Holley Sniper EFI installed on my 72 455!
#1
Holley Sniper EFI installed on my 72 455!
Hi everyone,
Last weekend I installed the Holley Sniper system on my Cutlass and I wanted to pass on my experience and recommendation.
My car is a 1972 with the original 455. Everything is stock, including the original Quadrajet. The car started and ran quite well (only has 59,000 miles on it). The only thing i struggled with was hot starts - i had a fuel percolation problem every time i shut it down. So i decided to give the Sniper a try. About 12 years ago I installed a Holley Pro-jection system on a 1969 Camaro, but after a year of trying to get it dialed in I went back to a carburetor and sold that system. The new Sniper self-tuning system caught my attention when it first came out and I've been reading a lot of good reviews about it, so Holley was my choice again.
I went with the Sniper 4150 model and Holley's "muscle car EFI module" fuel pump. $1329 for the entire system.
The fuel pump was a true drop-in replacement for the stock pick-up assembly. very easy install, just had to run a ground from the battery to it. The Sniper system includes a pre-relayed power feed wire in their harness to feed the positive side of the pump. I ran a new EFI rated fuel hose to the front to feed the Sniper, and there is no return line needed if you use the Holley Muscle Car EFI Module fuel pump. The pump has a built in regulator pre-set to the same 58psi that the Sniper requires. you simply plug the return port on the Sniper with a -6 AN plug.
The Sniper system would not bolt directly to my stock intake though. It does come drilled ready for both square and spreadbore bolt patterns, and Holley says that it will seal up to a spreadbore intake if you use the #9006 adapter plate, but my problem was that the Sniper throttle blades hit the 4-hole intake ports in the manifold at about 30% throttle. Luckily I had an old Mr Gasket spreadbore to squarebore adapter in my toolbox from a previous car. worked perfectly. I am certain you can still buy that adapter if you are running your stock manifold.
The rest of the Sniper was a very easy install, and it performs just as Holley claims! I am VERY impressed with the system! (and i am usually the type of guy to find the small quirks and disappointments in aftermarket products).
It started and ran pretty darn good on the initial fuel map that the system chose based on my engine parameters, then as i drove it and it started "learning", it only got better. Little fluctuations with the idle and a slight hesitation under power smoothed out within 10-20 miles of various driving. Today it was in the low 40's this morning and I decided to drive it to work. it started and runs terrific. Plus, I always thought my car performed well with the Quadrajet........ well it definitely had room for improvement, because it now performs much better.
Bottom line, I'm beyond pleased with the Sniper on my stock engine and I would highly recommend it to anyone.
Last weekend I installed the Holley Sniper system on my Cutlass and I wanted to pass on my experience and recommendation.
My car is a 1972 with the original 455. Everything is stock, including the original Quadrajet. The car started and ran quite well (only has 59,000 miles on it). The only thing i struggled with was hot starts - i had a fuel percolation problem every time i shut it down. So i decided to give the Sniper a try. About 12 years ago I installed a Holley Pro-jection system on a 1969 Camaro, but after a year of trying to get it dialed in I went back to a carburetor and sold that system. The new Sniper self-tuning system caught my attention when it first came out and I've been reading a lot of good reviews about it, so Holley was my choice again.
I went with the Sniper 4150 model and Holley's "muscle car EFI module" fuel pump. $1329 for the entire system.
The fuel pump was a true drop-in replacement for the stock pick-up assembly. very easy install, just had to run a ground from the battery to it. The Sniper system includes a pre-relayed power feed wire in their harness to feed the positive side of the pump. I ran a new EFI rated fuel hose to the front to feed the Sniper, and there is no return line needed if you use the Holley Muscle Car EFI Module fuel pump. The pump has a built in regulator pre-set to the same 58psi that the Sniper requires. you simply plug the return port on the Sniper with a -6 AN plug.
The Sniper system would not bolt directly to my stock intake though. It does come drilled ready for both square and spreadbore bolt patterns, and Holley says that it will seal up to a spreadbore intake if you use the #9006 adapter plate, but my problem was that the Sniper throttle blades hit the 4-hole intake ports in the manifold at about 30% throttle. Luckily I had an old Mr Gasket spreadbore to squarebore adapter in my toolbox from a previous car. worked perfectly. I am certain you can still buy that adapter if you are running your stock manifold.
