I do SCCA event tech and safety inspections and wouldn't let that run. I always use these double springs:

Five bucks or so from Summit, Jegs or the big box auto parts stores.

Cheers,
Jeff

 

I always use these double springs:

Five bucks or so from Summit, Jegs or the big box auto parts stores.

Cheers,
Jeff

Same ones that came with my Holley throttle bracket.
Some look to have one spring pulling back on the bottom from the cockpit side and another pulling forward from the top on the radiator side of the carb. Seems a bit overkill to try and reduce radial load on the throttle shaft. I just use both springs how Jeff shows them pulling from below as in this pic:

 

I had a similar question a few years back at an SCCA autocross tech inspection. I pointed out the springs wrapped around each throttle shaft in my 4 barrel carb when asked why I had only one tension spring. They let me run that day and checked again at the next event. I went to the hardware store and found a spring that was similar to the one I already had but w/ a longer 'j' hook on one end. I sized it so it was there but only applied minimum tension to the system.

 

I also tech at events, and same answer as Jeff.

Besides, a heavier throttle pedal will give you better gas mileage!

 

Another approach to dual springs. This is a Quick Fuel return spring kit.

 

Same as above ^^^^.

These two examples are the best way to implement throttle return springs.
The spring(s) should pull directly in line with the cable or throttle linkage (if you have hard linkage).
To have the springs on the opposite side of the carburetor bellcrank will cause accelerated wear of the throttle shafts and the bushings (if equipped - which is rare) - otherwise it will wear out the throttle body and cause binding as well as air leakage down the road..

I've also done SCCA Tech Inspections and while the rules just require more than one spring, they don't state where the springs should be located.

 

Also consider adding a return spring to your accelerator pedal. I have Russ Thompson's accelerator pedal. Tension from the accelerator cable did not feel like there was a positive pull on the pedal when returning to idle position. I added a spring and liked the result much better.

 

NORM! Buddy, Pal! Just hook an old bungie cord on it and call it bueno....so yeah, another spring is good. Now, Ace has the blue bins and they have a whopping selections of springs and i'm sure you will find something that suits your need. To bad you're not in Phonics ...that place was a shizwizzle of a H twizzwack store.

 

Speedway has a cheap stainless kit.with bracket..not sure if it will fit your application...but worked well for my Holleys.

 

All; thanks for the guidance/ideas. Redfish, the FAST TB has a Holley form factor, so I'll probably go that (kit) route, since there are few available mount points as is. I like Batty's bungee cord idea. Maybe snake it forward and hook it on a fan blade? Either way, I'll be adding backup return spring(s): the choice between $5+labor and unplanned WOT is an easy one ?

 

Cool, good luck. Here's the link to the one I have:

Speedway Carburetor Bracket and Throttle Return Springs - Free Shipping @ Speedway Motors

They have other styles as well...

 

Here's one from Lokar that I've used before. It works well.
http://www.summitracing.com/parts/lok-srk-4000

 

This is a Summit one. You do have to get the Ford throttle cable adapter. It is a few dollars more than some of the others shown, but it also gives you adjustment on the springs and cable. If you want to spend even more, you can get the exact same one with Holly or Trick-Flow stamped on it.

 

That's the same setup I have. I have mechanical throttle linkage. There was a bit of interference toward the back of the engine where the linkage came up from the firewall. I just filed it down a little bit and everything worked out nice. I ended up taking one of the springs off, it seemed like far too much pressure. However once I start pushing on it with my leg I may add it back.

 

Same as above ^^^^.