Why do our brakes suck?

[DEFYANT]

I posted this in another thread that did not get any reaponse.

We have the same brakes as the CVPIs, right?

Since I installed the new Baer brakes, I noticed how nice the MM stops. I also notice that my CVPI really took a beating the other day and the brakes never faded or warped. I have really put the CVPIs I have had to the test and never caused the brakes to give out. They do tend to run through a set of pads ever 20K or so. I began to wonder why the original MM brakes did not seem to be up to the same task with the comparable Marauder.

Then I realized. The MM has 18inch rims, the CVPI has the standard 17inch steel wheels.

Could the difference simply be in the leverage the larger wheels have under severe conditions?

Thanks<!-- / message --><!-- sig -->

[shakes_26]

Well, not an expert, but there are several factors here that come to play.

The larger diameter as you mentioned does play into it, thats why those idiots with 22" rims and oem brakes are rolling death traps.

Secondly rotational mass,I dont know the weight diff, betwen the CVPI rims and the Marauder, but if ours are heavier, this will require greater breaking force to slow down the the spinning mass of tire/wheel thus less effective braking

Okay so lets get physical, physics that is. I'm gonna simplify this down to make it less than a full college level dissertation. Basially the rotational mass, can be looked at as the moment of inertia. Which is defined by I = m*r2

where I = Inertia, m = mass, and r = radius. So any change in the radius (half the diameter) will make a larger percentage difference than the mass

In other words, bigger diameter has more effect than heavier, as far as the inertia is concerned.

I mistakenly referred to unsprung weight earlier, different problem, but it sort of plays into this as well.

Anyway thats the basic explenation, I'm sure someone will go off and weight the tire/rim combos and you can then plug them into the formula for comparison.

[merc6]

not just the size of rim...but the weight of the aloys vs the steel rims also comes into play.

*edit too slow* :(

[SergntMac]

Added together, the extra weight of the wheel and the tire could be twice that of a CV/PI assembly. Now, X that by four corners, and the Marauder is doing a lot of braking.

[mrjones]

[QUOTE=SergntMac]Added together, the extra weight of the wheel and the tire could be twice that of a CV/PI assembly.

Are you saying that you think the CVPI steel wheel and tire weighs more than the aluminum Marauder wheel and tire? I have absolutely no data on it, but I would've guessed the aluminum MM wheel is lighter than the steel wheel. The rear MM tire weighs 4lbs more than the standard CVPI 16" RSA, but I would think that the steel wheel would more than make up for that difference.

[ckadiddle]

Heck, I just figured our brakes kinda suck cause Ford cheaped out on them. I figured they engineered the cheapest possible way to be able to say "four wheel disc brakes" on the marketing material.

[shakes_26]

see my detail explenation earlier in the thread

basically for the same weight a taller (larger diameter) wheel/tire will have more inertia, and therefore require more braking force to counter act it.

[cyclone03]

The other factor is not so much the TOTAL weight of the tire/wheel package it's the LOCATION of that weight.

An 18" wheel/tire with 5 long spokes puts more mass farther from the center of the wheel than a steel wheel ass'y.That greater mass farther out puts more leverage(torque) on the brakes than a smaller set up.

I think the term is Polor Moment of Inertia.

Yes it's all still unsprung weight,and less is better,but if you need more mass it's better if it's close to the hub center.

[cyclone03]

:)
see my detail explenation earlier in the thread

basically for the same weight a taller (larger diameter) wheel/tire will have more inertia, and therefore require more braking force to counter act it.

Damn you fast typers!!!Beat me by 2 minutes.
:)

[shakes_26]

:)

Damn you fast typers!!!Beat me by 2 minutes.
:)
an hour and two minutes :)

Oh and the Marauder wheel weights 22lbs, the CVPI steel rim weighs 19lbs.

Dont ask me about tires, but using our formula the Marauder has an additional 47 lbs-ft of rotational inertia, if we add in the tires it gets worse. So thats why our brakes 'suck' versus CVPI, they have to work much harder to slow the wheel/tire combo.

Hey Charlie, that answer your question? :D

[Rider90]

I've been riding steelies for awhile now and I have not noticed a decrease in the crappiness of my brakes :dunno:

[Petrograde]

the rear wheel with the OEM tire weighs 63 lbs.

[baltimoremm]

not to hijack this thread, but i was curious how long/how many miles the baer brakes are lasting as opposed to OEM? and has anyone measured the stopping distance of each?

[DEFYANT]

not to hijack this thread, but i was curious how long/how many miles the baer brakes are lasting as opposed to OEM? and has anyone measured the stopping distance of each?

I dunno, but when my Baer brakes are broken in, I will find out.:D

Thanks for the responses. Sure makes sense.

[cyclone03]

an hour and two minutes :)

:D


That's wierd,your post was'nt there until after my reply posted.
Time warp maybe???
Time Zones?
Oh well.

