not enough to justify bigger brakes. But the turbo sure will. :)
 

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pwnd
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The main reason Im getting them is the old Kojimaism, why you are in there. My brakes are shot and have been for quite sometime. I dont do any racing but want the added stoping power of the ad22vf's. I do a bunch of highway driving and coming into Knoxville at the wrong time can put a hurting on bad brakes. Cruise set on 72 come around the corner and bam you are in bumper to bumper 10 mph traffic. Hauling the car down from 70 is scary in my current situation. Going to the convention when Larry blew a tire I was scared cause I almost bought a rear end of a NX trying to slow down with everyone and getting to the shoulder. I figure Im going to need new rotors anyway, and my calps for sure needed rebuilding so why not go to the ad22vf's. The reason my calps need to be rebuilt is the boots on the bolts are all tore or gone so im sure more work needs to be done to them. so 150 or so if i stay stock and refresh the system or 225 for the ad22vf's why not.
 

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Hmm.. I'm not qualified to answer this question for real, but I'll give it my best WAG.

(Actually this is mostly from reading MikeK's brake writeup on se-r.net)

Regarding the AD22VF upgrade, what you get is bigger calipers and rotors. This means that that you can get more stopping power with less pedal effort. This makes it a lot easier to modulate your brakes and keep from lock-up. Say you have to pretty much stand on the brakes right now to get the car hauled down. With the larger brakes you only have to press down half as hard (this is hypothetical) to get the same braking effort. I would imagine that this would allow for more finess in your braking.

Not only that, but the bigger brakes can absorb more heat, making reducing the risk of brake fade. And if you go for the BABK, you get 4 piston calipers I think which would allow an even lighter touch. I think my point is that brake upgrades not only allow for more stopping power and heat dispersion but more consistency as well.

I hope that was halfway accurate or informative.
 

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Discussion Starter #8
Ok, so like I may be able to carry my new 40 inch TV upstairs, but I use 100% effort to do it. If I worked out for a few months and tried it again, it would be as heavy, but I would only be using 90% of my effort and would be able to handle the load better and not scratch up the walls, the tv, myself, etc. :)

What about all those tests you see (probably in SCC too) where it says "stock brakes stopped from 60-0 in X feet, and with this brake upgrade they stopped in Y feet." ? Does more control equal feet less or stopping distance? I mean your tires have only so much friction with the ground.
 

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Sportbike fevah
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Ben said:
Ok, so like I may be able to carry my new 40 inch TV upstairs, but I use 100% effort to do it. If I worked out for a few months and tried it again, it would be as heavy, but I would only be using 90% of my effort and would be able to handle the load better and not scratch up the walls, the tv, myself, etc. :)

What about all those tests you see (probably in SCC too) where it says "stock brakes stopped from 60-0 in X feet, and with this brake upgrade they stopped in Y feet." ? Does more control equal feet less or stopping distance? I mean your tires have only so much friction with the ground.
Ultimately braking distance for a single stop is defined
more by the traction of your tires, then the size of your
brakes. Bigger brakes as far as I know, increase mostly
your heat dispersion, and depending on your M/C setup,
may help pedal feel.

I *hear* that the the ultimate stock Nissan brake setup
is AD22VF's on the front, and 89-94 Maxima rears on the
back. With that combo, and an Altima M/C added, the
bias is right on, the pedal feel is incredibly, and the stopping
rivals that of a front only BABK.

Once again, it's mostly about heat dispersion.

Energy=mass*inertia, more or less, right?

Stopping requires transforming that energy to
heat, via a pair of very large heat sinks - your
rotors. While the pads are the friction material
that allows the transfer of energy (now, heat)
to the rotors. There's a reason F1 cars vent air
over their rotors. It's to get rid of heat.

Peter
 

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wow...back from the dead...
 

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Sportbike fevah
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Search!

nismo91 said:
At first I was like wow Ben is posting again!!!!

LOL! It's all good. At least we know that you have SEARCH!!! But really, at least now there is another answer to the question.
Yep, I was searching for Scarpulla's thread on
NX2K rotors/calipers. I just ordered some calipers
from my local autozone, and couldn't find the
rotors from them. I've been thinking I wanted
to maybe grab some powerslots, to keep down
pad fade for when I finally make it out to a track.

I want to do the max rears, too, I'm pretty sure.

Found a local junkyard that wanted $35 a piece
for them, but I have to make absolutely sure
which ones I'm getting first. I *think* I said
89-94 Max.. I can't remember if it's supposed
to be the SE or not. I seem to think it'll take
those NX rotors, too, no?

Damn ... this thread is back from the dead!

Check it out! Email notification and search
capabilities. I'd really hated forums at one point,
but I've gotten to like the interface. I feel so
ashamed. It's like dumping FreeBSD for Windoze.

But an 3-something year old thread lives again!

That's too cool.
:)

Peter
 
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