smaller disc/4 piston caliper vs big disc/1 piston caliper

[switchblade327]

Hey gang,

I searched on this but didn't find any real comparison between these factors.

I'm rebuilding the front end of my '55 bel air and I want to go ahead and do the brakes and spindles while it's all apart. Right now it's on 2" dropped spindles with 10.5" gm discs. I want bigger and better then that but am working with ~$1000 budget.

In that ballpark, I can get a complete kit (new spindles included) with 13" drilled and vented rotors with single piston calipers, a 12" drilled and vented kit with GM III calipers or an 11" vented/drilled wilwood kit with 4 piston calipers. Obviously, I'm torn. I know bigger is better but I wonder which is more important in street-stopping duty: size or # of pistons (if you could only have one or the other)?

I'm inclined to lean toward the bigger brakes and single piston calipers since I assume they'll dissipate heat better, but then again the thickness of a smaller rotor vs a bigger one might effect this too.

The car is a '55 bel air that is going to be 95% street driven. I'll drive it hard and throw it around some, but probably nothing compared to what some of you guys do on the track for as long as you do it.

So of these options, which would you recommend for my application? Thanks in advance.

[chicane67]

I wonder which is more important in street-stopping duty: size or # of pistons (if you could only have one or the other)?

I'm inclined to lean toward the bigger brakes and single piston calipers since I assume they'll dissipate heat better, but then again the thickness of a smaller rotor vs a bigger one might effect this too.

So of these options, which would you recommend for my application? Thanks in advance.

Really.... it comes down to pad surface area. Most four piston calipers utilize larger pads and spread out the pressure over the larger area pad, making it IMHO..... a little better than a single piston. I am interested in your choices, if you are so inclined to share that.... but I would go for the four pot.

Larger rotors, in diameter offer greater leverage which is also a big help in performance as well as an increase in material..... which equals a larger 'heat-sync' to absorb and disapate heat. Thickness also has an increase in material but that alone does not effect the leverage advantage of the larger diameter. There are Pors and Cons to both..... but my money lies with the larger diameter and its torque advantage, as it still gets an increase in mass from the increase in diameter alone.

Give us what your brake options really are and we may better answer your quandry.

[switchblade327]

Thanks for the reply. Here were the options I mentioned:

13" single piston (turns out they're dual. I'd verify brand before purchasing):
http://www.danchuk.com/11_01_2_Dropped_Spindles.html#5364


12", single piston:

http://www.superiorspindles.com/chevy.html

The 11" wilwood kit I can't find the link for now, but this 12", 4 piston kit is only $200 more then the 13" kit:

http://www.superiorspindles.com/wilwood5557.html

12" and 4 piston calipers seem like they might be the right way to go for my application, as a compromise between 4 piston calipers and big discs but I welcome a more knowledgable opinion.

[chicane67]

Uhm..... the Wilwood four piston Dynalites are WAY too small for the weight of your vehicle..... heck they are even to small for a 2500lb liteweight F-body.

I'd do the Danchuck kit, if it were me. The caliper, rotor and small parts can be purchased anywhere (Ford, GM, Chrysler, Pepboys, Autozone etc) if you needed parts in a pinch. That assembly was originally used on the ZR-1 and Base Corvette models starting in 1993. Basically, it is the very same thing as the BAER "Track" kit. It would do nicely on your heavy Chevy.... LOL

Just the parts availability alone.... would sell me. For just a few more dollars (than your initial budget of $1K) will get you much more.... not just now, but later when you gotta replace a rotor or pad or piston seal. Replacement rotors are like $25.00 at NAPA.....

A couple of bucks now will save you lots later.

[Lawrence]

There are these ones as well:

http://www.superiorspindles.com/chevy.html

I was told they use an S10 spindle and can effect turning radius. I've been looking for 2" dropped spindles for my '55 that I can put decent brakes on with the rack that I hav on there and cant find any.

[ProStreet R/T]

That Danchuk setup is definitely looking like the best option. There are quite a few track day cars that use those same calipers and have no complaints at all. That and pads/parts are very easy to get even from local parts stores.

And as was stated it's the same caliper assembly used in the BAER PBR setup.

If you're handy with a mill you could likely build that whole kit for $600.

[switchblade327]

Wow, thanks for the feedback guys. What is about about the Wilwood dynalites that are bad with this car? Just the size of the pistons or something? I'm curious since it's a kit sold specifically for these cars and I know one guy with that same 12.19" setup that says his bel air will outstop his '05 GTO.

I called Danchuk on the 13" setup and they said superior made those spindles but didn't have much more info then that. They assumed it wouldn't push my wheels out any since it didn't say it would and they couldn't say for certain what the other parts were from. Do you guys just recognize those calipers or something? I'm a little leary of ordering something I have that little information on.

[chicane67]

Wow, thanks for the feedback guys. What is about about the Wilwood dynalites that are bad with this car? Just the size of the pistons or something? I'm curious since it's a kit sold specifically for these cars and I know one guy with that same 12.19" setup that says his bel air will outstop his '05 GTO.

I called Danchuk on the 13" setup and they said superior made those spindles but didn't have much more info then that. They assumed it wouldn't push my wheels out any since it didn't say it would and they couldn't say for certain what the other parts were from. Do you guys just recognize those calipers or something? I'm a little leary of ordering something I have that little information on.

The Dynalites are just plain 'MICRO' small. In reality, your friend is only saying that, because your friends BelAir doesnt come anywhere near as well as his '05 GTO. Not with that brake package. They may brake "well" in a one stop application, but I doubt they will stand up to more than one good stop from 60mph without serious performance degradation.

The other calipers are late 80's PBR two pistons. The are basically the exact same as what you would get from Baer, only with some cosmetic differences. They were OE on Corvette's, Camaros, Mustangs and the Dodge Viper.

[ProStreet R/T]

They were OE on Corvette's, Camaros, Mustangs and the Dodge Viper.

Close, never came on the Viper. They have currently, and always have had 4 piston aluminum fronts. The Gen I/II had various single piston rear calipers.

But yeah they were found on quite a few GM vehicles.

[switchblade327]

That's really weird they'd sell a kit with calipers too small for it, but that's why I'm asking here where people push their cars a little harder.
I guess the 13" kit it is.

Thanks for the help guys!

[chicane67]

They were OE on Corvette's, Camaros, Mustangs and the Dodge Viper.

Meaning that the PBR components were on these as OE components.

I should have been more specific in my statement about Chrysler's product line and that it was specifically used only on the rear of the noted application. None the less, PBR is/was OE on chrysler production vehicles.

My point was, that parts availibility isnt going to be a question when dealing with the PBR product line.

[BluEyes]

That's really weird they'd sell a kit with calipers too small for it, but that's why I'm asking here where people push their cars a little harder.

Alot of stuff in "street rod" catalogs is that way. Not trying to bash someone elses ride, but intended uses vary from one clique to the next.

How big of a rim are you going to run? In general you'll need a rim 3-4" larger than the rotor diameter. I know that's not a problem thesedays, but it is something to consider.

I would be inclined to go towards the 12" brakes, then check out Stainless Steel Brakes for their dual piston calipers which are a bolt-in replacement for the GM parts. Take the same pads, too. It looks like the standard GM 'metric' caliper and they make some pretty grabby pads for those.
My '70 Caddy does well with 12" brakes and your Bel Air is sure to be lighter.