Stopping a 6k lb 80 on 38's better than our bone stock LX450 with refreshed brakes. F+R "motorsport grade" brake upgrade.

[jcardona1]

Electronic will be button/switch operated. I don't expect to sell much if any of the rear kits. Mostly doing it for myself. I don't think the push button PB is what will scare people away. I can tell you right now it will be more than double the cost of the F+R Lite package. The cost is attributed to the 2 extra spot calipers, the parking brake module/controller and brackets. I've found most 80 owners won't be willing to spend this kind of money and if they are willing to double down on costs, then a switch operated PB is the least of their worries, and they know what they're getting into.

Think it'll work with the cable actuated calipers? Mounting looks the same as the electronic version.

I actually have a pair currently, been trying to figure out how to mount them over the rear rotors combined with E-Stopp actuator. I tried mocking up the electronic calipers but didn't have room as I have a custom coilover setup behind the axle.

I was thinking of something like this. Electronic parking brake but using cable calipers:

 

[jcardona1]

Electric were way too big given my coilovers and swaybar.

Cable version might work. Sorry for the hijack!

 

[synapse]

Electric were way too big given my coilovers and swaybar.

Cable version might work. Sorry for the hijack!

Not a highjack at all!

From first page

I do have a cable actuated caliper on hand. ^^

This is just a mockup of a 14.25"x1.1" rotor from Wilwood parts bin. It has exact same inner shoe diameter of 9.04", nearly same disc offset as factory, and is 6x139.7 that I thought was compatible but sadly the inner shoe surface is too far outboard to use with 80 internal drum. I was hoping this would save me from needing a spot caliper.

Wilwood says the cable actuated calipers are only compatible with 13" rotors max, but doesn't make sense since the EPB ones are the same exact body and pad. So chances are yes as EPB is 14" compatible.


There still is a chance this 1pc rotor can be saved though. Porterfield has made me custom one off pads for my Wilwoods that are currently on my other car, and they do offer custom brake shoe/drum pads as well, built from scratch. Need to reach out to them to see if they can push the radial pad out to match the offset of the Wilwood rotor.

 

[synapse]

@jcardona1 @Enders

SOOOO big update from my contact at Porterfield...

As mentioned in previous post the black rotor is a 14.25"x1.1" rotor from wilwood parts bin that has the same bolt pattern, same brake shoe ID, and almost same exact disc offset. Only issue that did NOT allow me to use it with our current internal drum is the offset, the internal surface area sit much further outboard than an OE rear 80 rotor.

BUT as per Portefield they are able to build me a custom brake shoe where the friction compound is offset further out to match the friction surface area of the rotor.

Using random photo from the internet to explain what I was requesting.

Once I start on these and send them a core I will request them to be over-bored to give some extra meat to grab onto since our parking brakes suck after being lifted.

I was originally looking into full custom iron rotor hats with integral drum and have the friction surface under-bored, but cost to have a foundry cast something for me was much more expensive than having to work with an EPB.

What does this mean? Much less development costs and makes EPB optional, not mandatory, with the eventual rear kit. I no longer need to design a rear hat, 1 pc rotor from Wilwood is already mass produced, bringing costs of rear down SIGNIFICANTLY.

 

[b16]

I saw somewhere on here a kit putting a rotor between the rear driveshaft and tcase and using an electric e brake caliper there. Seemed like an interesting solution.

 

[jcardona1]

@jcardona1 @Enders

SOOOO big update from my contact at Porterfield...

As mentioned in previous post the black rotor is a 14.25"x1.1" rotor from wilwood parts bin that has the same bolt pattern, same brake shoe ID, and almost same exact disc offset. Only issue that did NOT allow me to use it with our current internal drum is the offset, the internal surface area sit much further outboard than an OE rear 80 rotor.

BUT as per Portefield they are able to build me a custom brake shoe where the friction compound is offset further out to match the friction surface area of the rotor.

Using random photo from the internet to explain what I was requesting.

Once I start on these and send them a core I will request them to be over-bored to give some extra meat to grab onto since our parking brakes suck after being lifted.

I was originally looking into full custom iron rotor hats with integral drum and have the friction surface under-bored, but cost to have a foundry cast something for me was much more expensive than having to work with an EPB.

What does this mean? Much less development costs and makes EPB optional, not mandatory, with the eventual rear kit. I no longer need to design a rear hat, 1 pc rotor from Wilwood is already mass produced, bringing costs of rear down SIGNIFICANTLY.