[bugsys03]

I never thought my MM brakes sucked, I did think that there was a lot of travel in the pedal. Now that i have the Brembos, ANY other car I drive the brakes suck :D

[SergntMac]

Tire Rack says a stock rear tire for a Marauder weighs 32 pounds.

UPS says a Marauder wheel weighs 28 pounds tare, 31 pounds packed for shipping.

Petrograde is right on the money ^ there, except for one question.

Tom...Just how much does 36 pounds of Texas air weigh?

LOL!

Stuff to keep in mind here folks, about steel wheels vs. aluminum wheels, is strength vs. mass. Ask yourselves these questions...Please?

How big of a box will I need to pack a cube of steel that weighs exactly one pound?

How big of a box will I need to pack a cube of aluminum that weighs exactly one pound?

What does a one inch cube of steel weigh?

What does a one inch cube of aluminum weigh?

How large will a cube of aluminum have to be, to match the strength and durability of a cube of steel weighing one pound?

If you do this "light weight" math (excuse my pun), you'll see that steel wheels are lighter than cast/forged aluminum wheels of same size, and the are not only stronger in same size, but take up less space too.

However (and this is a big however), steel wheels are not as pretty, and I do not believe any of us would have found the Marauder attractive, if L.M followed science when looking for the most efficient way to build a Marauder.

Haven't noticed any aluminum wheels on any NASCAR type cars lately, have y'all?

[fastblackmerc]

Haven't noticed any aluminum wheels on any NASCAR type cars lately, have y'all?
Do we know what Toyota will be using???

[SergntMac]

Do we know what Toyota will be using??? No.

But I'll bet you 50 bucks they won't be aluminum.

You in on this Gentleman's bet?

[looking97233]

There is one difference in the brakes of a CVPI vs. other Panther cars...

The CVPI gets a different pad compound, more agressive.

Rod.

[Todd TCE]

Pad Cf change, rotor OD and piston area all effect the torque values.

Play with the bias calculator.
http://www.tceperformanceproducts.com/brake_bias_calculator.html

[wesman]

Todd what are the meanest pads I could put on your 13" kit for track only? Something that would last at Road America.

[Todd TCE]

Todd what are the meanest pads I could put on your 13" kit for track only? Something that would last at Road America.

Narrow bodied sixes are a bit more limited in choice for track duty pads:
Poly A, B, and H are the choices.

http://www.tceperformanceproducts.com/pads.html

A will eat rotors if you run them too cold.
B ramps up well and is 'standard' in my Lightning kit even.
H works well when hot and is not as abbraisve as A

Keep in mind that all these are 16mm pads. Meaning life is not as long as those calipers with 20mm pads found on other kits.

[merc6]

what was the marauder disc sizes?

[wesman]

Narrow bodied sixes are a bit more limited in choice for track duty pads:
Poly A, B, and H are the choices.

http://www.tceperformanceproducts.com/pads.html

A will eat rotors if you run them too cold.
B ramps up well and is 'standard' in my Lightning kit even.
H works well when hot and is not as abbraisve as A

Keep in mind that all these are 16mm pads. Meaning life is not as long as those calipers with 20mm pads found on other kits.

What would be your equivalent to a Hawk Blue or Hawk HT10 up front.
Plus what would I use on the backs to keep up. Right now Road America eats 1 set of rears per day of either hawk HPS or stockers.

[Todd TCE]

Personally I'd say the H is your best tried and track proven choice.
http://funkadelic.org/i/misc/wayot/sjgp/GX4A4305.jpg (never faded)

As for rears, can you do HP+ on them?

[wesman]

No HPS is as good as it gets for the MM from Hawk. If I went to your 13" rear kit what is available?
http://www.wessumner.com/videos/roadamerica2.JPG
Big time fade!

[Todd TCE]

No HPS is as good as it gets for the MM from Hawk. If I went to your 13" rear kit what is available?
http://www.wessumner.com/videos/roadamerica2.JPG
Big time fade!

That doesn't look good at all!

The rear kit would allow you all the pads on the pad page.
E would probably hold up well. Hardcore, jump to C maybe but might prove too much bite.

[studio460]

I've been riding steelies for awhile now . . .Why are you running steelies? I've been thinking about changing to steelies 'cause, oddly enough, I actually like how they look (and I've never found ANY black rims that fit that I liked) Now, I have a performance reason to change to steelies as well. Steelies only come in 17", correct? No 18" steelies, right?

[Rider90]

Why are you running steelies? I've been thinking about changing to steelies 'cause, oddly enough, I actually like how they look (and I've never found ANY black rims that fit that I liked) Now, I have a performance reason to change to steelies as well. Steelies only come in 17", correct? No 18" steelies, right?
It snows here. Steelies are 16"

[ex00p71]

06+ plus steelies are 17"