- Thread starter
- #81
sorry I don't know that and I'm not sure if these rotors are the same dia as a 100 rotor. I mounted up a 100 series caliper, took some measurements and found the rotor that fit that caliper mounted on the wrong vehicle.
LANDTANK - Front brake upgrade for 16" rims (1 Viewer)
- Thread starter landtank
- Start date
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I’m all how do you not know.....
Oh yeah that marked sense. Guesstimating, how much more father is the top of the 100 caliper from the center of the axle vs the 80 caliper? Is it a lot, a little?
A combination of the 100 calipers and your cool two piece rotors might work. Pedal travel due to increased fluid volume may still need to be addressed.
- Thread starter
- #83
What I actually did was I bought some junk yard calipers. Because there is an inherent offset difference between the 100 and the 80, I separated the calipers and mounted the inner half to the knuckle, installed the 80 hub/ rotor assembly and then measured the difference in offset and the rotor diameter needed. At this point I dug around various sites looking for what I needed and found it. This was 2 years ago. I would have told you to just look up the specs of the rotor on the wilwood site but I remember there being some discrepancy between what was advertised and what I measured. But I can’t remember how much. In the end I only cared about it fitting my needs. The rotor I’m using is larger than the 80 rotor but I can’t accurately recall by how much.
Per post #7 in this thread, the rotor is 12.625" diameter...which makes it 1/4" - 3/8" larger than stock.
Cool beans, amigo. I saw that, but have no clue on the actual diameter on the 80 rotors. Mine came with aftermarket slotted ones that work well.
However, the pads I removed were slightly taller than the rotor. They were 80 pads not 100 pads.
- Thread starter
- #86
I edited the above post with a cost for the kit that I'm providing.
I wanted to add some info concerning the LSPV mod that I came up with.
One of the things that I noticed a while ago while bleeding the brakes with the engine running is that under high pressure the sensing spring for the LSPV would deflect in a way that it would reduce the pressure to the rear wheels. After thinking about it my conclusion is that it's like a mechanical skid control. Imaging coming to a panic stop, the nose of the truck dips while the rear of the truck rises form the weight transfer forward. This in itself will drop the pressure to the rear and then if the pressure is high enough it will deflect the sensing spring further lowering the pressure to the rear wheels even more. The deflecting of the spring shows up in the cab as a soft pedal. When I stopped the spring from deflecting the pedal feel and firmness improved.
Given the fact that we often run larger tires and more weight which will increase out traction and ability to handle more rear braking I wanted to "stiffen" the sensing spring so more pressure would be transferred to the rear brakes.
A second obstacle with the LSPV is adjusting it accurately after lifting the truck. The main problem is that after lifting the upper control arm is in the way of just raising the point at the axle.
So what I've come up with is a drop block for the LSPV to lower it on the frame 2" and then a multi position plate for the axle that allows you to recreate the original configuration after the lift. The mounting holes at the axle have a spacing that is almost 1" .
So measuring the distance between the hub center to the underside of the flare of a front wheel and subtracting 20.5 gives me the lift height of the front. In my case it calculated to 4". Now if you have a level stance to your truck that would translate to 4" in the rear and you would install the 2" drop block and raise the mount on the axle 2 holes. In my case I have some rake and my rear is higher than the front so I installed the drop block and raised the mount at the axle 3 holes. This puts you real close to the stock position for the LSPV and if needed you can fine tune the system by adjusting the LSPV itself on the bracket and the length of the factory axle mount.
For dealing with stiffening the sensing rod I chose to install 2 layers of thick wall adhesive shrink tubing. I have a heat gun that I used to shrink the tubing but I think an oven would probably work better. I just need to see if there is a published temp for the tubing.
Attached are some pics of what is on my truck. What you are looking at is a proof of concept and not what will actually be included in the kit.
I wanted to add some info concerning the LSPV mod that I came up with.
One of the things that I noticed a while ago while bleeding the brakes with the engine running is that under high pressure the sensing spring for the LSPV would deflect in a way that it would reduce the pressure to the rear wheels. After thinking about it my conclusion is that it's like a mechanical skid control. Imaging coming to a panic stop, the nose of the truck dips while the rear of the truck rises form the weight transfer forward. This in itself will drop the pressure to the rear and then if the pressure is high enough it will deflect the sensing spring further lowering the pressure to the rear wheels even more. The deflecting of the spring shows up in the cab as a soft pedal. When I stopped the spring from deflecting the pedal feel and firmness improved.