That's good news. I'd still be interested in the Wilwood parking brake setup since I can't use the factory parking brake mechanism (coilovers). It just depends where/how the caliper mounts to see if I have the space.

I saw somewhere on here a kit putting a rotor between the rear driveshaft and tcase and using an electric e brake caliper there. Seemed like an interesting solution.

That was me, that option ended up being a non-starter. It doesn't work with the VC transfer cases which rules out most of the US market except for 91-92 Land Cruisers I think. Bummer because it was a really nice kit but it had to go back.

 

[1FZj80]

I really do think the rear brakes are the weakest link on our platform. Take a look at the size of the brake pads. These have no thermal capacity and feel pretty comfortable saying they overheat way before the fronts ever do.

For the rear I came up with a “lite” version as I am still working on a full rear upgrade. The lite version implements a high carbon rotor and the highest friction pads I could source for the 80 calipers. Benefits of high carbon is that they’re much more durable, have a higher thermal capacity, and they dissipate heat much faster than traditional iron rotors. I’ve found two quality rotor manufacturers that make rotors for the larger rear 80 rotors. Stoptech and DBA. Stoptech ones are side specific as they’re directionally slotted. And DBA has their T3 rotors(T2 are not high carbon). I”ve found DBA to be slightly lower in price.

why do you think the rears are a weak link?
i have been running 14" rotors for over 6-years and find the rears to be more than adequate.
what am i missing?

 

[synapse]

why do you think the rears are a weak link?
i have been running 14" rotors for over 6-years and find the rears to more than adequate.
what am i missing?

Thermal capacity. Look at how small the pads are. Not just surface area but pad volume. There's no mass to them.

Full line pressure at the rear(meaning fully open LSPV or Prop Valve), accounts for 42% braking forces on the 80. So up to almost half, but of course factory or aftermarket valve setting will decrease this amount some.

These pads overheat easily, considering there's not a lot of high heat range pads minus the Blue Stuff that I've found for the rear 80 caliper. Factory-like pads have a friction coefficient of around .35-.38 mu, give or take some. Some compounds might have a heat threshold of only 500F-600F. You go over that threshold you can easily go down to .2 mu, significantly decreasing braking performance.

Rear performance is fine if you're within the heat range. 13.15" rotor has decent leverage and it's not like the rear caliper has a small total piston area. Driving around town on emergency braking will probably be fine. Driving around mountain passes for several hours at highway speeds like we do here in BC and in my experiences in NZ, I wouldn't trust them and drive as cautiously as I can.

Top to Bottom
WW Aero Pad
WW Superlite 20mm Pad
OE 80 Rear Pad
Pen for size reference

While this video explains differen't tier of brake pads, the principle of going over a brake pads thermal threshold exists. You can see how on one of the budget pads, they drop to .2 mu even as low as 400F

On left chart red is temp, blue is friction coefficient, green is pressure(pedal feel).

 

[synapse]

Some data points for people:

Here I have calculated brake torque front and rear based off of completely unmolested rear line pressure(no factory or aftermarket proportioning valve) and a .37 mu brakepad friction coefficient.

Now here's with my current Stage 2-Lite setup using WW Aero caliper with WW BP-20 pads and rear stock caliper with EBC Blue Stuff pads.

Front caliper total piston area.

Factory 4.994 vs WW Aero 4.837, a 3% reduction. Lower total piston area provides firmer pedal, but 3% is negligible, much larger more rigid caliper is provides more benefit.

Front Rotor Torque

Factory 4819 vs Stage 2-Lite 6060, an increase by 25.7%

Rear Rotor Torque

Factory 3099 vs Stage 2-Lite 4355, an increase by 40.5%

Brake Bias

Factory 57.6(F) : 42.4(R) vs Stage 2-Lite 58.7(F) : 41.3(R)

Absolutely no difference, making kit compatible with factory ABS and LSPV.




Upgrade front only?

Let's see what happens...

Brake bias of 66.7(F) : 33.3(R)

Making a front only kit way too front biased and incompatible with ABS. It is not uncommon for larger FF(Front engine FWD) to be in the low 70% front bias, so you're reaching that territory and have unbalanced braking for what probably has a lot of extra weight in the rear(talking about overland setups and vehicles with heavy armor + large spare in the rear). Will it still stop? Sure. Will it stop an overweight 80 better than factory brakes? Probably, but could be greatly optimized. Huge room for improvement.

