13 inch front brake mod on pre 95/6 Vettes

[69MyWay]

I am just now finishing the 13" front brake mod to my 90. All 95/6 models got a 13" brake upgrade. It can be argued exactly the difference between a G.S., CE, or standard Vette brake option. All I can tell you is that the local Autozone only lists one size (there are different friction options) of brake pad for 95/6 models.


With that said, I was able to purchase a set of 13" VB&P rotors. The prior owner bedded the pads, then had them turned. I just applied a rust prevention agent in the cooling blades, and topped off an extra coat of black on the hub portion.

This came with a pair of 95/6 calipers with the mounting brackets and braided stainless brake hoses. It is basically a bolt on upgrade.

In the picture below, my stock 90 caliper is on the left, and the 13" caliper is on the right. It is hard to see from this pic, but the 13" variety is wider by about 1/2"

 

[69MyWay]

This is an OBVIOUS difference. The rotor on the left is the 12" stocker, and the rotor on the right is the new 13" model. The 13" rotor is bigger, thicker, and heavier. No doubt this extra width will increase the leverage available to clamp the rotor to a stop.

 

[69MyWay]

Here is a shot of the right side caliper/brake system installed. I turned the steering wheel to the left so you get get an eye shot of the unit mounted in place.

 

[69MyWay]

Here is a side shot. You will notice the black oversprayed high temp paint on the rotor surface. That will melt off the first time I stop.

 

[69MyWay]

Now here is an idea for you earlier model (pre two piston caliper guys) Vette owners.

I have not done any research on this yet, but if anybody wants to purchase my old 12" dual piston calipers, rotors, and hoses (the hoses are less than a year old) to upgrade your single piston cars, --- $100 and it is yours. The pads are in great shape (less than 5,000 miles), and the rotors were not warped when I last drove the car. They are however at or near minimum thickness.

So, if these will bolt to the one piston style vette spindles, you could instantly upgrade your braking power as well for less than you could purchase new pads and two new hydraulic hoses for your old one piston units.

 

[Vettelt193]

I am sure you will be happier with the bigger front brakes... they work much better...

As for autozone not carrying a different pad for the GS/CE, who knows why they don't.... If you check out www.hashmarks.com (hutch's page i think) there is a page about the GS/CE brakes matching up to Mustang Cobra brakes

 

[Springer's LT4]

As for autozone not carrying a different pad for the GS/CE, who knows why they don't

The front pads are all the same on 88 and up C4's regardless of the brake package.

 

[Vettelt193]

The front pads are all the same on 88 and up C4's regardless of the brake package.

Considering they offered 12 and 13 inch front brakes from 88-96, that would be quite impressive... LOL

Anyway, The pads are different in some way, I am not sure what way exactly and/or if Autozone carries a pad that works with both.

I do know, parts stores don't really have all the information they could.... I know WalMart's filter selector lists the LT5 for 1996, but no LT4:confused

 

[tntcorvette]

13" brakes are definetly the way to go. I have the Mid America Design ZR-1 brake upgrade kit with 13" "spot drilled" rotors, along with stainless steel brake lines up front.

O.E.M. rear new pads, rotors & brake lines.

13" rotors will disapate heat quicker and the larger brake pad has more braking surface to work with.

 

[twiget]

Stupid brake question

The way I understand brake systems is that they are pretty much a hydraulic caliper that clamps a rotor which is attached to the wheel/tire. When the caliper clamps down on the rotor it turns the energy of the spinning tire into heat (which is radiated out) and stopps the car. That much is easy enough to understand. What I dont get is why 13" brakes are better than 12" brakes (other than larger surface area means better heat dissipation).

From what I understand, 12" brakes have enough power to lock the wheels of a car fairly easily, which is why we use ABS systems. The larger 13" brakes would lock sooner than with 12" brakes and require more use of the ABS system.

It seems (to me anyway) that stickier tires would make the car stop faster/better than bigger brakes. Because whats really happening is when the brakes lock the tires, they are essentially over comming the tires grip on the road, and forcing it to stop rotating. If the tire was more sticky, it would take more force from the brakes to reach the locking point, thereby giving you more control and possibly a faster stop under heavy braking conditions.

That being said, with all things being equal, except larger brakes, the car still stops quicker. Whats missing in my theory?