Given the fact that we often run larger tires and more weight which will increase out traction and ability to handle more rear braking I wanted to "stiffen" the sensing spring so more pressure would be transferred to the rear brakes.
A second obstacle with the LSPV is adjusting it accurately after lifting the truck. The main problem is that after lifting the upper control arm is in the way of just raising the point at the axle.
So what I've come up with is a drop block for the LSPV to lower it on the frame 2" and then a multi position plate for the axle that allows you to recreate the original configuration after the lift. The mounting holes at the axle have a spacing that is almost 1" .
So measuring the distance between the hub center to the underside of the flare of a front wheel and subtracting 20.5 gives me the lift height of the front. In my case it calculated to 4". Now if you have a level stance to your truck that would translate to 4" in the rear and you would install the 2" drop block and raise the mount on the axle 2 holes. In my case I have some rake and my rear is higher than the front so I installed the drop block and raised the mount at the axle 3 holes. This puts you real close to the stock position for the LSPV and if needed you can fine tune the system by adjusting the LSPV itself on the bracket and the length of the factory axle mount.
For dealing with stiffening the sensing rod I chose to install 2 layers of thick wall adhesive shrink tubing. I have a heat gun that I used to shrink the tubing but I think an oven would probably work better. I just need to see if there is a published temp for the tubing.
Attached are some pics of what is on my truck. What you are looking at is a proof of concept and not what will actually be included in the kit.
Last edited:
i would consider making the lspv portion of the kit optional as i know that some people have deleted it and wouldnt need it. im sure that the cost on the bracket will be minimal so it probably wouldnt affect the total cost that much.
concept kit for the lspv looks good, nice work with the brackets
concept kit for the lspv looks good, nice work with the brackets
- Thread starter
- #88
thanks, I was also thinking that the LSPV mod would also help anybody who is still running it and was going to offer it separately. Making it optional is probably a good idea.
So real quick comment on the torque and size increase ... if this was linear, it would be the 2.9% increase. However, because this is round, it’s now a straight percentage increase but quadratic bc it’s about the force generate from the area of the circle.
so ... (320/311)^2 = 5.9% more brake area. If you’re running 315s, your tire radius is already 4.6% bigger than stock, so the brake area (which is a rough proxy to increase in braking force) is back in-line With and a bit better than “stock” measurements, with further improvement coming from greater clamp force and bigger pads. Nets a 1-2% gain va stock feel off the bat.
Then you need to factor this in based on your vehicle’s weight ... that indicates brake efficiency, aka “how soft” the brakes feel when you use them. Most of us take these vehicles up to 7500 lb dry, which is 12-15% over stock GVWR, so a combo of pads and clamp pressure that is 12-15% greater than stock would make it feel “normal”. 3% here, 5% there adds up quick to address the brake issue on our rigs.
This is the theory / design side. It can’t necessarily help address some of the feel issues that LANDTANK identified, and would only be good to spec the details of truly “how much” better this design is versus stock to help with performance validation. Happy to help if someone can provide detailed specs.
2 good sets of engineering equations below:
Engineering Inspiration - Brake System Design Calculations
so ... (320/311)^2 = 5.9% more brake area. If you’re running 315s, your tire radius is already 4.6% bigger than stock, so the brake area (which is a rough proxy to increase in braking force) is back in-line With and a bit better than “stock” measurements, with further improvement coming from greater clamp force and bigger pads. Nets a 1-2% gain va stock feel off the bat.
Then you need to factor this in based on your vehicle’s weight ... that indicates brake efficiency, aka “how soft” the brakes feel when you use them. Most of us take these vehicles up to 7500 lb dry, which is 12-15% over stock GVWR, so a combo of pads and clamp pressure that is 12-15% greater than stock would make it feel “normal”. 3% here, 5% there adds up quick to address the brake issue on our rigs.
This is the theory / design side. It can’t necessarily help address some of the feel issues that LANDTANK identified, and would only be good to spec the details of truly “how much” better this design is versus stock to help with performance validation. Happy to help if someone can provide detailed specs.
2 good sets of engineering equations below:
Engineering Inspiration - Brake System Design Calculations
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I get the idea of regular braking and panic braking acting different because of the nose dive, but the lspv rod pivots at the valve under the boot so I don't understand reinforcing the rod.
- Thread starter
- #91
The rod by Toyota's definition is a spring. And just like our coils it has a 3 dot color code and I think that indicates it's strength. During my evaluation of the stock system I noticed that the sensing spring would deflect under heaving braking with the engine running. During that time that deflection would influence the valve to alter the proportioning to the rear by lessening it. With our heavier trucks and larger tires I feel that increasing the stiffness of the rod and retaining more of the stock proportioning under heaving braking is beneficial.
