PE Engineering’s Innovative Easy to Install Pedal Box

PE Engineering's Racing Pedal Box: The Easy To Install Pedal Box

by Mike Kojima

When building a race car, the only way to get true brake proportioning is to install twin master cylinders and a balance bar. If you are not familiar with this sort of setup, we're talking about having a master cylinder for the front brakes with a separate master cylinder for the rear brakes.  The brake pedal activates both master cylinders at once through a threaded rod or balance bar.  As the balance bar is turned, the brake pedal's fulcrum point moves right or left which gives the brake pedal more leverage on the front or rear master cylinder thus adjusting the proportioning. 

This, unlike hydraulic valves used on production cars, changes the slope of the brake bias curve where a hydraulic proportioning valve only changes the line pressure around a knee point.  To get a racing dual master cylinder system in your typical car requires hanging pedals and master cylinders from a bar on the roll cage or from a fabricated and reinforced area of the firewall if you want top hung pedals.  If you want bottom pivoting pedals, a pedal “box” has to be constructed to mount the pedal and master cylinders assemblies in. 

Although this is SOP for an experienced race car builder, it is a lot of fabrication and beyond the skills of many home builders. When installing a racing pedal assembly in a unibody production car, you also have the issues of trying to install a highly leveraged part that generates a lot of force into a shell of thin sheetmetal. You want pedal boxes and pedal assemblies to be very solidly mounted as flex in any of the the brake system greatly reduces brake feel and even braking power!

 

PE Engineering's pedal assembly is a pre fabricated self contained pedal box that is ready to mount.  Basically just drill holes, bolt in and go.  

The bracketing completely contains the pedals, pivots and master cylinders for the brakes and clutch.  The box assembly is lightweight and very stiff using FEA and a lot of common sense by making the loads push right into the cylinders and the heart of the brackets.  The whole assembly is quite light weighing in at 7.7 lbs complete cylinders and all!

 
The PE Engineering pedal box comes with a front brake master cylinder with a 0.625″ bore, a rear brake master cylinder bore of 0.750″ and a clutch master cylinder with a 0.750″ bore. The cylinders are all contained within the boxes footprint. 
The throttle pedal has an adjustable motion ratio, a built in positive stop and adjustable pedal pads. The pedal box assembly is made of CNC machined, tig welded and anodized 6061 aluminum.  The pedal pivots are all made from lightweight titanium. 
The PE Engineering pedal box is mounted via these two widely spaced swiveling mounting feet.  You can bolt these to a unibody sheetmetal floor with several M6 bolts and have a very stiff mount without a lot of fabrication!  This is perhaps the PE Engineering pedal boxes greatest feature. Most other pedal assemblies only have a tiny, highly leveraged mounting pad and need a flat, reinforced surface to be mounted on. 

 

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