Anyone add a return spring at the pedal?

[Papa]

I'm noticing very slight sticking on the throttle with my new setup.

Inglese 8-stack intake with cable fixture.
Lokar throttle cable in typical S configuration for Roadster
Russ Thompson pedal

I can't add a spring at the intake, and don't have any real options to re-route the cable. I do think I could add a spring at the pedal pretty easily and wonder if anyone feels that is a bad idea?

Dave

[Jeff Kleiner]

No a solution Dave. With Russ’ pedal the cable is pulled when you step on it however the pedal does not return the cable to idle. In other words, the cable could hang but the pedal could return since it is sliding through a grommet on the end of the pedal arm. Kind of like the old adage that you can pull a rope but you can’t push it! Look up under there and you’ll see what I mean. I think you’re going to have to devise a way to add a spring to the cable or linkage.

Jeff

[Chopper]

Dave,

Not sure this is helpful, but I wonder if looking at replacing the cable with a mechanical linkage would help?

-Brandon

[Papa]

Jeff,

I understand what you're saying.

[Papa]

Dave,

Not sure this is helpful, but I wonder if looking at replacing the cable with a mechanical linkage would help?

-Brandon

That really isn't an option. The stacks are designed for a cable and the thought of converting to solid on a finished car nauseates me.

[EZ$]

Dave, not exactly the same, but with my Speedmaster stack unit I decided to install Forte's mechanical linkage. Took a bit to figure how to connect to the eccentric (??) pull in the center of the manifold, but once I solved that it worked great. I'd send a picture, but I'm not sure I have access on this computer. If I can find it, I'll send it later.

Also, I was able to add a return spring at the pedal. Also a RT unit. I figured it couldn't hurt.

[drewr]

There's got to be a place for a return spring on that set up somewhere. Carbs, FI, even Webers have a return spring. Maybe you can make an easy bracket where the cable attaches to the throttle body. Or use an aftermarket bracket from LAPS. There must be a bolt you can use as an attachment point. Or call Inglese, and see how he does it.

[Railroad]

If it easy to disconnect the cable, maybe feel of the stacks opening by hand. Do not know if the throttle blades can stick in the bore after tuning. If not check how the cable feels with the stacks disconnected. You might be able to improve whichever has the most resistance.
good luck,

[Papa]

There's got to be a place for a return spring on that set up somewhere. Carbs, FI, even Webers have a return spring. Maybe you can make an easy bracket where the cable attaches to the throttle body. Or use an aftermarket bracket from LAPS. There must be a bolt you can use as an attachment point. Or call Inglese, and see how he does it.

The capstan is spring loaded. It has solid connections to the butterfly linkage. The cable sits in a groove around the perimeter of the capstan and is attached using a brass bushing. The spring is pretty strong.

[Chopper]

I wonder if you could increase the radius of the two 180 degree turns your throttle cable is making (I think), the first coming out of the footbox and reversing to go along the driver's side head, and the second to turn 180 to go between the stacks. if you let the cable go up over the valve cover a bit and be diagonal (further away from the stacks on the back of the block, closer to the stacks on the front of the block), it would possibly relieve it a bit. However, I fully acknowledge this would not go well with your very cleanly mounted cable and beautifully deployed engine bay and is probably not a great option.

[Rdone585]

I think there could be a way to convert to a mechanical assembly. Having said that, when I put the new pedal and the mechanical assembly in mine I had to fabricate a new arm for the pedal. The arm that comes with the pedal assembly is designed to control a cable exiting the footbox in the front. It's not aligned properly to work with the mechanical assembly AND the mustang pedal assembly. If you have the Wilwood pedal assembly MAYBE but I can't speak to that. If you find that a cable is mandatory, and that the cable is the problem, and that a new cable won't solve it, you could run a cable only from the stacks to the lever arm of the mechanical assembly. Don't also overlook that the final arm of the assembly doesn't have to be straight, it could be slightly curved or even an "S" shape. It will still translate the throttle position to the end point. I only introduce this because after converting, I'm a believer! The mechanical assembly is far superior to the cable in these cars.

[Chopper]

It's not aligned properly to work with the mechanical assembly AND the mustang pedal assembly. If you have the Wilwood pedal assembly MAYBE but I can't speak to that.

I have a Wilwood pedal box, and ended up adding an extension to the RT gas pedal arm to make it taller (past the pivot), giving it more throw, and also offsetting it about 1/4" for my mechanical linkage. I do agree that the concept of adding a mechanical linkage with the tight space available is intimidating on a complete build.

