Accelerator pump duration spring tuning

[novadude]

Just curious if anyone has had any success playing with the duration spring to tune the pump circuit.  It seems to me that this might have the same effect as changing the discharge nozzle size (stiffer spring = more initial shot, shorter duration, while softer spring = less initial shot, longer duration).  Wouldn't the stiffer spring create more pressure, moving more volume through a given nozzle size faster?  Thanks!

[qjetsrule]

TECHNICALLY YOU ARE CORRECT, BUT FOR EVERY ACTION THERE IS AN EQUAL AND OPPOSITE REACTION. THE EXTRA EFFORT REQUIRED TO PUSH THE FUEL THROUGH MAY RESULT IN WORN OR BENT LINKAGE PARTS. IT WOULD PROBABLY BE BETTER TO LEAVE THE SPRINGS ALONE AND TUNE THE DISCHARGE HOLE PER APPLICATION. GOOD LUCK

[novadude]

I was actually looking at going the other way.  Running one of Cliff's high performance pumps / springs, and I was thinking of trying a softer spring to reduce the initial shot.  Just something I was thinking of trying to see how the car reacts.

[qjetsrule]

I USE CLIFF'S KITS EXCLUSIVELY, THE ACCEL. PUMPS ARE FIRST RATE AND YOU COULD LAUNCH A FIGHTER OFF A CARRIER DECK WITH THE SPRINGS. TIMING THE PUMP SHOT WITH A STOPWATCH MAY VERIFY YOUR THEORY. GOOD LUCK, LET US KNOW IF YOU ARE RIGHT.

[Cliff Ruggles]

The size of the discharge holes will have the greatest impact on "duration" of the pump shot.  Only so much fuel can pass by them once the accl pump is fully compressed.

The amount of fuel trapped under the pump would be the second contributor to duration.  The springs will have some impact, but in any and all cases, we use our later design pump and custom wound springs. 

The pump and springs have been tested and will delivery the quickest response, pump shot, etc, and hold up in this new fuel when nothing else will.

Sine the q-jet has a very good POE system for the secondary side, we only need enough avoid stumble/hesitation/bog and help get things started as the huge secondaries begin to open.  POE, choke pull-off release time and secondary airflap shaft spring tension will take over and provide seamless transition and power thru the entire loaded rpm range.....Cliff