So then. Can someone explain Jaguar’s thought processes with this? Inboard rear disk brakes… Working on my XJ6’s and upped power with a supercharged LS3 and a twin turbo RB26 in the other. For obvious reasons had to upgrade the entire braking system. Though the original layout makes it a b@$7@r& to replace and service. Basically have to drop the rear subframe out, rather than pull off a wheel.
Inboard brakes reduce unsprung weight. There’s less weight traveling up and down so the suspension can react quicker over irregularities in the road surface.
Reduces te u sprung weight, allowing the suspension to control the wheel better (less inertia when it bumps and rebounds) Also moves the weight inboard, aiding in balance
This may sound stupid but putting the front caliber at the front would push the front of the car down in braking, so wouldn’t outing the caliber at tr back of the front wheel push the back of the car up? I know that this will in reality still push the front of the car down due to physics but wouldn’t there be a small difference being as the brake caliber is slightly further back? I dunno if anyone will understand what I mean..
Sorry my typing is appalling :/
You almost got that right. In reality, what happens is the contrary: front positioned calipers push the wheel up when braking, due to the reaction of the braking force. You can try that out with a bike: lift the rear by hand so that the brake is in front of the rear wheel, spin the wheel on the last gear and brake hard. You’ll notice that the bike is pushed up when braking.
It’s a minor thing, probably other factors like steering and suspension geometry are more important, but if you can position the calipers at the rear wheels of the wheel without compromising other things, do it.
The Nissan LMP1 GT-R got front calipers down low.
I’ve never wondered why they’re there, because, why it should be on other place? It had to be somewhere :D
The Alfa 75, because having brakes on the hubs it for normal cars.
sweet :D
reason for that is pretty much because race car. Lower unsprung weight so better handling.
I’ve always wondered why din’t more cars have it, it only makes sense! less unsprung mas. the masses are more compact and in the center of the car. the only thing against it is that you need provably a stronger linking shaft to handle the forces at breaking, you could cool them with lower vents and have them enclosed so that the air enters and escapes cooling them down… of course maintenance could be a bit more expensive to change the pads and way more on changing the rotors/discs but totally worth it!! are there any more drawbacks??
This guy tought me so much about cars, extremely appreciated!
Not rotors - brake discs 😩
I have always considered another factor that may or may not be a significant. I am fairly sure I have the signs correct of the forces applied, I have never bothered finding values though. What I am talking about is force applied to the frame by the caliper, as it is in contact (experiencing friction) with the rotor.
I am going to just refer to the rear wheel and explain the two situations I am talking about. In both cases the caliper will be mounted to the hub that holds the wheel bearing and my assumption is that this attachment is centrally located within the wheel. So with EE’s diagram, its mounted in the middle of the wheel, and then extends out to the edge of the rotor in one of the quadrants. I believe this is where I would be wrong if I am, so feel free to argue the legitimacy of the assumption. So now for the two cases, Forward quadrant vs rear quadrant. If the caliper is mounted on the rear of the wheel, when the brakes are applied friction is created between the rotor and the pads/caliper. The force on the rotor would counter its clockwise movement therefor being in an downward, in a Free Body Diagram (FBD), direction due to its location. So therefore the force on the “car” through the calipers would be upwards. Opposite situation is having the Caliper on the forward side of the wheel. When the brake is applied friction creates two forces again. The force on the rotor would counter its movement therefor being in an upward direction in a FBD. This upward force again is countered by the force being applied Downward by the “car” and the Caliper.
I am starting to doubt myself as I have explained this because you can’t move the suspension from a force acting on the wheel, Its not really two sets of free bodys. I am still not convinced though because it could still apply that force down and compress the rubber of the tire, not the suspension.
Am I crazy or is this a factor at all?
And yes I know that the much much larger force would be momentum moving all the weight to the front of the car and taking it off the rear wheels. Since that IS the case though I would argue that a factor why the calipers in front are in the back of the rotor is because one does NOT want so much force down in order to keep pressure in the back.
Am I crazy or does this make sense? Do I need to clarify anything?
When you brake, the force created by the friction of the pad on the rotor is trying to stop it from spinning. So if the caliper is at the rear of the wheel, this force is downward. The downward force loads the tires, as the rotor is connected directly to the wheel. More load = more traction.
Like I said to the other guy’s question, if you don’t believe me you can try that out on a bicycle. The force is very minor, so other stuff like steering and suspension geometry are more important, but if you can freely choose, you should always put the caliper at the back of the wheel.
