I have a Holley 750cfm double pumper carb on my car right now and Im thinking about swapping it out for the Holley Sniper efi. Has anyone used it and what do you think of it?

 

I'd like to know what sort of fuel mileage is possible once you install a Sniper, have deceleration fuel-cutoff, etc.
I'd think with a Sniper and HEI at least 18mpg should be possible. Perhaps 20.
Granted, you can't perform mileage-boosting tricks like advancing the timing while EGR is operating at cruise etc.
But it's a light car, little back pressure ...
I suppose the rear end ratio is the #1 thing, eh?

$5 gasoline makes me think about such things.

 

I’m pretty sure everyone loves it.

 

I wouldn't waste my time, or money. Does nothing for performance, and nothing better than a carb. If you are doing it because "its starts easier".....really? Give me a break. Another solution looking for a problem.

 

I have one on the shelf, have yet to try it, I hear nothing but good things about them.

 

It depends on your end goal. IF you want it to start without pumping the throttle, or to get rid of the gas smell it will help. If you are changing altitudes a lot like living at the base of a mountain and travel up and down it a lot, it will help. If you are a tech head and love the newest coolest gadget then its for you. It may give you better gas mileage than the double pumper. But if you expect a big fuel mileage change I wouldnt count on it. My Quadrajet got about 2 mpg better on its best day over the Sniper, but I never drove it like I was trying to get good gas mileage.

It wont hurt performance if its set up correctly and it works with most intakes. Your best bet is to use a single plane as all EFI intakes are single planes and the benefits of a dual plane are wasted on EFI and depending on your engine set up, it may cause issues. I ran a old low profile tarantula single plane on my 327 and it ran great. I swapped in a big block and ran the 396 stock low profile dual plane and the motor literally drowned in fuel. I was over the coolness of the EFI and went to TRIpower since that was always a dream. This is a great way to get to know how your engine works and performs and you will learn a lot about tuning EFI and carbs if you do all the work yourself. I think its a great way to cut your teeth on Fuel injection and understanding how it works. In my future when I get bored I may go to stack injection https://www.holley.com/blog/post/the...chevy_engines/ or a 4x2 weber setup and this system helped me learn a lot about carb tuning as well as EFI

Cost wise be aware that the tank, fuel line filters and fuel pumps adds up. AND to if you want the full benefits and to make installation easier get the Sniper distributor as well. You can get the same benefits as well with an MSD but the Sniper dizzy is easier to set up. Also just get the in tank Holley pump with the fuel mat. THe fuel mat will absorb the fuel all the way to the bottom of the tank if you are close to running dry, the fuel pump is quieter inside the tank and it has a regulator right there so there is no need for the return line if you choose not to run it. And you use your old tank, no need for an EFI tank
And in the end get the fuel map set up by a pro. IT will run at its best with a professional tune over the self learning tune. And if you buy new look at getting everything from https://www.efisystempro.com/ they will help you every step of the way

 

Thats a great write up and super helpful. I dont really care about the gas mileage too much and I like the efi for the self tuning. I have spent a lot of time learning about carburetors and even though they are technically easy to use there are so many minute adjustments and each one changes another and I am tired of trying to get it just right.

I had an efi system on a CJ7 that I had and even thought the system was an older efi it worked perfectly everytime. This one did need to be connected to a laptop for tuning but once that was done it always worked.

 

The Snipers can be connected to laptops as well and opens up all the super tuning aspects of them. There is a lot information available once you connect the lap top. Another real cool thing is you can save tunes so you can go on a cruise. Save the tune, down load a different tune and do the same course and see if there is a difference. There is some cool stuff to it but like a carb one thing affects the other like the map Sensor and the tps settings.

Just pay attention to the mechanical settings as they affect the way the other settings will play out.

And if you run a big cam it can affect your idle settings as well. The biggest issues i ever had was tuning the transition at 2000 rpm
Its the same as the off idle or transition circuit on a carb

 

How about running the O2 sensor on side pipes? I saw a youtube video where a guy said he had to switch back to stock exhaust (granted he had a 427) but he said he could never get the angle right on the O2 sensor and went through like one per week.

