Front brake size comparison

K

Kanab

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4th generation 4runner "Sport" - 13.3 front
GX470 - 13.3 front
4th generation 4runner "SR-5" or "Limited" - 12.6 front
2004 Sequoia - 12.6 front

They all have -12.2 rear brakes.

2001 Lexus LX 470 - 12.2 front and 12.8 rear

Based on this, the Sport should stop in a shorter distance then all of the others. I wonder why Toyota put the bigger front brakes on the Sport and the GX470? I would assume that the new LX470's and Landcruisers also have the larger 13.3 brakes upfront but I don't have any information on this. Comments or information?
 
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I don't know how much it would be to make the switch but the current LC and LX470 are a 1998 design. I'm sure when they get a new generation they will upsize them. BTW what size wheels are on the LC and LX470?
 
toybox said:
I don't know how much it would be to make the switch but the current LC and LX470 are a 1998 design. I'm sure when they get a new generation they will upsize them. BTW what size wheels are on the LC and LX470?
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I would assume that when LC and LX470 went with the larger wheel size they upgraded to the 13.3 just like the sport and the GX470. It does seem a little weird that Toyota put the larger front brakes on the sport but not on the SR5 or the Limited?
 
toybox said:
BTW what size wheels are on the LC and LX470?
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LX470 had 16" wheels up until '03 when they got 18" wheels. The LC also had 16" wheels up until recently. Now they are either still std 16" with optional 17" or maybe it's std 17" with optional 18", not sure.
 
GatorGreg said:
LX470 had 16" wheels up until '03 when they got 18" wheels. The LC also had 16" wheels up until recently. Now they are either still std 16" with optional 17" or maybe it's std 17" with optional 18", not sure.
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I'm really looking for a brake discussion and insight into Toyota's reasoning for the size brakes they put on different models??? Example the Sequoia (12.6) that weighs close to 1000 lbs more than the 4runner Sport (13.3) but has smaller front brakes. This does not make sense??
 
Pitbull said:
I'm really looking for a brake discussion and insight into Toyota's reasoning for the size brakes they put on different models??? Example the Sequoia (12.6) that weighs close to 1000 lbs more than the 4runner Sport (13.3) but has smaller front brakes. This does not make sense??
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You're right, it does not make a whole lot of sense. :confused:
One would think the heavier the vehicle, the bigger the brakes. I guess this will help the S/E while towing; should make it a little easier on the brakes when trying to slow down those big loads.
 
See this thread:

http://www.toyota-4runner.org/showthread.php?s=&threadid=2480

As for the LX, the disc brake size has remained the same from 1998 to 2004. Despite this, the LX470 has very short braking distance for a SUV, on par with the 4runner/GX470. Why?? Well, it's tire contact patch is larger, which is the main component of braking distance. The LX uses 275-width tires, compared with 265-width for other Toyota SUVs. The LX is heavier, so that offsets it's bigger tire patch. Basically, the LX is able to stop the same distance as GX because it's wider tires and heavier weight, both of which offsets each other.

The other minor factors: weight distribution, number of pistons & size of caliper on each brake system, suspension (anti-dive) characteristics, etc.. As for weight distribution, EBD (electronic brakeforce distribution) supposed to help this.

Now, FADE is where the LX may have a slight disadvantage when compared to GX/4runner Sport because it has smaller discs. This may be noticeable when towing a heavy load. However, caliper size may be larger in the LX, which would offset this.

As for Sport vs. Limited 4runners, see the thread above.
 
I'll clarify that the Limited does NOT have bigger brakes, 03 or 04, Xreas or not. I have 2 friends with 03 and 04 limiteds with xreas. They are not the bigger rotors.

So far, just the Sport.
 
Very simple answer for you all. The SE comes with 17" wheels, so they are able to fit a 13.3" disc behind them. In turn, the 12.6's are all mated up with the 16's.

Billy
 
fourunnabilly said:
Very simple answer for you all. The SE comes with 17" wheels, so they are able to fit a 13.3" disc behind them. In turn, the 12.6's are all mated up with the 16's.

Billy
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Billy the 2004's all seem to have 17 inch wheels. My dealer did not have 1 4runner that had 16 inch wheels. I did not know that my 2004 Sport had the bigger 13.3 inch front brakes until I started reading this site. Then it struck me as odd that the Sport had the bigger brakes just like the GX470 but the SR5, Limited, Sequoia and the Landcruiser/LX470 all had smaller brakes, thought that was weird and wanted to know if anyone had any insight into why that was??

So next question, does that mean that the Sport and the GX470 use their own special disc pads? If so what are the part numbers so I can make sure that the Dealer does not try to use the smaller pads on my bigger brakes. Wonder if the Sprot and GX470 fronts wear longer than the others? Seems like if you drove both the same the 13.3's should last longer than the 12.6's.
 
how many pistons are on each brake caliper of the 4th generations? one of my co-workers was telling me of this brabus SL55 that his friend was working on has 12 pistons per caliper! 6 on each side of the disc!!! whoa mama... AND its got 15 inch discs.
 
