15" Wheel on 2003 Silverado Build Thread
09-25-2014, 01:00 PM
#93
Kenneth, I just want to make sure you know the rotor in your notes is not the rotor I designed the brackets for. You will need the thinner rotor for my brackets. Make sure the rotor is 1" thick instead of the 1.25" thick one.
Good info you gathered in that document. What I'm worried about with the 3500 calipers though is the mounting bolts being the same dimension and the caliper piston not being centered over the rotor. With a bigger piston, you will have to move the caliper out to center the piston which will not allow 15" wheels with smaller inner diameters to be used. Not a deal breaker but I'd be interested to see someone try it. Looks like the pad dimensions will work with my brackets.
Good info you gathered in that document. What I'm worried about with the 3500 calipers though is the mounting bolts being the same dimension and the caliper piston not being centered over the rotor. With a bigger piston, you will have to move the caliper out to center the piston which will not allow 15" wheels with smaller inner diameters to be used. Not a deal breaker but I'd be interested to see someone try it. Looks like the pad dimensions will work with my brackets.
Not a scientific or definitive analysis, but comparing the photos the spacing from the piston bore to the mounting hole seems reduced for each larger piston suggesting a common mounting position. However, the 3500 calipers do look taller from the mounting hole to the top of the caliper body suggesting that the increased piston diameter is all added to the outside of the caliper, where the piston already overhangs the pad on the 1500 calipers.
09-25-2014, 01:10 PM
#94
Actually, that is something I had though of doing if I were to ever add a large rotor/caliper setup in the front. Otherwise, I think it would completely screw up the brake bias. Deleting ABS and incorporating an adjustable proportioning valve, the dual rear calipers could prove beneficial to those running bigs&littles all the time on the street as you could apply more clamping force to the higher traction axle.
How overkill would that be??
09-25-2014, 01:23 PM
#95
I don't know much about brake systems but I'd guess that the rear brake lines would have to be enlarged for more fluid volume to the calipers. The brake lines that feed the rear calipers are tiny so adding two more back there would do what??
I was thinking I could run -4 teflon line from the ABS module back to the rears and add a wye at each wheel. So it would go from -4 from the ABS to two -3AN teflon lines to each caliper. But I really don't know if that is necessary or if it would even have an effect on braking.. Any experts?
I was thinking I could run -4 teflon line from the ABS module back to the rears and add a wye at each wheel. So it would go from -4 from the ABS to two -3AN teflon lines to each caliper. But I really don't know if that is necessary or if it would even have an effect on braking.. Any experts?
09-25-2014, 01:32 PM
#96
Larger lines would add even more volume the master cylinder would have to move when engaging the brakes. Since hydraulic fluid is not compressible, it moves very quickly thru the small lines. You would just need to make sure the master cylinder is capable of moving the volume of the extra piston. If the rears have more volume than the fronts, swapping line positions on the master may be needed.
09-26-2014, 05:15 PM
#99
In my quest to find the 1" rotors locally, I have discovered yet another caliper. In my previous post, I thought the 75mm/2.95" piston was the base or non-F44 pistion but isn't. The base piston for a 1990 model non-F44 is 2.5"/63mm. The 75mm pistion is the F44 option for the early year OBS(88-91) and eventually became standard in '92 with the 1.28"/32.7mm thick rotor.
09-28-2014, 04:45 PM
#100
TECH Regular
So what is the Inside Diameter of your average 15 inch wheel where the calipers are. I have a 2005 VHO that came with drum brakes, a previous owner switched it to the single piston disc brakes which I about a year and a half ago changed to the dual piston disk brakes. At the time I never thought I would make enough HP to need a 15 inch wheel but I have since put a trick turbo kit on my truck and am currently making 708 rwhp. With my current setup I can roast my 20's at a 70mph roll. It would be nice to run the same DR Oakley has on his truck if I could because I really don't want to go down to a under 30" tire and I don't really want to go to a bias ply slick either, which are my only options in anything other than a 15" wheel. I have a 14 bolt rear end though and wonder if Oakley's brackets would work on my 14 bolt.
I was on Wilwoods website and they make a bunch of different calipers. I wonder if they have some 2 or 4 piston calipers that would be able to work with those brackets and rotors also. If traction wasn't a factor it would be nice to be able to build as much boost off the line as possible. I can't see those obs single piston calipers being as strong as the dual piston ones I have now but maybe the Wilwoods would hold the same or better even on a smaller rotor.
What do you guys think?
I was on Wilwoods website and they make a bunch of different calipers. I wonder if they have some 2 or 4 piston calipers that would be able to work with those brackets and rotors also. If traction wasn't a factor it would be nice to be able to build as much boost off the line as possible. I can't see those obs single piston calipers being as strong as the dual piston ones I have now but maybe the Wilwoods would hold the same or better even on a smaller rotor.
What do you guys think?