Holley EFI Sniper or Sniper Stealth

Discussion in 'High Tech Retrofits' started by br80z, Feb 23, 2020.

  1. br80z

    br80z Veteran Member

    Likes Received:
    Apr 6, 2001
    Fuquay Varina, NC
    I think I have finally had enough of fighting with my carburetor and looking at the Holley efi Sniper and Hyperspark ignition setup. What's the difference between the sniper stealth and sniper, other than one looks like a carb. Will a drop base filter fit the same with either one?

    For those of you wondering why I'm considering the switch.

    I've dealt with carburetors before mostly quadrajets, back when they were still plentiful, but this Quickfuel vacuum secondary is driving me nuts. For about a year I've been been trying to get my car to idle at less than 1500 rpms without cutting off, and it had an off idle stumble so bad the engine would backfire though the carb and die If I didn't slowly ease into the throttle. Today for the first time in 3 months I actually had time to work on it, and got rid of the off idle stumble, but now the idle fluctuates between 1500-2500 rpms without touching the throttle. I'm guessing a vacuum leak? Will be couple of weeks before I can look at again. Right now I just want to drive it without spending all my limited free time working on it.
  2. biker

    biker Veteran Member

    Likes Received:
    Dec 7, 2014
    New Liskeard Ontario Canada
    Sure sounds like a vacuum leak. Basic steps I would look for is
    • Eliminate vac leak
    • What is your base timing? Make sure it is dialed in for whatever your cam likes. Timing is super important to set properly. Hope you have a good light. Plug vac advance, set idle mixture screws, idle speed. Repeat.
    • Use a vac hand pump to see what vac reading your vac advance starts to move at and what reading it maxes out at.
    • Measure engine idle vac, make sure u are making enough vacuum to make vac advance usable
    • Plug vac advance into full engine vacuum, adjust idle mixture and speed until u get desired idle speed.
    • You have enough fuel pressure to keep your carb happy at idle? Floats set properly?
    There are better guys here to get into how to dial your carb in for the rest of the rpm range, but the stuff above should get you idling well.
    br80z likes this.
  3. Zee

    Zee Veteran Member

    Likes Received:
    Feb 6, 2000
    Montgomery IL
    I am in the process of installing the sniper stealth on my car. There is no difference in the performance or specs on either the Sniper Stealth and the Sniper 4150. The differences are purely asthetic and cost. Well, the sniper 4150 has a dual drilled flange to physically bolt on to spreadbore applications where the stealth does not. The stealth maintains most of the dimensions of the 4150XP carb. The 4150 comes with a built in regulator while you will need to purchase an external regulator with the stealth. The only other thing I can think of is all of the wires for the stealth, exit out the rear.

    br80z and Delpha80 like this.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.