The rest of the Sniper was a very easy install, and it performs just as Holley claims! I am VERY impressed with the system! (and i am usually the type of guy to find the small quirks and disappointments in aftermarket products).
It started and ran pretty darn good on the initial fuel map that the system chose based on my engine parameters, then as i drove it and it started "learning", it only got better. Little fluctuations with the idle and a slight hesitation under power smoothed out within 10-20 miles of various driving. Today it was in the low 40's this morning and I decided to drive it to work. it started and runs terrific. Plus, I always thought my car performed well with the Quadrajet........ well it definitely had room for improvement, because it now performs much better.
Bottom line, I'm beyond pleased with the Sniper on my stock engine and I would highly recommend it to anyone.
#3
Fuel injection is definitely the way to go. I had a laundry list of issues on my 1979 Mark V: hard to start when hot, choke issues when cold, vapor lock, bogging, etc. Fuel injection cured them all. The difference in driveability is huge. My '68 Cutlass project is going to get fuel injection also. The newer units (I use FiTech brand) with their self-learning features are very easy to set up and use.
#6
The Holley fuel pump - part number 12-303 includes a sender that is calibrated for the OE gauge. Just connected my stock wire to the new unit and my gauge reads correctly! Very slick set up
#10
I actually set out to buy the new Quadrajet version of it, but the Holley rep I talked to told me that other than eliminating the adapter there was no reason to spend the additional $250 on the Q jet version. Same unit, but styled to look like a q jet and of course has the spreadbore base.
#11
I put a sniper EFI on my 69 last year. So far, I haven’t been able to duplicate the quarter mile times that I ran with the Q-Jet, and fuel economy is about the same. I will admit, it’s nice not haveing the long crank time the q-jet has after sitting a few days, the wife can start it without trouble.
I used a Holley fuel tank with the pump inside, it is LOUD!!
I used a Holley fuel tank with the pump inside, it is LOUD!!
#12
That very helpful and glad it works as it is supposed to. This makes putting on the Sniper that much easier.
#14
Holley rates it at less horsepower as well 500 vs 650. I still may consider it especially if they drop the price some. I spent grind time on a Qjet 1" open spacer. Any issues with a jumpy throttle? Some say the progressive linkage is necessary.
Last edited by olds 307 and 403; October 2nd, 2018 at 05:47 AM.
#16
Yep, it will control timing also. Holley has a line of Sniper plug n play distributors called Hyperspark, but unfortunately they dont offer an Olds version of it. You can go with their Dual Sync distributor but it's a bit more expensive and requires an adapter. I'm going to wait it out to see if they release a Hyperspark Olds one.
#20
I used the Spectra EFI gas tank on my 67. It has a calibrated gauge sender, in-tank pump with baffles and fits in the stock location. I got it from Rock auto with the 5% discount for less than $300. I ended up replacing the pump with a Walbro on a flyer, turns out I had a high pressure leak hiding in a hard to reach fitting.
Tim
Tim
#21
Regarding the throttle, yes, just as I had read previous to buying the Sniper, the stock throttle linkage is not very good. it doesn't have enough arc to it to produce a smooth stock-like throttle feel. I tried it and although it functions fine, I didn't like the feel. You have to be really delicate to get a smooth easy acceleration out of it. So I added the suggested bolt-on throttle extension and that worked just perfect for me. Feels just like the Q-jet did. I had to grind a tiny bit off the top edge of the extension because it hit my stock air cleaner assembly.
#24
Sniper and Dual Sync
Hi, I bought the Holley Sniper master kit with the Dual Sync Distributor included. The instructions recommended installing the fuel injection first and getting the issues resolved before installing the dist., so that is what I did. It was a good thing too as I got the car dialed in great, then the distributor was to be installed. Well, it was not so smooth, as the car would not run properly. It was backfiring out of the exhaust and intake. After doubting my work I reinstalled it and had a mechanic neighbor of mine do it also, to no avail, it still ran the same.
