Installed Roe 14" front brake kit

[Tom F&L GoR]

So......
Dave and Tom,
What are your recommendations for a 2000 with stock wheels for the street only?

A loaded question!

Depends on how you want it to look : "Classic OEM" or handsome & modern?

And how quickly you want to do it : few hours of R&R vs. getting more calipers and a little cutting and modifying.

And finally cost : frugal vs. a nice present for yourself!

I think a 2000 already has the larger diameter wheels, so you don't have any clearance to worry about, either.

 

[Tom F&L GoR]

Tom, are you saying the 38mm upgrade I got from you was actually a 40mm? I think you may have had a mild lapse... which is rare, so I had to mention something!

You got me. I'm doing my taxes and the numbers are killing me.

OEM was 36mm; early "conversions" were 38mm, currently is 40mm. Sorry.

 

[Dave's Big Brakes]

A loaded question!

Depends on how you want it to look : "Classic OEM" or handsome & modern?

And how quickly you want to do it : few hours of R&R vs. getting more calipers and a little cutting and modifying.

And finally cost : frugal vs. a nice present for yourself!

I think a 2000 already has the larger diameter wheels, so you don't have any clearance to worry about, either.

Thanks Tom

What Tom just said Bling and or MONEY

Big Brake Dave

 

[GBS]

I have an 02 ACR that I recently purchased and I want to upgrade the brakes on it so I have enjoyed really this thread for a number of days now. I love the GII Vipers but I must say the brakes really **** espcially compared to a lot of other cars. My Lamborghini Gallado has 8 piston Brembos in the front and 6 piston Brembos in the back so it stops on a time. The brakes on my 08 Z06 stop nicely although not as nice as an 08 Viper from what I have read.

I have been looking at the the 6 piston Brembo 14" Rotors in the front and 4 pistons Brembo 13.6" rotors in the back from Roe Racing. I love the 18" BBS ACR Wheels so I don't want to go to a 19" wheel.

It sounds like Dave's big brakes does offer a nice (but not as nice) more economical option that would be a big improvement over the OEM brakes.

At this point I'm still not sure what I'll end up getting but I'm definitely going to upgrade the brakes. It's good to read what other people have to say and see what's out there before making a decision. Thanks for the information and opions.

 

[RTTTTed]

My 98 GTS had the 40mm rear caliper upgrade with all Eradispeed 2 pcs rotors. It worked excellent and the previous owner said that the difference with the rear caliper upgrade was awe-inspiring. My 01 also works well with the 2 pcs rotors, but the front rotor had heat check/stresscracks and heat colored rotors. Since I bought it the colors are gone and the rotors look good again. The rear's look normal so I figured the fronts needed upgrading, not the rears. The 14" lightweight rotors from Roe are slotted and not drilled so I figure they'll be more than I need, even if I track the car.

Since my rotors came flat black and my car is Sapphire I bought a caliper paint kit in Blue. The calipers aren't obvious in flat black, but I figure the Blue will show through the Forgeline VR1's with ease.

Ted

 

[TexasPettey]

Just to add more confusion to the mix, I got this reccomendation from a friend who does a lot of closed course road events. His assertion is that there are two sepate elements: Braking Torque and Braking Longevity. Torque helps you stop faster and longevity lets you do it consistently from start to finish. They are separate. However, like suspension, changing one often changes the other.

His suggestion to check braking torque is simple. He said that you should pick your top 3 braking zones. Hit the brakes hard at speed, straight line of course. Don't worry about turn in for that lap. If you can lock up or kick in the ABS, you have enough brake torque. If you can't, you could use more. If you can lock up on 1 or 2 of your top 3, it's probably not worth it for more, since you're optimizing for a small section of the course. The rest of your zones should be easier on your brakes, and more torque won't help you.

There are two ways to increase torque: increase pad friction on the rotor & move the pad further from the wheel center. Increasing pad friction is: 1) pads with better bite, 2) Larger pads, 3) Stronger pressure on the pad. Move the pad further is a larger rotor.

Longevity is easy to look at by examining the brake wear from one event to the next and brake fade from start of session to the end. Since longevity and fade are largely about heat buildup, you can increase longevity by 1) Adding coolers, 2) Getting better rotors, 3) Increasing pad size.

There is also the element of ease of driving. Since it's not always practical to stand on the brakes, e.g. when you're doing a heel-toe, having more brakes than you need helps.

I'm checking down the following ordered list of brake upgrades. I'm on #3, and I'm able to hang with folks that have much more theoritical brakes. I'll be heading up to #4 & #5 as I learn to use more and more of what I have. Remember, as you move up in pad and rotor size, the cost of brakes goes up. I'm likely never to step up to the very expesive rotors. They are not worth the marginal improvement relative to the price per rotor.

1) Track pads
2) Front coolers
3) Basic rear upgrade (get to 80-20 ratio)
4) Larger fronts
5) Larger rears

 

[wastntim]

I still don't understand why Dodge would put matching calipers on the rears of the Gen III and IV if they are underutilized? Based upon some of the comments it almost makes the brakes unsafe!

If the antilock brakes on a gen III fail is the car going to wipe out?

