Technical Under floor brake pedal instal?

Anyone ever put this set up in? How do I know where to locate the pedals? How much of the curved part should come through the floor? I have looked, but haven't found what I am looking for. I believe that the straight part of the pedal should run in the same plane as the angle of the floor, please correct me if I am wrong. There is also a clutch pedal also.

 

In my 49 international pickup we put the pedal in a similar location to the factory pedal. Which ended up between the fuel pedal and column. On ours a lot of the curved area stuck through the floor at first. Now we did end up adjusting it down so that the pedal didn't come up so high. Basically we had full pedal travel too high above the floor. The curved area allows like 6" of possible travel through the floor and we only needed like 4" of travel.

In the picture your pedal looks like it's 90 degree to the floor. Ours ended up being more like 45 degrees to the flat part of the floor. Otherwise it's really awkward to use.

Not sure if that was anything but garblety gook.
-Jeremy

 

I am going through the exact same thing. Making pedals from scratch. Been racking my brain trying to figure it out. I believe the curve of the pedals should be 90 degrees to the angle of the floorboards where they are going through. Hopefully others will offer up some info.

 

Check out this picture I lifted off the chassis engineering website (model A). You want a curve on the pedal arm so the actual pedal and remains constant relative to the floor board throughout its travel. The pedal ratio plays an important role also which I would research before committing to a design. Good luck!



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I forgot to mention that on my roadster the lower part of the curved pedal arm is roughly parallel to the toe board at resting position and only the top curved section protrudes through the floor.


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Oops. Knee jerk responses on my part. I didn't look at the pic. You already know what's going on. Sorry. I'm guessing that the manufacturer left the pad end of the pedal long so that it can be cut down to fit if necessary. If I'm wrong, someone please correct me.


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What pedal arm assembly is that?
Is it something you bought and are trying to make fit, or is it something you fabbed?

 

I bought the clutch brake pedal from Welder series. I will bend it if I have to. This kit lets me put the booster up to 20 inches back.

 

Well if it's power brakes, you wont/ shouldn't need 6" of that travel, ie curve thru the floor. But that depends on what pedal ratio is built into it.
and with a long rod you have options.

 

Ideally you should figure out where you want each pedal and work from there back to the MC. Spend some time and get it right, and you'll be a happier motor vehicle operator..

 

BBC b


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Something doesn't look right about that.
I'd like to see the pivot higher/closer to the flat part of the floor.
Regardless...the pedal pivot should go in line with the toe board.
Basicly you project a line or a straightedge along the angled toeboard and this line should pass thru or as close as possible to the pivot point location.
It just makes things go smoother that way for me anyway.
Doing it like that also makes it easy to seal to the floor by using a disc welded to the curved part (under the floor) and you can add a felt washer to seal it completely/act as a return stop, when the brake pedal is at rest.

 

That looks a lot like my '42 Faro truck. Do you have the original pedal assembly to work off of?

 

Most importantly, it should bottom out on MC and NOT the floor!

 

Basically pedal should bottom out at master cylinder not the floor. This insures full travel of the master cylinder.
pedal ratio about 6:1. pedal travel has no obstructions. Pedal between gas pedal and steering column. Try not to have to lift your knee to your chin to step on the pedal also make sure the pedal allows master cylinder to return fully.
hope this is helpful..

 

Fortunateson, I do not have the original pedals to work off of, and it is a 1937 Dodge. Hackerbilt, you think the pivot should be at the toe board, I would have to move it up past the top of the frame. Does anyone have a pic of there pedal setup in there car, or truck? Pics of the floor would be nice to. Believe it or not those pics are hard to come by. I think I have it close to the position I need, now for the fine tuning. I do have the seat in the truck, but I don't have the floor pieces, so I am just putting boards where I think they should be. I will take a pic of where I am at today.

 

There's no way to get a good picture of this, unless there's a cutaway or artist's conception.

Not all brake pedals are equal, a small jog in the pivot end can change everything.
It can make the master higher or lower in relation to the frame.
Depending on the design and placement of the loop to master can change the amount of stroke and it can cause a stroke ratio that changes if it's not optimal or centered.

The best way is to draw this up full size to see how the arcs work, pedal position changes, and the master gets activated

 

Maybe another way to do this is look at a similar set of pedals installed on a vehicle and draw it up full size like 31Vicky says above, based on what is actually happening with those pedals. Then you could map those actual (likely) factory mechanics onto your setup and make sure it functions. I am about to hang a set of F1 pedals in my AV8 project. I will try to post a picture later.

 

These two are very similar, right?



See how the slight jog changes a whole bunch of geometry. Each one has its place where it will work better than the other. Similar but very different

 

I agree on laying everything out, and I believe that I have the right pedal ratio, for power brakes. I am mainly looking for location, like where it comes through the floor. Do I have to build a mount to get it up higher?

 

Then lay it all out- draw it up.
You'd instantly pick up the problem here.

When I look at this picture I see the pivot needs to come up ( closer to the horizontal floor board). a lot,

the pedal pads motion is loosing more than 1/2 of its travel





From your layout,
What's the required pedal motion to fully stroke the master?

Where's the optimal location for the master loop attachment? Do you have that where it needs to be.

In your layout you can see how the degrees of rotation and travels in arcs translate into linear motion.

 

I don't have a master cylinder yet, so I don't know the stroke, but I am running 4 wheel disc from a Jag. I figured that I could mount the m/c after the pedals were mounted. These are the things I didn't know to ask.

 

Man...looks like you will be pressing the brake with your heel to me!

The pedal ratio is preset for you so we can ignore it. (I bet I get jumped for saying that! LoL)
Sit in the car and have a friend measure up from the floorboard location (allowing for floor covering thickness of course) to determine where the pedal pad should be to make brake operation comfortable and allow the full range of lever motion required, before the pad bottoms out on the toeboard.
Keep in mind that the pedal pad and lever should move in an arc that is comfortable to use.
Thats really the most important items to address in all this...other than the already locked in lever ratio of course.

 

another thought mount on the firewall as in hanging pedals.

 

I moved the pedal up as high as I could, without it coming through the floor, and it still looks like it is to low. I know my pedal ratio is 4.5 :1. Looking at the pedals that 31Vicky put up, is it possible to get a taller pedal with the same ratio. I believe that this would help. To me the pedal seams short. I am looking to keep the firewall clean, so putting a m/c there is not a option. To me the pedal should go up.

 

Pedals come in all sorts of shapes and favors.
You could put I small kick in the end and make it higher,
You could add a little and make it higher
Some are bent in all kinds of crazy ways on top of the side profile.

 

If I cut it, add a piece in, will this change the ratio? Is the ratio set with the angle coming off of the bushing area?

 

In this picture the straight part of the pedal arm seems almost parallel with the toeboard. That being the case,
can you move the mounting bracket further aft to allow more pedal arm to protrude through the toeboard?
Once you do that successfully you can either cut some of the pedal arm off or weld on an extension, putting
the pedal where you want it and allowing for the full range of lever motion.