Willwood Vs. Brembos

Continued from pulsating brake thread .... Thinking new rotors and pads... but i am contemplating new calipers. $1200 for Willwoods and $1500 for Brembos. I have 3 questions.

 

1) Is it necessary to get new calipers?

 

2) Can the seized, destroyed brembo bolt problem be prevented by replacing the standard steel bolt in the aluminum caliper with an aluminum bolt in an aluminum caliper? it would make sense.

 

3) Has anyone heard any reason NOT to buy the Willwoods?

1) No

2) Don't know

3) No

That about covers it.

LOL. Another plus for the WIlwood is cheaper pad and rotor replacement costs

Continued from pulsating brake thread .... Thinking new rotors and pads... but i am contemplating new calipers. $1200 for Willwoods and $1500 for Brembos. I have 3 questions.

 

1) . . . . . .

 

2) Can the seized, destroyed brembo bolt problem be prevented by replacing the standard steel bolt in the aluminum caliper with an aluminum bolt in an aluminum caliper? it would make sense.

 

3) . . . . . .

 

 

Aluminum bolt on a mission critical component in a daily driven street application???? This does not make "sense". It is also not sound engineering.

 

Aluminum has far less strength than steel on a volume for volume basis (meaning same sized fastener). This affects the load carrying capability in several ways. First, the shear strength of the bolt would be far reduced, not a good thing in high load environments like the suspension or brakes.

 

Second, as most bolts are not interference fit, they do not have to rely on shear strength alone, but rely on the compressive force between two components due to the tension produced in the bolt. The friction provided by the clamp force is actually what holds the pieces in position relative to each other, unless some type of dowel pins or interference fit components/fasteners are used. Because aluminum has a lower shear strength, the tensile load on an aluminum bolt would be lower than on its steel alloy size equivalent, as the threads themselves are the region of the fastener exposed to shear forces. Now you have the combined problem of decreased torque on the bolt head (to avoid shearing it off), and the lower tensile load allowable overall, which will result in a decrease in the clamping force.

 

Third, aluminum under load will undergo stress relaxation, requiring constant re-torquing until the failure limit of the material (no problem in a race application, strip it down and replace it), whereas steel based alloys undergo work hardening and properly selected, will last the life of the vehicle or machine.

 

Fourth, although the anodized coating on aluminum will decrease galling between like components, the surface treatment can only undergo so many stress cycles before it fails and native metal is exposed. If you think steel and aluminum is bad, aluminum on aluminum will gall far worse (cold weld, microscopically) and your chances of shearing off a fastener will be greater, the longer it is left without being serviced. (No problem, just buy shiny new ones every time you service your vehicle, preferably weekly, the bolt maufacturers will love you).

 

The preferred solution is to use an anti-seize compound with corrosion prevention properties on disimilar metals, or better yet, an insert, of which there are several types. One of these is a helicoil, which is a popular and easy repair solution, and is often mentioned on this site. My preference is to use something more substantial in a situation like this:

 

http://alcoafastener.thomasnet.com/category/keenserts-reg-inserts?&plpver=10&bc=3001584|1041

 

For safety's sake, just say no to aluminum bolts in your suspension or brake systems.

LOL. Another plus for the WIlwood is cheaper pad and rotor replacement costs

 

I had the impression Wilwood didn't use dust seals so the calipers had to be rebuilt every 10k to 15k miles.

I had the impression Wilwood didn't use dust seals so the calipers had to be rebuilt every 10k to 15k miles.

This was covered awhile ago but I think I remember reading that because the Wilwood uses SS pistons, there's no risk of rusting or corrosion. Of course, this topic had it's defenders and it's opposition. Some threads here:

http://legacygt.com/forums/showthread.php?t=89776&highlight=wilwood

and here:

http://legacygt.com/forums/showthread.php?t=96941&highlight=wilwood

and here:

http://legacygt.com/forums/showthread.php?t=97210&highlight=wilwood

But rust and corrosion aren't the same are dirt/grime binding the pistons. Whatever. Just wanted to point the matter out.

Stoptech

You are more likely to find a set of used Brembos than any other make, but if you are buying new, Brembos don't make financial sense.

Brembos weigh quite a bit more than the Wilwood's, right?

Aluminum bolt on a mission critical component in a daily driven street application???? This does not make "sense". It is also not sound engineering.

 

Aluminum has far less strength than steel on a volume for volume basis (meaning same sized fastener). This affects the load carrying capability in several ways. First, the shear strength of the bolt would be far reduced, not a good thing in high load environments like the suspension or brakes.

 

Second, as most bolts are not interference fit, they do not have to rely on shear strength alone, but rely on the compressive force between two components due to the tension produced in the bolt. The friction provided by the clamp force is actually what holds the pieces in position relative to each other, unless some type of dowel pins or interference fit components/fasteners are used. Because aluminum has a lower shear strength, the tensile load on an aluminum bolt would be lower than on its steel alloy size equivalent, as the threads themselves are the region of the fastener exposed to shear forces. Now you have the combined problem of decreased torque on the bolt head (to avoid shearing it off), and the lower tensile load allowable overall, which will result in a decrease in the clamping force.

 

Third, aluminum under load will undergo stress relaxation, requiring constant re-torquing until the failure limit of the material (no problem in a race application, strip it down and replace it), whereas steel based alloys undergo work hardening and properly selected, will last the life of the vehicle or machine.

 

Fourth, although the anodized coating on aluminum will decrease galling between like components, the surface treatment can only undergo so many stress cycles before it fails and native metal is exposed. If you think steel and aluminum is bad, aluminum on aluminum will gall far worse (cold weld, microscopically) and your chances of shearing off a fastener will be greater, the longer it is left without being serviced. (No problem, just buy shiny new ones every time you service your vehicle, preferably weekly, the bolt maufacturers will love you).

 

The preferred solution is to use an anti-seize compound with corrosion prevention properties on disimilar metals, or better yet, an insert, of which there are several types. One of these is a helicoil, which is a popular and easy repair solution, and is often mentioned on this site. My preference is to use something more substantial in a situation like this:

 

http://alcoafastener.thomasnet.com/category/keenserts-reg-inserts?&plpver=10&bc=3001584|1041

 

For safety's sake, just say no to aluminum bolts in your suspension or brake systems.

 

Thanks for the intro to materials, thermodynamics and structures. I must have been absent on structures, thermodynamics and materials day back in med school.

I had the impression Wilwood didn't use dust seals so the calipers had to be rebuilt every 10k to 15k miles.

 

is that really true? that seems like a hassle...

See links in post 7

See links in post 7

 

This can be debated back and forth. Bottom line is the pistons in the Wilwood are far superior to stock. It isnt like pebbles and rocks are going to get in there.

 

Stock calipers are typically made out of aluminum or some type of metal that can corrode. Wilwood pistons are non-corroding stainless steel. Not to mention dust boots typically get torn in regular street use and if you track your LGT at all, they will tear or melt.

I've had the dust boots on my stock front calipers melt from the high temperatures generated by repeated hard breaking on track. I've replaced them only to have them melt again next track outing so have given up on replacing them.