Front caliper upgrade?

[Phil 83K20]

Funny thing about me is I like to be able to a stop…

My calipers are pretty crusty anyhow and I was toying with the idea of a more powerful braking experience. I came across Wilwood’s 140-11290 kit which is a D52 replacement bolt on caliper set that has dual 2” pistons rather than the single 2 15/16 OEM piston.

Now, I’m not a rocket surgeon but I have access to a calculator. Wilwood comes right out and says their piston surface area in these is 6.28 square inches. By my calculations, the single piston OEM has 6.77 square inches. So I’m having a hard time getting my wee brain around the idea of Wilwood’s calipers being an upgrade unless the dual piston design somehow distributes force on the pads better or maybe I’m missing something altogether and the internals of the OEM are less than they appear.

Any insight on the matter before I dump $500 on something that won’t work as well as the off the shelf reman parts is appreciated.

 

[CalSgt]

Well, doesn't the large stock piston extend past the brake pad backing plate on 2 sides? Does that surface area count in the equation?

I don't know anything about the Wilwood's or brake science but my Dad just bought a set of Wilwood calipers and 2 piece rotors for his '56 Chevy and it seems like quality stuff...

 

[Keith Seymore]

Funny thing about me is I like to be able to a stop…

My calipers are pretty crusty anyhow and I was toying with the idea of a more powerful braking experience. I came across Wilwood’s 140-11290 kit which is a D52 replacement bolt on caliper set that has dual 2” pistons rather than the single 2 15/16 OEM piston.

Now, I’m not a rocket surgeon but I have access to a calculator. Wilwood comes right out and says their piston surface area in these is 6.28 square inches. By my calculations, the single piston OEM has 6.77 square inches. So I’m having a hard time getting my wee brain around the idea of Wilwood’s calipers being an upgrade unless the dual piston design somehow distributes force on the pads better or maybe I’m missing something altogether and the internals of the OEM are less than they appear.

Any insight on the matter before I dump $500 on something that won’t work as well as the off the shelf reman parts is appreciated.

Correct.

1 - Two pistons distribute the load on the pad better.

2- The smaller pistons have a better "L over D" ratio. That is, the single piston is really short and large in diameter, which can make it more prone to "cocking" in the bore, especially once you start to get some taper wear on the pad (it just feeds on itself from there). The dual pistons are smaller diameter and longer, allowing the load to be placed more axially with less scraping on the side of the bore.

K

 

[Grit dog]

^Exactly.
Force = pressure x surface area.
In a static situation and discounting any small efficiencies or losses of a slightly different design, the force able to be applied for any given pressure is 100% a function of surface area.
It’s what Keith said that makes the difference.

However an honest seat of the pants comparison/opinion is needed. I don’t have any experience with wil wood or other upgraded brakes.

 

[Redfish]

I was just looking at these exact calipers last night. I am seriously considering trying these out. I am enjoying driving the truck all stock and so far the braking has been adequate. But this is a modification that no one can easily see and I like that a lot.

 

[Phil 83K20]

Well, doesn't the large stock piston extend past the brake pad backing plate on 2 sides? Does that surface area count in the equation?

The surface area of the inside of the piston(s) is in direct proportion to the force that can be applied with a given amount of hydraulic pressure.

So a caliper with larger piston area pushes harder than one with smaller of the brake is stepped on with the same force.

 

[Bennyt]

I bought a set for my sons truck as part of the brake upgrade and I felt was a very high quality part. They go on sale every once in awhile and I believe I paid roughly $275 for a pair unloaded through CPP 2-3 years ago. Stock calipers rebuilt will cost you almost half that so an extra $150 was well worth it. I used Powerstop Rotors/ pads from Summit. CPP Hydroboost and rebuilt the rear using the larger rear drums that came on some of the trucks. Unfortunately, haven't driven the truck yet so no feedback on that.

 

[Ricko1966]

I'd be interested in how it affected front to rear brake bias,it's something to consider.

 

[Phil 83K20]

I'd be interested in how it affected front to rear brake bias,it's something to consider.

Definitely a consideration for a straight swap without any other changes.
I already swapped the rear to discs and will be using an adjustable proportioning valve whenever I get around to plumbing.

 

[Scott91370]

Looks like they're $375 now, with pads. That's really not a bad price.

I look forward to more reviews!

 

[MrHorsepowerLSx]

Correct.

1 - Two pistons distribute the load on the pad better.

2- The smaller pistons have a better "L over D" ratio. That is, the single piston is really short and large in diameter, which can make it more prone to "cocking" in the bore, especially once you start to get some taper wear on the pad (it just feeds on itself from there). The dual pistons are smaller diameter and longer, allowing the load to be placed more axially with less scraping on the side of the bore.

K

This right here is why multi piston brakes are better then single piston setups.

I bought my set for $290 IIRC last year with pads. You will need a different banjo bolt than factory. I want to say they are 7/16-20

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[Ricko1966]

I'll address my only concern right here,and I'll let people think for themselves,do their own research and take in all the comments everyone else wants to throw in. I have done brake upgrades on several cars been more than happy sometimes,not so much others. The worst was when I was young and dumb on a Porsche which are tricky to drive fast anyway but got my brake bias off nothing a proportioning valve wouldn't cure. I've also had steering issues by using spindles recommended by millions of people on the internet,and other times things have gone great just like I expected. Think,do your research,if another 50 bucks will make things better spend it.