Yea I agree it creates too much of a split between normal and panic braking. I've driven myself crazy testing and tuning before I had realized the different behavior. The more I think about it, I just want to replace it with a proportioning valve to keep it consistent, even though I feel mine is adjusted pretty well.
- Thread starter
- #93
I often do long range wheeling, meaning I pack the truck and drive hours/days to an event and then wheel unloaded. I want the LSPV in place. And I really like how the setup works now. Stiffening the rod basically mutes that split you are seeing. I drove around doing a bunch of panic stops the last one was pulling into my driveway.
Coming from the center of town you approach my driveway coming down a hill and then turn left into the driveway. I was cruising about 45mph and my test was to wait well past the time I would normally start braking to start braking. I basically cut the difference in half. I stood on the brakes, no dive, no drama and ended up letting off before I turned in. I wouldn't discard the factory setup just yet.
- Thread starter
- #94
time for an update. I got the rotor hats in but unfortunately only 9 sets. I'm waiting on the LSPV drop and what I thought was a simple square block turned into a rather complex design. I still need to make the float harnesses and source the sockets for the hat bolts but we are getting close. Attached is a brake system inspection guide that might help those with just poor brakes as well as those contemplating this upgrade.
- Thread starter
- #95
So I'm on the home stretch for releasing the kit. I just finished the float harnesses, got the LSPV drop bracket and axle rod lift. Need to order some bolts but otherwise I should be good to go by next week.
The master Cylinder I'm using is a dorman part. I tried to locate aisin to no avail. I put a dorman in my truck and didn't see any short comings and they are readily available.
The LSPV drop block and axle lift will be a separate purchase and anyone with a lift that is still running the LSVP should consider installing it. It really did make a substantial improvement and will work with the stock brake s up front.
You will need to transfer the connector from your float onto the supplied harness as I couldn't find that housing.
One nice feature of the new master cylinder is that it partitions the front of the bowl from the rear half. I had a line break while on a trip and with the single bowl design we have, it drained all the fluid out of the bowl basically leaving me with little to no brakes.
Installing the LSPV drop will require removing the bracket from the cross member of the frame. Not a pleasant job by any means especially the two bolts facing the gas tank. I have both a 6-point 12mm and 10mm box wrench. Being from New England the heads of the bolts shrink over time and can rust in. A 6-point wrench will often either remove the bolt or break the head off of it. Either of those outcomes works for the rear facing bolts because we won't be using the frame holes after installing the drop. The bottom verticle bolts need to come out clean, those will be used again. The sooner you start working on those bolts the better. It's definitely the worst part of the upgrade.
watch the vendor marketplace for its release.
The master Cylinder I'm using is a dorman part. I tried to locate aisin to no avail. I put a dorman in my truck and didn't see any short comings and they are readily available.
The LSPV drop block and axle lift will be a separate purchase and anyone with a lift that is still running the LSVP should consider installing it. It really did make a substantial improvement and will work with the stock brake s up front.
You will need to transfer the connector from your float onto the supplied harness as I couldn't find that housing.
One nice feature of the new master cylinder is that it partitions the front of the bowl from the rear half. I had a line break while on a trip and with the single bowl design we have, it drained all the fluid out of the bowl basically leaving me with little to no brakes.
Installing the LSPV drop will require removing the bracket from the cross member of the frame. Not a pleasant job by any means especially the two bolts facing the gas tank. I have both a 6-point 12mm and 10mm box wrench. Being from New England the heads of the bolts shrink over time and can rust in. A 6-point wrench will often either remove the bolt or break the head off of it. Either of those outcomes works for the rear facing bolts because we won't be using the frame holes after installing the drop. The bottom verticle bolts need to come out clean, those will be used again. The sooner you start working on those bolts the better. It's definitely the worst part of the upgrade.
watch the vendor marketplace for its release.
- Thread starter
- #96
at this point I have everything on hand for 9 front disk upgrades and 19 LSPV upgrades. Right now I'm really busy and don't have time to do a fancy release of the products. So if you have been following and am interested PM me and I can take care of you individually.
Thanks for watching
Thanks for watching
brettk
SILVER Star
May I ask what benefit it is to have an adjustable panhard bar and a delta bracket? I thought most people either bought one or the other.
FJRanger
SILVER Star
Fine tuning. Many already had the adjustable panhard before getting the Delta bracket.
