MSD Atomic FI
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
Don't believe everything you read or the online videos that show the minimal install under pristine test conditions.
I have been researching a few of these 'wet flow' throttle body EFI kits and there are some 'gotchas'. Here are a few:
1) If you aren't running an electronic 'triggering' device for your distributor then you won't have a clean enough tachometer signal in most cases for the EFI to operate properly - meaning you will need to add an MSD 6 or MSD 6AL box if you don't already have one. Some HEI dizzys can work but not all.
2) The appealing 'returnless' external electronic fuel pump system will only operate in the most optimal conditions you can imagine. Meaning you will almost surely need an 'in tank' electronic fuel pump with a return line. MSD has a 'scoring' system to help you determine if you can use the returnless pump and very few conditions will allow it.
Even if you do put the pump in the tank - on certain cars with shallow tanks (such as my '67 Chevelle) folks have quickly found out that you can starve out the system on hard launches or sharp turns with less than 1/2 tank of gas.
3) You will need an extra temperature sending unit port somewhere if you want to run BOTH the EFI and a temperature gauge - some cars may have them; but some may not.
4) If you choose the 'fuel only' approach (meaning the EFI controller does not regulate the cars timing) then you are getting only partial benefit of the system. If you DO want to regulate timing then you have to already have, or purchase and install, an electronic system such as the MSD 'ready to run' distributor or the like.
5) You are still prone to suffering the vagaries of fuel distribution just like with a carburetor since you are still injecting the fuel into an intake manifold and not individual cylinders as in modern EFI 'rail-based' systems.
You can easily dump $3K into one of these setups and potentially be not much better
off than if you calibrate and 'dial in' a good carb setup.
FTF
I have been researching a few of these 'wet flow' throttle body EFI kits and there are some 'gotchas'. Here are a few:
1) If you aren't running an electronic 'triggering' device for your distributor then you won't have a clean enough tachometer signal in most cases for the EFI to operate properly - meaning you will need to add an MSD 6 or MSD 6AL box if you don't already have one. Some HEI dizzys can work but not all.
2) The appealing 'returnless' external electronic fuel pump system will only operate in the most optimal conditions you can imagine. Meaning you will almost surely need an 'in tank' electronic fuel pump with a return line. MSD has a 'scoring' system to help you determine if you can use the returnless pump and very few conditions will allow it.
Even if you do put the pump in the tank - on certain cars with shallow tanks (such as my '67 Chevelle) folks have quickly found out that you can starve out the system on hard launches or sharp turns with less than 1/2 tank of gas.
3) You will need an extra temperature sending unit port somewhere if you want to run BOTH the EFI and a temperature gauge - some cars may have them; but some may not.
4) If you choose the 'fuel only' approach (meaning the EFI controller does not regulate the cars timing) then you are getting only partial benefit of the system. If you DO want to regulate timing then you have to already have, or purchase and install, an electronic system such as the MSD 'ready to run' distributor or the like.
5) You are still prone to suffering the vagaries of fuel distribution just like with a carburetor since you are still injecting the fuel into an intake manifold and not individual cylinders as in modern EFI 'rail-based' systems.
You can easily dump $3K into one of these setups and potentially be not much better
off than if you calibrate and 'dial in' a good carb setup.
FTF
Last edited by Frankie the Fink; Mar 3, 2013 at 09:41 PM.
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
Don't believe everything you read or the online videos that show the minimal install under pristine test conditions.
I have been researching a few of these 'wet flow' throttle body EFI kits and there are some 'gotchas'. Here are a few:
1) If you aren't running an electronic 'triggering' device for your distributor then you won't have a clean enough tachometer signal in most cases for the EFI to operate properly - meaning you will need to add an MSD 6 or MSD 6AL box if you don't already have one. Some HEI dizzys can work but not all.
2) The appealing 'returnless' external electronic fuel pump system will only operate in the most optimal conditions you can imagine. Meaning you will almost surely need an 'in tank' electronic fuel pump with a return line. MSD has a 'scoring' system to help you determine if you can use the returnless pump and very few conditions will allow it.
Even if you do put the pump in the tank - on certain cars with shallow tanks (such as my '67 Chevelle) folks have quickly found out that you can starve out the system on hard launches or sharp turns with less than 1/2 tank of gas.
3) You will need an extra temperature sending unit port somewhere if you want to run BOTH the EFI and a temperature gauge - some cars may have them; but some may not.
