gas mileage Mechanical vs Vacuum Secondaries

LXguy said

I got my information from the sheet that came with my Quickfuel carb.

Here is the same information on Summit's website:

http://www.summitracing.com/parts/QFT-Q-650/



You are correct. Mine runs great. But that's a big IF-most folks can't tune one of these to save their life. And if I wasn't racing, I wouldn't bother with it. And my fuel mileage would probably be better also.

Click to expand...

That's a plug in there and it can be removed and replaced with a power valve, they don't come without a provision to add one like my holley 4777.

BTW, the density altitude here ranges from 4500 to 9800 ft., and that's here in Denver. Drive to the mountains and it's a whole 'nother ball of wax.

The DP vs. VS argument is really combination specific and much depends on the ability of tuner himself.