Can you feel when the secondaries open?

[Stallion]

In reference to the QJet, I was wondering if you guys know and can feel when our secondaries open. I remembered earlier of a guy saying that he heard and felt when they opened, but in my experience I can't say I did.

Isn't the QJet secondaries vacuum operated? So it doesn't matter how much you pull the throttle? Wouldn't it only matter that with the higher revs comes the lower vacuum and I guess that's when they open?

Thanks!

Stallion

 

[78SilvAnniv]

I don't know how it works...

...but when it does works, you KNOW IT!

With my 78, my secondaries had not been opening for almost 2 years...and I hadn't noticed because I rarely 'punched it'.
We had the carb rebuilt last summer and when Kenny test drove it he observed that the secondaries weren't opening so our mechanic friend who rebuilt the carb made an adjustment. (took 5 minutes)

Let me tell you, the difference was like NIGHT and DAY! I don't know how I missed the secondaries not functioning for so long. Now that I know what is supposed to happen (and I keep 'testing' them) I will be able to keep on top of the situation and not let it go for as long as I had.

I think you could 'test' your secondary function by driving sedately, and whatever gear you are in (I think a lower one would work best) suddenly punch it. If it sounds like you have just unleashed a beast and she surges forward with power and rpms climb rapidly, then the secondaries are operating normally. But, if it does not sound louder, does not surge forward with purpose and the rpms rise steadily but slowly, then I'd have to conclude that your secondaries are not functioning.
Heidi

A difference between our SAs is that mine is auto and yours is manual. Many times, when I step into it, it kicks me down into a lower gear for added power when the secondaries open. With a manual the driver has to select the gear s/he wants to gain optimum power during acceleration, I don't know when the secondaries would operate with a manual tran vehicle.

 

[Stallion]

Well I'm pretty sure that we don't have mechanical secondaries. I think they are vacuum. So it depends on the amount of revs, I believe. But I could be totally wrong.

I'll have to try this out. Say I'm in 1st of 2nd gear. I have punched it before, and trust me, she pulls like a beast. Hmmm...about hearing? It is loud when I really put my foot in it. And I do feel a heck of a yank. Maybe this is them opening.

Stallion

 

[78SilvAnniv]

Sounds like it is.

When the secondaries open they are dumping more fuel into the carburator and you can see/hear/feel the difference.

When my secondaries were not opening, I recall feeling that she just didn't 'pull' as well as she used to and figured I needed a tune up. At that time, when I would step on it, she would accelerate smoothly, but with little pull back into the seat (certainly no yank) and seem to take a while to get up to the speed I needed (as in passing) and just seemed "dogged".
Heidi

 

[Stallion]

Okay, I guess she is working fine. Thanks!

Stallion

 

[quickjagg]

when driving it should sound like rrrrrrrrrr, and when the secondaries open it will sound like RRRRRRRRRRRRRRRR.

-Chris

 

[CS72Roadster]

Yes, with the engine off and the air filter removed, you can look down and see if the secondaries are opening simply by opening the throttle all the way. However, the AV flaps on the top of the secondaries are vacuum operated and will not open without air flowing through the carb. This is were adjustiing the spring tension on the AV flap comes into play. If it is set too tight, even when you stomp the gas you get little or no air flow through the secondaries. If it is too loose, you get too much to quick, resulting in bog. The trick is to getting it just right and it takes driving it after adjustment to know. I set mine up and just cracking the throttle all the way it operated fine. When driving it, it bogged. I had to go back and tighten the spring tension just a little. On mine, I can feel them open, but it seems to "feel" like a somewhat progressive openning and they may not be an accurate way to describe it. It is a noticeable improvement over how it previously drove. Yes, you can hear it too. I am running the chambered exhaust and the exhaust tone is different also. Hope this helps.

CS

 

[Rodney Gold]

Just run the car foot flat in top gear, if your secondaries are not opening you wont be going very fast and wont be able to rev much.

 

[MaineShark]

it seems to "feel" like a somewhat progressive openning and they may not be an accurate way to describe it.

I'm fairly sure that the Sharks use a progressive linkage, so you're feel is probably correct.

Joe