• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Need member input on Sniper installs

dan juhasz

dan juhasz

FBBO Gold Member
FBBO Gold Member
Local time
3:25 AM
Joined
Aug 5, 2016
Messages
1,689
Reaction score
1,943
Location
Whiting NJ
Finished the install of Holleys Sniper on my 66 Hemi Coronet 4 speed. Very pleased all around but I have one issue that perhaps another member has experienced with their install and can help me out.
When running it is difficult (near impossible) to feather out the clutch and apply throttle without car acting like I'm trying to launch it, very hard to leave a stop sign without spinning tires. Accelerator pedal is pretty hard right from the get go but once past say 10/20 percent application it behaves normally. With the engine off the throttle feels much smoother and predictable. I don't understand why when running it has the hard pedal just off idle. I have tried adjusting the cable, changing the location on the tbi with brackets etc. The cable is a new longer version to reach. Mechanical linkage seems fine.
Going to call Holley tech tomorrow but I figure maybe another member has experienced something similar and has a fix. Only thing I changed on the factory adjustment was base idle as it was idling at over 1000 rpm, so I followed the instructions and requested 650 rpm idle speed and backed off the curb idle screw until I had around 10 percent iac at idle.
Any ideas? I know other members have mentioned how good throttle response is but this is nuts.
 
I've got a friend considering doing this to his hemi. Are you running a single 4 barrel or duals? Got any pictures that you can post?

:thumbsup:
 
Single sniper, and yes I will post pictures for you. I bought the mopar crate 426 hemi intake.
I found my problem also but not with Holley's help. :-(
 
And the fix was........?
 
I don’t do Facebook.
 
Problem is that sniper opens all 4 barrels simultaneously. Even without an additional return spring, just relying on the springs they put on each shaft, the initial opening (up to about 25 percent) is very stiff. After that it becomes fluid. So try to release a clutch and apply a gas pedal that is fighting you.
I found the fix through google. It is a link that when installed in the place of the factory one makes the secondaries progressive. They come in at about 40 percent throttle. You have to get the latest software from Holley and reflash the handheld device so you can tune for progressive linkage. I'm also going to add a Holley link that extends the point of the throttle cable to give it more of a gentle sweep, and not be so abrupt.
Holley tech has no idea the software is even available. The link is for the 4500 series. An adjustable link is also available if you want to tinker with the opening percentage.
 
dan juhasz said:
I'm also going to add a Holley link that extends the point of the throttle cable to give it more of a gentle sweep, and not be so abrupt.
Click to expand...
So do you mean just fitting an extra long arm on the throttle shaft so that the pedal travel is effectively slowed down ?
 
Factory chrome air cleaner lid fits perfect on the custom base.

20180512_120207.jpg 20180512_120235.jpg 20180522_171630.jpg 20180522_171610.jpg 20180522_171558.jpg 20180522_171544.jpg
 
Pros and cons
Better fuel economy
You can work around the car with the engine running without dying.
Starts instantly
No lingering fuel odor after shut down in the garage. (Happy wife).
Excellent crisp throttle response.
Cons
Seems a little less insane at 3/4 to full throttle.
Even after progressive linkage modifications, it still has a little initial hard accelerator pedal. But it is manageable now.
It was expensive, all totaled close to 2500 bucks.
 
no, I bought that manifold, it was a new take off from a 426 hemi crate engine. had the center plenum milled down one inch and installed
 
dan juhasz said:
Problem is that sniper opens all 4 barrels simultaneously. Even without an additional return spring, just relying on the springs they put on each shaft, the initial opening (up to about 25 percent) is very stiff. After that it becomes fluid. So try to release a clutch and apply a gas pedal that is fighting you.
I found the fix through google. It is a link that when installed in the place of the factory one makes the secondaries progressive. They come in at about 40 percent throttle. You have to get the latest software from Holley and reflash the handheld device so you can tune for progressive linkage. I'm also going to add a Holley link that extends the point of the throttle cable to give it more of a gentle sweep, and not be so abrupt.
Holley tech has no idea the software is even available. The link is for the 4500 series. An adjustable link is also available if you want to tinker with the opening percentage.
Click to expand...

Right idea but might not be a good idea. The Sniper would be better if progressive linkage was an option but it isn't. You can make the Sniper work with progressive linkage but you'll need to redo the AE tables. Out of the box the Sniper AE curve (acclerator pump for you carb guys) is designed to match a 1:1 linkage. (all four barrels opening up at the same time). When you change the linkage to progressive then you only have 2 barrels opening for the first 30% of throttle travel. You'll need a different AE curve to match that. Holley doesn't recommend using progressive linkage with the Sniper. It is not a supported feature. If you don't know how to reprogram the AE tables yourself then you might want to stay with a 1:1 linkage.
 
andyf said:
Right idea but might not be a good idea. The Sniper would be better if progressive linkage was an option but it isn't. You can make the Sniper work with progressive linkage but you'll need to redo the AE tables. Out of the box the Sniper AE curve (acclerator pump for you carb guys) is designed to match a 1:1 linkage. (all four barrels opening up at the same time). When you change the linkage to progressive then you only have 2 barrels opening for the first 30% of throttle travel. You'll need a different AE curve to match that. Holley doesn't recommend using progressive linkage with the Sniper. It is not a supported feature. If you don't know how to reprogram the AE tables yourself then you might want to stay with a 1:1 linkage.
Click to expand...
I actually went back to the stock configuration. But not so much because of having an issue with the acceleration pump curve just because after driving it for awhile it didnt make much of a difference for for real problem of having a stiff gas pedal the first 15 percent otof travel. Holley does have software to download which I did that has a check mark for using progressive linkage and also a needed percentage value of throttle opening that has to be entered to tell the ecm at what percent throttle application does the secondary start to open.
My problem was helped somewhat by buying a quality Lokar cable and extending the height of the linkage at the sniper to slow down the throttles application. The real issue is the factory gas pedal and bell crank. At idle the cable is at a severe angle with the conduit and that does not straighten out until about 15 to 20 percent application. Unless i'm willing to go with some aftermarket gas pedal assembly it is as good as it will be. Everything so far has been bolt on with no permanent changes down to the car. So I really frown on putting in an aftermarket pedal that may resolve the root problem.
 
You must log in or register to reply here.

Similar threads

Greg - Mopar2U
Holley Sniper on '71 Charger: install thoughts/opinions
2
Replies
24
Views
3K
rmchrgr
rmchrgr
K
Sniper 2 throttle cable linkage, b body. 1969 Dodge charger
Replies
9
Views
415
kaj750
K
Loulang
Sniper tach
Replies
15
Views
697
Loulang
Loulang
J
Need help adjusting my fast idle cam on a 4bbl Carter Thermoquad (1979 Chrysler Cordoba)
Replies
8
Views
512
4406bbl
4
C
1964 Sport Fury Throttle and Kickdown linkage HELP
Replies
3
Views
407
Geff McCarthy
G
Auto Transport Service
Back
Top