Any takers?:L

Jason

 

[Vettelt193]

that is true as long as the brakes are not overheated.... even driving around town can make brakes too hot.

I have had both 12 and 13 inch front brakes: the 12 inch were on a '93 with a 255/45/17 tire up front. On a clean, dry road the tires would not lock up (no ABS activation) no matter what you did.

The '96, with a 275/40/17 front tire and 13 inch brake, will activate the ABS on a dry road.

so... if you can get the tires to lockup/abs activate, sticky tires will help, if you can't they won't do you any good as far as stopping is concerned.

 

[Springer's LT4]

Considering they offered 12 and 13 inch front brakes from 88-96, that would be quite impressive... LOL

Might want to do your homework and call around from brake pads for the front of 88 to 96's... regardless if they are a 12 inch or a 13 in setup, they all use the same pad. The main benifit of the 13 inch setup is for heat only... the pads contact area is no larger on the J55 setup.

 

[69MyWay]

Jason,

You must take advantage of the first possible opportunity to autocross eyecandy. It won't take you long to get a real apprecation for brakes, and the differences between them. Plus, you will get a first hand experience at overheating your brakes if you push the car too hard.

You will be amazed at how all the technology on your car starts to go into action during the extreme driving conditions at speeds under 60 mph! Top end is great, but turning, breaking, and keeping it between cones under WOT will be the biggest thrill of your automotive life!

 

[No Go]

Or in a 45 minute period, you complete 23 laps hitting over 125 on front straight braking down to 55 mph and 110 on back straight down to 60 and finally 105 down to 45 on the short shoot...then notice all the cracks in your rotors in the pits.

Heat capability is one key...

 

[SR94]

The 13" rotors are thicker in addition to larger diameter. This adds up to better heat dissipation and are less prone to overheating. The pads are identical, and I believe that the pistion area is the same, so this means that the clamping force is no different than the 12" rotors, but since the calipers are mounted further outboard on the 13" rotor, they provide more stopping force by virtue of having a bigger moment arm.

Steve

 

[69MyWay]

The 13" rotors are thicker in addition to larger diameter. This adds up to better heat dissipation and are less prone to overheating. The pads are identical, and I believe that the pistion area is the same, so this means that the clamping force is no different than the 12" rotors, but since the calipers are mounted further outboard on the 13" rotor, they provide more stopping force by virtue of having a bigger moment arm.

Steve

Yep, I agree.

You see, when I have autocrossed this car in the past, my brakes would go away on me after I got them hot and I would loose the abilit to run deep and hot into the curves towards the end of the course. I am hoping this larger design will give me more time to have solid brakes with less heat fade.

 

[kfehling]

The main reason that larger brakes stop a car better than smaller one is based upon physics. Essentially the farther out from the center of mass (in this case, the brake rotor), the easier it is to stop. Swept area, better heat dissapation all play a role too, of course, but everything plays a part and one of the biggest is the size of the rotor. However, you start to worry about other factors creeping in and playing a role as you increase rotor size such as unsprung weight.....

 

[Jeffvette]

I'll toss in my two cents on the brake upgrades

For the 84-87 guys, the best bang for the buck is going to the C5 setup. The cost is actually cheaper or near the 13" GS update kit.

For the 88-94 guys, If you're just looking to make your calipers look better and get the GS brakes.For performance, going to a completely different aftermarket set up is better. The marginal difference between the 2 piston 13" and the C5 13" system isn't very noticeable.

Hence this is what I've done. Hopefully the URLS work, if not cut and paste into your browser.

Initial picture of caliper. Nice and shiney
http://www.corvetteforum.net/c4/jeffvette//im002681.jpg

Inside of caliper showing 2 of the 4 pistons
http://www.corvetteforum.net/c4/jeffvette//im002682.jpg

Other side of the caliper
http://www.corvetteforum.net/c4/jeffvette//im002683.jpg

Elongated view from the top
http://www.corvetteforum.net/c4/jeffvette//im002684.jpg

Mounted Driver side, and yes the rotors need cleaning. Been sitting for a while
http://www.corvetteforum.net/c4/jeffvette//im002685.jpg

View looking straight down
http://www.corvetteforum.net/c4/jeffvette//im002686.jpg