Alcon brakes with 3 pistons?!?

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Sep 30, 2016 | 10:02 AM

#16

LetsGetThisDone

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From: Las Vegas

Quote:

Originally Posted by GTijoejoe

Its very interesting design, I've never seen.
I'm going to ask one of my colleagues who use to design actual calipers for Indy, champ car, F1 applications if he has a thought.
I doubt it is lighter from a mono block radial mount caliper.
This design loses 3 pistons, however the bushing and brkt setup likely over comes that weight. There is always a trade off between caliper and knuckle... it would be interesting to investigate that more.
Because the caliper body is what it is, fitting it in the wheel vs fix would make no difference.

My guess from my experience is likely the environment of rally and wheel offset/size.
In snow applications (and maybe even mud/dirt

) the ice will lock a fix caliper pretty good. We see this in winter test for supercar applications. A floating caliper because of the motion will break the ice loose (generally)
Given the packaging of the wheel offset, the outboard bank loses the pistons, so the caliper can be narrower in that section to provide clearance to the wheel.

That's a lot of material off the caliper, especially the big stainless pistons. But yes, the floater bracket probably adds the weight back now that I think about it more. Wheel clearance definitely makes more sense. Especially gravel and/or snow wheel packages.

Sep 30, 2016 | 10:22 AM

#17

GTijoejoe

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From: Ohio

Quote:

Originally Posted by barneyb

Driving my Evo hundreds of miles in horrible winter weather conditions, conditions where I worried about the total weight of the vehicle due to ice and snow accumulation, worried about engine cooling because the entire front of the vehicle was encased in ice and snow, where I worried about even being able to exit the vehicle due to how the doors were iced up, no wheel imbalance and no braking problems. So, I'd suggest the fixed caliper installation on the Evo has no winter weather related problems when used with stock size wheels.

The only real problem I encountered on the above mentioned trip was seeing as the wipers kept freezing up and not working. Everything else, not a problem.

On your trip my friend, how cold was it? Temperature will significantly change how snow/ice develop.

Luckily for us Mits already did winter testing and we assume it passed

There are many many factors to winter testing. Driving conditions to normal people for hours on snow packed roads is much different than driving a car through a 6" of slush box in weather 0F maximum and through various terrain consistantly, where the focus is to gain hundreds of pounds of ice weight on the chassis.

Generally, fixed calipers are typical to lock in winter OEM testing. This is a known fact in the brake industry. Mits OEM caliper is different than a rally car and so is the wheel, suspension, knuckle.... all of which will effect the snow and ice build up, not to mention the vehicle usage environment.

I agree that our OE vehicle and parts as is should be fine

I provide this info for insight and better understanding

In addition, my colleague mentioned this caliper's intention for design is for wheel offset packaging. He is familiar with this setup.

Sep 30, 2016 | 11:39 AM

#18

barneyb

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From: Grand Island, NE

Quote:

Originally Posted by GTijoejoe

On your trip my friend, how cold was it? Temperature will significantly change how snow/ice develop.

I don't know what temperature. My wife and I had taken refuge in a motel on I-25 at Windsor, Colorado. We got so much snow there the motel staff was given rooms at the motel. It snowed every day we were there. So, we drove snow each day locally (gotta love the ability of an Evo with snow tires). After four days of that we decided to break East for home. The first part of the trip was cold with snow and drifts on the highway. Then after we passed through a front it continued to snow but now there was slush on the highway, the ground on this side of the front was warm but the air was below freezing. At first on I-80 there were no East bound trucks but once they appeared in abundance the ice bath commenced. Here's a picture taken after we returned home and after the vehicle had been through a car wash.

I think the secret of the Evo is the small clearance between the wheel and caliper. That knocks off the ice and keeps the wheels from going out of balance.

I'm not doubting what you say about brakes in general but only that this vehicle seems immune.

Last edited by barneyb; Sep 30, 2016 at 08:02 PM.