Need brakes… 9k altitude

[Fifty]

Got a good trip in this week, up in the mountains.
Found a nice 23 mile fairly easy trail but lots of wash outs and silt… a few g outs.

One thing I noticed was the worst brake fade I’ve ever had. So bad that at the end of the trail; there was a relatively steep (eh… not bad) down hill switch backs.

I found that putting it in tow mode made the rear brakes hotter (super scientific by touching the rear wheels and sensing where the burning brake smell was coming from and how pungent. I’m gonna get a nobel in off-road brake science)

I was chatting with @Dudebro about this today when I got to cell service. He has done some big miles in the Baja region… and not suffered the brake issues that I had.

Now, he probably drove the whoops faster than me, and maybe I take the corners faster then he… but we aren’t racing and leave plenty of room for error.

And my last trip I didn’t have nearly the same brake issues.

Ahhhh. The altitude. This trip had me clear 9k feet and it was 100°

My last trip was at about 1k feet… and much cooler.

I think the lack of air density and added ambient heat really knocked things up.

Engine oil temps hit 265, air intake temps 160… trans temps around 210…. (Our transmission cooler rocks!)
I put new tell tale stickers on the shocks, but I’m too tired and they are all too dirty to see. Tomorrow I’ll get that.

So anyways… it’s time for brakes.

Anyone with a sale on Alcon brakes? I am working for Carbon for free. I don’t make money, I am stealing my kids college funds for my toys.
Wife said if I can find a sale on a set of brakes she will allow it. (It helped having her there smelling the brakes)

Pics are from day 3 when we went ghost towning!

 

[Dudebro]

265 oil is spicy! 240 is the highest I’ve seen and that was 100 degrees out

 

[FULLTHROTTLERICK]

265 oil is spicy! 240 is the highest I’ve seen and that was 100 degrees out

Wow we've seen 250s-260s for sure. Im suprised you've only seen 240. Double check the next time you're running her hard man and you might be surprised!

 

[FULLTHROTTLERICK]

Got a good trip in this week, up in the mountains.
Found a nice 23 mile fairly easy trail but lots of wash outs and silt… a few g outs.

One thing I noticed was the worst brake fade I’ve ever had. So bad that at the end of the trail; there was a relatively steep (eh… not bad) down hill switch backs.

I found that putting it in tow mode made the rear brakes hotter (super scientific by touching the rear wheels and sensing where the burning brake smell was coming from and how pungent. I’m gonna get a nobel in off-road brake science)

I was chatting with @Dudebro about this today when I got to cell service. He has done some big miles in the Baja region… and not suffered the brake issues that I had.

Now, he probably drove the whoops faster than me, and maybe I take the corners faster then he… but we aren’t racing and leave plenty of room for error.

And my last trip I didn’t have nearly the same brake issues.

Ahhhh. The altitude. This trip had me clear 9k feet and it was 100°

My last trip was at about 1k feet… and much cooler.

I think the lack of air density and added ambient heat really knocked things up.

Engine oil temps hit 265, air intake temps 160… trans temps around 210…. (Our transmission cooler rocks!)
I put new tell tale stickers on the shocks, but I’m too tired and they are all too dirty to see. Tomorrow I’ll get that.

So anyways… it’s time for brakes.

Anyone with a sale on Alcon brakes? I am working for Carbon for free. I don’t make money, I am stealing my kids college funds for my toys.
Wife said if I can find a sale on a set of brakes she will allow it. (It helped having her there smelling the brakes)

Pics are from day 3 when we went ghost towning!

We had almost 0 brakes when we were at 10-12k feet last week but my brakes were also completely covered/caked in mud so i attribute that to some of the issue. You might wanna check out the Alcon brake thread as someone just returned a set after a bad experience.

 

[Fifty]

Yea. That was a bad brake pad batch.

Alcon has been cagey with me about pad shape size and material.

Rotora may be my go to, I’m trying to find their pad shape to see if I can option my own pad material from hawk or Carbotech with out extra cost of custom cut pads.