I pulled the dual sync out and put the Mallory Unilite back in and again it ran great. Holley wanted to blame E85 fuel, (which is not available in Canada), my engine, etc. I sent the dist back and it looks like they had assembled it incorrectly in China!! Not sure what they are going to do to remedy this as they still have my dist in Bowling Green. I may just use my Mallory, its working amazingly.
All in all, the Sniper EFI is great, lots of pull, no lag, and no dead spots.
I pulled the dual sync out and put the Mallory Unilite back in and again it ran great. Holley wanted to blame E85 fuel, (which is not available in Canada), my engine, etc. I sent the dist back and it looks like they had assembled it incorrectly in China!! Not sure what they are going to do to remedy this as they still have my dist in Bowling Green. I may just use my Mallory, its working amazingly.
All in all, the Sniper EFI is great, lots of pull, no lag, and no dead spots.
#26
I didn't know there were Olds distributors other than the one offered by FAST that can be controlled by aftermarket EFI. Let us know what happens. If they don't get you a good replacement then they should offer you a big discount. BTW, what's the part number of the master kit you got?
#27
I didn't know there were Olds distributors other than the one offered by FAST that can be controlled by aftermarket EFI. Let us know what happens. If they don't get you a good replacement then they should offer you a big discount. BTW, what's the part number of the master kit you got?
#28
MadDoc, is this the kit you bought?
https://www.jegs.com/i/Holley/510/550-516K4/10002/-1
It's listed for the small block and big block Chevy. I guess you never mentioned what you insalled it on. Did you install a kit on your 442 in your avatar pic? Does it have an Olds engine?
https://www.jegs.com/i/Holley/510/550-516K4/10002/-1
It's listed for the small block and big block Chevy. I guess you never mentioned what you insalled it on. Did you install a kit on your 442 in your avatar pic? Does it have an Olds engine?
#29
MadDoc, is this the kit you bought?
https://www.jegs.com/i/Holley/510/550-516K4/10002/-1
It's listed for the small block and big block Chevy. I guess you never mentioned what you insalled it on. Did you install a kit on your 442 in your avatar pic? Does it have an Olds engine?
https://www.jegs.com/i/Holley/510/550-516K4/10002/-1
It's listed for the small block and big block Chevy. I guess you never mentioned what you insalled it on. Did you install a kit on your 442 in your avatar pic? Does it have an Olds engine?
#31
Hi everyone,
Last weekend I installed the Holley Sniper system on my Cutlass and I wanted to pass on my experience and recommendation.
My car is a 1972 with the original 455. Everything is stock, including the original Quadrajet. The car started and ran quite well (only has 59,000 miles on it). The only thing i struggled with was hot starts - i had a fuel percolation problem every time i shut it down. So i decided to give the Sniper a try. About 12 years ago I installed a Holley Pro-jection system on a 1969 Camaro, but after a year of trying to get it dialed in I went back to a carburetor and sold that system. The new Sniper self-tuning system caught my attention when it first came out and I've been reading a lot of good reviews about it, so Holley was my choice again.
I went with the Sniper 4150 model and Holley's "muscle car EFI module" fuel pump. $1329 for the entire system.
The fuel pump was a true drop-in replacement for the stock pick-up assembly. very easy install, just had to run a ground from the battery to it. The Sniper system includes a pre-relayed power feed wire in their harness to feed the positive side of the pump. I ran a new EFI rated fuel hose to the front to feed the Sniper, and there is no return line needed if you use the Holley Muscle Car EFI Module fuel pump. The pump has a built in regulator pre-set to the same 58psi that the Sniper requires. you simply plug the return port on the Sniper with a -6 AN plug.
The Sniper system would not bolt directly to my stock intake though. It does come drilled ready for both square and spreadbore bolt patterns, and Holley says that it will seal up to a spreadbore intake if you use the #9006 adapter plate, but my problem was that the Sniper throttle blades hit the 4-hole intake ports in the manifold at about 30% throttle. Luckily I had an old Mr Gasket spreadbore to squarebore adapter in my toolbox from a previous car. worked perfectly. I am certain you can still buy that adapter if you are running your stock manifold.