[Rdone585]

I just took a look at the last couple of pages of your build thread. Your engine bay is awesome by the way. I agree, it may be tricky to convert to a complete mechanical assembly. I noticed where you installed the throttle cable before installing the stacks. There is a lot going on running down the center of the stacks. But, it is something to be proud of and looks like a million bucks.

[rich grsc]

It's not that difficult.
169765

[Alan_C]

Yup, I went with the Russ Thompson pedal assembly. The return spring as part of the FI on the 4.6L DOHC engine just did not return the pedal the way I thought it should be. So I added my own return spring under the dash between the pedal and firewall. Not rocket science, just need to identify a spring that will work. I think I bought a package of assorted springs and chose the one best in terns of length and strength. It was th right thing to do.

[nucjd19]

Stupid question fellas but I thought I would throw it out there. I have the Forte Linkage and hydraulic clutch TO on mine so I have not messed with the cables. Is it possible to lubricate the housing and decrease the friction ?

[GoDadGo]

Eight of throttle plates to move I guess makes a big difference when trying to close them all.
Please keep us posted as to your solution.

[Blue Viking]

Dave, not exactly the same, but with my Speedmaster stack unit I decided to install Forte's mechanical linkage. Took a bit to figure how to connect to the eccentric (??) pull in the center of the manifold, but once I solved that it worked great. I'd send a picture, but I'm not sure I have access on this computer. If I can find it, I'll send it later.

Also, I was able to add a return spring at the pedal. Also a RT unit. I figured it couldn't hurt.

I have the exact same setup, very pleased with it. Don't have a return spring at the pedal though.

[rich grsc]

If you want to track the car, most tech inspections require a return spring on the carb throttle (stack) pivot.

[Papa]

If you want to track the car, most tech inspections require a return spring on the carb throttle (stack) pivot.

That's what I was thinking I could do. I'll take a closer look. There may be a way to do it without a lot of work. The EFI is a lot more congested than your picture.

[BRRT]

I agree with the above posts - engine bay of your car is an absolute work of art. Beautiful.

Adding a spring is just treating the symptom by powering through the issue. You need to work the problem. Find the point of "sticktion" or bind and fix it. It could be in any of the many moving points in all that beautiful mechanism.
Could be something as simple as a small chunk of poo caught in an individual pivot point.

Your overall setup looks solid. It would be a shame to throw it all out without trying to fix it.

-----------------------------------------

Jeff

[rich grsc]

That's what I was thinking I could do. I'll take a closer look. There may be a way to do it without a lot of work. The EFI is a lot more congested than your picture.
I took a picture of my spring. It's just a basic throttle spring, maybe it'll give you an idea how to do your's
169788

[Papa]

Stupid question fellas but I thought I would throw it out there. I have the Forte Linkage and hydraulic clutch TO on mine so I have not messed with the cables. Is it possible to lubricate the housing and decrease the friction ?

I have a cable lubing tool and will shoot some lube into the sheath.

Motion Pro Cable Luber V3 Tool https://a.co/d/6ZoUI3V

[65BYBYE]

You may also want to check the angle/bends in the throttle cable going to the gas pedal to make sure it is not binding some how. Little stuff but I have seen this be the issue before.

[stacked33]

I'm noticing very slight sticking on the throttle with my new setup.

Inglese 8-stack intake with cable fixture.
Lokar throttle cable in typical S configuration for Roadster
Russ Thompson pedal

I can't add a spring at the intake, and don't have any real options to re-route the cable. I do think I could add a spring at the pedal pretty easily and wonder if anyone feels that is a bad idea?

Dave

Hard to explain without photos but I couldn't get in to take any that would be helpful.
I added an opposing cable that was about 18 inches long to the opposite side of the throttle linkage with a remotely mounted spring to pull the throttle linkage back. That way I could sneak the cable into tight spaces but mount the spring down low on the fire wall where I had more room.
So basically a second throttle cable pulling the linkage back with a remotely mounted spring instead of a gas pedal. Works awesome.
Stacked33

[CraigS]

I just looked at your engine in your build thread. Beautiful! Like Aredone said I think the cable plus mechanical might be a help. Thinking mount a shaft w/ bell cranks on the firewall and run your cable to it. One shaft end and bellcrank could align w/ the cable that is running along the valve cover. Then the other shaft end and bell crank would align with a rod to the capstan like Rich has. That would reduce the two 180deg cable bends to one 180 deg bend