Are there ANY differences between a Gen III brakes and 02 ABS vipers other than the caliper size and rotors?

 

[Tom F&L GoR]

There are two ways to increase torque: increase pad friction on the rotor & move the pad further from the wheel center. Increasing pad friction is: 1) pads with better bite, 2) Larger pads, 3) Stronger pressure on the pad. Move the pad further is a larger rotor.

I'd want to hear the explanation of how a larger pad increases brake torque. Stoptech's tech papers nicely lay out the physics and it is a function of clamping force (which is the size of the piston and pressure behind it) and the friction coefficient. Size doesn't matter.

http://www.stoptech.com/tech_info/formulas _vehicle_braking_dynamics.pdf first equation

http://www.stoptech.com/tech_info/The Physics of Braking Systems.pdf see page 4

I believe the ABS controller between Gen 2 and Gen 3 is different. I've read that Gen 2 is three channel and Gen 3 is four channel, so Gen 3 should be better. The master cylinder is the same, calipers are of course all different. Gen 2 ABS rear calipers are small, so ABS failure doesn't seem to be too bad. I hope - and maybe someone can tell us - that there is still some sort of mechanical prop valve in the Gen 3 system should ABS fail.

As for the size of the rear caliper, here is Stoptech's discussion about that:

StopTech : Balanced Brake Upgrades

 

[TexasPettey]

I'd want to hear the explanation of how a larger pad increases brake torque. Stoptech's tech papers nicely lay out the physics and it is a function of clamping force (which is the size of the piston and pressure behind it) and the friction coefficient. Size doesn't matter.

http://www.stoptech.com/tech_info/formulas _vehicle_braking_dynamics.pdf first equation

http://www.stoptech.com/tech_info/The Physics of Braking Systems.pdf see page 4

Using the papers from StopTech as a basis, I believe that it is in the coefficient of friction between the pad and the rotor. It's the same effect of a larger tire in lateral acceleration terms. If the size of the contact surface had no effect, then one could create pinsized pads and tires. In the equation sense, point pressure and contact size are inverse proportion. However, there are a lot of variables not contemplated by the equations.

 

[Tom F&L GoR]

That's kind of why I asked. A larger tire of the same compound won't make a car automatically corner faster, since it is the same weight car pushing down on the rubber. (Ignoring weight transfer, tire deformation, etc.)

And we do have an example of a pinpoint brake pad - the OEM rears! They work until they get too hot, I'm sure. Anyway.......

 

[RTTTTed]

I'd like to thank you guys for adding all the knowledge to my thread, especially the stoptech links! That my lightweight front rotors had color in them when I bought the car proves all the info in this thread.

It's good to know that I had brake uogrades figured correctly.

Thanks,

Ted

 

[TexasPettey]

Would you agree that given the same piston size and pressure, a larger pad will do better? Although, as you get larger and larger, there is an steep decline in gain.

Clearly, give the same pad size, the larger piston will do better. I was not trying to infer that it was not or that it wasn't the major contributor to braking force. Piston size and the resulting clamping force are the easiest/cheapest way to get better claming force. Higher friction pads are more expensive, don't last as long, and eat up rotors faster.

 

[Tom F&L GoR]

With the same piston size and pressure, the psi behind the piston is spread over the in^2 of pad. The surface of a larger pad will create lower psi against the rotor. But since the frictional force is {psi X friction coefficient X in^2} the slowing of the rotor should be the same. However, once you add the real world details like heat build up, wear, the temperature peaks and valleys, etc, a larger pad should do better.

And that's the key; there is a balance that can be created for that first stopping event but now maintain that balance for the 100th stopping event in a row.

 

[RTTTTed]

I decided that I'd use a caliper paint kit and paint the calipers and alum hubs Blue.

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Since I have VR1's and a Sapphire car I like the shiny med Blue much better than the flat Black.

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Ted

 

[dave6666]

Bling winter bling project bling?

Nice job BTW.

 

[SilverSnake]

I think you should of powercoated them . Won't the paint flake off with heat and time ?

 

[wastntim]

Based upon the things that have been stated, my frame of mind at this time is I would be better going to a 14" front kit and, although I could leave the rears alone, since I would like to add a little bling to the rears, I should move my fronts to my rears. Based upon the picture of the pads, this will add a small amount of additional pad size for heat dispersion, but not nearly the amount that would be added if I were to add srt calipers to the rear. Thus by increasing the front and the rear both incrementally, I am more likely not to upset the balance between the two and any small amount of imbalance I do add should be able to be managed by my ABS.

Anyone disagree?

 

[RTTTTed]

I think you should of powercoated them . Won't the paint flake off with heat and time ?

Since this is "Caliper paint" I assume it's as good as you can get, excepting powdercoating. No I don't expect they will flake off. If they do I'll post.

Ted

 

[RTTTTed]

Since I painted the fronts, I had to paint the rears as well. The larger piston calipers do not interchange with other Gen 2's in case anyone was thinking of switching (I tried). Here's pics of the painted rear ABS calipers with Eradispeed lightweight rotors. I think the pics are big enough that the wear can be seen on the rotors, with no color.

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Ted