78 NYB Holley Sniper install.. the end of my lean burn fun

[72RoadRunnerGTX]

Interesting older thread on the Sniper 1 install, nice job. I ran one on a 400 in one of my cars for a while and played with converting it to a progressive linkage. The later firmware supports it, do have to replace the link rod, using a different hole location in the primary throttle lever. It also involves noting the throttle position point where the secondaries begin to open and program it into the Sniper progressive settings manually to set the acceleration enrichment for the rear bores to come in at the right time. It did tame the touchy throttle response of the original throttle configuration a bit.

Recently swapped out the 400 with a mildly built 440, installing a Sniper 2. Interestingly it comes with a slight progressive function out of the box. Appears to be about 5-10 degrees on the primary throttle before the secondaries begin to open. Don’t have a lot of driving time on it yet, it does feel better than the Sniper 1 original configuration, nowhere near as touchy off idle.

 

[CBODY67]

So the progressive throttle function allows the unit to come off-idle on only the primaries, then adds-in the other set of throttle plates from that point on?

Just curious,
CBODY67

 

[72RoadRunnerGTX]

So the progressive throttle function allows the unit to come off-idle on only the primaries, then adds-in the other set of throttle plates from that point on?

Just curious,
CBODY67

Exactly, out of the box the original Sniper (1) was configured to open both throttle shafts at the same time, right from idle, made for touchy off-idle throttle response. I found it also interfered with the transmission throttle pressure to throttle position relationship. A shorter link was available that would allow a more conventional “mechanical secondary” function, starting to open the rear throttle blades at about 40 degrees of primary throttle position.