6 pack guru's please help

[lewtot184]

For my lightly modded 71 440 in my 70 V code Roadrunner, the biggest improvements in performance came when I got the center and outboard carbs idle mixture screws tuned correctly, the outboard linkage was a little sticky when I first got the car but a slight adjustment of the rods that are on the driver's side fixed that, went to #65 jets in the center carb (I'm at sea level) and I have a 509 lift 292° duration purple stripe cam with headers, 4 speed and a 3.54 Dana, and a FBO ignition system helped too vs the Chrysler electronic ignition.
Good luck!

i like those new FBO's with the rev limiter. very good bang for the buck.

 

[biomedtechguy]

Yep. Don was helpful and did a good job setting up the dizzy for an out of the box great starting point. I want to play with the advance curve some, as well as initial and total timing, but that takes time and preferably a chassis dyno or test and tune day at the track. I plan on using a chassis dyno to see how my A/F ratio looks at idle AND throughout the RPM range doing a simulated 1/4 mile run, so maybe I can bring some springs/weights with me for a quick swap to see what that does.
The rev limiter really gave me the confidence to power shift every run I made at the annual track day a couple of weeks ago, and I am sure that not lifting really contributed to the 6/10ths improvement over the previous year.

 

[Garys1969RR]

As stated earlier, I get a slight hesitation when the end carbs open. I am using the stock yellow springs, and I really don't mind it. It's only a 1/4 second hesitation, if that. That's prob why they recommend the heavier spring, to slow the opening rate. But as lewt just pointed out, with a black spring the secondary carbs may never open fully, and you will see a reduction in performance.

 

[lewtot184]

As stated earlier, I get a slight hesitation when the end carbs open. I don't really mind it. It's only a 1/2 second if that. That's prob why they recommend the heavier spring, to slow the opening rate. But as lewt just pointed out, with a black spring the secondary carbs may never open fully, and you will see a reduction in performance.

from my experience the hesitation from a roll with yellow springs diminishes when taking off from a standing start. i'd suggest trying purple springs for a better feel from a roll. plain springs will eliminate the hesitation but add about 2 tenths to the e.t. cold intakes (heat blocked) will have a more pronounced feel/hesitation than intakes with full heat. i try to manage the heat by modifying the intake or drilling a couple of 1/2" holes in the block offs of the intake gasket.

 

[66Satellite47]

As stated earlier, I get a slight hesitation when the end carbs open. I don't really mind it. It's only a 1/2 second if that. That's prob why they recommend the heavier spring, to slow the opening rate. But as lewt just pointed out, with a black spring the secondary carbs may never open fully, and you will see a reduction in performance.

My experience indicates adjustment of the end carb idle screws would cure that. Trying different vacumn springs is also something to try. I got great results from adjusting the end carb idle screws.

 

[Garys1969RR]

Come to think about it, there is no hesitation coming off the line. Only when flooring the throttle from a roll. Maybe I should try opening the end carbs idle mixture screws a 1/4 turn.

 

[66Satellite47]

Try the end carb idle screws. A 1/4 turn will make a lot of difference. It was a nite & day difference with my setup. Just try it.

 

[lewtot184]

i also toss the .031" squirter in the center carb. i use a .025" with tubes and a white 218 cam on the #1 position.

 

[68 HEMI GTS]

Ive had different experiences with the springs. Every combo is different and needs tuning as such. I start out stiff and walk them down till I get a bog in high gear from a roll. I'll usually go back up one color from there. I've ran black springs in my carbs and went mid 11's on a 440 (lighter did not work) Same carbs on a 511 like the lightest springs I could find and the car runs high 10's. it's trial and error, there is no set recipe. You gotta play. And yes, sometimes a small bog on the street may be covered up at the track from a dig. Once again is trial and error.

 

[polywideblock]

so use the six pack tuning info I already have but substitute yellow or purple springs for the black one recommended . and I don't need the idle solenoid

 

[lewtot184]

so use the six pack tuning info I already have but substitute yellow or purple springs for the black one recommended . and I don't need the idle solenoid

if it's the moparts tuning toss it. never run blacks unless the kill bleeds are blocked.

 

[66Satellite47]

You need to just try the different springs to see what works best with your setup. The squirter size doesn't seem to vary much. Stock or a couple sizes bigger with the aluminum manifold I ran.

 

[440fish]

Agree with you need to experiment. The yellow / purple and black springs sucked on my 493 stroker. Fell on its face when i nailed it. Stiffer springs were in order. A/F meter confirmed the lean condition.

 

[68 HEMI GTS]

I've ran blacks with open kill bleeds. They were right for that particular combo. Once again I'll say every combo is different and needs to be tuned as such. Never say never. If nothing else the black springs are a good starting spot to get the center carb dialed, then lighten em up to you find what works for your combo. Not hard, and certainly not rocket science. If nothing else atleast you won't be starting with a bog. From there you'll feel the changes your making. I would never install any springs and call it good, if you don't try different combos your leaving power in the table.

 

[oldbee]

I go along with "68 Hemi", never ran "triples" myself but always liked Holley's for ease of tuning with the acc.pump cams,etc. Everything is always different; just have to try everything.

 

[66Satellite47]

It takes trying different parts. Six Paks work differently on different cars. You need to try things springs, squirters to see what works. The end carb idle screws are a major issue. In stock position you be sure to have a boog. 1/4 turn makes all the difference in the world.

 

[roadrunner69440]

Great read !!!