This is why these kits will only be sold as a matched front and rear package. With motorsport brands like Stoptech, they don't actually increase front brake rotor torque, they might increase the leverage using a larger diameter rotor, but then match it with smaller pistons in the caliper to give a firmer pedal(desirable on the track). Keeping brake bias, but greatly increasing thermal capacity to prevent heat fade and give much more consistent braking.


I'm willing make a huge bet even the Stage 2-Lite I've currently come up with will absolutely demolish Tarrox and Powerbrake 80 series upgrade and come in at a lower price point.

 

[Azca]

DAMN DUDE! Definitely a number crunching and researching maniac! I love it! Look forward to where this ultimately goes. Can't say yet if I will be in the market, I still don't have mine on the road. In the process of changing to hydro boost. Out of curiosity, how do you think your upgrade would work with a hydro boost setup?

 

[ATXnative]

I'm willing make a huge bet even the Stage 2-Lite I've currently come up with will absolutely demolish Tarrox and Powerbrake 80 series upgrade and come in at a lower price point.

Ok NOW we’re talkin!

 

[HMM]

Very well done!

 

[b16]

That was me, that option ended up being a non-starter. It doesn't work with the VC transfer cases which rules out most of the US market except for 91-92 Land Cruisers I think. Bummer because it was a really nice kit but it had to go back.

Ah! That’s a bummer. Was it the physical dimensions of the VC case vs non VC that were the issue? Do you see any possibility of making a different kit that would work? My current e brake levers at the at the wheels where the cable connects get stuck in the on position if I use it, making it useless. I really don’t want to spend the money on replacing the stock system just to have that happen again.

Sorry to hijack the thread. This kit looks awesome. I ran wilwood 4 pot calipers and large rotors on the front of my Honda Civic I used for road racing. They were fantastic.

 

[mudgudgeon]

Ah! That’s a bummer. Was it the physical dimensions of the VC case vs non VC that were the issue? Do you see any possibility of making a different kit that would work?

Older cruisers and Nissan Patrols had a drum park brake on the rear of the t-case. One major problem is if you park on uneven ground with poor traction under one rear wheel, the rig can run away. Even though the driveshaft is locked, the rear differential can rotate allowing them to shift. Can be disastrous offroad.

 

[1FZj80]

These pads overheat easily, considering there's not a lot of high heat range pads minus the Blue Stuff that I've found for the rear 80 caliper. Factory-like pads have a friction coefficient of around .35-.38 mu, give or take some. Some compounds might have a heat threshold of only 500F-600F. You go over that threshold you can easily go down to .2 mu, significantly decreasing braking performance.

Rear performance is fine if you're within the heat range. 13.15" rotor has decent leverage and it's not like the rear caliper has a small total piston area. Driving around town on emergency braking will probably be fine. Driving around mountain passes for several hours at highway speeds like we do here in BC and in my experiences in NZ, I wouldn't trust them and drive as cautiously as I can.

looks like you analyzing the numbers and taking the time to put together a well designed kit. But, FWIW i have been running 14" rotors w/ Wilwood Superlites on BP-20 pads, stock rears w/ EBC pads, no lspv or abs and a T1000 MC for over 6-years and there is no issue with the rears. my braking is freaking mental! Sooooo good.

BTW, your post has been a kick-n-the-pants for me to complete my design. i have a new cnc and will be cleaning up the design with new hats and brackets similar to yours. thanks!!!

edit: i will add some temp tape to the rears and report back with temps i am seeing.

 

[on the rocks]

This is why these kits will only be sold as a matched front and rear package. With motorsport brands like Stoptech, they don't actually increase front brake rotor torque, they might increase the leverage using a larger diameter rotor, but then match it with smaller pistons in the caliper to give a firmer pedal(desirable on the track). Keeping brake bias, but greatly increasing thermal capacity to prevent heat fade and give much more consistent braking.

That's unfortunate. No rear only if already running a 14" super-lite 6 piston combo up front? If still no maybe offer the rear caliper bracket only?

 

[synapse]

looks like you analyzing the numbers and taking the time to put together a well designed kit. But, FWIW i have been running 14" rotors w/ Wilwood Superlites on BP-20 pads, stock rears w/ EBC pads, no lspv or abs and a T1000 MC for over 6-years and there is no issue with the rears. my braking is freaking mental! Sooooo good.

