Throttle cable query.

[Mad4slalom]

Morning all. Was about to have a go at fitting a new throttle cable, I had issues with the old one a bit frayed and catching a tight spot making for jerky acceleration. It was also routed in a way rhat gave two really sharp bends . Even re routing it hasnt helped much. I have A holley 650 dp carb. I think with the holley set up the stock cable is actually just too long. Wondered How have others got around this problem. Is it to go with a lokar cable and adjustable bracket? Any recommendations on exactly which parts to go for and where to buy. Is the lokar cable shorter than stock?
TiA

 

[Roscobbc]

This was a 'can of worms' for me.
I had similar problems to you but perhaps for differing reasons. Firstly '68 has a 'first design' gas pedal. This is susceptible to bending and as a resu;t has less than ideal movem,ent. was quickly upgraded by GM....whilst not an issue with the stock inlet manifold and Quadrajet....or for that matter with the Torker 11 and Holley 750 DP I later installed it would become an issue later. The stock throttle cable does in fact have quite an extreme 'S' bend in it.....but TBH it wasn't really a problem on my 427 engine.
When I installed the new engine with its Edelbrock inlet the carb mounting pad is about 2" taller than the stock unit. The 950 DP carb has the same dimensions as 750 but the extra inlet carb pad height 'stretched' the stock throttle cable too much and I couldn't get much more than 3/4 throttle opening.
I sourced a Lokar throttle cable and a good quality fully adjustable billet throttle cable bracket which helped to resolve things (certainly re. getting 100% throttle opening)

But for my build (and perhaps yours too) the billet throttle cable bracket wouldn't fit under the stock GM drop-down air filter base.
I had to then use a 'higher' base filter bottom that would clear the top of the billet throttle bracket. Even with the additional height of the L88 hood I had installed the stock filter element now sat too high. Subsequently replaced with lower 2" element and K & N air filter 'top' to get back some of the reduced air flow a of the 'slimmer' element.

 

[Oneball]

There’s a specific L88/Holley bracket. 69-72 ACCELERATOR CABLE SUPPORT BRACKET WITH HOLLEY CARBURETOR :: Corvette Kingdom

Stock cable and above bracket.

 

[Mad4slalom]

This was a 'can of worms' for me.
I had similar problems to you but perhaps for differing reasons. Firstly '68 has a 'first design' gas pedal. This is susceptible to bending and as a resu;t has less than ideal movem,ent. was quickly upgraded by GM....whilst not an issue with the stock inlet manifold and Quadrajet....or for that matter with the Torker 11 and Holley 750 DP I later installed it would become an issue later. The stock throttle cable does in fact have quite an extreme 'S' bend in it.....but TBH it wasn't really a problem on my 427 engine.
When I installed the new engine with its Edelbrock inlet the carb mounting pad is about 2" taller than the stock unit. The 950 DP carb has the same dimensions as 750 but the extra inlet carb pad height 'stretched' the stock throttle cable too much and I couldn't get much more than 3/4 throttle opening.
I sourced a Lokar throttle cable and a good quality fully adjustable billet throttle cable bracket which helped to resolve things (certainly re. getting 100% throttle opening)

But for my build (and perhaps yours too) the billet throttle cable bracket wouldn't fit under the stock GM drop-down air filter base.
I had to then use a 'higher' base filter bottom that would clear the top of the billet throttle bracket. Even with the additional height of the L88 hood I had installed the stock filter element now sat too high. Subsequently replaced with lower 2" element and K & N air filter 'top' to get back some of the reduced air flow a of the 'slimmer' element.

There’s a specific L88/Holley bracket. 69-72 ACCELERATOR CABLE SUPPORT BRACKET WITH HOLLEY CARBURETOR :: Corvette Kingdom

Stock cable and above bracket.

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Thank you both for the input . I will go and look at my bracket and see how it compares with the one you suggested from ck. if i can use the new stock cable with it then that is a bonus. Otherwise I eill have to look at adjustable lokar cable. I will report back, thanks again both

 

[Roscobbc]

I have a feeling that I may have used the stock throttle cable - image from the opposite side of the engine doesn't show how the billet bracket attaches to both front and rear carb mounting stud - I was having issues with stock bracket not being rigid enough (only being fixed to rear carb stud) - you'll perhaps notice that the billet bracket moves the throttle cable mounting point further outboard of the engine and in a better position relative to where the cable goes through the firewall. CVR 64150R CVR Billet Throttle Linkage Brackets | Summit Racing

 

[Mad4slalom]

Thank you both for the input . I will go and look at my bracket and see how it compares with the one you suggested from ck. if i can use the new stock cable with it then that is a bonus. Otherwise I eill have to look at adjustable lokar cable. I will report back, thanks again both

Well i bought a holley bracket but then it is almost the same as whats there already, the cable still looks like if it was 2-3 inches shorter it would almost route straight from the bulkhead hole to the carb linkage without all the excess bending around. Has anyone had success shortening a stock cable as that is my next plan . I cant see why the cables are supplied pretty obviously too long . Any other suggestions welcome .

 

[Roscobbc]

Well i bought a holley bracket but then it is almost the same as whats there already, the cable still looks like if it was 2-3 inches shorter it would almost route straight from the bulkhead hole to the carb linkage without all the excess bending around. Has anyone had success shortening a stock cable as that is my next plan . I cant see why the cables are supplied pretty obviously too long . Any other suggestions welcome .

Wonder if a cycle shop could shorten inner/outer cable for you?

 

[Mad4slalom]

Wonder if a cycle shop could shorten inner/outer cable for you?

There are plenty of cable kits online with various nipples , adjusters etc. i may deconstruct the old vette cable and shorten it to correct length and then alter new one to same . Got to be better than trying to bend all the excess around the chrome ignition wire shielding.

 

[Mad4slalom]

Throttle cable came back today, 5 cm shorter , looks like it should fit lets hope it is smooth, light and has all the travel I need. Looking forward to gettin under the dash to fit,
Before and after pics .

 

[Mad4slalom]

Hi again, I may have a go at fitting new cable tomorrow, am I right in thinking that it detatches from the carb lever and the carb bracket clamp, then the one bolt from the cabin side of the firewall and disconnect the plastic clippy thing at the pedal and withdraw cable from inside the cabin? ( nothing to undo at the engine side of the firewall) then feed new cable from inside cabin and re attach to pedal, firewall , carb bracket and carb lever ? Any other pointers welcome. I did read that it is best to remove pedal pivot and drop pedal to remove and re fit cable at that end. ( I have a new plastic pedal pivot to fit while in there )
TiA