Why Big Brakes Won't Stop You Faster but Wider Tires Will - Friction and Surface Area Explained

That and having larger heavier tires affects braking distance, # of pistons and dia of them, type of stock brakes vs the upgrade, on and on and on. Too many variables and he only covered one small topic and now more confusion and more bad information is on the interwebs. Funny how back in the day pretty much every car mag has done probably 100s of different BBK upgrades and found improved braking distance and better performance some better than others.

 

I ain't the biggest brain in the room, but I would have thought an elementary component of applied force would appear in his pontificating. The dude doesn't even list his credentials...

 

Abs is my limiting factor in stopping, as once one tire starts to chirp the Abs kicks in and ruins the pedal feel.
For example, my truck has a lot of weight sway both front-rear and side to side, so sometimes theres hardly any load on the unloaded side, thus that brake will start to lock up even though its "fine" to lock up that floating wheel that has no grip anyways.

 

He took his first physics 101 class learned that one equation and applied it like it was the one and only true answer. Meanwhile in the real world there's a lot more to it than a simplistic answer such as that which sadly we see many flock too as the one correct answer.

 

I’d like to flock to one of these BBK manufacturers who actually tested their BBK’s against the oem brake system. Motorweek has been testing new vehicles as long as I can remember watching their weekly tv show. Besides these single semester physics genius’s providing actual science, all you BBK PhD’s have provided is argumentative subjective opinion without substantiation. We in the “flock” would really like some objective information to support $3k on a BBK

 

OEM flexible rubber brake hoses have more expansion under brake pedal force giving a "softer pedal".
vs
Stainless steel braided flexible brake hoses have a lot less expansion under brake pedal force giving a "firmer pedal".

https://us.goodridge.com/performance-automotive
https://ebcbrakes.com/products/ebc-high-performance-brake-lines/
https://www.powerstop.com/product/stainless-steel-brake-hoses/
https://www.mfcp.com/product/hose/brake-hose-stainless-steel-braided

 

smh...all those upgrades and it only has lap belts.

 

I forgot when did science only look at one variable and not the whole picture. If you're watching motorweek then you should of seen where the Viper got a brake upgrade and improved it's braking performance back in the 90s they went to a huge wheel (for that era) larger rotors, bigger calipers, larger MC and upgraded the ABS system and beat their previous yr by like 10ft. It was huge news because it was one of the quickest stopping cars of the time beating out its competitors. You should also realize that all high performance cars are getting 20+" wheels and rotors and calipers that take up the whole wheel and are using larger and larger calipers and more exotic materials that provide higher coefficient of friction. But we should tell those engineers all they need to do is upgrade the tires right........ I'm sure they did a lot more science than this youtuber.

 

That’s what I’m looking for. Real proof to the benefits of the BBK on a Tacoma. So far I haven’t seen any model specific proof. Or does Viper benefit automatically signal Tacoma benefit? I’m no physics expert, nor scientist, not even a mechanic. Just some schmuck trying to justify the actual benefits of a $3k BBK on a heavy taco with 315/75r16 treads over the stock braking system. There is a 325mm BBK touting this incredible improvement. Or is that only the larger kits requiring larger wheels? Therefore my skepticism is appropriate considering the BS meant to sucker in 16” wheel owners into a BBK? I’m understanding the science dismantling the BBK might not be complete but the argument for feels a lot like the crowd touting real CAI benefits.

 

So my truck on 37s stock brakes sucks. Upgraded to the 5thgen 4runner brakes and discs in the rear with a much bigger MC and bypassed the ABS the braking still sucks and is worse than stock. It doesn't suck as bad as the stock brakes and I got some improvement. What's really killing us is the mass of the tire is so far away from the rotational axis and where the brake torque is. Also big ass heavy wheels and tires take a lot more to stop. Not just the weight of the vehicle although that factors in as well. Switch to smaller more just your typical HT tire and you'll see huge improvements. Bump up to bigger wheels and stuff them with as big of rotors and calipers as you can along with upgrading the whole system and you'll probably get back to stock level braking. These companies tout their findings on stock trucks with stock stuff not heavily modified heavy ass vehicles. Where you'll see the most improvement would be in heat dissipation and brake fade. There is only so much brake you can package in a 16" wheel.

 

Did you watch the video or are you just reacting to the video title?

 

Thank you!! That’s about the most complete answer I’ve heard. Not a guarantee but at most a slight improvement. Equation is way more complex than we’d like to think.

 

If the brakes have enough torque to lock up the tires, adding more does not help. The limiting factor of braking distance is the frictional/adhesive force of the tires on the road surface.

 

Yes I watched the video, you're just too dense to look beyond what he's saying and actually look at the total picture and not just what one person says. Did I ever say I disagreed or didn't support what he said NO I said he's not looking at the total picture. I even gave an example and agreed to a point but that wasn't all there is to it.

Yes and No. I could lock up my 37s with stock brakes and lock them up with my upgraded brakes guess which one stops faster the upgraded brakes. Any car can lock up tires. But you loose distance and time to lock up by having smaller brakes. Upgrade the braking system that delay until a tire locks up is lessoned and the distance before lockup is shortened. Then it's all in the driver. I've got a library full of car magazines that have tested all sorts of BBKs ALL of the well engineered ones saw improvement some greater than others. Difference is they actually published their data and didn't just talk about it. Lets see him prove his stance in the real world.

 

Can stock brakes lock up the tires at high speed? Say 80+ mph?

BTW, that video made me want to add shoulder belts to my lap belt vehicle.

 

Actually the math is pretty simple. If your brakes have enough force to lock the rotor, the only thing left is the coefficient of adhesion of tire on surface and cycle time of abs. That's it for a panic stop.

 

You are just one data point. You may be right for your specific application but physics don't lie. Lock the rotor and abs kicks in and it truly becomes a function of tire adhesion on road surface, which changes a lot depending on several factors like new pavement, old pavement, concrete, etc.

 

Excellent video, I like the simple examples he uses.

On a side note I do an on doing the factory BBK. Not for reducing braking distance but to reduce brake fade when driving in the mountains. My user name speaks for itself.. I like to to drive fast.

 

I’ve got nothing more to say to you.

 

I’ve never tried that, but I suspect the Toyota engineers made sure that was possible.