Brakes

[TeamAllen]

I need to replace the rotors on my Toyota 4Runner. I have read a few forums about the topic and wondered if any of you had an opinion.

Generally I stay factory stock on most things with my cars. Brembo is a company with a reputation for quality and a strong background in high perf. racing. They suggest a drilled rotor instead of the standard for improved braking.

The discussions I have read all lead to loss of braking surface area and shorter pad life when you change to drilled rotors. It's like re-engineering something. If you increased the caliper size that might offset the loss of braking surface? As always one modification leads to another.

This isn't really about my 4Runner, I don't really use it for much towing, but I thought this would be a good question in general for all of our tow rigs. I would have done anything for my old 3/4 Suburban. That thing had terrible brakes!

What do you think?

[spharis]

While it's true that you lose some potential energy conversion surface by drilling holes, you gain stopping power due to the increasing bypass flow of the braking gases.

Whenever you apply brakes, the kenetic energy has to be converted to heat. That's what the pads and rotor do. The pad is a friction compound that uses the energy of the rotor to heat the rotor up. This heat has to go somewhere, so it is vented out through the vents (look at a rotor and you can see them). What also happens when you brake is that gases are built up under the pad as a byproduct of the heat on the friciton material. It also has to go somewhere. Usually, a pad as a few lines etched into it to aid in capturing the gas and allowing the rotor to stay in contact, but it is not optimal. A drilled rotor on the other hand has pockets to allow the gas to evacuate from the pad surface, thereby increasing braking by allowing the pad to stay in contact with the rotor surface, and keeping the pad cooler. Make sense?

The downfall of a drilled rotor is exactly what you stated. It removes overall surface area so there is less material to use to convert the energy to heat. Usually, to compensate for this, a manufacturer or engineer will go up in rotor size 1 or 2 inches to allow a larger heat disappation surface. One other porblem with a drilled rotor is strength. In many cases (think ebay) a mcahine shop simply takes a rotor and drills it. The significantly weakens the rotor, so stress cracks a premature failure appear overtime. A properly drilled rotor is a very well engineered design, not a drilled OEM unit. I would never tow with a drilled unit.....It would warp or crack very quickly due to the increased heat per surface area.

A better alternative in my opinion is a slotted rotor. It has the great cavitating properties of the drilled surface, by removing a negligabile amount of rotor surface. I do prefer them over a drilled or standard rotor. I always replace to slotted rotors whenever I need to replace an OEM unit. The cost difference is minimal, and the increased braking is immediately realized. A slotted rotor in most cases will also drop right into an OEM setup. No changing of caliper brackets, or pads is required.

All in all, the difference is there, but if you are like many people, a standard OEM unit is obviously the best choice. It offers recommended braking (think engineers designed this thing) for your vehicle and an acceptable wear rate. The size and material in them is also optimized for the towing capabilities of the rig. Look at the rotor size/caliper pressure on a 3500 vs. a 1500. If you are having problems braking a trailer, you are better off investing in trailer brakes vs. upgrading rotors.

My order of preference:
Slotted
OEM
Drilled

[Domsz06]

If the car didn't come with drilled, I wouldn't put it on. I agree with spharris to a T. My z06 came with drilled, and they work fine. I put them on one of my cars and had nothing but problems. I have used slotted and they work very well as well.

I would rather put electronic brakes on my trailer, and run dual brakes on that, before I mess with my trucks brakes.

Just my .02

[TeamAllen]

Thanks for sharing your knowledge and experience. No on the drilled. I see what you are saying about the concern for quality on the drilled rotors.

Brembo makes drilled and slotted. I'm interested to hear more. I think I'll have to read the reply again.

I did a disc brakes brake conversion on my trailer last earlier this spring. It was a good decision. Less maintenance and the reverse backup thing was a great benefit.

[Domsz06]

I want to upgrade my brakes to dual electric soon. It's my next project I thik I'm saving for. No more of this crappy surge stuff

[spharis]

Don't get me wrong, a drilled rotor has its place, say on drag strips, and circle tracks; Z06s; but I wouldn't want the increased wear and decreased lifetime associated with them. The amount of energy that needs to be dissapated is the same, so that equates to higher heat in a given surface area. That increased heat is going to cause cracks, and warping before it would show on a standard unit, to what overall braking gain.....a few feet? Performance parts are meant for performance vehicles. If you aren't driving like a BOOH, then save your change, get some pads that don't throw a ton of dust instead.

As far as your suburban.....those things are bohemoths. The rotor onthem was standard on all K1500 rigs...even RCSB pickups. So you were stopping a 5000+ pound vehicle on brakes under-designed for it. It is a known issue, and many people upgrade the master cylinder, caliper, and rotors to beefier units when doing things like bagging, and dropping big blocks in them; the people who do it right anyway.

[Domsz06]

and there has been issue on people tracking their z's. if they have not cooled the brakes down by say a cool down lap people have cracked their rotors. I'd be pissed I know that if it happened to me on a truck or something. Just get something that is cheaper and for all intensive purposes just as good at stopping.

[chpthril]

I would stick with factory Toyo parts. Over the years I have not seen an aftermarket OEM brake pad that performed as good as factory.

Be sure to torque the lugs to spec, the #1 cause of warped rotors is unevan/improper torque.

Replace, do not machine rotors. With the loss of metal mass, the rotors will heat up faster and to higher temps, this will decrease stopping distance and reduce pad life.

[TeamAllen]

Thanks for the advice. I ordered the standard vented rotors from buybrakes.com. I'll see how that goes.

I will use Toyota OEM pads as suggested. I know about the torque problem. I learned from experience on that one. We bought the car used and I think they did the standard brake job and turned the rotors. I think that is why they are warping with so much pad life left.

I'm still want to to learn more about the reason spharis likes the slotted rotors.

[chpthril]

Drilled rotors are great when you drive the $@!* out of one and don't care about how often you have to change brakes.

The slots = less loss of surface area than drilled, but still allow the gas/heat to escape. Like spharis said, it would be easy for someone to take OEM rotors and drill them and sell them on the internet I've done it for my V dubs but would never consider selling them.

Co's like Brembo, AP racing, and Ferodo do make top of the line brake broducts, but they are for performance/race applications, I dont think they would perform as well (noise, life) on a daily driver as OEM.

[Domsz06]

Drilled rotors are great when you drive the $@!* out of one and don't care about how often you have to change brakes.

The slots = less loss of surface area than drilled, but still allow the gas/heat to escape. Like spharis said, it would be easy for someone to take OEM rotors and drill them and sell them on the internet I've done it for my V dubs but would never consider selling them.

Co's like Brembo, AP racing, and Ferodo do make top of the line brake broducts, but they are for performance/race applications, I dont think they would perform as well (noise, life) on a daily driver as OEM.

I agree with you chpthril. Racing their products rock, but daily drivers, not so much!

[spharis]

A good true drilled rotor is going to be a complete kit: calipers, hoses, etc. You will be effecively changing the braking, not just a rotor, and the materials are usually different. Most of those kits run in the $1500-$2500 range. ouch....

[TeamAllen]

My stock replacement rotors should arrive today.

It seems the slotted rotors are kind of an in between product. Close to the same surface area, as OEM, with improved braking performance. Would the pads wear more rapidly?

Those braking kits are very expensive. I would have done it to my Suburban had I kept it. Again, those brakes were garbage.

[spharis]

no...wear is about the same.