I know that this is a hard debate to test without some doubt from someone. However, does anyone have any numbers for stopping distance for the two? Or first hand experince of the two?
Rear drum vs. Rear Disk brake stopping distance.
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Couldn't find the rear drum specs, but found a road test by "Motor Trend" magazine in March 1993 of the '93 model 80 with rear disk brakes. It went from 60 MPH to 0 in 128 feet. Quoting the mag: "the best we've recorded on any sport/utility."
Unpossible. Everyone knows the 80 can't stop and needs major mods and untold numbers of aftermarket brake parts to be safely driven on public roads.
-Spike
When I swapped out my Semi float drum axle for a 94 FF Disk axle, I didn't really notice any difference. But then, I really wasn't swapping for the brakeing power reason, more for the full floater reason. In addition, I had bypassed the LSPV with the plan to put a manual one in. Without the LSPV, I had more breaking power in the rear than the truck could handle. Rear locked up before the fronts on the blacktop with both axles. Fine tuning the manual vlave gave me the most bang for the buck in braking power.
That was stock, Spike. Not with all the "improvements" you've made. Don't believe me? Go to your local library and check it out. "Motor Trend", March 1993
I have run all stock components on both my 80's, and they both stopped quite well. I bought into the hype on 100 series pads and tried them, and they also stop quite well, although I honestly can't tell the difference. The above comment was entirely sarcastic.
-Spike
-Spike
Your right, it was sarcastic. But, you started it. I'm not talking brake component mods. I'm talking tire and wheel size, suspension mods - and I'm just as bad. If you mess with what Mr. T engineered - the consequences are not always positive. And bigger tires and wheels need bigger brakes, you've changed the leverage. Suspension mods raise the COG. No offence intended!!!
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I'm not a believer that bigger tires and wheels necessitate bigger brakes. The tires are bigger, the leverage changes, but so does the rotation speed. The net energy required to stop the vehicle shouldn't change, unless the weight of the vehicle changes significantly. Bigger tires are heavier, which means more rotational force against the brakes, but IMO the difference is negligible. In other words, before anyone gets all bent, I don't believe that bigger tires tax the stock system enough to overburden it, although there may be slightly more force required to stop the vehicle. The braking system is not designed to be able to stop only 4800 lbs with 29" tires- there's got to be quite a bit of headroom in the system. For example, the truck is rated at around 6200 lbs GVW, plus the ability to tow another (3500? 5000? I forget) pounds, which had to be factored in to the brake system by Toyota when designing it. I see the 80 brakes as being overbuilt for the (stock) application, and in proper working condition capable of safely stopping the 80 with a lift and at least 37" tires (not having known anyone with larger than 37's, I can't project any further than that). Of course, that statement presupposes normal braking such as is commonly seen in city or highway driving, or even offroad. Riding the brakes down a long hill will certainly tax the system more, and it's not designed for that. If I were going to race an 80 I would probably look into the aftermarket realm to control fade and overheating from continued hard braking.
In my own experience with a lifted truck on large tires I can still lock up all 4 at will (ABS disabled). With the ability to lock up the wheels, the stopping distances are dictated by tire compound, road surface friction, and brake application (driver skill or ABS). The brakes themselves can not do better than lockup. All the aftermarket parts in the world are only going to make them lock up easier- which might be a desirable effect for some people, but doesn't make the truck capable of stopping faster. And no aftermarket brake component in the world is going to alleviate any effect the higher COG might have on the system, unless there's a fancy LSPV on the market I haven't seen.
All of which is fun to talk about, but does nothing to help answer the original poster's question.
I would guess that since the rear brakes account for less than 30% of the stopping force (I'm thinking more like 10%, but I don't have any hard data on hand so I'm going big) the difference between disc and drum rear brakes is probably hard to quantify by the average person. I'm positive the disc brakes are more capable, and simpler, and easier to maintain, and probably less prone to failure.All of the above statements are my personal opinions and experience, and are not backed by anything. Take them for what they're worth.
-Spike
I don't think you will find a lot of difference between the two, as long as the drum rear is set up and adjusted properly.
Keeping in mind that the disc brake rear needs no special setup or adjustment...
Keeping in mind that the disc brake rear needs no special setup or adjustment...
Ok, we've heard you opinion,now listen to some facts.
"Motor Trend" road test in March of 1993 recorded a stopping distance of 128' from 60MPH - 0 for the '93 80 series with rear disk brakes. The main advantage disk brakes have over drum brakes is fade resistance. Disk brakes also have better performance in wet and inclemate conditions. They are simpler mechanically and easier to maintain. Notice I didn't say cheaper.
There's all kinds of opinions out there and for what it's worth, Spike, the OP was looking for stopping distance or first hand experience of the two, not opinions.
OK, now you're arguing with yourself, and you're not even offering both sides. What was the stopping distance of the '92 with drum brakes?
I'm on your side. I believe disc brakes stop better than drums. I doubt that the average person would be able to feel a great difference in daily driving. I made a joke about 80 brakes in general, which was off-topic, and I apologize. You are coming off as very antagonistic and defensive about your 'position', which I never even argued against. Chill, my friend.
-Spike
I'm on your side. I believe disc brakes stop better than drums. I doubt that the average person would be able to feel a great difference in daily driving. I made a joke about 80 brakes in general, which was off-topic, and I apologize. You are coming off as very antagonistic and defensive about your 'position', which I never even argued against. Chill, my friend.
