Q-Jet secondary adjustment

You can drill out the restriction in the choke pull off, then create custom opening rates by taking a section of a golf tee, approx 3/4 of an inch long, drill a 1/8 hole towards the center from both ends, ensuring you have at least 1/8 material that hasn’t been drilled through, then take your small numbered drills, do 16 a thou hole….put the modified golf tee piece in the vacuum hose, test your rate by using the vacuum pump on the choke pull off, time how long it takes the choke pull off to extend once the vacuum is released (this simulates the WOT - no vacuum scenario). You can create several, experiment so you have a 1.5, 2, 2.5 second release, find what works best. Likely more power, stall converter will like the faster release. Less power, heavy car, highway gears - slower release. Again make sure your current choke pull off is holding vacuum……if it leaks, replace it.

 

^^ Yep, that

 

It's key to dial the primary circuit dead nuts before messing with the secondaries. Any kind of skip/bog on the primary side will result in a major snafu when the secondaries are opened..

 

I believe so, I had Ken @ Everyday Performance go thru it ( my original Q-Jet) 'bout 4 years ago.
I ran it on the Stage 1 DP intake, ran awesome.
Switched to the SP3, ran awesome till you floored it.
Bought an 850 AED DP for the SP3, Runs awesome, You can plank it anytime, no bog.
The ONLY advantage to the DP carb is no hesitation when slamming to WOT, the fuel is there when you want it.
I have noticed I gained 2" of idle vacuum with the Q-Jet
Throttle response with either carb is excellent
As a side note, I think the SP3 is an awesome manifold, I like it better than the Stage 1 DP, I lost zero torque down low, as my 60' is still 1.9, same as the Stage 1 DP.
My plugs color evenly with the SP3, not so much with the Stage 1.
My theory on that is the open plenum, every cylinder has an equal shot at A/F more or less, its not so much dictated by runners, some short, some long.

 

I like that idea.
Being the Q-Jet has no dedicated pump for the secondary's, I would THINK as soon as the secondary throttle plates BEGIN to open, you want that intake vacuum drawing IMMEDIATLY on the secondary air doors/flaps to get the fuel moving ASAP into the plenum, and NOT wait for a pull off diaphragm to release allowing the doors to open, it may only be a second or two, but thats too long.
Im going to try it, I'll report back

 

Horrible idea even though some folks think it works OK like that.

The pull-off does double duty, opens the choke flap on a cold start to the ideal angle and keeps the secondary airflaps from whipping open when you go quickly to full throttle.

A correctly timed pull-off does NOT delay the opening, it avoids a lean condition by keeping them from opening too quickly and too far the instant the secondary throttle plates open.

IF you remove the pull-off link up to the secondaries you will then have to wind the spring too tight to prevent stumble/hesitation/bog.....FWIW.....Cliff

 

I just removed the pull off and capped the nipple from the carb, took it for a ride, I cant verify the bog/hesitation is gone, as Im on street tires and I tried a WOT from a 20 mph roll, it down shifted to first, and spun all the way into second till I let off. that doesnt tell me anything, theres no traction/load on the engine

Since I dont use the choke, are there any other downsides to removing the pull off, as long as the secondarys are adjusted to compensate?
I have the secondary's pretty tight, same adjustment I just had WITH the pull off operating.
WITH the pull off operating, it seemed the engine wanted more sooner.
WITHOUT the pull off, the engine took all it had to offer.
The Q-Jet is a badass carb for a factory 4 bbl.
I just need some guidance and experience
On my combo the driveability is seamless.
The track will tell I suppose

 

Yes, the pull-off MUST be in place to prevent the secondary airflaps from whipping open and causing a lean condition. Even if you wind the piss out of the spring there will still be a noticeable transition going quickly to full throttle.

You should feel no transition whatsoever, just smooth/steady power from idle to the shift point. The "butt-meter" feels the transition, or as folks like to say "felt the secondaries kicking in". That scenario is NOT as good as smooth linear power or a "locomotive" like power curve.

The problem is that the "butt meter" evaluates the big lunge as an improvement over a smooth transition so folks think they are helping things out by removing the choke pull-off and link to the secondary airflaps.

Here is my car at the track, no big "rush" of power anyplace, actually feels a little "boring" on a full throttle hit as the power is super smooth with not the first hint of any transition from the primaries to the secondaries.......

