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All, My apologies for not replying; we just got back from a weeklong vacation.
I have tracked down the numbers to run the formula Pirate4x4 suggested. I was expecting that the '05 MC would have a larger bore, and that the '13 would have an even larger bore. Neither of these things were true for the non-hydroboost. Here is what I found:
So, running those numbers through the math (assuming 6:1 pedal ratio and 50 lbs of foot force), I get
Line pressure with my 1.375" MC = 202 psi
Line pressure with a 1.313" MC = 221 psi
1. Are these numbers right?
2. Why did Ford reduce the MC bore size when they went to larger brakes? Was it because they were first splitting the difference by using just one MC bore for both hydroboost and vacuum, and then they went to different MCs that suited the different systems more precisely?
3. Running the numbers, the difference to changing the MC to 1.313 would be 10% greater line pressure but 10% less volume. Not sure if that is worth the re-plumbing that I would need to do to change the output side from right to left.
4. It looks like there would be almost no impact either way with the rear brakes; the 1.375" had the 1.75 rear piston and the 1.313 had the almost identical size 1.77" rear piston.
5. Looking at the front caliper numbers, it looks like the reason for the increased pedal travel is not so much the slightly larger front pistons (2.36 instead of 2.12, an 11% difference) but that they are distributing that force by squeezing much larger brake pads (they look absolutely huge in comparison to the original 2000 pads).
In any case, the brakes worked great on the trip, and I am looking forward to putting in a new MC and getting the ABS sensors machined to fit.
Finally, for those running the OEM Michelin LTX AT2 275/65r20 tires, they really seem to like 80 psi on the highway. I had let them get down to 70 (that is all the usual gas station pumps will do) but I went to a truck stop and used a big rig air hose to set 80 all the way around--the steering tracking was MUCH better, the noise was reduced and the MPGs went up .5.
stoked you are keeping us updated and nice work on doing the math.
1. I am on the road so will need to sit down and work them when I am not swerving in the fast lane.
2. Ford used the master that worked with the whole package. As far as hydro boost vs vacuum power brakes, I’ve never looked into it but I am certain they are tuned to provide the same level of power assist. Just a diffrent way of achieving.
3. I consider 10% a substantial change and it the performance world guys would spent thousands to achieve a 10% gain on most systems.
4. Again, 11% is substantial change. Pad size has no bearing on pedal travel. Pedal travel is the sum of the smaller master cylinder piston displacing enough fluid to move the larger caliper piston far enough to make solid contact. This distance includes the air gap between the pads and rotors and the flex in the caliper between the front and rear pads plus any slack in the pedal rod and piviots.
Example if you have a 1” master and a 2” caliper piston the master will have to move 2” to move the caliper 1” plus any slack in the system.
and finally, 80psi might be less noisy but I bet it also increases stop times, Remember, you can only brake as hard as your tires do not skid, once the tire is skidding all the brakes in the world are not going to decrease stopping distance.
of course even with increased stopping distance at night psi you still have the main benefit of bigger brakes and that is better heat soak and disapation so at least you will be able to repeatable have longer stopping distances
Data from actual test vehicles, what I still have. Booster output and pedal ratios should never be presumed to be equal between gas and diesel. Hydroboost trucks had an advantage of hydraulic pressures at max pedal effort. Longer travel with hydroboost but way better pedal effort for the hydraulic pressure.
Data presented 3 ways depending on what we're looking for, but for you guys the first graph of each situation is best.
Checked before every test so we knew if all the air was bleed from the lines. Air will cause a quicker runout and therefore less overall pressure during maximum effort stops. 2005 gas SRW vs 2006 diesel DRW.
Glad to share. It’s data most people don’t get to see.
FMVSS 105 for these weight vehicles when built not only has targets for stopping distance under varied conditions, including failed booster and failed ABS, but during all of the sections requires no more then 150lbs pedal effort. That’s a high value, but easily achieved even with the fairer side of the species in a panic stop. Actually, active guys can push up over 200lbs as we had to do for integrity tests.
