SLOTTED BRAKES.....12 or 6 slots

The place for all technical car discussions. If you haven't already, read our Disclaimer first!

Moderator: The Mod Squad

Postby Stealer Of Souls » Tue Mar 29, 2005 3:53 pm

Something was said earlier about the pads binding to the rotor... this is probably what's happening. The article link I posted earlier eludes to this. It says something about cheap pads basically "coating" the rotor with a high friction layer. The pad then grabs this layer and just sticks. So no time for weight transfer and grip becomes exceeded...
This would mean that only an insanely grippy tyre could stop that from happening...
'86 AE85.5 Levin

I don't claim to know everything... That doesn't mean it isn't true....

Click here to see "My Black Hole"
Stealer Of Souls
Toyspeed Member
 
Posts: 2054
Joined: Mon May 20, 2002 10:42 pm
Location: West Auckland

Postby suberimakuri » Tue Mar 29, 2005 4:25 pm

Your suggestion and experience at the track is good information Simon. I understand that situation.

I don't think it's a 'grabby' issue.... as i've had some crappy ($15) pads that don't grab. But the wheel still locks up.

I've been hesitant in using "wheel/tire locks up", as it can be read that the tire is failing to keep grip.

So, I think i'm going to be stubborn and lean to this statement: "cheaper pads will bind quicker for whatever reason".
User avatar
suberimakuri
Toyspeed Member
 
Posts: 1296
Joined: Tue May 14, 2002 12:58 am
Location: Auckland, NZ

Postby BZ-G » Mon May 16, 2005 10:06 pm

I don’t know how slotted rotors really work…. But all I know is that drilled rotors tend to crack a lot easier under heavy braking… that’s why I have used slotted instead of drilled…
Cost of Brembo 6 slot front rotors on AE111 BZ-G is only $380NZD… So it’s cheap compared to DBA and an upgrade price from standard rotors… Part # DR708V…

If you do go on the track… what really stops a car is not only rotors and brake pads… you got to incorporate tires, suspension, brake fluid, brake line, master brake cylinder stopper and disable the ASB system… after all this you can out brake any race car with an AE111…. Like me… :lol:
Phil

AE111 Trueno BZ-G
BZ-G
Toyspeed Member
 
Posts: 86
Joined: Fri May 13, 2005 8:56 pm
Location: What ever

Postby GT4 20 » Mon May 16, 2005 11:22 pm

BZ-G wrote:I don’t know how slotted rotors really work….


Not quite sure what you're saying, but the slots are designed to allow gasses to escape. As a result of heat, pads can give off a gas which can build up between teh pad and rotor. This gas effectively reduces friction - sometimes to the extent where brake fade is experienced. The slots simply allow the gas to escape and at the same time, help deglaze the pad.
Gary
1999 Subaru Legacy B4 RSK TT
GT4 20
Toyspeed Member
 
Posts: 1086
Joined: Thu Jun 10, 2004 5:03 pm
Location: Auckland

Postby TygerTung » Mon May 16, 2005 11:44 pm

Putting bigger brakes on your car won't make it stop quicker, but you you'll be able to stop quickly more times.

My factory 1975 corolla brakes can lock the wheels at too kmh no worries.
TygerTung
Toyspeed Member
 
Posts: 291
Joined: Fri Oct 29, 2004 1:35 pm
Location: Christchurch.co.nz

Postby matt dunn » Tue May 17, 2005 12:42 am

TygerTung wrote:Putting bigger brakes on your car won't make it stop quicker, but you you'll be able to stop quickly more times.

My factory 1975 corolla brakes can lock the wheels at too kmh no worries.



So two cars with 1000kg weight,

One has 135mm discs and one has 325mm discs and four pot calipers,

You say that if they both are driving at 150k and then stop as quik as they can that they will stop in the same place?
7AGTE - DX20VT - viewtopic.php?t=59733
Discussion - viewtopic.php?t=59751
matt dunn
Toyspeed Member
 
Posts: 7109
Joined: Fri Sep 12, 2003 1:01 am
Location: Timaru

Postby Al » Tue May 17, 2005 12:53 am

Providing the smaller of the two braking systems can infact lock the wheels and the cars are identical, even down to tyres. Yes.