BTW, your post has been a kick-n-the-pants for me to complete my design. i have a new cnc and will be cleaning up the design with new hats and brackets similar to yours. thanks!!!

edit: i will add some temp tape to the rears and report back with temps i am seeing.

Kit will not leave anything on the table that's for sure! I'm comfortable claiming these will demolish anything out there because I've been running Wilwood's for 18 years, building and tweaking my own personal kits for almost 10 years, and thought about every possibility out there for the 80 series, including exactly what you're running. Ask @BayArea80, he went with something similar to you minus the larger master cylinder after talking everything over with me for countless hours. While he say's it's a big improvement over stock, he does say if he had the time to wait, he would prefer to go with my kit. Even now he still feels the need to upgrade the rear once I do come up with a full rear package. I'll go over exactly why I recommended against the t100 master cylinder.

First I'm confused at which Superlite caliper would warrant a larger master cylinder in your case. I'm guessing you're using the FNSL and not the full size Superlite as there's no good match for the front's in the full size Superlite 6 piston family. Largest FNSL 6 piston has a total piston area of 4.86 in ^2, largest 4 piston Superlite has a total piston area of 5.18 in ^2(I Have this caliper on hand and chose to go 4 piston Aero route with a 4.84 in ^2 total piston area). Largest 6 piston FNSL and my 4 piston Aero is 3% smaller in total piston area, while largest 4 piston(5.18in^2) is 3.7% larger. Nobody will notice how this affects pedal input, even the most veteran'd motorsport drivers.

Many people don't know this but the BIG problem with going to a larger master cylinder is that they decrease line pressure. decreased line pressure means less clamping force on the rotor.

Case in point:
All factory 80 specs comparing 1.0 vs 1.125 master cylinder bore. Going from 1.0 to 1.125 master cylinder is a reduction in roughly 20% in line pressure and therefore 20% brake rotor torque!

Now don't get me wrong, if you solely want a firmer pedal at the sacrifice of line pressure and braking performance, then you hit your goal. In motorsports it's not uncommon to delete the brake booster because preference in firmer pedal, pedal modulation & feedback outweighs the reduction in line pressure/clamping force. There's ways to regain that back through higher friction pads, larger rotor diameter etc. I mean I have calves that rival in size to some gym-bro's biceps, but I sure wouldn't want a brake boost delete on a daily driver lol

Also in regards to rear, larger master cylinder on stock rear brakes is basically cancelling out your LSPV delete as many go LSPV delete to increase line pressure.

Anyways what I'm trying to say is I've made a lot of these mistakes when I was fairly new to performance brake systems, and there's still plenty of things for me to learn While everything I tried in the past was in comparison better than stock, they were never fully optimized until I started digging deeper in how to get them better. Even now I'm contemplating revision #3 on my VW's BBK. Will revision #3 be as big of a difference as revision #2 was? I'll doubt there will be much improvement. Will it allow me to have more awareness on braking performance? Absolutely.

I'm glad you're happy with your setup and they're more than enough for you, if you're looking to optimize would definitely start with what's above. I see you're in Tahoe? I visit family the Bay Area quite often, maybe @BayArea80, @jcardona1, and us can get together and compare braking performance. I think all of us are running something completely different from each other, but you and BayArea80 are probably most similar. Would be a fun shootout!

 

[synapse]

That's unfortunate. No rear only if already running a 14" super-lite 6 piston combo up front? If still no maybe offer the rear caliper bracket only?

I may make very few exceptions As mentioned in above post, I helped @BayArea80 with pros and cons to different options out there, and he still wants to run my rear with his FNSL + 14" tundra rotors.

 

[Jasonazx]

@synapse have you considered the DBA XP pads for the basic (lite) rear version? Are there performance advantages the EBC's have over the DBA's? I know you're using a DBA rotor, was curious why not match the pads to the rotors?

 

[synapse]

@synapse have you considered the DBA XP pads for the basic (lite) rear version? Are there performance advantages the EBC's have over the DBA's? I know you're using a DBA rotor, was curious why not match the pads to the rotors?

Looked at DBA pads briefly but couldn't find more detailed info about them. They only seem to state temperature ranges and nothing about friction levels. I needed rear pads that had high enough friction level to match the power up front.

Personally been running Wilwood, EBC, Hawk, and Porterfield pads for quite a long time, so went with something I knew.