There is a thread over in the 60 series section where a few people have done it with the 4 barrel units with good results. According my email with Holley they suggested this would be even better due to the more appropriate cross section
Holley Sniper 2 barrel conversion
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There is a thread over in the 60 series section where a few people have done it with the 4 barrel units with good results. According my email with Holley they suggested this would be even better due to the more appropriate cross section
- Thread starter
- #22
I wish more people would post their installs, first impressions and overall results. I was debating posting this in the 60 section as I assume more people over there will be interested in EFI.
Well I apprieciate you doing it. I bought an offy dual plane F intake before they came out with the two barrels with the intent of doing this. A cooked harness derailed my plans so I’m rebuilding that (slowly.) Thabk you, I’ll be following your build closely
OK, what I've learned in my last year using the Holley 4bbl Sniper on my old 327.
Holley Sniper forum/tech-support
Sniper EFI
I was originally considering the FiTech and was doing research on it before I made the purchase. I talked to a guy that had the FiTech and could never get it to work correctly, and said the FiTech tech support was bad. He ditched the FiTech and installed the Sniper, and couldn't have been happier. He said the learning and computer software was better with Holley, and a couple other things I don't recall. This was enough to tip the scales for me to Sniper. I read as of last year FiTech couldn't keep up with production and tech support. This is all hearsay, but my experience with the Holley tech support and computer software has been very good. Don't know about FiTech or if they've caught up.
Getting the Holley USB "dongle" allows you to plug the EFI into your laptop and give you a lot more flexibility tuning and many more options, if you want them. You can monitor engine parameters and make correction in real time. Very slick.
CAN-To-USB Dongle
BTW, I highly recommend this website for questions and purchases. The owner seems to be one of those honest, straight-shooting and knowledgeable people that stands behind his products. No affiliation..
They had a run on damaged fuel pressure regulators, therefore I suggest getting a fuel pressure gauge to confirm the correct fuel pressure at the TBI. This will tell you about fuel supply adequacy, fuel pressure regulator function, and having an adequate return line. If any of those are off it won't run as well. Holley shipped me a new FPR at no charge.
Fuel pressure gauge info:
High Fuel PSI - Page 5
Speaking of fuel return lines. It's necessary to have a good flowing return line from the TBI. Any excess back pressure will increase the fuel pressure to the TBI that same amount. I had to replumb my two fuel tanks and selector valve to correct this. One solution (I haven't tried) is to add a remote pressure regulator, and delete the long return line. Seems like a pretty slick way to do it, but there are a drawback or two.
Holley EFI 12-875 Holley EFI Filter Regulator 3/8" NPT
The TPS isn't water proof so don't aim a hose near it. I found this out the hard way.
These EFI components, TPS, Oxygen sensor, IAC, etc are available off-the-shelf or from Amazon, at a cheaper price, than from the Holley website. You just need to do a little research to find the compatible item. There is a list somewhere on the Holley forum.
On some application the Sniper will make a loud whistle noise at certain throttle setting. This can be corrected with a 1/4" thick or greater 4-hole base gasket (2-hole, for those of you with two holes). Had some discussions online and someone finally figured it out. And my youtube video of the whistle.
Throttle tip-in can be abrupt on some vehicles. Making a simple throttle arm extension at the TBI can correct this.
Accelerator Pedal Very Touchy
The Sniper does timing control. I already had my big-cap HEI dialed in nicely, and am not using the control. Timing control would be pretty sweet though. People seem to love the ease of setup with the Holley duel-sync distributor. Not cheap though.
Distributors
You can install the Sniper software and look it over without actually having a Sniper. Kind of gives you an idea of whats going on. Also available here are installation manuals and all that.
Tech Resources
Well that's all I can think of at the moment (thank God)
Hope it helps,
B.
Oops, first impressions and overall results.
first impression: Wow, nice quality, attractive, and very complete kit!
overall results: Great. Took more work tuning and dialing in than I expected, but I'm a little (?) OCD when it comes to that stuff. It will self-tune to about 80 percent great, then it takes effort to get it all perfect. Am extremely happy with it and runs like a champ. Better torque than a carb too, since it doesn't depend on airflow at low RPM to adjust the mixture. It did take quite a bit of work to get all dialed though, not nearly plug-and-play.
B.
Holley Sniper forum/tech-support
Sniper EFI
I was originally considering the FiTech and was doing research on it before I made the purchase. I talked to a guy that had the FiTech and could never get it to work correctly, and said the FiTech tech support was bad. He ditched the FiTech and installed the Sniper, and couldn't have been happier. He said the learning and computer software was better with Holley, and a couple other things I don't recall. This was enough to tip the scales for me to Sniper. I read as of last year FiTech couldn't keep up with production and tech support. This is all hearsay, but my experience with the Holley tech support and computer software has been very good. Don't know about FiTech or if they've caught up.
Getting the Holley USB "dongle" allows you to plug the EFI into your laptop and give you a lot more flexibility tuning and many more options, if you want them. You can monitor engine parameters and make correction in real time. Very slick.
CAN-To-USB Dongle
BTW, I highly recommend this website for questions and purchases. The owner seems to be one of those honest, straight-shooting and knowledgeable people that stands behind his products. No affiliation..
They had a run on damaged fuel pressure regulators, therefore I suggest getting a fuel pressure gauge to confirm the correct fuel pressure at the TBI. This will tell you about fuel supply adequacy, fuel pressure regulator function, and having an adequate return line. If any of those are off it won't run as well. Holley shipped me a new FPR at no charge.