During normal brake application we typically push in the range of 200-250psi hydraulic pressure no matter the weight. You generate about a 3-5fpsps deceleration, 0.09-0.16g. During best effort incipient skid efforts with a Superduty at GVW you need about 1200psi to achieve rear wheel skid. Typically in most test sections the test driver just goes as close as possible to 150lbs pedal effort and let’s the ABS control the incident skid. This way you push through the incipient skid limitation of the rear tires due to lower tire traction and get the most out of the front brakes with a higher pressure it takes for them to skid or be ABS controlled. Therefore the shortest stopping distance possible in order to meet the limitation laid out in the Federal Register under FMVSS 105. BTW, there are no government laws that govern stopping ability of aftermarket brake material as there is in Europe.
Anyway the point of this, as long as the vehicle manufacturer meets the stopping distance, and as long as the public is comfortable with the effort to stop the vehicle under all conditions, they are good to go. But their are variations in something like a Superduty that utilizes the same brake system with not only a range of GVW weight classes but type of brake actuation, utilizing both a vacuum and pressure assistance in braking depending on gas or diesel. The failed booster section still has to be met no matter the actuation.
And at this point I’ll leave you guys to yourselves to interpret the data above.
VERY interested in learning your progress on the ABS sensors. I have a 2WD PSD that I tow heavy loads with, and could really use some more brakes. I, too, installed the OEM Michelin LTX AT2 275/65R20 tires, with take-offs from a 2017 F-250; transformed the handling while towing.
OK, I just got the truck back after some follow-up work. All the issues have now been solved:
1. The ABS sensors? Big shout out to Jacksonville 4x4 (Jacksonville NC) who fixed this along with everything else--nothing daunted them. Retaining the original ABS sensors as the core, they just used the casings from an older generation Chevy truck as shims (some assembly required). Works perfectly and looks great. Thanks for making this unique project a reality.
2. The soft brake pedal? It just needed a good bleed. If I ever get around to changing the rears, I might go to the new 1.313" MC, but for now the 1.375" original MC works just fine.
3. Tire rub? Well, I was using the wheel spacers to make the 2017 wheels work with the 2000 front end. But of course, I now have the main parts of a 2017 front end. After removing the wheel spacers (anyone need 2x BORA 2" spacers?) the wheels are back where they belong, and do not rub at all.
I will answer the question about cost in a separate post.
Greg,
Go for it! It was exactly $1,303.26 in parts. Sounds like a lot, but it came with a huge amount of stuff that needed to be replaced anyway at 236,000 miles. At long last, the thing steers and holds a line on the highway like a normal vehicle. As you say, the new wheels and tires are better, but the larger knuckles with brand new ball joints function better too. And of course the main thing is that the brakes are now more than equal to the wheels and tires.
Here is the full and complete list, minus the old chevy abs sensors they used to make the ABS work.
2013-16 2WD Spindle/knuckle RH passenger DC3Z-3105A Ford $274.51
2013-16 2WD Spindle/knuckle LH driver DC3Z-3106A Ford (new old stock) $188.95
2013-16 2WD front brake caliper w/brackets RHBRCF-258 Raybestos PG $140.18
2013-16 2WD front brake caliper w/brackets LHBRCF-258 Raybestos PG $140.18
2013-16 2WD front brake rotors 14.29" BRRF-311 Power Stop drilled and slotted $261.66
2013-16 2WD front brake pads BRSD-1680 Power Stop Evolution Clean Ride $35.78
2013-16 caps, retaining clips + nuts for spindles Ford $72.00
2013-16 Bearings and seals for spindles Ford $135.00
2013-16 17" spare tire (minus sale of original) Ford $55.00
Parts total: $1,303.26
If I were towing regularly, I might go with more aggressive pads--the ones I got are very quiet and linear in progression, but are a little lacking in that initial bite. I went with the slotted rotors because they have proven to be the most effective remedy against warping.