 

Ehhh,...I'll keep taking them off,...same reason guys like 30° of overlap on their cruise in toys,..the butt meter is where the fun is,..to each is their own

 

Inaccurate information and piss-poor advice is still what it is. The idea for these Forums is to provide accurate, up to date and useable information for others, nothing more, nothing less. I could really care less what anyone does, and I've seen about all of it. Had a Q-jet come in recently where the owner/user completely removed the pull-off and link and attached a hardware store variety spring between the bracket and the air flap shaft. I called and asked him about it and he was quite proud of that, and the fact that a working choke on one of these vehicles was "for sissy's".

After strict instructions not to remove his spring or modify that deal in any way I promptly walked over to the shipping table, placed his carb back in the box it showed up it, attached a return label and sent it back........to each his own.......

 

If you could care less then why get worked up haha,..so by taking the pot off and tightening the spring a little to compensate its your stance that the world as we know it will end and the car will explode upon startup? I fully understand that one that opens nice and smooth is its intended purpose and its not hindering actual performance,...I also understand that stock and pure stock guys carry several different ones to adjust for track conditions on the stock tires,....but all I'm saying is that for the guy that likes to feel the punch or hear them drop open what's it gonna hurt?

If a guy comes and says hey man I wanna roll thru the burger joint choppin,....what am I gonna do take his money and put a "properly" sized cam with low overlap to better suit his combination and customer leaves upset...OR,..would you explain that hey man you're gonna give up some low rpm power in exchange for that lopey idle,..and he leaves with a big smile and tells his friends how who the hell ever provided exactly what he ask for,...OR,....just nahh your stupid and don't know what you want from your car and I don't want anything to do with it,.you or your money,..or anyone you knows money?

 

I swear am I the only one here that has ever had a conversation with car guys at a bar or whatever and had contradicting ideas without someone getting sand in their pants?,..seems like every time someone has a different approach or idea someone gets twisted haha

Mark seemed to think it felt better,...he knows his car and how it responds,....I'm sure he will tinker with opening rates of pulloff,...maybe he finds the sweet spot,..maybe he doesn't,...maybe he says the he'll with it it feels good and I like it and gonna leave it alone,..who knows I'm sure he'll report his findings,....and chokes are for sissies,....especially when it's just along for the ride with going thru an act of congress hooking up a hot air Pontiac style or Electric conversion when using an aftermarket intake or blocked off crossovers

 

I'm not discounting your experience, but you are arguing with the guy who is probably the best q-jet guy in the world who is gracious enough to offer free advice to the average guy. He's a pretty good resource to have around, and its much appreciated, at least by me.

I've also learned pretty quick that lots of folks think that their combo is some magical collection of parts that have never before been all in the same car. that requires all conventional tuning wisdom to be thrown away. These are usually the dummys who think that their "camel hump 327 with pop up pistons" is 400 hp. I'm not insinuating that this is the case with Mark, but I could only imagine the crap Cliff deals with.. i would not touch that homemade secondary spring crap either. Why put your name on someone else's abortion?

 

I know Cliff knows his **** never doubted it,...but it's not the answer to every scenario is all I'm saying,...that was the point I was making with the cam selection,...hell I'm not even arguing haha,..just give an alternative "piss poor" suggestion hell I want even call it a solution haha

 

And I fully understand about putting your name on something that can hurt you in the long run,...I do it with my paint job selection all the time,...I don't like doing $4500 scuff and shoots,. BUT,...I do like and need money so I don't run them off unless it's I see there being an issue front and center that's gonna bite me on the dick,...the way I look at it there are plenty other of my 20k show jobs out there to quite anyone that runs across the rare bird that was trying to save a buck and I didn't go all out on it.

 

Yep!! I like girls with lots of tatts,..daddy issues,..bad attitudes and a nice ass,...they are terrible people usually and not what's best for me,...but,..they are fun!!!

But I get it,..getting carbs sent in that's been butchered up and what not,....just for fun I'm gonna post a pic of my "Ole Faithful" it's to be buried with me,..no I'm not joking i told my sister where it is and it goes in the box with me.

I put this carb together when I was 19 or 20,..it is has been the best running Qjet I've EVER had,...and I'm talking on the track and street,..and on multiple different combos