Comments
So then. Can someone explain Jaguar’s thought processes with this? Inboard rear disk brakes…
Working on my XJ6’s and upped power with a supercharged LS3 and a twin turbo RB26 in the other.
For obvious reasons had to upgrade the entire braking system. Though the original layout makes it a b@$7@r& to replace and service. Basically have to drop the rear subframe out, rather than pull off a wheel.
Inboard brakes reduce unsprung weight. There’s less weight traveling up and down so the suspension can react quicker over irregularities in the road surface.
Reduces te u sprung weight, allowing the suspension to control the wheel better (less inertia when it bumps and rebounds)
Also moves the weight inboard, aiding in balance
This may sound stupid but putting the front caliber at the front would push the front of the car down in braking, so wouldn’t outing the caliber at tr back of the front wheel push the back of the car up? I know that this will in reality still push the front of the car down due to physics but wouldn’t there be a small difference being as the brake caliber is slightly further back? I dunno if anyone will understand what I mean..
Sorry my typing is appalling :/
You almost got that right. In reality, what happens is the contrary: front positioned calipers push the wheel up when braking, due to the reaction of the braking force. You can try that out with a bike: lift the rear by hand so that the brake is in front of the rear wheel, spin the wheel on the last gear and brake hard. You’ll notice that the bike is pushed up when braking.
It’s a minor thing, probably other factors like steering and suspension geometry are more important, but if you can position the calipers at the rear wheels of the wheel without compromising other things, do it.
The Nissan LMP1 GT-R got front calipers down low.
I’ve never wondered why they’re there, because, why it should be on other place? It had to be somewhere :D
The Alfa 75, because having brakes on the hubs it for normal cars.
sweet :D
reason for that is pretty much because race car. Lower unsprung weight so better handling.
I’ve always wondered why din’t more cars have it, it only makes sense! less unsprung mas. the masses are more compact and in the center of the car. the only thing against it is that you need provably a stronger linking shaft to handle the forces at breaking, you could cool them with lower vents and have them enclosed so that the air enters and escapes cooling them down… of course maintenance could be a bit more expensive to change the pads and way more on changing the rotors/discs but totally worth it!! are there any more drawbacks??
This guy tought me so much about cars, extremely appreciated!
Not rotors - brake discs 😩
I have always considered another factor that may or may not be a significant. I am fairly sure I have the signs correct of the forces applied, I have never bothered finding values though.
What I am talking about is force applied to the frame by the caliper, as it is in contact (experiencing friction) with the rotor.
I am going to just refer to the rear wheel and explain the two situations I am talking about. In both cases the caliper will be mounted to the hub that holds the wheel bearing and my assumption is that this attachment is centrally located within the wheel. So with EE’s diagram, its mounted in the middle of the wheel, and then extends out to the edge of the rotor in one of the quadrants.
I believe this is where I would be wrong if I am, so feel free to argue the legitimacy of the assumption.
So now for the two cases, Forward quadrant vs rear quadrant.
If the caliper is mounted on the rear of the wheel, when the brakes are applied friction is created between the rotor and the pads/caliper. The force on the rotor would counter its clockwise movement therefor being in an downward, in a Free Body Diagram (FBD), direction due to its location. So therefore the force on the “car” through the calipers would be upwards.
Opposite situation is having the Caliper on the forward side of the wheel. When the brake is applied friction creates two forces again. The force on the rotor would counter its movement therefor being in an upward direction in a FBD. This upward force again is countered by the force being applied Downward by the “car” and the Caliper.
I am starting to doubt myself as I have explained this because you can’t move the suspension from a force acting on the wheel, Its not really two sets of free bodys. I am still not convinced though because it could still apply that force down and compress the rubber of the tire, not the suspension.
Am I crazy or is this a factor at all?
And yes I know that the much much larger force would be momentum moving all the weight to the front of the car and taking it off the rear wheels. Since that IS the case though I would argue that a factor why the calipers in front are in the back of the rotor is because one does NOT want so much force down in order to keep pressure in the back.
Am I crazy or does this make sense? Do I need to clarify anything?
When you brake, the force created by the friction of the pad on the rotor is trying to stop it from spinning. So if the caliper is at the rear of the wheel, this force is downward. The downward force loads the tires, as the rotor is connected directly to the wheel. More load = more traction.
Like I said to the other guy’s question, if you don’t believe me you can try that out on a bicycle. The force is very minor, so other stuff like steering and suspension geometry are more important, but if you can freely choose, you should always put the caliper at the back of the wheel.