I’m a fan of the hawk 5.0 and the Carbotech xp6 and xp8

Rotora has the 4 wheel kit which is nice. Skinnier than the Alcon kit (36mm vs 42mm) but still thicker than stock (30mm iirc or is it 32mm?)
And it looks like the pads are thinner on the rotora vs the Alcon. I’d like a 17mm or even a 19mm pad. It just helps insulate the pistons and Not to mention the pads last longer.

That’s what is really needed on our trucks is a thicker rotor.

 

[Two]

Okay, now I'm curious.

Obviously altitude has an effect on lots of things.... but the brakes??? How would they know what altitude they're at?

 

[RoNiN]

I would assume that with less air at altitude it wouldn’t cool as well… that’s just me speculating though.

 

[Two]

You may be onto something there, as heat doesn't travel well, if at all, in a vacuum. But that's a long step from a mere 9,000 feet.

Closest comparison I have is driving way too fast on curvy roads between 7,500 and just over 10,000 feet, but that's with a Challenger equipped with much better brakes. Yet, people who track them claim that the brakes can start fading after a couple of laps, and those tracks are generally at lower altitudes.

 

[Nick797]

Yea. That was a bad brake pad batch.

Alcon has been cagey with me about pad shape size and material.

Rotora may be my go to, I’m trying to find their pad shape to see if I can option my own pad material from hawk or Carbotech with out extra cost of custom cut pads.

I’m a fan of the hawk 5.0 and the Carbotech xp6 and xp8

Rotora has the 4 wheel kit which is nice. Skinnier than the Alcon kit (36mm vs 42mm) but still thicker than stock (30mm iirc or is it 32mm?)
And it looks like the pads are thinner on the rotora vs the Alcon. I’d like a 17mm or even a 19mm pad. It just helps insulate the pistons and Not to mention the pads last longer.

That’s what is really needed on our trucks is a thicker rotor.

If you are gonna go with Rotora, Just skip them and go right to Alibaba your self..probably will be the same exact lead time & fraction of the price.

 

[Fifty]

That is my fear. I’m trying to do research on them.
I hate that our brake options for oem wheels are limited to:
1) unknown parts from unknownsource
2) parts that are smaller than stock which trade one problem for another
3)alcon who won’t tell you pad shape to give you options.
4)…? I may just get porterfield pads and a decent slotted oem size rotor

 

[Fifty]

Okay, now I'm curious.

Obviously altitude has an effect on lots of things.... but the brakes??? How would they know what altitude they're at?

Air density. It’s significantly less at 9k feet than say 1k
If you reduce sea level ability by 20%… on a brake system that is already a weak link on our trucks.

One example that shows the issues real well is the F1 race in Mexico. The air density is so low that they have tons of power unit cooling, brake cooling issues, and they also have problems with aero/downforce issues because the lack of molecules engaging with the aero platforms.
(No im not comparing there’s brakes to f1 brakes) but its a very talked about and explained effect in that sport.

Same with engine power reduction when going up in altitude. And how lower octane gas is better than higher octane gas in high altitude low air density (I haven’t looked at tuning and logging of trx so I’ll continue putting 91 in my truck when I go to the mountains)

 

[Two]

Same with engine power reduction when going up in altitude. And how lower octane gas is better than higher octane gas in high altitude low air density...

As mentioned, lots of things are affected by altitude, I just didn't think that brakes were.

And lower octane does help our Can Ams (supposed to run on 91) start much better in the winter. Or old gas works, too.

 

[Fifty]

While I figure out what to do, I ordered a set of the Raybestos slotted rotors.

And the big debate was pads. Which pads.
I figure anything is going to be better than stock. I couldn’t get my hawk sd experience out of my mind and the fear was that the pads would suck on my daily driving use. So it made me pick the LTS pads.

Now just to wait for the parts to come in and I need to get a set of pin boots. Dang ram wants a lot for those.