Doesnt matter how big the brakes are for one stop, you only have two friction points. The pad/rotor and the tyre/road. If you can lock the pad/rotor then the only way to stop quicker is by increasing the friction with the road.
85 Corolla GT - 08 Blade Master G
Image
User avatar
Al
Toyspeed Member
 
Posts: 6146
Joined: Mon Jan 20, 2003 11:52 pm
Location: Christchurch

Postby matt dunn » Tue May 17, 2005 1:28 am

You have obviously never been in a car with truly big brakes then.
7AGTE - DX20VT - viewtopic.php?t=59733
Discussion - viewtopic.php?t=59751
matt dunn
Toyspeed Member
 
Posts: 7109
Joined: Fri Sep 12, 2003 1:01 am
Location: Timaru

Postby Perky » Tue May 17, 2005 6:39 pm

Providing the smaller of the two braking systems can infact lock the wheels and the cars are identical, even down to tyres. Yes.

Doesnt matter how big the brakes are for one stop, you only have two friction points. The pad/rotor and the tyre/road. If you can lock the pad/rotor then the only way to stop quicker is by increasing the friction with the road.

This must be correct, but doesn't it assume that the wheels of the two cars are locking at the same time? Until the wheel locks the larger brakes have more friction and I'd expect them to scrub off speed more quickly and lock earlier. Since, ideally, most braking won't involve wheel locking, this should make a difference but maybe in emergency stops the wheels lock so quickly that it is irrelevant.
Perky
Toyspeed Member
 
Posts: 103
Joined: Wed Nov 03, 2004 7:01 pm
Location: Wellington

Postby JT » Tue May 17, 2005 7:14 pm

matt dunn wrote:You have obviously never been in a car with truly big brakes then.


Bigger brakes fight heat better after repeated stops.

What this means is, in a single 100-0 stop you will only slow well as brakes can fight the heat and the tires can keep traction. The brakes don't have that much heat to fight in one single stop and you could lock up most road car tires with the brakes from a good stomp on the pedal.

All a brake upgrade is going to do is make the brakes more resistant to fade, unless you get better tires too.

The car you have been in with truly big brakes probably has racing slicks on too? This means the better brakes can stop the car quicker because the tires will not lock up so easily
User avatar
JT
** Moderator **
 
Posts: 1896
Joined: Fri Aug 15, 2003 12:21 am
Location: Christchurch

Postby Al » Tue May 17, 2005 7:28 pm

matt dunn wrote:You have obviously never been in a car with truly big brakes then.


I bet the cars you went in with these truly big brakes also had nice sticky race rubber as well :wink:
85 Corolla GT - 08 Blade Master G
Image
User avatar
Al
Toyspeed Member
 
Posts: 6146
Joined: Mon Jan 20, 2003 11:52 pm
Location: Christchurch

Postby TygerTung » Tue May 17, 2005 9:03 pm

matt dunn wrote:
TygerTung wrote:Putting bigger brakes on your car won't make it stop quicker, but you you'll be able to stop quickly more times.

My factory 1975 corolla brakes can lock the wheels at too kmh no worries.



So two cars with 1000kg weight,

One has 135mm discs and one has 325mm discs and four pot calipers,

You say that if they both are driving at 150k and then stop as quik as they can that they will stop in the same place?


Yeh mate, as long as the 135mm brakes don't overheat during that stop,(which they shouldn't) You'll be able to stop the same time.

But if you want to do it more times, you'll need the bigger brakes, as each time you do it, the brakes will get hotter and hotter.
TygerTung
Toyspeed Member
 
Posts: 291
Joined: Fri Oct 29, 2004 1:35 pm
Location: Christchurch.co.nz

Postby lill fuk » Wed May 18, 2005 9:11 pm

ok so on the subject of brakes wot can i do to mine standard sw20 mr2 if i wonted to do the targa tour thingy nxt year do i worry bout rotors as its not a competitive event or do i jst get decent pads?
lill fuk
Toyspeed Member
 
Posts: 5
Joined: Sun May 15, 2005 4:04 pm
Location: Auckland

Previous

Return to Tech Questions

Who is online

Users browsing this forum: No registered users and 25 guests