 

I have side pipes and that O2 sensor is a concern for me as well. I think the only reason I am considering a Holley Sniper is the smaller profile if it. I have a double pumper now and the stock air cleaner doesn't work with it. I would like to use the stock air cleaner with my cowl induction hood and I do not want to go back to stock intake and carb to do it.

 

I think if you buy a good quality carb like the holley xp or equivalent carb it will work very well, the only thing I do have to do with my ac system is run my throttle up a little higher but works well since I auto cross my car .

 

Tberes a few guys on here with the aftermarket pipes and made it work. I have factory style pipes and I have the O2 sensor just before the 90 degree bend to the rear. Theres just enough clearance before the frame to get mine to work

 

My Holley carb'd LT-1 has performed extremely well for 30 years, but it did require quite a bit of tuning in the beginning. Weeks of trial and error. But once competed, it was has always stayed spot-on.
I just spent a couple weeks this summer putting an EFI on a ZZ383 for a customer. To do it really "right" with running new dual hard fuel lines, AN fittings, new gas tank, fuel pump, soldered wiring, new fuse block, larger alternator, etc etc It was a lot of work and time to install. And expense for the customer. In the end it does fire up instantly, basically no matter what. That part is better than my LT-1. The tuning is in the handheld vs mechanical bits on a carb. But other than that does it run better or get better mpg? No. Would it ever be worth it for me to do it on my own car. No. It modernized the 69 to the point that I felt like it lost some of it's old car character. It just fired up like my daily driver. Does that make it better? And worth it?

 

So I just pulled the trigger and bought the Holley Sniper system. I guess Ill see how it goes.

 

Explain why "starting up easier" is even an issue? Is there something I am missing? Anyways....people spend money on stuff because they want to.....and thats America. Even if it doesn't make any sense to me.

 

And I put EFI on my car. And would have to say, the self learning bit is a bit of a scam. It will learn a base map to what you tell it to learn to. But there are a LARGE number of parameters that need to setup and adjusted. Many, many threads and articles all over the net on this.
I work with fuel injection everyday in my line of work and even still I ended up asking a number of questions to get my tune just right.
In the end, yes startup and warm up is sooooo much better.
But also general drivability is also much better. Fuel economy on long trips up 15 percent. Ripping around the hills on twisting roads, not so much.
I'm not going back to a carburetor.

 

You'll love it. Biggest piece of advice I can give for the system is to FOLLOW. THE. DIRECTIONS. Do not deviate when it comes to wiring the system up. The biggest issues with the Sniper and other similar EFI systems pop up when someone decides they can shortcut the directions and wire things their own way (with power blocks, added relays, and other crap). If it says run a wire directly to 'X", run it directly to "X". I did a Holley Sniper on my '80 in January, followed the directions exactly, and I have had 0 issues with it. The start-up wizard and the self learning will get you going and be good for 95% of people. You can have your system tuned (and the self-learning turned down or off) and get the last remaining few percentage points of power out of it if you wish.

Will it provide more power than a perfectly tuned carburetor? No. Optimum air/fuel ratio is optimum air/fuel ratio, no matter what kind of system is supplying the fuel. But the Sniper will self correct for weather and fuel conditions, whereas a carb cannot.

I also purchased a new fuel tank for my car and used a Holley drop-in fuel tank module, which is definitely worth the cost just to save some headaches. I did not go with a Sniper controlled distributor setup. I'm still using a stock HEI style ignition system.

 

https://www.corvetteforum.com/forums...ide-pipes.html

 

Ok, so I am going to order the drop in fuel tank module but I want to stick with my MSD 6AL and tach drive distributor.

 

You can do that, I did. They suggest letting it learn first without letting the EFI control the timing. Then after you get that where you like it, then let the EFI control the timing. If you can find a tuner to take care of giving it a real tune, ask then what they suggest