Overland Journal: Discovery I, 5-speed

[Antichrist]

For the Adventure Trailer, I am fitting an adapter from the Toyota lug pattern to the Land Rover lug pattern.

Why not replace the hubs with Disco hubs? Then you have two complete spares in your travels. You can probably get a set of used hubs + stub axles for less than the cost of adaptors.

Step two: Brakes
I am still investigating here, but the brakes need to be serviced in the rear and upgraded in the front. Most likely the front will be upgraded to DBA rotors and stock pads. The vented rotors will aid with reduced fade, etc. I may upgrade the rear rotors as well. The Expedition Exchange brake lines are of interest as well for their increased length and better brake feel.

Going to Defender brakes helps a lot.

As far as the winch goes I would opt for the 8274 for sure, the extra weight way out front is a good thing on a disco.

The first winch I had on my Disco was an 8274. I decided that without recessing it in to the grill it just stuck out way too far, killing my approach angle.

 

[Scott Brady]

Why not replace the hubs with Disco hubs? Then you have two complete spares in your travels. You can probably get a set of used hubs + stub axles for less than the cost of adaptors.

Tom,

Great question. The reason is actually more one of convenience and long-term usage. I plan on getting another Toyota for the fleet, which will be our "shop" truck. I expect that the 5x6.5 and Rover pattern will both be quite useful on that trailer throughout its life. Functionally, the adapters are actually quite useful for the Rover application, as the tire/wheel combo is so much smaller. The adapter pushes the track-width out, aiding with stability, etc.

Going to Defender brakes helps a lot.

I like this route. Taking it a step further, are there even larger calipers and rotors fitted to 110s or 130 hi-caps? Braking performance has more to do with clamping force than anything, so a larger caliper (possibly with more pistons) would be ideal. On my Tacoma, the Porterfield rotors and pads were a significant improvement, though that truck mostly suffered from fade, not stopping power.

Time for more research on this...

The first winch I had on my Disco was an 8274. I decided that without recessing it in to the grill it just stuck out way too far, killing my approach angle.

I love the idea of an 8274 or Husky 10 on the Disco, but I just find it unnecessary for this application. The M8000s have always proven themselves for travel in the Southwest and Mexico (where this truck will be used), and I like the idea of taking it a step further with the sealed solenoid, etc.

 

[R_Lefebvre]

I like this route. Taking it a step further, are there even larger calipers and rotors fitted to 110s or 130 hi-caps? Braking performance has more to do with clamping force than anything, so a larger caliper (possibly with more pistons) would be ideal. On my Tacoma, the Porterfield rotors and pads were a significant improvement, though that truck mostly suffered from fade, not stopping power.

Time for more research on this...

What exactly are you looking to fix? More braking power, or more thermal capacity (long, repeated stops).

Don't increase your piston area without a subsequent increase in master cylinder area, or you'll get a long pedal which isn't confidence inspiring. You can go to 4 pistons, while keeping the area the same, and the braking will improve just because the caliper is stiffer. The best ways to improve stopping power is by going to a 4 piston caliper, or increasing rotor diameter. Both are significant undertakings.

If you need better thermal performance, larger rotors help, as does the larger pads that come with larger calipers. Again, significant undertakings. Improvements can also be seen with a different pad compound. Unfortunately, there isn't much selection here for trucks. Some high performance pad manufacturers will put a high performance compound on a set of backing plates you send them.

Slotted and drilled rotors don't really improve fade resistance.

Many people miss the fact that just putting new standard pads and rotors will improve braking performance all-around. The pedal gets noticably firmer, and thermal performance is improved a bit as well. This is usually the cause for glowing reports when putting on new drilled rotors. A new standard rotor would have given the same feel.

 

[Antichrist]

I like this route. Taking it a step further, are there even larger calipers and rotors fitted to 110s or 130 hi-caps?

You'll find drum brakes on them, at least the older ones. I don't know if the new ones will fit or not.
The D90 fronts are a direct bolt on and offer significant improvement, from all reports. I've got all the parts sitting on the shelf to do mine, just been putting it off while I gather parts to do a complete front axle rebuild.

 

[R_Lefebvre]

What exactly is the spec on the Defender brakes? Back in 2005, I was working on a prototype 2007 110. I remarked that it had Alcon 4 piston calipers up front, and IIRC the back too. That would be a pretty nice setup if it was available and it fit.

 

[Michael Slade]

My 145 has front brakes from a Shoreland armored 110. The calipers are about 25% larger than the stock 110 calipers. I have a part no. somewhere...

I know it's archived on Pirate too...I can't seem to find a photo of them anywhere.

I also put RRC ABS front calipers onto the rear Salisbury axle with vented rotors. They work pretty well.

 

[R_Lefebvre]

Those look like 4 piston opposed? Nice. The difference that opposed piston calipers make over floating is pretty incredible.

