Early 944 brakes
11-09-2020, 12:23 PM
#16
Drifting
[QUOTE=willrobinson;17013934]They act on both sides of the pad, but does that translate to the effort equation? It's still a ratio of master to slave area is it not?[/QUOTE
How can you make the Porsche piston area equavilent to 2X what the brake fluid is in contact with, it is 1X??
The amount of braking torque is a combination of the brake pad surface available x the applied braking force from the brake system.
So if one assumes the brake pad areas are equivalent, then the brake pressure ratio for Volvo vs Porsche is 1:2, to have the same braking torque. Or stating another way, the area of the Volvo pucks is twice the area of the Porsche single piston. Force = pressure x area. The force(Volvo) = force(Porsche)
pressure (Volvo) = (pressure Porsche * area Porsche)/area Volvo.
pressure Volvo = (pressure Porsche * 2289)/4534
pressure Volvo = 0.50 pressure Porsche.
This is hypothetical assuming brake pad surfaces are the same. The other issue is brake fluid volume. Assuming the same amount of movement, the brake volume to move the Volvo pucks is twice the Porsche single piston.
How can you make the Porsche piston area equavilent to 2X what the brake fluid is in contact with, it is 1X??
The amount of braking torque is a combination of the brake pad surface available x the applied braking force from the brake system.
So if one assumes the brake pad areas are equivalent, then the brake pressure ratio for Volvo vs Porsche is 1:2, to have the same braking torque. Or stating another way, the area of the Volvo pucks is twice the area of the Porsche single piston. Force = pressure x area. The force(Volvo) = force(Porsche)
pressure (Volvo) = (pressure Porsche * area Porsche)/area Volvo.
pressure Volvo = (pressure Porsche * 2289)/4534
pressure Volvo = 0.50 pressure Porsche.
This is hypothetical assuming brake pad surfaces are the same. The other issue is brake fluid volume. Assuming the same amount of movement, the brake volume to move the Volvo pucks is twice the Porsche single piston.
Last edited by T&T Racing; 11-09-2020 at 12:37 PM.
11-09-2020, 10:58 PM
#17
Hates Family Guy
Rennlist Member
Rennlist Member
The porsche caliper slides, so the piston is doing the work of both sides of the disk. The same amount of fluid goes into one piston that is acting on both pads as if you had a theoretical fixed caliper with two Porsche sized pistons, half the fluid acting on each piston. Make sense?
11-10-2020, 08:10 AM
#18
Drifting
The porsche caliper slides, so the piston is doing the work of both sides of the disk. The same amount of fluid goes into one piston that is acting on both pads as if you had a theoretical fixed caliper with two Porsche sized pistons, half the fluid acting on each piston. Make sense?
11-10-2020, 09:03 AM
#19
Rennlist Member
Thread Starter
The reason that I went with the Volvo brakes was because of comments by Odonnell's post of 2016 and that of StoogeMoe...Seemed to be a bit of constructive info for my build..I'll keep my original calipers and rebuild them after I get the car on the road. One user went with the double line arrangement (non-ABS) and it is pictured in that thread, with a Tee fitting and using the single brake line from the car. The shipping info on the caliper said they weighed in about 10 lbs each...I appreciate all the comments and math about this..Much more in depth than the original posts...
Last edited by Tiger03447; 11-10-2020 at 09:04 AM. Reason: spelling