Another detail that I learned about my Sniper EFI TB (throttle body) is that the primaries & secondaries do not work like they do on a standard carb. My TB opens all four butterflies/barrels at the same time. They call this 1:1 linkage. Not sure if all TB fuel injected systems are the same. But I found this next topic very interesting.
There is tons of info online about what is called a progressive linkage for the Sniper. Aftermarket companies sell this easy to install linkage which allows secondaries to open at about 40% (varies on some cars) of acceleration. There are a few steps to follow in order to reconfigure the software & tell the ECU what is going on & what to do. That is where my head starts to spin, my vision gets blurry & limbs go numb haha. TMI haha. I’m not that smart haha. Some guys make it sound easy & some make it sound complicated. It seems that the guys who know what they are doing are using a laptop computer to reconfigure the ECU 🤷🏻♂️
Bottom line:
Some guys LOVE the progressive linkage & claim that Holley should sell the TB’s with this setup. I agree.
Most guys had issues with the setup causing their cars to run like poop. So they went back to the 1:1 linkage & reconfigured the ECU to original settings.
All this to say Holley actually does NOT recommend this modification haha. So if something goes wrong it’s on the user/installer. Although, the Holley Sniper apparently has a progressive linkage option in the setup/startup menu 🤷🏻♂️.
My car runs great with the 1:1 linkage. The only linkage issue I had was with the angle in which the throttle pedal pulled the TB linkage. I bet some guys who want to switch to the progressive linkage only want it to fix the same problem I had. But that may not be the answer. Anyway, I thought I would post this update for those interested in going with an EFI system.
RockinRiviDad, you are truly ROCKIN! This is the answer I have been searching for. I just had a Holley Sniper installed on my '64 Rivi with a 425. Right off the bat, the gas pedal was trash. It barely moved and was all or nothing when I got it back. In the interest of not paying someone else to tinker with it, I took it home and have been trying various modifications over the last week. The first problem, as you pointed out, was that there was no travel in the pedal. Even with the throttle arm threaded all the way in, I had to put deeper bends into the stock arm to shorten it. Once there was more play, I tried various spring setups to increase tension as the accelerator was pushed. This helped tremendously and allowed me to control the acceleration at slow speeds. But it still goes WOT when trying to accelerate quickly. I similarly concurred that it was the location of the throttle arm attachment on the Sniper linkage. It should attach at a point allowing for linear movement of the linkage. But the stock attachment point on the linkage is slightly lower than horizontal in the range of motion causing it to jump once it reaches horizontal. This bracket setup appears to correct that and I'm planning to fabricate one next week.
My one question is: Why did you modify it by welding in the tab that moves the throttle arm attachment point closer to the Sniper? It looks like the stock bracket would work just fine as is and the throttle arm has tons of side to side play in it. Was there a clearance issue or a conflict with the kickdown setup?
Your posts and additional feedback are greatly appreciated!
Holley Sniper EFI on my Nailhead
in Buick Riviera
Posted
RockinRiviDad, you are truly ROCKIN! This is the answer I have been searching for. I just had a Holley Sniper installed on my '64 Rivi with a 425. Right off the bat, the gas pedal was trash. It barely moved and was all or nothing when I got it back. In the interest of not paying someone else to tinker with it, I took it home and have been trying various modifications over the last week. The first problem, as you pointed out, was that there was no travel in the pedal. Even with the throttle arm threaded all the way in, I had to put deeper bends into the stock arm to shorten it. Once there was more play, I tried various spring setups to increase tension as the accelerator was pushed. This helped tremendously and allowed me to control the acceleration at slow speeds. But it still goes WOT when trying to accelerate quickly. I similarly concurred that it was the location of the throttle arm attachment on the Sniper linkage. It should attach at a point allowing for linear movement of the linkage. But the stock attachment point on the linkage is slightly lower than horizontal in the range of motion causing it to jump once it reaches horizontal. This bracket setup appears to correct that and I'm planning to fabricate one next week.
My one question is: Why did you modify it by welding in the tab that moves the throttle arm attachment point closer to the Sniper? It looks like the stock bracket would work just fine as is and the throttle arm has tons of side to side play in it. Was there a clearance issue or a conflict with the kickdown setup?
Your posts and additional feedback are greatly appreciated!