Bigger Discs on the Rear than the Front?

[tigeraid]

So, I'm putting together this S-10, for Autocross and maybe track days. LS/4L60E swap.

I'm gonna try my best to improve the weight distribution, set the motor back as far as possible, battery and fuel cell in the back, light hood, light rad, light suspension components, etc...

A popular swap for these trucks is the 8.8 Ford rear out of an Explorer. Stronger, beefier, better gearing, bigger axles--and also disc brakes, for the newer ones. I've got a line on a really good deal for a disc brake rear, and I think I might jump on it.

My concern though, and it doesn't seem to be mentioned elsewhere in various S-10 forums, is that the discs from the Explorer are 11.25" in diameter. Front rotors on an S-10 are only 10.5"!

I had been hoping to retain stock rotor size, at least with the first layout of the truck, because I already have a set of lowering spindles. I was just going to upgrade the calipers (Afco oversize) and pads, and cooling. Should I be worried if the rear brakes have a fair bit more braking surface? Being a pickup truck already, I'm kinda leery of having this thing get squirrely going into corners...

[SSLance]

I have been running that almost exact same brake setup on my Monte Carlo for over 4 years now. I put a 9" with Ford Explorer 11" rotors in my car and didn't change anything else in the brake system (at first). Some said I'd need to upgrade the proportioning valve to one that the Camaros with 4 wheel disc brakes use, but I never did.

My results were, with OEM type pads front and rear and the same size tires all the way around, under a panic stop situation the rears would tend to lock up just a bit faster than the fronts. Changing to 245/40/17s up front and 275/40/17s out back remedied this situation and it would brake pretty evenly.

When I started autocrossing, I ran 275/60/16 Hoosier A6 slicks all the way around and found at times it would start to lock the rears up a bit early but was able to tune my way around that a bit with driving changes and shock adjustments. Swapping Porterfield R4 pads into the front calipers tilted the brake proportioning back toward the fronts and it would brake pretty well.

Currently I'm in the process of upgrading to the 2.75" calipers in the fronts with EBC yellowstuff pads and the calculations show that will heavily swap the brake proportioning to the fronts and if the fronts start to lock up before the rears too much I'll put a more aggressive pad in the rear calipers to compensate.

My point is, I've got along with larger rotors on the rear than the front for several years, there are other ways to work around adjusting the front to rear brake ratio without having to change your rotor size only.

[lzdick]

Sounds to me like a manual proportioning valve would suit you both very well...a simple twist of the knob and you would be good-to-go.

[SSLance]

If needed as a fine tuning tool, I will go that direction.

[tigeraid]

Yeah, those Afco oversize calipers are 2.75" pistons. The stock Exploder ones are 1.89" or so. So maybe that change would be enough to offset the extra brake torque from the increased surface area out back?

[HellPhish89]

OP, this is actually something i would like to know as a few stock cars today are using larger rear rotors from OEM. dont really get why epecially if a majority of braking is on the front of the car.

i dont seem to get why its done or why it works well.

[no go nova]

How about doing the LS1 front brake swap?

[SSLance]

If you look at this chart posted in the sticky thread at the top of this forum, you will see the LS1 swap only nets one a couple hundred pounds of brake force over the 2.75" caliper on a stock rotor.

https://www.pro-touring.com/attachment.php?attachmentid=89671&d=1391546707

You can gain more braking by just swapping to a more aggressive brake pad without having to add the extra weight of a larger rotor plus cutting the stock spindles up.

Pretty good reading for anyone interested in improving their braking in this thread...

https://www.pro-touring.com/threads/104584-Brake-sizing-and-selection-tutorial-featuring-Ron-Sutton-and-Tobin-of-KORE3

[MrQuick]

OP, this is actually something i would like to know as a few stock cars today are using larger rear rotors from OEM. dont really get why epecially if a majority of braking is on the front of the car.

i dont seem to get why its done or why it works well.

I believe it has to do with vehicle weight distribution and space limitation on the rear due to suspension layouts and components.


If you look at this chart posted in the sticky thread at the top of this forum, you will see the LS1 swap only nets one a couple hundred pounds of brake force over the 2.75" caliper on a stock rotor.

ou can gain more braking by just swapping to a more aggressive brake pad without having to add the extra weight of a larger rotor plus cutting the stock spindles up.

Pretty good reading for anyone interested in improving their braking in this thread...

https://www.pro-touring.com/threads/104584-Brake-sizing-and-selection-tutorial-featuring-Ron-Sutton-and-Tobin-of-KORE3

Great points, true testing and data points are the only way to properly set up a brake system that works for you. Getting the balance of working and over working is a process.