When tuning the vacuum secondary spring, does this affect the secondary jets?

I usually tune the vacuum secondary spring dead last and leave the carb alone after that. I've never checked to see if changing the spring would affect the jets. For instance, if I put in an extremely light spring, could I put in bigger secondary jets to make up for the extra burst of air? And if I install bigger jets, won't that richen up the mixture quite a bit after that initial air comes into the system (I already know the answer to that question)?

I think I'm doing this right by leaving the jets alone after I tune the spring, but this is tuning for the street. If it were for the strip, would it be a bad thing to be running the secondaries a little rich? And wouldn't it help if the secondaries opened a little quicker and earlier? Would this act somewhat like a DP in this way (except for the 2nd squirter)?

Changing the spring is no different than changing how your right foot behaves in relation to the primary jetting. It varies throttle opening a lot on the primaries. Jetting will affect A/F, whereas the spring only affects opening rate. I would think once you dialed your secondary jetting in, (providing you have a secondary metering block) your A/F ratio should stay pretty consistent regardless of spring changes.

I understand all that. But when your secondary spring is too light it lets in too much air too early and screws up the A/F mixture (and no secondary squirter to fix the A/F). But if you add larger seondary jets, could they "act" as a secondary squirter?

I'm not considering doing this at all. I just want to know for a better understanding of carbs.

A larger jet will allow more fuel but it won't get there any faster, the air will still get there faster.

If your carb has a sec power valve you might be able to run a higher number sec PV so it opens sooner when going wot and then run a bit lighter spring opening the sec's sooner.

Originally posted by DjD:
A larger jet will allow more fuel but it won't get there any faster, the air will still get there faster.That was what I was looking for. Thank you.