4) If you choose the 'fuel only' approach (meaning the EFI controller does not regulate the cars timing) then you are getting only partial benefit of the system. If you DO want to regulate timing then you have to already have, or purchase and install, an electronic system such as the MSD 'ready to run' distributor or the like.
5) You are still prone to suffering the vagaries of fuel distribution just like with a carburetor since you are still injecting the fuel into an intake manifold and not individual cylinders as in modern EFI 'rail-based' systems.
You can easily dump $3K into one of these setups and potentially be not much better
off than if you calibrate and 'dial in' a good carb setup.
FTF
I have been researching a few of these 'wet flow' throttle body EFI kits and there are some 'gotchas'. Here are a few:
1) If you aren't running an electronic 'triggering' device for your distributor then you won't have a clean enough tachometer signal in most cases for the EFI to operate properly - meaning you will need to add an MSD 6 or MSD 6AL box if you don't already have one. Some HEI dizzys can work but not all.
2) The appealing 'returnless' external electronic fuel pump system will only operate in the most optimal conditions you can imagine. Meaning you will almost surely need an 'in tank' electronic fuel pump with a return line. MSD has a 'scoring' system to help you determine if you can use the returnless pump and very few conditions will allow it.
Even if you do put the pump in the tank - on certain cars with shallow tanks (such as my '67 Chevelle) folks have quickly found out that you can starve out the system on hard launches or sharp turns with less than 1/2 tank of gas.
3) You will need an extra temperature sending unit port somewhere if you want to run BOTH the EFI and a temperature gauge - some cars may have them; but some may not.
4) If you choose the 'fuel only' approach (meaning the EFI controller does not regulate the cars timing) then you are getting only partial benefit of the system. If you DO want to regulate timing then you have to already have, or purchase and install, an electronic system such as the MSD 'ready to run' distributor or the like.
5) You are still prone to suffering the vagaries of fuel distribution just like with a carburetor since you are still injecting the fuel into an intake manifold and not individual cylinders as in modern EFI 'rail-based' systems.
You can easily dump $3K into one of these setups and potentially be not much better
off than if you calibrate and 'dial in' a good carb setup.
FTF
Bill
Drifting
Joined: Jun 2003
Posts: 1,874
Likes: 68
From: Rochester Hills Michigan
Take a look at the Edelbrock Pro Flo XT system I installed one on my 57 with a 383 stroker last spring and am really pleased with the results. The only down side for mewas the need to have the car dynoed for the final tune
Last edited by Low Rider; Mar 31, 2013 at 08:46 AM. Reason: Add picture
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
... when i was 'tuning' my EFI there were MANY times i wanted to find a tall building and jump off....which makes me wonder how these are supposed to constantly self-tune and adjust...
Bill
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
All of my above comments apply to all of the wet flow throttle body systems....particularly the fuel pump issues. If you mount it externally without a return line it will be very prone to over-heating and cavitation. I've looked at Atomic, EZ EFI, Holley, Performance Products, Edelbrock and some lesser known conversion kits.
They all suffer from pretty much the same shortcomings. Do some research and see what folks with some actual miles on these kits are saying. They can be made to work but require more effort than the hype and media blitz would have you believe and are not a cheap alternative to carbureation.
They all suffer from pretty much the same shortcomings. Do some research and see what folks with some actual miles on these kits are saying. They can be made to work but require more effort than the hype and media blitz would have you believe and are not a cheap alternative to carbureation.
Drifting
Joined: Mar 2011
Posts: 1,402
Likes: 214
From: Iowa
From my experience, these throttle body EFI setups aren't really worth the effort.
For example, I bought the PowerJection III kit and it is junk. I was almost 3K into that POS and it never really did much better than the 750 Holley I had on the car. I had a nice 383 stroker, AFI heads, healthy cam, 500+hp and it ran rather poorly compared to the carb. The customer support was limited at best...mostly not helpful. The linkage was mechanical, same as my Holley, and had slop in it, so the timing of the throttle body opening wasn't precise and caused hiccups with the software and dorked up the a/f ratios. The software wasn't at all setup to account for other than sea level tuning, (I am at 7k ft) which required a bunch of math on my part to account for power loss, etc...made tuning nearly impossible. I can continue but I will spare you...
If I was going to do another EFI, I would do something like the Edelbrock system which has its own intake, fuel rails, injector for each cylinder, etc...this is much closer to a modern LS setup than a throttle body carb style system.