-Spike
Most people get "antagonistic and defensive about their position" when treated like a liar. Please refer to my first post where I said that I didn't have drum stats but offered what I had on disk stats. Then you chime in with yatta, yatta, yatta, basically blowing me out of the water. I don't know you and to me it sounded like you were telling me that i was full of chit. Apology accepted, and now I'll take your posts more lightly.
real life seat of the pants
I dont have hard numbers but Ive owned both a 91 and a 96 Landcruiser. They both had the same 33" tires so the comparison is as fair as can be. Speaking objectively, I can say one of the first things I noticed was the very distinct difference in the braking power with the rear discs vs drums. I can tell you that my rear drums were clean and adjusted frequently so they were at top performance.
If you arent sure about the drum vs disc debate, try driving a friends 4 drum 40 series and panic stop from speed (esp if youve jsut driven through some water). You will have to change your shorts afterwards....
I dont have hard numbers but Ive owned both a 91 and a 96 Landcruiser. They both had the same 33" tires so the comparison is as fair as can be. Speaking objectively, I can say one of the first things I noticed was the very distinct difference in the braking power with the rear discs vs drums. I can tell you that my rear drums were clean and adjusted frequently so they were at top performance.
If you arent sure about the drum vs disc debate, try driving a friends 4 drum 40 series and panic stop from speed (esp if youve jsut driven through some water). You will have to change your shorts afterwards....
in dry conditions, properly maintained and adjusted, I would be reluctant to believe that any of us could tell the difference between drums and discs in the rear.
Add in some neglect, or some water or mud... and the discs are less likely to be compromised.
another advantage to properly maintained discs is that the ebrake is a completely different system, whereas in drums the it shares components with the braking system. Having said that, if I were to completely lose braking fluid throughout the system and have to stop the vehicle using only the ebrake, I would much rather have rear drums than rear discs to do the work.
Add in some neglect, or some water or mud... and the discs are less likely to be compromised.
another advantage to properly maintained discs is that the ebrake is a completely different system, whereas in drums the it shares components with the braking system. Having said that, if I were to completely lose braking fluid throughout the system and have to stop the vehicle using only the ebrake, I would much rather have rear drums than rear discs to do the work.
In addition to rear disks beginning in '93, front rotors and calipers also got larger. I would venture to bet that the majority of decreased stopping distance from '92 to '93 model years came from those larger components in the front.
I've swapped a disc brake/full float axle onto my '91 and did not really notice any improvement in braking.
80toytlc,
I don't want to prolong this, but I think you missed the point that from the beginning Spike was totally in agreement with essentially everything you said and somehow you guys are getting your feathers up over it. You're both right. Sorry, I just can't watch two guys in agreement end up arguing.
As to the OP, I've owned a brand new 92 rear drum 80 and a brand new rear disc 80 and did not notice any difference in braking competence at all. At the time I was a Product Planner for Lexus/Toyota and had a well calibrated butt for that type of vehicle behavior. So, the message is don't swap rear axles seeking better everyday braking. If you were planning to tax the vehicle to the max for racing or similar demanding service then I'd say it worth adding the newer system with its larger capacity but that's a pretty serious undertaking as you'd need to change everything from the brake pedal on.
DougM
I don't want to prolong this, but I think you missed the point that from the beginning Spike was totally in agreement with essentially everything you said and somehow you guys are getting your feathers up over it. You're both right. Sorry, I just can't watch two guys in agreement end up arguing.
As to the OP, I've owned a brand new 92 rear drum 80 and a brand new rear disc 80 and did not notice any difference in braking competence at all. At the time I was a Product Planner for Lexus/Toyota and had a well calibrated butt for that type of vehicle behavior. So, the message is don't swap rear axles seeking better everyday braking. If you were planning to tax the vehicle to the max for racing or similar demanding service then I'd say it worth adding the newer system with its larger capacity but that's a pretty serious undertaking as you'd need to change everything from the brake pedal on.
DougM
Yeah, Doug, I had a book that I got from MAF along with a bunch of stuff that I ordered several years back: "Toyota Land Cruiser 1988-1997". Its a collection of road tests by different publications on the 80 series and some 70 series thrown in. I thought I remembered seeing specs for stopping distance for both versions of the 80's rear end, but I could only find it for the FF disk brake set up. I posted it thinking it might help the OP. I mis-understood Spike, thinking he was saying it was bogus information. I got pushed out of shape and realized later he was just being sarcastic about the 80's brake reputation. It was my fault, I'm not much of a blogger, but I'm learning!
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HDJ80's have rear disk brakes from the beggining, but, after 1993, when 16" wheels were introduced, they also introduced bigger brakes.
There is definetly a difference between pre-93 and post-93 models, but not for the fact of disc or drums just for bigger disks. I'm talking about HDJ80's, I don't know about FJ or FZJ's as we don't have them in Spain.
Anyway, a friend installed "super friction" break pads in his 80 to improve the braking. The improvement was unbelieveable, I'd even say it was too much braking (and that's with 285/75/16 and lots of weight) BUT they only lasted 15000 km (about 10000 miles).
There is definetly a difference between pre-93 and post-93 models, but not for the fact of disc or drums just for bigger disks. I'm talking about HDJ80's, I don't know about FJ or FZJ's as we don't have them in Spain.
Anyway, a friend installed "super friction" break pads in his 80 to improve the braking. The improvement was unbelieveable, I'd even say it was too much braking (and that's with 285/75/16 and lots of weight) BUT they only lasted 15000 km (about 10000 miles).
