Twin caliper on Renault Laguna BTCC cars

[MadMatt]

Hello guys !

I remember that the Renault Laguna BTCC had a twin caliper setup. I cannot find any pictures of it. As I remember it was used as a sort of "abs" system to prevent the wheels to lock, but does anybody has actually the real meaning of this with some more technical information about it ?

The car in question is this one :



Thanks in advance !

[Arunas]

AFAIK this is not Megane

[747heavy]

the car in the photo is a Laguna BTCC
the BTCC Lagunas where built and raced by Williams

The twin front caliper layout was "in fashion" for a while in Supertouring cars.
Here a similar layout on a Honda Accord



I think later cars, including the Laguna, did not use this layout.
(I´m not 100% sure why, perhaps a rule change, limiting max. pad area)

It was used for different reasons.
Some of the reasons

- increased pad area
- higher stiffness then mono caliper with similar pad area
- to balance force/torque from braking around the upright

[747heavy]

you find them today (for different reasons) on the rear axle of some pro drift cars.

[747heavy]

and an old F1 layout, in the early days of carbon brakes

[Caito]

I'd bet that on drift cars its sole purpose is handbrake,

[MadMatt]

Awww stupid me, of course its the Laguna.

Thank you 747 heavy for the infos ! I bet it would be impossible to find any technical paper from a team using this stuff, but who knows ! Would be nice to know what the teams really wanted to achieve with this !

[747heavy]

IIRC there where some articles about the layout in Race Car Engineering and/or RACE TECH magazine, back in the days when it was popular.

So if you have access to the back issues from ~1994-1996 it´s maybe worth a try.
As I said, for a while it was quite popular in Supertouring cars.

[MadMatt]

Yes, I will try to see if I can find those magazines. I remember there were also used on the Lotus 79 cars at the back, more than 30 years ago !

[RacingManiac]

I remember in Donington Museum seeing many of the old McLaren in the 80s run twin caliper....

Might be the old days you can't machined the multi-piston monoblock caliper like we do today?

[matt21]

In F1 you´re only allowed one caliper with 6 pistons and two pads per wheel.