I am not bitter over wasting good money on such a folly
...hell, with the money I pissed away, I could have been half way to a fresh LS3 crate engine...oh, not to mention the hours I spent installing, fabbing fuel lines, fittings, electrical, etc.
Good times...
Frank
For example, I bought the PowerJection III kit and it is junk. I was almost 3K into that POS and it never really did much better than the 750 Holley I had on the car. I had a nice 383 stroker, AFI heads, healthy cam, 500+hp and it ran rather poorly compared to the carb. The customer support was limited at best...mostly not helpful. The linkage was mechanical, same as my Holley, and had slop in it, so the timing of the throttle body opening wasn't precise and caused hiccups with the software and dorked up the a/f ratios. The software wasn't at all setup to account for other than sea level tuning, (I am at 7k ft) which required a bunch of math on my part to account for power loss, etc...made tuning nearly impossible. I can continue but I will spare you...
If I was going to do another EFI, I would do something like the Edelbrock system which has its own intake, fuel rails, injector for each cylinder, etc...this is much closer to a modern LS setup than a throttle body carb style system.
I am not bitter over wasting good money on such a folly
...hell, with the money I pissed away, I could have been half way to a fresh LS3 crate engine...oh, not to mention the hours I spent installing, fabbing fuel lines, fittings, electrical, etc.Good times...
Frank
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Melting Slicks
Joined: Feb 2006
Posts: 3,044
Likes: 210
From: Toronto ON
I own three vehicles that each have a carbureted 350 SBC:
'65 Corvette - Edelbrock 350 Performer crate engine
'75 Silverado - Original 350 SBC
'80 Baja boat - Original Mercruiser 260hp
I can see benefits of an EFI swap in each case, but right now I'm holding back - something I expect many of us are doing. It's a matter of priorities, money and time/hassle associated.
A body-off chassis restoration/preservation, body strip and repaint for both the Corvette and Silverado are imminent (within the next 5 years, with the truck first as it's already begun.) After working on the boat on-and-off for the past six years, the boat's body and trailer have been completely redone and soon as the new floor is 'glassed in this spring - it's going in the water for summer.
As for the EFI - all vehicles are currently running well enough - so I can wait for the options to further play out in the field. LS swaps become more common and EFI retrofits are becoming more field-tested, so the price and hassle can only drop.
I attended an MSD tech seminar on their Atomic product when it was launched last year, and to me it looks to be currently the most promising - but I left fairly certain I'd need to do a return line on my tank in the Corvette. After all, a return line is the proper way, but it does open up a new can of worms. If I do either the EFI retrofit or LS swap as part of my larger body-off plans, I'll be able to get to all the associated electrical and fuel line issues.
In the meantime, I'm going to be very interested reading about everyone else's experience with choosing an EFI retrofit or LS swap, and looking very closely at the so-equipped Corvettes and Trucks at Carlisle!
'65 Corvette - Edelbrock 350 Performer crate engine
'75 Silverado - Original 350 SBC
'80 Baja boat - Original Mercruiser 260hp
I can see benefits of an EFI swap in each case, but right now I'm holding back - something I expect many of us are doing. It's a matter of priorities, money and time/hassle associated.
A body-off chassis restoration/preservation, body strip and repaint for both the Corvette and Silverado are imminent (within the next 5 years, with the truck first as it's already begun.) After working on the boat on-and-off for the past six years, the boat's body and trailer have been completely redone and soon as the new floor is 'glassed in this spring - it's going in the water for summer.
As for the EFI - all vehicles are currently running well enough - so I can wait for the options to further play out in the field. LS swaps become more common and EFI retrofits are becoming more field-tested, so the price and hassle can only drop.
I attended an MSD tech seminar on their Atomic product when it was launched last year, and to me it looks to be currently the most promising - but I left fairly certain I'd need to do a return line on my tank in the Corvette. After all, a return line is the proper way, but it does open up a new can of worms. If I do either the EFI retrofit or LS swap as part of my larger body-off plans, I'll be able to get to all the associated electrical and fuel line issues.
In the meantime, I'm going to be very interested reading about everyone else's experience with choosing an EFI retrofit or LS swap, and looking very closely at the so-equipped Corvettes and Trucks at Carlisle!
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
There would be some advantages if these things worked as advertised. For instance on A/C equipped cars they have a true 'step up' for the idle needed for the extra load of the compressor; unlike the hokey Holley carb 'step up' solenoid that works when you step on the gas but will not increase engine speed on its own at idle (the solenoid isn't strong enough). Cold starts would certainly be better too. An EFI that constantly adjusted the A/F mixture for varying throttle and temperature conditions would be a big help for mileage and driveability as well.