Pitbull said:
Billy the 2004's all seem to have 17 inch wheels. My dealer did not have 1 4runner that had 16 inch wheels. I did not know that my 2004 Sport had the bigger 13.3 inch front brakes until I started reading this site. Then it struck me as odd that the Sport had the bigger brakes just like the GX470 but the SR5, Limited, Sequoia and the Landcruiser/LX470 all had smaller brakes, thought that was weird and wanted to know if anyone had any insight into why that was??

So next question, does that mean that the Sport and the GX470 use their own special disc pads? If so what are the part numbers so I can make sure that the Dealer does not try to use the smaller pads on my bigger brakes. Wonder if the Sprot and GX470 fronts wear longer than the others? Seems like if you drove both the same the 13.3's should last longer than the 12.6's.
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The reason you can't seem to find any '04 SR5s with 16" wheels is because the dealers are ordering them with 17s. But, if you check the standard size wheels, they are supposed to be 16s. From what I have heard, the 17" wheels are installed at the port, so the vehicle is shipped with 16s and then upgraded, so they would have to have the smaller brake disk so the 16s would fit.

As for the reason for the difference, not sure. but it just might be an engineering attempt to provide a slightly improved brake for the 'Sport' model. I would also consider that if the pads are different between the 12.6 and 13.3 setup, the calipers might also be different. You might not be able to install the 'larger' pads in the 12/6 caliper mounts.
 
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I don't have access to a Sport model to look at and compare with my SR5, but if I understand correctly the overall brake-design is basically the same...please correct me if I'm wrong. If the brake pads are similar in size there would be NO difference in braking performance regardless of a 12.6" or a 13.3" rotor, because it would be creating the same amount of resistance. Even if the pads have 10% more surface area (to complement the 10% larger rotor surface), it doesn't seem to me it would be a vastly-noticeable difference performance-wise. Our SR5 stops on a dime, I don't know how it could be improved upon.
 
bluewolf said:
I don't have access to a Sport model to look at and compare with my SR5, but if I understand correctly the overall brake-design is basically the same...please correct me if I'm wrong. If the brake pads are similar in size there would be NO difference in braking performance regardless of a 12.6" or a 13.3" rotor, because it would be creating the same amount of resistance. Even if the pads have 10% more surface area (to complement the 10% larger rotor surface), it doesn't seem to me it would be a vastly-noticeable difference performance-wise. Our SR5 stops on a dime, I don't know how it could be improved upon.
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Heh, don't know about you but if the bigger pads allow me to stop 5 feet shorter that's a bonus to me and something very noticeable. 5 feet can stop me from running into the back of a semi or running down a pedestrian. I know, both very drastic examples but still very possible in the real world. I agree, my SE stops on a dime but any improvement is substantial. I guess I'll have to check my local parts dealer to verify if they use the same pads.

July
 
Even if the pads are the same size, a larger rotor (in theory) will stop faster and easier than a smaller one.

To see the theory in action, look at a bicycle brake. It grabs the rim - effectively a large rotor. Imagine trying to stop the wheel at the hub- effectively a small rotor- it would require exponentially more power and generate more heat to stop in the same distance.

Try to stop a spinning bicycle wheel by grabbing the tire. Now try it by trying to grab the hub. MUCH harder to stop it by the hub!

When the brakes grab a larger rotor, realize that an object spins faster at the ends than in the center. The outside of a wheel is spinning faster than the center. So, you have more surface area to grab on a larger rotor. The smaller rotor is moving slower and you need to apply more pressure to stop in the same distance- this generates more heat and thus, more fade.

I think the benefit in the 4Runner's case is less brake fade. That is more important than ultimate stopping distance when you are off-roading and braking often (or using DAC) or when towing and fade becomes a real concern on downgrades with repeated braking.

The reason for the different size brakes:
1. smaller rotors are cheaper and Toyota already has them in the "parts bin"
2. The SE is a special package intended as the rough and tumble model that you would most use for off roading (thus the 17" standard, no leather option, etc)
3. SR5 is the base model and value is highlighted, not performance.
4. Limited is a luxury package where ammenities is highlighted not performance.
5. The larger rotors are "parts bin" GX470 so it's no sweat off Toyota since they both come off the same assembly line.
6. Why does the GX have luxury AND bigger rotors (performance)? Market strategy- gotta go upmarket for more features!
 
sharp4runr said:
Heh, don't know about you but if the bigger pads allow me to stop 5 feet shorter that's a bonus to me and something very noticeable. 5 feet can stop me from running into the back of a semi or running down a pedestrian. I know, both very drastic examples but still very possible in the real world. I agree, my SE stops on a dime but any improvement is substantial. I guess I'll have to check my local parts dealer to verify if they use the same pads.

July
Click to expand...

Oh...I see your reasoning. Perhaps you should have your SE outfitted for 14" brakes. Then, you'll gain 6 feet of stopping distance! After all, you might need an extra foot in the "real world" :p
 
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