I did it...finally I did it!

[Spook50]

I have the 4000 series slotted rotors on my rig, and I love 'em. Run them with metal based pads, so they didn't last too long though. This time around I'm using regular Brembo rotors with ceramic pads (I'm using the '92 4Runner calipers) since I've heard the ceramic are damn nice, won't gas out and are quiet.

Using ceramics on the back as well (Monte Carlo calipers), so it'll be interesting to see if there's a reduction in stopping power from the slotted rotors once the new stuff is broken in.

 

[rover67]

i use the stock master and it works great IMHO

 

[lehiguy]

I don't think it's that big of an issue, but the bigger pistons of the calipers really beg for a larger master, from a T100 for example. Bolts in and has much more volume.

Guys, lets do some basic math. The mechanical advantage you have when pushing on the brakes is basicly the volume of the area behind the pistons in your calipers divided by the volume of the fluid you displace from the master cylinder. Going to a larger diameter caliper piston, you indeed gain brake power at the expense of pedal travel. Now if you enlarge them both, the master cylinder and the caliper piston diameter, you may very well end up right where you started only without any money left.

 

[GLTHFJ60]

Guys, lets do some basic math. The mechanical advantage you have when pushing on the brakes is basicly the volume of the area behind the pistons in your calipers divided by the volume of the fluid you displace from the master cylinder. Going to a larger diameter caliper piston, you indeed gain brake power at the expense of pedal travel. Now if you enlarge them both, the master cylinder and the caliper piston diameter, you may very well end up right where you started only without any money left.

You would end up right where you started in terms of pedal travel, but the larger volume of fluid pushed through the larger master cylinder would mean that you have a greater potential for stopping power. More volume in the caliper with the same at the master cylinder = less pressure. Upgrade both retains the stock pedal travel with more stopping power.

My thought, but then again I haven't done the swap yet. Experience only from what I've read.

 

[lehiguy]

You would end up right where you started in terms of pedal travel, but the larger volume of fluid pushed through the larger master cylinder would mean that you have a greater potential for stopping power. More volume in the caliper with the same at the master cylinder = less pressure. Upgrade both retains the stock pedal travel with more stopping power.

My thought, but then again I haven't done the swap yet. Experience only from what I've read.

If you change the math around to a situation where you are pushing more fluid into the calipers, (and this would be best expressed as a ratio) the pedal would decrease in travel but increase in firmness and you would lose braking ability simply becuase you would have to push harder on the pedal to achieve tha same pressure at the caliper. It's a mathematical fact that a smaller master cylinder diameter would increase the pressure at the caliper. So would a larger diameter caliper piston. The best scenario, and one that has yet to be achieved, are larger diameter rotors and a caliper location to accomodate that change. I only wish my Cruiser could stop like my BMW which weighs less and has far bigger rotors.

 

[TLCAddict]

don't mean to burst ur bubble, but if you go off-roading in the mud, watch out for mud build-up in the slots...

 

[BillyGHusk]

Guys, lets do some basic math. The mechanical advantage you have when pushing on the brakes is basicly the volume of the area behind the pistons in your calipers divided by the volume of the fluid you displace from the master cylinder. Going to a larger diameter caliper piston, you indeed gain brake power at the expense of pedal travel. Now if you enlarge them both, the master cylinder and the caliper piston diameter, you may very well end up right where you started only without any money left.

What if you keep stock calipers and upgrade the master?


Tim

 

[Spook50]

don't mean to burst ur bubble, but if you go off-roading in the mud, watch out for mud build-up in the slots...

Not so much in the slots, but the holes are what'll tear the pads all to hell. Even if they're clean, they'll increase pad wear a great deal. Some companies are now putting a chamfer into each hole and that's helped reduce pad wear alot on road vehicles. Doesn't solve the problem of possible hotspots forming and cracking the rotors though.

 

[lehiguy]

What if you keep stock calipers and upgrade the master?


Tim

If the "upgrade" is to a master cylinder with a larger bore, your peddle travel will decrease and the effort required will increase. Of course, if your current master cylinder is shot, you may find the change to be benneficial.

 

[GLTHFJ60]

If you change the math around to a situation where you are pushing more fluid into the calipers, (and this would be best expressed as a ratio) the pedal would decrease in travel but increase in firmness and you would lose braking ability simply becuase you would have to push harder on the pedal to achieve tha same pressure at the caliper. It's a mathematical fact that a smaller master cylinder diameter would increase the pressure at the caliper. So would a larger diameter caliper piston. The best scenario, and one that has yet to be achieved, are larger diameter rotors and a caliper location to accomodate that change. I only wish my Cruiser could stop like my BMW which weighs less and has far bigger rotors.

I'm not trying to argue, I'm just trying to clarify. Just thought I'd say that.

If you're talking about caliper piston and master cylinder comparisons as a ratio, then to keep the stock ratio, if you increased the volume of the caliper end then wouldn't you have to increase the master cylinder size to keep the stock feel with better performance?

 

[worshhim]

UPDATE

Stopping power has greatly increased with the new rotors. I have never been able to stop as quickly as with these rotors. Haven't actually measured it, but the stopping distance is much shorter and I don't have to slam on the brakes! IMHO this is the best set of rotors I've ever had on any vehicle.