+- Forums (https://www.vdrift.net/Forum)
+-- Forum: Community (https://www.vdrift.net/Forum/forumdisplay.php?fid=3)
+--- Forum: Cars & Tracks (https://www.vdrift.net/Forum/forumdisplay.php?fid=11)
+--- Thread: Car brakes review and fixes (/showthread.php?tid=2182)
Car brakes review and fixes - NaN - 07-29-2015
I've run our cars through vdrift -cartest looking into brake performance, mainly fixing friction coefficients to have more realistic values (0.3 - 0.7) and increasing brake system pressure where required.
There are a few cars that should have much more aggressive brakes now.
I've ran into one interesting case. TC (Toyota Celica ST185 Rally) reports
60-0 stopping distance (no ABS): 124.708 ft
60-0 stopping distance (ABS): 2326.04 ft
No idea what is going on with the ABS there, will look into it.
EDIT:
There are also a few cars with max power not matching torque curve it seems, which results in incorrect top speed estimation.
RE: Car brakes review and fixes - NaN - 07-30-2015
The issue with the Celica turned out to be a non issue
I've added some engine rev up code to the testing logic, which happened to interfere with braking commands for some cars, depending on their transmission setup.
RE: Car brakes review and fixes - arturo - 12-14-2015
NaN Wrote:I've run our cars through vdrift -cartest looking into brake performance, mainly fixing friction coefficients to have more realistic values (0.3 - 0.7) and increasing brake system pressure where required.
I would say that most of the cars are using piston areas that are way too large. In the project I am working on, I just reduced the suggested value of 0.015 m2 to 0.00501, which is that of a pretty impressive 6-piston caliper AP Radi-CAL CP9660:
http://www.apracing.com/drawings/2015 Product Catalogue/2015 Brake Calipers.pdf
To compensate, I've set max-pressure to a higher value of 1.4e7 pascals, equal to 140 bars.
That was indeed my adjustment factor when I was testing at the Nordschleife in the hard-braking approach from Tiergarten to Hohenrain:
2.5e7 -- enough stopping power (with ABS)
1.1 ---- too little
1.5 ---- enough
1.3 ---- too little
1.4 ---- enough
Pressures up to 250 bars are at least within the realm of possibility:
https://www.fte-automotive.com/aftermarket/products/workshop-equipment/brake-pressure-tester.html
On the other hand, I have never heard of a piston area of 150 cm2. The largest I have found are 70 cm2 -- intended for 410mm disks!
I know there are some 8-piston calipers out there, but I don't think they can cover that much.
RE: Car brakes review and fixes - NaN - 12-14-2015
(12-14-2015, 08:57 AM)arturo Wrote:NaN Wrote:I've run our cars through vdrift -cartest looking into brake performance, mainly fixing friction coefficients to have more realistic values (0.3 - 0.7) and increasing brake system pressure where required.
I would say that most of the cars are using piston areas that are way too large. In the project I am working on, I just reduced the suggested value of 0.015 m2 to 0.00501, which is that of a pretty impressive 6-piston caliper AP Radi-CAL CP9660:
http://www.apracing.com/drawings/2015 Product Catalogue/2015 Brake Calipers.pdf
To compensate, I've set max-pressure to a higher value of 1.4e7 pascals, equal to 140 bars.
That was indeed my adjustment factor when I was testing at the Nordschleife in the hard-braking approach from Tiergarten to Hohenrain:
2.5e7 -- enough stopping power (with ABS)
1.1 ---- too little
1.5 ---- enough
1.3 ---- too little
1.4 ---- enough
Pressures up to 250 bars are at least within the realm of possibility:
https://www.fte-automotive.com/aftermarket/products/workshop-equipment/brake-pressure-tester.html
On the other hand, I have never heard of a piston area of 150 cm2. The largest I have found are 70 cm2 -- intended for 410mm disks!
I know there are some 8-piston calipers out there, but I don't think they can cover that much.
Yeah, would be nice to have this fixed too (even if it doesn't matter much for the sim: force = area * pressure). I am all for more realistic values.
RE: Car brakes review and fixes - RJARRRPCGP - 04-30-2016
Hello folks.