EFI - need more pull on my 318 throttle body

[josh72ooh2]

I have an EFI set up but the gas pedal is only pulling about 2/3 of the potential throttle. If I step on the pedal to the floor, I’m not able to pull the throttle the whole way. 

what are the EFI guys doing to get full leverage out of the pedal to the throttle body? 
 

attached is a video. 
https://youtube.com/shorts/EQzVpQ06rsg?feature=share

 

Edited August 1, 2023 by josh72ooh2

[colorobo2002]

Let's see the other end of the cable and how its attached there.

Edited August 1, 2023 by colorobo2002

[josh72ooh2]

54 minutes ago, colorobo2002 said:

Let's see the other end of the cable and how it’s attavhed there.

It’s at my friends shop an hour away. Next time I’m there, I’ll try to get the pedal box off and see. 
 

I'm curious what others have done to solve this. 

[Dudeland]

You may be able to extend the lever by the pedal box.  Do you have much slack?

[josh72ooh2]

Just now, Dudeland said:

You may be able to extend the lever by the pedal box.  Do you have much slack?

That was a thought I had to but not sure it will give me everything I need. The cable has Barely any slack at all. 

[Dudeland]

7 minutes ago, josh72ooh2 said:

That was a thought I had to but not sure it will give me everything I need. The cable has Barely any slack at all. 

Yes a bit of a bugger to get things rolling correctly.  I used this cable below.  It works smoothly on my sniper setup. 
 

You may need to lengthen the lever to get full motion.  The challenge then becomes regulating the throttle. 
 

Send some picks when you get a chance. 
 

 

Lokar TC-1000HT36 36" Hi-Tech... https://www.amazon.ca/dp/B000CONKFQ?ref=ppx_pop_mob_ap_shareLokar

 

[tzei]

Confirm visually where tb plate is fully open regards to linkage on side. Then you’ll know where you need to be. No need to go over that poin. Can’t remember how far that tb can open but check it.

[sczapiga]

Are you using a bell crank? I know there’s been a lot of talk about throw and modulation. The bell crank from Speedway seems to be a good option because of the multiple mounting holes giving different ratios. Just a thought…

 

 

[TobyB]

More pedal travel, progressive linkage, or different motion ratio.

 

Classical physics.

 

Also, the last 1/3 of travel isn't good for much more than the last 1/16th of da powah.

 

t

 

[Son of Marty]

5 minutes ago, TobyB said:

Also, the last 1/3 of travel isn't good for much more than the last 1/16th of da powah.

Yeah but isn't that what we pay the big bucks for?

[josh72ooh2]

Here’s a photo of what’s on the pedal end. I’m wondering if some sort of pulley system might increase the pull necessary for the throttle body. 
 

 

or… what if I welded another two inches onto the pedal arm so it pulls more when I step on it? 
 

 

Edited August 19, 2023 by josh72ooh2

[Mark92131]

You would get more pull if the cable connection at the lever was more vertical instead of inline with the lever itself.  I solved this on my car by running the cable along side support for the brake booster and attaching it to a "L" bracket I fabricated.  It allows the pedal box lever to pull the cable straight down.

 

The pull on the S14 is different so I fabricated two pieces, the "L" bracket that attaches to the side of the brake booster support and another piece that attaches to the top bolts holding the booster to the support.  

 

Mark92131

 

[josh72ooh2]

11 minutes ago, Mark92131 said:

You would get more pull if the cable connection at the lever was more vertical instead of inline with the lever itself. 

 

 

 

So in theory, I could lengthen the cable a bit and adjust that pedal box arm on the splines so it is more inline (parallel) with the master cylinder and get a bit more pull out of the cable by having it pull straight down? 

 

[TobyB]

Pardon me if I'm being dense, here- are you at the limit of travel on the INSIDE of the car?

 

As in, can you simply rotate the external pullrod, shown in your pic above, on the threads of the shaft that goes

through the bucket into the car?   Thus, raising the static position of the pedal.

That will give you more travel, up until the internal position of

the bent rod's at too steep an angle to effectively slide on the pedal.

 

Otherwise, yes, lengthen the pullrod from the pedal (is there room?)

 

But in your video, I'm only seeing maybe 1.5" of cable movement indicated-

the stock- length pullrod moves easily that far in normal, cable- operated rod setups.

So I think your pullrod's slipped.  It's a common problem...

And without seeing how your cable's attached, below, it's hard to offer more insight...

 

t

 

[Mark92131]

Make sure your pedal lever inside the car is straight.  Mine was bent and was limiting the travel of the arm by the gas pedal.  To make sure the arm is tight enough on the splines, you can take remove the throttle arm from the pedal box and take a cutoff wheel to open up crack slightly, so the tightening bolt has more travel to chinch the throttle arm to the splines.  Yours looks maxed out.

1 hour ago, josh72ooh2 said:

So in theory, I could lengthen the cable a bit and adjust that pedal box arm on the splines so it is more inline (parallel) with the master cylinder and get a bit more pull out of the cable by having it pull straight down? 

 

Yes, in theory this may help.  Remember, in the OEM setup, the throttle lever is pulling the rod straight down vertically to maximize the travel.  In your current application's angle, you aren't pulling much of the cable until the throttle arm passes horizontal.  That's why I ended up fabricating the "L" bracket for the booster support to position cable for a vertical pull with the throttle arm.

 

Mark92131