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Lonnie
The general rule for both clutch and brake M/Cs push rods, is a max of 7* input angle, but my guess is that you could get away with 10* before you really start having seal and wear problems. I really do not think you are going to use but about half of the travel of your current system. What is the system Dia's. Area ratio size for a clutch should be [5 to7] to 1.
I would 2nd the use of a pedal stop on the clutch lever. Shifting is so much easier with a short pedal travel. For my stop, I used a 2nd rod attached above the M/C push rod. The rod slides inside a tube, with an adjustment nut on the stop rod to limit the travel. If you would like a photo, ley me know.
Davew

Thanks for the info, Dave. Yes, the photo(s) would be welcome. I plan to start working on stops for the pedals late this afternoon.

One of the reasons I publish photos and details of these little issues I encounter is as a learning experience for others. Also, the help I get here on the Locost.USA forums from doing so usually leads to a better solution than I would come up with on my own. I think it also gives an appreciation of the level of detail necessary to get a good design. It's hard to get things totally "right" on your first try.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

I second this as well. For some clutches such as a twin-disc, it's not an option, as extending the throwout bearing too far can destroy the assembly or even the engine. I was able to afford the otherwise very expensive clutch because the previous owner hadn't installed a clutch stop and destroyed the thrust bearing in his engine.

As was said, the big plus is that with a stop installed, it makes for much faster shifts.

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Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

Here a photo of my clutch pedal stop. [upper rod]
The stop is just a clevis pinned to the clutch pedal, with the rod extended into a tube that is attached to the M/C bulk head. I had to add a couple washers on the front end of the tube, because I was limited on the amount threads in the clevis. My pedal stop is adjust so there is only a 1/4" of additional travel past the clutch release. DaveW

@KB58
Thank you, Kurt. I appreciate the input. I am going to implement a clutch pedal stop.

@davew
Thanks for the photo, Dave. I'm on my first cup of coffee right now. I'll come back to your photo after my second cup. My pea brain is too foggy to get it right now.

Thank you for uploading it.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

Got it, Dave. That's a nice, clean approach.

What ever I come up with needs to be accessible and adjustable. So far, I've been looking at solutions that go in back of the pedals. Your approach has me thinking maybe I can do something in front of the pedals, with a limiting link or strap even though your solution clearly is different than that.

Honestly, I'm spending more time on this setup than I wanted. I'd rather be moving on to another task. However, it's easier to solve the problem now versus when the scuttle and side panels are in place. I think I better stick with it.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

Lonnie
My opinion is you can not spend to much time on pedal placement or adjustability. It's worth the effort. If your foot well panel is strong enough a simple bolt an lock nut that contacts the pedal lever, or foot well would work. but it would be a PITA to adjust. Even with my seat removed I can not fit in the foot well under the dash. [ I could tell you a funny story about that ] All three of my pedal adjustments are accessible thru the top of pedal box, accept for fore/aft which is on the end of the pedal. Being able to place the pedals that fit you perfectly is a big plus while driving. DaveW

Work has been continuing on the pedal box. I had a setback with the clutch pedal as the throw designed into the pedal for the Wilwood "Shorty" master cylinders proved to be inadequate for the Girling-style master cylinder supplied with the hydraulic clutch kit.

There was a suggestion to move the rod mounting location to the rear of the pedal, behind the pedal pivot point. That would work, but the rod to the master cylinder, only 5/16" diameter, would be too long, and possible subject to bending. I needed to take another approach.

I found a nice little free kinematic program on the Internet called "Linkage." It works on windows and looked to have everything I needed for my design. I downloaded it and spent a couple of days learning it, then started on new designs.

It took 9 different iterations of my basic idea to get what I wanted. For me it's a "good" solution in that: 1) I understand it; 2) it satisfies the basic functional requirements; and 3) I can actually fabricate the parts necessary without hiring a machine shop. Here's what the logic looks like graphically:


It does 4 things. It makes the travel of the master cylinder rod pretty close to linear, varying just slightly (< 1/4") over it's complete movement. I now have slightly more than 1.65" of travel and I need 1.4", so I have a slight surplus, which I will limit with a stop. I can change the relationship of travel to pedal movement (should I ever need it) by changing to a different link shown as DEJ in the graphic. And, last, it keeps everything in front of the pedal which will be nicer from a safety and aesthetic point of view.

Here's a detail of part of the realized design shown in the kinematic graphic:


I've made several of the parts already:





Rather than use very thick steel, I welded some 16 gauge spacers onto the clevis attachment flange to take up slop. It ended up working quite well and does not require a washers, etc.

I want to improve the brake pedal situation too, but for different reasons. It needs some stops and return springs. However, developing a new kinematic solution for the clutch made it possible to preserve all the other work I've done thus far.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

I’ve adjusted my wilwood clutch once and need to do it again. Iam finding with the Mazda clutch it only needs about 1-1/2” throw to disengage. I have about 4” of throw. It is a challenge to get down there to shorten up my push rod. The plunger on the wilwood pushes in very short distance then pushes past the orafice and hits a dead zone where nothing happens. I don’t know if helps an observance anyway.

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Steve

My build : http://www.locostusa.com/forums/viewtop ... 35&t=17160

MGB/GT V8 5.0L. viewtopic.php?f=36&t=20782

You identified my big concern, Steve. I don't know how much throw I'll actually need in practice, or how it will influence the "feel" of the clutch for the driver. I'm a long way from hooking up my clutch hydraulics and just trying things out. The only thing I know for sure is that the engineer I spoke with at the hydraulic clutch conversion kit manufacturer told me I need at least 1.4" of travel for the master cylinder.

So, I made sure I had a little surplus travel, just in case. I just have to wait until I can test to know if that was a good decision or not. If it's in the "not" category, I now only have to change the geometry of one link (& make a new one) to alter the clutch's operation. I've done the best I can do at this point.

Thanks for the input.

Cheers,

_________________
Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

You can rig up a bracket to hold the clutch MC and a lever to actuate it.

OEM clutches vary a bit in operating pressure, but for a ballpark number, '94 Fox Mustang factory clutches should be 32 pounds new, 36 worn, at the pedal. A lever two or three feet long would let you operate the clutch by hand while a helper turned the driveshaft.

@TRX

Thanks for the suggestion. I'm actually feeling good about the setup right now. It's flexible and I can modify it if needed in the future.

The clutch conversion kit does come with all the bracketry to install the clutch slave cylinder, but I have to remove and modify the bellhousing to install it. I'll do that later on.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

For some reason I was thinking you had one of those hydraulic throwout bearings. If you have an external cylinder you should be able to cobble up a bracket, a nut, and a piece of threaded rod to find the engagement stroke.

@TRX

The design engineer at the clutch conversion company told me if I got 1.4" of movement on the clutch master cylinder (it's a supplied part of their kit) that I'd be good. I now have 1.6", so I feel pretty good about the setup. I'm building an adjustable stop for the clutch pedal, so I don't go overboard and blow out the slave cylinder.

Thanks very much for the good ideas, however.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

I'd love to contribute something here as I had a bit of trouble with my throwout bearing going through the driven plate. Alas I don't remember the solution

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Larry in Seattle