Greg,
Go for it! It was exactly $1,303.26 in parts. Sounds like a lot, but it came with a huge amount of stuff that needed to be replaced anyway at 236,000 miles. At long last, the thing steers and holds a line on the highway like a normal vehicle. As you say, the new wheels and tires are better, but the larger knuckles with brand new ball joints function better too. And of course the main thing is that the brakes are now more than equal to the wheels and tires.
Here is the full and complete list, minus the old chevy abs sensors they used to make the ABS work.
2013-16 2WD Spindle/knuckle RH passenger DC3Z-3105A Ford $274.51
2013-16 2WD Spindle/knuckle LH driver DC3Z-3106A Ford (new old stock) $188.95
2013-16 2WD front brake caliper w/brackets RHBRCF-258 Raybestos PG $140.18
2013-16 2WD front brake caliper w/brackets LHBRCF-258 Raybestos PG $140.18
2013-16 2WD front brake rotors 14.29" BRRF-311 Power Stop drilled and slotted $261.66
2013-16 2WD front brake pads BRSD-1680 Power Stop Evolution Clean Ride $35.78
2013-16 caps, retaining clips + nuts for spindles Ford $72.00
2013-16 Bearings and seals for spindles Ford $135.00
2013-16 17" spare tire (minus sale of original) Ford $55.00
Parts total: $1,303.26
If I were towing regularly, I might go with more aggressive pads--the ones I got are very quiet and linear in progression, but are a little lacking in that initial bite. I went with the slotted rotors because they have proven to be the most effective remedy against warping.
Let me just say, WOW! That's a lot of research and work to get what I am sure is a very good upgraded brake setup. And here I was looking at the SSBC Tri-Power 8 piston Quick Change Front Caliper Kit and wondering if it really improves braking that much?
Let me just say, WOW! That's a lot of research and work to get what I am sure is a very good upgraded brake setup. And here I was looking at the SSBC Tri-Power 8 piston Quick Change Front Caliper Kit and wondering if it really improves braking that much?
not likely, calipers have the same piston area as your stock calipers and they go on stock size rotors. They just look cool.
Go for it! It was exactly $1,303.26 in parts....At long last, the thing steers and holds a line on the highway like a normal vehicle...If I were towing regularly, I might go with more aggressive pads
Thanks for the info! I'm tempted, I may make that a winter project.
Are you saying that the truck tracks better now? Is there a change in front suspension geometry? It might be worth it just for that.
BTW, I resolved the rubbing by chamfering off the bottom corner of the fender/trim with a Sawz-All. Don't worry, I made it look nice... Still rubs occasionally on my stock mud flaps though (had to trim those, too.)
I use Hawk LTS pads. Fantastic all-around and towing compound.
not likely, calipers have the same piston area as your stock calipers and they go on stock size rotors. They just look cool.
What I noticed in the pricing for the upgraded brake setup in this thread is that you already have to have the larger than standard 16" rims/tires, or you need to add them to the cost of the project as well. I think I am Correct? Or will this work with the 16"?
I also linked to the wrong item with the SSB caliper. I meant to link to the 8 piston version as in my text. https://www.summitracing.com/parts/ssb-10133 I'll start a new thread on that.
What I noticed in the pricing for the upgraded brake setup in this thread is that you already have to have the larger than standard 16" rims/tires, or you need to add them to the cost of the project as well. I think I am Correct? Or will this work with the 16"?
I also linked to the wrong item with the SSB caliper. I meant to link to the 8 piston version as in my text. https://www.summitracing.com/parts/ssb-10133 I'll start a new thread on that.
ya I figured you meant the caliper for the Ex / f250.
check the specs yourself, they use smaller but more Pistons, adds up to the same piston area as the stock calipers.
08-11-2018, 10:30 PM
Still rubs occasionally on my stock mud flaps though (had to trim those, too.)