 

[Scott Brady]

What exactly are you looking to fix? More braking power, or more thermal capacity (long, repeated stops).

Both. The braking system looks to be upgradable to the D90 system, which has a vented front disc. I am still researching the possible improvements to the calipers as well, keeping in mind the limitations of the stock master cylinder.

Unfortunately, there isn't much selection here for trucks. Some high performance pad manufacturers will put a high performance compound on a set of backing plates you send them.

I had good luck with Porterfield pads on the Tacoma.

Slotted and drilled rotors don't really improve fade resistance.

drilled - no, as there is reams of documentation on the downsides of drilled rotors, which I do not intend to regurgitate here.

However, slotted appears to have its advantages for both bite and pad performance in wet conditions. Disc Italia and Powerslot both make slotted only rotors, but I have no experience/testing time with either to know the quality. Most are the slotted and drilled, which I do not want.

Even if I cannot find slotted only rotors, just the upgrade from the solid rotor to a vented D90/Later RRC rotor will make a nice improvement in fade resistance IMO.

 

[JSQ]

There was a set of the up-armored front calipers and rotors for sale on the D-90 source very recently.

 

[R_Lefebvre]

Shoot, I didn't realize, does the D1 come with solid front rotors? That's what threw me off when you said "vented", some people refer to drilled as vented. Anyway, I'm glad we don't have to get into that.

Yes, slotted do have some advantages for bite and clearing mud from between the pads. However, they still suffer from cheese gratering the pads, and that seems to be made worse with dirt. I have a friend who is a sponsored KTM rider who's switching to solid non-drilled/slotted rotors so the pads last longer. Pretty hard to find parts as everything on the market is wave/drilled/slotted.

For the calipers, all you need to do is match the total piston area to the originals. I worked with Todd at TCE Performance for a setup on my Focus. The pedal feels is pretty amazing. Too many bad brake kits on the market where they increase piston area in the erroneous effort of trying to improve clamping force. Which, it does, but you get a long squishy pedal. Mine shortened up quite a bit over stock because of the stiffness of the system.

If you've got that much room that a 4 piston would fit, perhaps you could try a Wilwood caliper. They have a version (DynaPro) which includes dust boots which I think could work for an Expo type application. The nice thing about going that way is easy access to countless types of good pad compounds. And cheap! Set of Q pads for my Forged Superlights is $60 IIRC. Also looks like it could be a pretty straight forward install given the mounting in that photo. Todd at www.tceperformanceproducts.com would probably work with you. He started out doing kits for under-serviced models and looks like he's branched into everything now.

 

[Mike_rupp]

Those look like 4 piston opposed? Nice. The difference that opposed piston calipers make over floating is pretty incredible.

The D1 comes from the factory with 4 piston front calipers.

The main difference between the Discovery and D90 front setup is that the D90's calipers have slightly larger pistons, larger pads. and vented rotors.

 

[Antichrist]

Both. The braking system looks to be upgradable to the D90 system, which has a vented front disc. I am still researching the possible improvements to the calipers as well, keeping in mind the limitations of the stock master cylinder.

No one who's done the conversion has mentioned any issues with the MC that I've seen.

And cheap! Set of Q pads for my Forged Superlights is $60 IIRC.

$60 for pads doesn't seem that cheap to me when D90 pads generally are in the $30-$40 range.

 

[R_Lefebvre]

The D1 comes from the factory with 4 piston front calipers.

The main difference between the Discovery and D90 front setup is that the D90's calipers have slightly larger pistons, larger pads. and vented rotors.

4 piston calipers... and non-vented rotors. That's odd. Why did they do that?

$60 for pads doesn't seem that cheap to me when D90 pads generally are in the $30-$40 range.

Yeah, but what quality are those pads? I'm comparing $60 for a set of pads, or $80 for a set of racing pads, compared to $120-150 for a set of typical racing pads for stock type car calipers. And then the Wilwood setup last about 50 times longer.

 

[Yorker]

4 piston calipers... and non-vented rotors. That's odd. Why did they do that?

Probably because it worked well enough for most people ever since they started using them with the RRC in the early 1970's.

"'Better' is the enemy of 'Good Enough',""Le mieux est l'ennemi du bien." engineering mentality? :sombrero:



(they were dual line originally though.)

 

[Antichrist]

Yeah, but what quality are those pads? I'm comparing $60 for a set of pads, or $80 for a set of racing pads, compared to $120-150 for a set of typical racing pads for stock type car calipers. And then the Wilwood setup last about 50 times longer.

I doubt he's going to be racing his D1. Plus the D90 conversion is an extremely simple conversion, not much more than replacing stock calipers and rotors, just need to bend the brake line a bit at the caliper. Add to that everyone who I've read about who's done it is very happy with the setup.