Fuel pressure gauge info:
High Fuel PSI - Page 5
Speaking of fuel return lines. It's necessary to have a good flowing return line from the TBI. Any excess back pressure will increase the fuel pressure to the TBI that same amount. I had to replumb my two fuel tanks and selector valve to correct this. One solution (I haven't tried) is to add a remote pressure regulator, and delete the long return line. Seems like a pretty slick way to do it, but there are a drawback or two.
Holley EFI 12-875 Holley EFI Filter Regulator 3/8" NPT
The TPS isn't water proof so don't aim a hose near it. I found this out the hard way.
These EFI components, TPS, Oxygen sensor, IAC, etc are available off-the-shelf or from Amazon, at a cheaper price, than from the Holley website. You just need to do a little research to find the compatible item. There is a list somewhere on the Holley forum.
On some application the Sniper will make a loud whistle noise at certain throttle setting. This can be corrected with a 1/4" thick or greater 4-hole base gasket (2-hole, for those of you with two holes). Had some discussions online and someone finally figured it out. And my youtube video of the whistle.
Throttle tip-in can be abrupt on some vehicles. Making a simple throttle arm extension at the TBI can correct this.
Accelerator Pedal Very Touchy
The Sniper does timing control. I already had my big-cap HEI dialed in nicely, and am not using the control. Timing control would be pretty sweet though. People seem to love the ease of setup with the Holley duel-sync distributor. Not cheap though.
Distributors
You can install the Sniper software and look it over without actually having a Sniper. Kind of gives you an idea of whats going on. Also available here are installation manuals and all that.
Tech Resources
Well that's all I can think of at the moment (thank God)
Hope it helps,
B.
Oops, first impressions and overall results.
first impression: Wow, nice quality, attractive, and very complete kit!
overall results: Great. Took more work tuning and dialing in than I expected, but I'm a little (?) OCD when it comes to that stuff. It will self-tune to about 80 percent great, then it takes effort to get it all perfect. Am extremely happy with it and runs like a champ. Better torque than a carb too, since it doesn't depend on airflow at low RPM to adjust the mixture. It did take quite a bit of work to get all dialed though, not nearly plug-and-play.
B.
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- Thread starter
- #25
Brian, thanks for the tips! I just ordered a cable, hoping to use a tablet as my gauges with it as well.
I will definitely check fuel pressure after startup, I am tuning 3/8 delivery and return. So should be good there.
Thanks for the link on the touchy throttle, I’ll check that out,
Money is dwindling so I won’t be using timing control, but I do plan on it with an fj60 distributor when I can afford it.
Can’t thank you enough for all the links and info!
I will definitely check fuel pressure after startup, I am tuning 3/8 delivery and return. So should be good there.
Thanks for the link on the touchy throttle, I’ll check that out,
Money is dwindling so I won’t be using timing control, but I do plan on it with an fj60 distributor when I can afford it.
Can’t thank you enough for all the links and info!
S4Cruiser
SILVER Star
In for details and results. Once you get it all installed and running as you expect, it would be nice to get a cost breakdown for those of us potentially considering something like this.
I personally have no issues with it being relatively costly but am interested in how long it takes to dial it in. I've read enough Efi threads that I only remember the negative troubleshooting parts
I personally have no issues with it being relatively costly but am interested in how long it takes to dial it in. I've read enough Efi threads that I only remember the negative troubleshooting parts
Glad to help. I usually can't offer too much on this site with all the brainiacs here, so I do try to help when and if I can.
Good luck and let me know if I can assist any more.
B.
Downey
SILVER Star
Brian, you just became one of the "Brainiacs"
- Thread starter
- #29
I got my adapter mocked up today. Still waiting on my intake/exhaust gasket.
Looks like plenty of clearance for the throttle body. I think a -6an 90* fitting should do the trick for the delivery line and a 45* on the return side.
Using a factory carb spacer on the intake sidewould be ideal for clearance around the manifold bolts, but I chose to just clearance the adapter plate instead.
Still doing wiring, I am taking my time trying to keep it clean while fixing some other issues at the same time.
Looks like plenty of clearance for the throttle body. I think a -6an 90* fitting should do the trick for the delivery line and a 45* on the return side.
Using a factory carb spacer on the intake sidewould be ideal for clearance around the manifold bolts, but I chose to just clearance the adapter plate instead.
Still doing wiring, I am taking my time trying to keep it clean while fixing some other issues at the same time.
That's quite a compliment coming from the man himself!!! Thanks!
- Thread starter
- #31
Small update, Got the stock distributor stabbed, I only have a few more wires to hook up. Planning to start it up on Tuesday or Wednesday next week!
Awesome. Looking forward to hearing how it goes!
JohnnyC
Long ago TLCA# 2231
- Thread starter
- #34
Not soon enough... just a few wires
Still waiting on intake/exhaust gasket. Ordered from the dealership. It’s on the slow boat here. I sure am excited though!
There are a couple more things about how the Sniper learns, that I'll share, once it's up and running.Still waiting on intake/exhaust gasket. Ordered from the dealership. It’s on the slow boat here. I sure am excited though!
- Thread starter
- #36
I’ve read a lot that the sniper needs a “clean” 12v source. A battery with auxiliary terminals is recommended. What are you running?
Yes, I read that too and didn't mess around. Power and ground straight to the battery with crimped and soldered ring terminals.
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- Thread starter
- #38
It runs. Idles very high, but does indeed run!
- Thread starter
- #39
Sweet! Is the throttle cable bracket Done?