The rest of the Sniper was a very easy install, and it performs just as Holley claims! I am VERY impressed with the system! (and i am usually the type of guy to find the small quirks and disappointments in aftermarket products).
It started and ran pretty darn good on the initial fuel map that the system chose based on my engine parameters, then as i drove it and it started "learning", it only got better. Little fluctuations with the idle and a slight hesitation under power smoothed out within 10-20 miles of various driving. Today it was in the low 40's this morning and I decided to drive it to work. it started and runs terrific. Plus, I always thought my car performed well with the Quadrajet........ well it definitely had room for improvement, because it now performs much better.
Bottom line, I'm beyond pleased with the Sniper on my stock engine and I would highly recommend it to anyone.
Last weekend I installed the Holley Sniper system on my Cutlass and I wanted to pass on my experience and recommendation.
My car is a 1972 with the original 455. Everything is stock, including the original Quadrajet. The car started and ran quite well (only has 59,000 miles on it). The only thing i struggled with was hot starts - i had a fuel percolation problem every time i shut it down. So i decided to give the Sniper a try. About 12 years ago I installed a Holley Pro-jection system on a 1969 Camaro, but after a year of trying to get it dialed in I went back to a carburetor and sold that system. The new Sniper self-tuning system caught my attention when it first came out and I've been reading a lot of good reviews about it, so Holley was my choice again.
I went with the Sniper 4150 model and Holley's "muscle car EFI module" fuel pump. $1329 for the entire system.
The fuel pump was a true drop-in replacement for the stock pick-up assembly. very easy install, just had to run a ground from the battery to it. The Sniper system includes a pre-relayed power feed wire in their harness to feed the positive side of the pump. I ran a new EFI rated fuel hose to the front to feed the Sniper, and there is no return line needed if you use the Holley Muscle Car EFI Module fuel pump. The pump has a built in regulator pre-set to the same 58psi that the Sniper requires. you simply plug the return port on the Sniper with a -6 AN plug.
The Sniper system would not bolt directly to my stock intake though. It does come drilled ready for both square and spreadbore bolt patterns, and Holley says that it will seal up to a spreadbore intake if you use the #9006 adapter plate, but my problem was that the Sniper throttle blades hit the 4-hole intake ports in the manifold at about 30% throttle. Luckily I had an old Mr Gasket spreadbore to squarebore adapter in my toolbox from a previous car. worked perfectly. I am certain you can still buy that adapter if you are running your stock manifold.
The rest of the Sniper was a very easy install, and it performs just as Holley claims! I am VERY impressed with the system! (and i am usually the type of guy to find the small quirks and disappointments in aftermarket products).
It started and ran pretty darn good on the initial fuel map that the system chose based on my engine parameters, then as i drove it and it started "learning", it only got better. Little fluctuations with the idle and a slight hesitation under power smoothed out within 10-20 miles of various driving. Today it was in the low 40's this morning and I decided to drive it to work. it started and runs terrific. Plus, I always thought my car performed well with the Quadrajet........ well it definitely had room for improvement, because it now performs much better.
Bottom line, I'm beyond pleased with the Sniper on my stock engine and I would highly recommend it to anyone.
Holley support gave me the same advise on the 4150 vs Quadrajet option. They also recommended only a 100u filter between the tank and Sniper, I would think a finer filter would be preferred.
Is the throttle extension you mention the Holley 20-14 ?
#32
Fred, for fuel line I suggest generic 3/8" fuel line available at the parts store or on-line:
Then you can use the SS braided hose from the fuel sending unit to the pump/filter mounted on the frame near the fuel tank. You can also use it between the throttle body and the filter/frame in the engine bay.
https://www.amazon.com/Allstar-ALL48328-Foot-Coiled-Tubing/dp/B006K8MC34/ref=sr_1_15?ie=UTF8&qid=1542382304&sr=8-15&keywords=3%2F8+fuel+line
Then you can use the SS braided hose from the fuel sending unit to the pump/filter mounted on the frame near the fuel tank. You can also use it between the throttle body and the filter/frame in the engine bay.
#33
Hi Fred,
I used 3/8" EFI line from Napa. I think it was called Dayco Vapor something.... had the green liner in it.
