how do you guys achieve crisp off idle response?

[thetex]

holley 770 stereet avenger just put on and I'm looking for that perfect throttle response.  360  bored 40 over, eddy victor 340 intake. 509/292 cam, 3.55 rear end. I know there are plenty of variables but what size shooters and which cam (I have a black one in hole #1) works well for the crispest response off idle?  I'm not sure the shooter size, imagine it would be what came in the box.  I have adjusted the screw at the pump arm but I think it can get better.   Thanks for your input.

[Oldschool]

You are on the right track with the cams, accelerator pump arm settings, and shooters. Does your carb already have the 50cc pump diaphragm on it?  If not, get one of those to. Double pumper?--get two. It allows you to make the needed adjustments and have plenty of fuel for a high volume, long duration shot. Generally speaking, the shot needs to come on at the beginning of throttle tip-in. There needs to be enough pump to continue spraying until the car "catches up" with the main jets. Each engine/car combo wants something a little different.  Just keep fiddling with it until you get what you need.  Just my         ................Oldschool

[Chryco Psycho]

it really is trial & error , if there is no bog go to a smaller squirter , when it bogs step back up 1 size , same with the cam use the smallest cam with no bog 

[thetex]

OK guys, I'll tinker with it.     
Thanks

[Chryco Psycho]

long duration cams like lots of initial advance start around 16* at idle , just make sure the advance curve is shortened so you still have 36-38* toal advance at 3000 rpm

[67Vette427]

Chryco's last post is pretty much along with what I feel. Also, with the long cams the gears come into question. Do you have real tall tires on the back reducing the 3:23's? On my Vette I run a cam maybe a little more than what you have and it can be touchy on start and its running two 600's. The Hemi car had the same cam as yours and the 4:10's off set the long duration. The timing is crucial too. Adjusting that can help you out a lot.

[thetex]

Update on this-  changed from a 25 squirter to a 31- no help. I think I need to look at the secondary spring (now silver) because when I punch it from a dead stop I get a poof.  I think the secondary is opening too quickly. What advice do you have for tinkering with the secondary?  This is basically a street car but I want it to respond when I goose it. 

[Chryco Psycho]

the secondary should not be opening off idle & causing a bog + silver is not a light spring & I usually drop down to yellow or purple for most applications
 something else has to be causing the bog

[thetex]

Think I should try a larger squiter?  Now a 31.     

[Chryco Psycho]

possibly , there are 52 available
 check to be sure there is NO play in the accelerator pump linkage first , play is removed by lengthening the screw in the pump arm

[kudakidd]

I've found that the 'pink' cam is generally the all round best to use. The rest is in the discharge nozzles.

[thetex]

turns out that the little Eclip is missing on the pump bracket. I'm going to secure that and adjust to the .015 gap. 

[Chryco Psycho]

there should be no gap in the pump linkage , just make sure the pump is not bottoming out @ WOT

[thetex]

Explain why I shouldn't follow the holley directions to set this with a .015 feeler guage.   

[Oldschool]

I'm with Chryco on this one.  When you set the gap at 0.015 the result is this:  when you initiate throttle opening, you are opening the main butterflies, which is feeding the engine air. So for a short amount of time, you are giving it air and NO fuel to go with it.  What Chryco is saying is simply this.  To help with throttle response, the engine needs fuel instantly to go with the air, or it will lean out for a short period. This is one reason for the bog off the line.   It needs fuel With the initial air rush, not shortly after. Give it the fuel on throttle tip-in. Look down the throat of the carb and see how much the butterflies move before the pump begins activation.  Should be almost simultaneous for best off-idle crispness.  I'm running 2 Holley 4 bbl's and the throttle response is instant quick. Try no gap and the 0.015 and check it out. You'll go back to the no gap.  Just my 0.02.       ....Oldschool