On balance, these systems over-promise and under-deliver and I, for one, am going to stay away from them.
On balance, these systems over-promise and under-deliver and I, for one, am going to stay away from them.
Heel & Toe
Joined: Dec 2006
Posts: 17
Likes: 0
I just installed the atomic efi on my 81 vette about 6 weeks ago. Went the returnless system with intank pump. So far it has been flawless, there has been a seat of the pants improvement in performance, I do not have any numbers yet as I will be taking it to the track to compare it to older 1/4 times in a month or so. The ease of starting and smooth idle and progressive feel from the throttle response has made a believer of me. Will update if issues arise.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
Good for you .... perhaps you have the perfect conditions. Around Orlando, in summer with 1/2 tank of gas the fella I know that set up the MSD has had nothing but trouble (no return line). Did you hook up the ignition option or just go "fuel only" ?
Drifting
Joined: Oct 2002
Posts: 1,818
Likes: 13
From: ar
Last year 8 members of the stingray registry took a 6 or 7000 mile trip to the west coast. 3 cars had the new atomic efi installed 2 big blocks and 1 small block. They had nothing but praise for their systems. We drove high elevations in Tahoe to sea level in San Fran.
2 guys are active members here on the forum, Gerry mossy66 and Roy (67-427ci). I know Roy had tried other efis that didn't work out but seemed pleased with the atomic system.
Maybe they will chime in.
Jeff
2 guys are active members here on the forum, Gerry mossy66 and Roy (67-427ci). I know Roy had tried other efis that didn't work out but seemed pleased with the atomic system.
Maybe they will chime in.
Jeff
Drifting
Joined: Oct 2002
Posts: 1,818
Likes: 13
From: ar
My point is, they put the atomic systems on right before the trip and headed out. I was skeptical but after seeing the units perform trouble free for over a combined 15000 miles on 3 different engines If I was thinking about that type system I would not hesitate.
But I will be sticking with my tuned port for now.
Jeff
Melting Slicks
Joined: Feb 2011
Posts: 2,892
Likes: 168
From: Middletown Ohio
2016 C1 of Year Finalist
EFI build it yourself
WMF62.
This is the setup in my 62 Corvette.
I modified a 2 1/16" Hilborn 8 stack injector to EFI for less then $4000.00
My goal was to keep it from looking "electronic".
Notice there are NO fuel rails.
and 1 fuel line feeding the fuel distribution block (looks like the old barrel valve).
Worked out pretty cool. See attached picture. Ignore the 2 different types of stacks, trying different ones.
We plumbed a plenum under the intake to get vacuum from all 8 runners and use MAP for fuel control along with the other sensor inputs.
Megasquirt ECU and relay box, GM 32 pound injectors, O2, Incoming air temp, water temp, throttle position sensor.
DIY self tune software and it runs great.
I'm controlling fuel only but have capability for ignition control, nitrous, boost plus lots more,
[IMG]http://i1094.photobucket.com/albums/i459/ohiovet
/57%20Gasser/005.jpg[/IMG]
This is the setup in my 62 Corvette.
I modified a 2 1/16" Hilborn 8 stack injector to EFI for less then $4000.00
My goal was to keep it from looking "electronic".
Notice there are NO fuel rails.
and 1 fuel line feeding the fuel distribution block (looks like the old barrel valve).
Worked out pretty cool. See attached picture. Ignore the 2 different types of stacks, trying different ones.
We plumbed a plenum under the intake to get vacuum from all 8 runners and use MAP for fuel control along with the other sensor inputs.
Megasquirt ECU and relay box, GM 32 pound injectors, O2, Incoming air temp, water temp, throttle position sensor.
DIY self tune software and it runs great.
I'm controlling fuel only but have capability for ignition control, nitrous, boost plus lots more,
[IMG]http://i1094.photobucket.com/albums/i459/ohiovet
/57%20Gasser/005.jpg[/IMG]
Last edited by ohiovet; Mar 29, 2013 at 12:31 PM.
Safety Car
Joined: Dec 2009
Posts: 4,171
Likes: 335
From: Homewood Alabama
From my experience, these throttle body EFI setups aren't really worth the effort.