I ordered the in-line filter from Holley, whichever they recommended, and I used a Demon throttle extension from Summit. Part number 1952
I had to grind a little off the very top of the throttle adapter because it hit the bottom of my stock air cleaner assembly.
I used 3/8" EFI line from Napa. I think it was called Dayco Vapor something.... had the green liner in it.
I ordered the in-line filter from Holley, whichever they recommended, and I used a Demon throttle extension from Summit. Part number 1952
I had to grind a little off the very top of the throttle adapter because it hit the bottom of my stock air cleaner assembly.
#34
I'm thinking of putting this in my wagon. https://www.aeromotiveinc.com/produc...extension-kit/ I think I would have to run this kit with the Aeromotive Phantom kit to get to the bottom of the wagon tank.
#35
Hi everyone,
Last weekend I installed the Holley Sniper system on my Cutlass and I wanted to pass on my experience and recommendation.
My car is a 1972 with the original 455. Everything is stock, including the original Quadrajet. The car started and ran quite well (only has 59,000 miles on it). The only thing i struggled with was hot starts - i had a fuel percolation problem every time i shut it down. So i decided to give the Sniper a try. About 12 years ago I installed a Holley Pro-jection system on a 1969 Camaro, but after a year of trying to get it dialed in I went back to a carburetor and sold that system. The new Sniper self-tuning system caught my attention when it first came out and I've been reading a lot of good reviews about it, so Holley was my choice again.
I went with the Sniper 4150 model and Holley's "muscle car EFI module" fuel pump. $1329 for the entire system.
The fuel pump was a true drop-in replacement for the stock pick-up assembly. very easy install, just had to run a ground from the battery to it. The Sniper system includes a pre-relayed power feed wire in their harness to feed the positive side of the pump. I ran a new EFI rated fuel hose to the front to feed the Sniper, and there is no return line needed if you use the Holley Muscle Car EFI Module fuel pump. The pump has a built in regulator pre-set to the same 58psi that the Sniper requires. you simply plug the return port on the Sniper with a -6 AN plug.
The Sniper system would not bolt directly to my stock intake though. It does come drilled ready for both square and spreadbore bolt patterns, and Holley says that it will seal up to a spreadbore intake if you use the #9006 adapter plate, but my problem was that the Sniper throttle blades hit the 4-hole intake ports in the manifold at about 30% throttle. Luckily I had an old Mr Gasket spreadbore to squarebore adapter in my toolbox from a previous car. worked perfectly. I am certain you can still buy that adapter if you are running your stock manifold.
The rest of the Sniper was a very easy install, and it performs just as Holley claims! I am VERY impressed with the system! (and i am usually the type of guy to find the small quirks and disappointments in aftermarket products).
It started and ran pretty darn good on the initial fuel map that the system chose based on my engine parameters, then as i drove it and it started "learning", it only got better. Little fluctuations with the idle and a slight hesitation under power smoothed out within 10-20 miles of various driving. Today it was in the low 40's this morning and I decided to drive it to work. it started and runs terrific. Plus, I always thought my car performed well with the Quadrajet........ well it definitely had room for improvement, because it now performs much better.
Bottom line, I'm beyond pleased with the Sniper on my stock engine and I would highly recommend it to anyone.
Last weekend I installed the Holley Sniper system on my Cutlass and I wanted to pass on my experience and recommendation.
My car is a 1972 with the original 455. Everything is stock, including the original Quadrajet. The car started and ran quite well (only has 59,000 miles on it). The only thing i struggled with was hot starts - i had a fuel percolation problem every time i shut it down. So i decided to give the Sniper a try. About 12 years ago I installed a Holley Pro-jection system on a 1969 Camaro, but after a year of trying to get it dialed in I went back to a carburetor and sold that system. The new Sniper self-tuning system caught my attention when it first came out and I've been reading a lot of good reviews about it, so Holley was my choice again.
I went with the Sniper 4150 model and Holley's "muscle car EFI module" fuel pump. $1329 for the entire system.
