OK heres what i was thinking about today, If i take out the linkage rod from the can to the flaps would i get a bog? I already have adjusted the spring tension, but would this allow the flaps to open even faster or would the car just stumble on me?
thanx for the info
later

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keep the stang's far behind u and the cops even farther

 

I'm sure somebody will disagree with me on this, but I would remove it and adjust the spring tension until the bog is gone. I've done this on a lot of GM cars and it always worked for me.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

Like 82, i too have experimented with no vacuum brake on the AV flaps, and IMHO it's not worth it.
Why...you simply don't need your AV to open THAT fast. IMO the amount of spring tension you need to run to avoid a bog when fully warmed up (let alone if it's a little cold out) will actually DECREASE performance. Why? Because the air coming in has to fight the spring tension on the AV doors, which means, chances are they will not fully open unless you have a really bas *** engine. And even if you have a bad *** engine, thats extra work it has to do.
What the vacuum brake does is band-aid the bog when you nail it, but once it's fully open, thats it, the doors are free to stay open with a lot less spring tension (i run 0 tension on my cars, though my GP could use some help) Therefore, i know that i am getting full secondary flow at WOT after a couple seconds, which in the case of my now departed camaor was when it was needed. The slight extra jump in opening rate was useless, I could smoke my tires way off the line with the secondaries stuck shut (happened a few times, also had them unstick past the 60' mark one time and the sudden jump in power was enough to blow the tires off, with the vacuum brake connected.)
...ed

 

I agree with Ed.

You might be interested to know that the vacuum can assy. from an Edelbrock #1910 performance QJet clone will bolt right onto your Computer Controlled QJet and it opens much faster than most stock cans.

My expereince is that the can really only needs to be doing it's job for the first fraction of a second after the secondary throttles open. It's that first strong pulse of vacuum hitting the bottom of the air valve that causes it to actually SLAM full open and then closed again that causes the bog. I know this cause I drove around n my Malibu once with the hood off and no air cleaner and WATCHED it happen.

 

Some of it may depend on your car and it's set-up. Deep gears/stall converter/light car will work well with a fast opening secondary. High gears/low stall converter/heavy car will require a slower opening secondary and may also require the vacuum to be hooked up.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro