A friend here where I race uses a vac. sec. Holley and does very well. Very consistent car on gas. They are almost non-existent so I'd like to know if there are some out there.

I used a 3310 750 years ago. It worked ok once I got it dialed in. But not necessary, a double pump set up right is better.

You will probably get more responses in the tech section

I've had much luck bracket racing my street car with a factory Chrysler Six Pack setup (Vacuum Outboards). Car varied at most .05 through the day if weather stayed consistent. It has varied as much as .08 from early morning to late afternoon in warmer weather. The last two times I ran the car, I won an 8.50 index street car race twice, went to the semi's in Pro once, and lost in third round of Pro once. I typically double enter the car, it's a blast to race and cruise home.

For what it’s worth. I have three VS 780 carbs for my stocker 427. Two were good but the third is the Quick Fuel 780 VS for stock/SS and it’s by far the fastest and most consistent I’ve had. Faster than my Holroyd 780 and thats saying something. Hope this helps.

BP

Great. For a footbrake car that leaves at low RPM, I don't see why a VS carb would not work as well as a DPer. Quick Fuel makes an expensive Q-series VS 750 carb with billet base plate and metering blocks. Thanks for sharing your experience.

Some extras thoughts...

I think it would also depend on how you have the vacuum secondaries setup. I typically run a sticky DOT tire, and I have light springs in the outboards so they open quicker. I'm not concerned with blowing the tires off with DOT tires and a 3.23 gear though. I think a more traction limited car (someone running a regular street radial, for example) may benefit from a heavier spring in the secondary so they don't open as quick, potentially blowing the tires off.

quote:

Originally posted by 62Galaxie:
Great. For a footbrake car that leaves at low RPM, I don't see why a VS carb would not work as well as a DPer. Quick Fuel makes an expensive Q-series VS 750 carb with billet base plate and metering blocks. Thanks for sharing your experience.

I leave anywhere between 2500 and 3500. It responds extremely well. 2500 is wheelie bracket mode and 3500 is fast. Sending you a PM.

I used a 3310 for quite a few years, still have the carb. It was a mild FB motor and the vac secs worked great.

I've run an HP950 VS for many years, helped calm down the launch. Car ran 10.20 at 129 with this carb. Footbrake launch at 2000.