The fuel pump was a true drop-in replacement for the stock pick-up assembly. very easy install, just had to run a ground from the battery to it. The Sniper system includes a pre-relayed power feed wire in their harness to feed the positive side of the pump. I ran a new EFI rated fuel hose to the front to feed the Sniper, and there is no return line needed if you use the Holley Muscle Car EFI Module fuel pump. The pump has a built in regulator pre-set to the same 58psi that the Sniper requires. you simply plug the return port on the Sniper with a -6 AN plug.
The Sniper system would not bolt directly to my stock intake though. It does come drilled ready for both square and spreadbore bolt patterns, and Holley says that it will seal up to a spreadbore intake if you use the #9006 adapter plate, but my problem was that the Sniper throttle blades hit the 4-hole intake ports in the manifold at about 30% throttle. Luckily I had an old Mr Gasket spreadbore to squarebore adapter in my toolbox from a previous car. worked perfectly. I am certain you can still buy that adapter if you are running your stock manifold.
The rest of the Sniper was a very easy install, and it performs just as Holley claims! I am VERY impressed with the system! (and i am usually the type of guy to find the small quirks and disappointments in aftermarket products).
It started and ran pretty darn good on the initial fuel map that the system chose based on my engine parameters, then as i drove it and it started "learning", it only got better. Little fluctuations with the idle and a slight hesitation under power smoothed out within 10-20 miles of various driving. Today it was in the low 40's this morning and I decided to drive it to work. it started and runs terrific. Plus, I always thought my car performed well with the Quadrajet........ well it definitely had room for improvement, because it now performs much better.
Bottom line, I'm beyond pleased with the Sniper on my stock engine and I would highly recommend it to anyone.
#36
Earlier this year I had an injector quit on my Sniper. Holley replaced the entire unit and since they were out of stock on the part number I had, they sent me the Quadrajet version. I’m extremely pleased and should have gotten the Quadrajet version in the first place. The progressive throttle is WAY better than the regular Sniper. I had even tried the progressive linkage mod on the original but could never get the tuning correct. The Quadrajet version is so much better. Smooth, easy throttle. I added the Hyperspark distributor this year also. It was just and OK upgrade until I learned how to tune the timing map myself. Then is was a HUGE improvement. The stock timing map that Holley provides is pretty lame.
#37
Earlier this year I had an injector quit on my Sniper. Holley replaced the entire unit and since they were out of stock on the part number I had, they sent me the Quadrajet version. I’m extremely pleased and should have gotten the Quadrajet version in the first place. The progressive throttle is WAY better than the regular Sniper. I had even tried the progressive linkage mod on the original but could never get the tuning correct. The Quadrajet version is so much better. Smooth, easy throttle. I added the Hyperspark distributor this year also. It was just and OK upgrade until I learned how to tune the timing map myself. Then is was a HUGE improvement. The stock timing map that Holley provides is pretty lame.
#38
What did you use for the fuel line? I just got the same Sniper and fuel pump and I've been going back and forth on what to use for the fuel line. Replace stock with Stainless steel, Earls Vapor Guard or SS braided hose ??
Holley support gave me the same advise on the 4150 vs Quadrajet option. They also recommended only a 100u filter between the tank and Sniper, I would think a finer filter would be preferred.
Is the throttle extension you mention the Holley 20-14 ?
Holley support gave me the same advise on the 4150 vs Quadrajet option. They also recommended only a 100u filter between the tank and Sniper, I would think a finer filter would be preferred.
Is the throttle extension you mention the Holley 20-14 ?
Thanks
#39
Yes I have the OAI hood. The Sniper fit fine, but when I swapped to an Edelbrock intake I had to cut the foam in half to make things fit. If you have the stock intake you’ll be fine. Shoot me a private message and I’d be happy to share my fuel and timing maps
#40
Dc2x4drvr,
hmmm.... I’d have to go look. I don’t recall where I found a switched source. I will say that I did a decent, clean install but nothing crazy show quality, and I’ve had zero RFI issues. I read constantly on the Sniper Facebook page about all the problems with RFI and feel fortunate that I don’t have those problems.
hmmm.... I’d have to go look. I don’t recall where I found a switched source. I will say that I did a decent, clean install but nothing crazy show quality, and I’ve had zero RFI issues. I read constantly on the Sniper Facebook page about all the problems with RFI and feel fortunate that I don’t have those problems.