For example, I bought the PowerJection III kit and it is junk. I was almost 3K into that POS and it never really did much better than the 750 Holley I had on the car. I had a nice 383 stroker, AFI heads, healthy cam, 500+hp and it ran rather poorly compared to the carb. The customer support was limited at best...mostly not helpful. The linkage was mechanical, same as my Holley, and had slop in it, so the timing of the throttle body opening wasn't precise and caused hiccups with the software and dorked up the a/f ratios. The software wasn't at all setup to account for other than sea level tuning, (I am at 7k ft) which required a bunch of math on my part to account for power loss, etc...made tuning nearly impossible. I can continue but I will spare you...
If I was going to do another EFI, I would do something like the Edelbrock system which has its own intake, fuel rails, injector for each cylinder, etc...this is much closer to a modern LS setup than a throttle body carb style system.
I am not bitter over wasting good money on such a folly...hell, with the money I pissed away, I could have been half way to a fresh LS3 crate engine...oh, not to mention the hours I spent installing, fabbing fuel lines, fittings, electrical, etc.
Good times...
Frank
For example, I bought the PowerJection III kit and it is junk. I was almost 3K into that POS and it never really did much better than the 750 Holley I had on the car. I had a nice 383 stroker, AFI heads, healthy cam, 500+hp and it ran rather poorly compared to the carb. The customer support was limited at best...mostly not helpful. The linkage was mechanical, same as my Holley, and had slop in it, so the timing of the throttle body opening wasn't precise and caused hiccups with the software and dorked up the a/f ratios. The software wasn't at all setup to account for other than sea level tuning, (I am at 7k ft) which required a bunch of math on my part to account for power loss, etc...made tuning nearly impossible. I can continue but I will spare you...
If I was going to do another EFI, I would do something like the Edelbrock system which has its own intake, fuel rails, injector for each cylinder, etc...this is much closer to a modern LS setup than a throttle body carb style system.
I am not bitter over wasting good money on such a folly
...hell, with the money I pissed away, I could have been half way to a fresh LS3 crate engine...oh, not to mention the hours I spent installing, fabbing fuel lines, fittings, electrical, etc.Good times...
Frank
I agree. I too tried the powerjection on a car a few years ago and i have never been so frustrated in my life. I attempted to tune the car for 8 months, spent 600 taking it to the dyno, and finally pulled it off and sold it for half the initial price. What a nightmare! It ran, but not well and depending on if the stars were aligned correctly, it might start. I was stranded due to that system more than once. Every time i see a set up like it brings back bad memories and I cringe. The only one i have used in the past that actually worked as advertised was the mass-flo efi system, but it had a few small hiccups. However, it ran well and made the car enjoyable, but was it worth the money over a carburetor??? probably not.
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
WMF62.
This is the setup in my 62 Corvette.
I modified a 2 1/16" Hilborn 8 stack injector to EFI for less then $4000.00
My goal was to keep it from looking "electronic".
Notice there are NO fuel rails.
and 1 fuel line feeding the fuel distribution block (looks like the old barrel valve).
Worked out pretty cool. See attached picture. Ignore the 2 different types of stacks, trying different ones.
We plumbed a plenum under the intake to get vacuum from all 8 runners and use MAP for fuel control along with the other sensor inputs.
Megasquirt ECU and relay box, GM 32 pound injectors, O2, Incoming air temp, water temp, throttle position sensor.
DIY self tune software and it runs great.
I'm controlling fuel only but have capability for ignition control, nitrous, boost plus lots more,
[IMG]http://i1094.photobucket.com/albums/i459/ohiovet
/57%20Gasser/005.jpg[/IMG]
This is the setup in my 62 Corvette.
I modified a 2 1/16" Hilborn 8 stack injector to EFI for less then $4000.00
My goal was to keep it from looking "electronic".
Notice there are NO fuel rails.
and 1 fuel line feeding the fuel distribution block (looks like the old barrel valve).
Worked out pretty cool. See attached picture. Ignore the 2 different types of stacks, trying different ones.
We plumbed a plenum under the intake to get vacuum from all 8 runners and use MAP for fuel control along with the other sensor inputs.
Megasquirt ECU and relay box, GM 32 pound injectors, O2, Incoming air temp, water temp, throttle position sensor.
DIY self tune software and it runs great.
I'm controlling fuel only but have capability for ignition control, nitrous, boost plus lots more,
[IMG]http://i1094.photobucket.com/albums/i459/ohiovet
/57%20Gasser/005.jpg[/IMG]
Bill