A couple of months back I installed the Atomic EFI setup on my 64 Dodge 330 with a 480 Cubic Inch Hemi in it. I built a return system for fuel supply instead of there return less system they offer with the kit. I am extremely satisfied with it. The throttle response is outstanding, much better than the 950 cfm Pro Systems carb I had on the car before, and it ran real good. Idle is great, car starts just like a new vehicle does, hit the key (without touching the gas), and it starts. And the cream on top, it went from 11 MPG on the highway to 15 MPG. I had a LM-1 wide band and I thought I had the carb tuned pretty good, but I was very happy with the 4 MPG gain. I have not checked the around town MPG yet, I will post when I do. All in all I think it might have been the best mod I have made to the car next to changing to HEMI power. If anyone is considering the Atomic I would say give it a try.

Glad to get some feedback on how they run. Been thinking about buying one myself but I'm still balking at the cost.

That all sounds great. You said a couple of months ago installed, how many miles have you driven the car? I years ago installed 2 Holley EFI systems, they both ran GREAT, for 2 weeks, then kaput. I'm sorry, I've been burnt. Otherwise

I have around 1000 miles on it so far.

Thanks for the report I'm about ready to pull the trigger on one for Da Bee.

With all the great carb advice given on this site, it's tough to hear that a new injection system is online that works really well and gets a glowing review. The MPG's don't lie though...........

May I ask why you altered the system and went with a return line? The Magnums have returnless fuel systems and they seem to work ok.

Thanks for the review, been kind of wondering how this system was going to work.

I wanted to get the benefits of a return system, cool fuel, (I used a Weldon Pump)fuel cooling the pump. It also occurred to me that 99.9% of factory EFI setups utilize a return system.

Thanks for the info. Does it seem to have the same power as it did with the 950?

Thanks: That MPG is a big deal. $80 to fill up the Coronet does start to hurt and the ring life is bound to be much better. I'm thinking about a dual system on a Stage V manifold for my 572, there's getting to be lots of systems to choose from now.

Sheldon

It seems like it has more power. It runs better in all aspects. For example I have a 727 in the car, I used to mash it at 40 MPH and it would go like hell, now it not only goes like hell but it brakes the tires loose to boot.
I have a 355 rear end gear in the car now, I wonder what kind of MPG I could get with a 5 speed?

It sounds like your carb tuning left quite a bit on the table.
An EFI system won't make more power than a well tuned carb in most cases. What it will do is retune the engine for every atmospheric change.
To get a jump in mileage like you did, there was an issue with the carb tuning.

I'm a big supporter of EFI and can't wait to install it on the Imperial. However, unless there are some major issues that I'm unaware of the mileage and performance won't change by a large amount.

The biggest benefits you get from EFI are the reliable starts, consistent performance, and a level of tune that simply feels that little bit better. That last one is hard to describe but it's there. The engine is a touch smoother, the exhaust sounds a wee bit better, the exhaust doesn't burn your eyes, and things like that.

The carb tuning may have left some on the table. When using the wide band I could never get all aspects of the carb tune good at the same time. I found to get a good idle tune you gave up some in the cruze tune, to get a good wide open throttle tune you gave up some in the cruze area, or the part throttle area, and vice a verse. I adjusted for 3 years always trying to get it better with a tweak here and an air bleed adj. there. What I always ended up with was a compromise of all ckt's of the carburetor tune. I think with the EFI it nails it in all areas. I am no expert but it is just my 2 cents.

This is encouraging for me. I have researched different EFI systems and have pretty much decided to buy the MSD Atomic for my 528 Hemi.
Do you have any suggestions? I'm doing this on a Street driven 68 B body with a stock fuel tank, and plan to run a 3/8" steel line.

I can't really comment on the return less system, you could give it a try. I had to put a new tank on my car 5 years ago and I welded in a sump with a supply and return bung in it, before I installed it. That was another factor in not using the return less system as I was already set up to make a return system easily work. I live in the midwest and it gets HOT here in the summer (hell it's been hot everywhere this summer), if you go to the Atomic website and in the instructions there is a checklist to fill out to see if a return less system will suit your application. I really spent a lot of time and effort tuning my carburetor, I learned a lot about carburetors and how they function, I am sure a carb super guru could have done better, when I took the carb off it was running better than it had ever run, I mean it ran good. With the EFI it runs better than it ever did with the carb. If you can afford it I would go for it, I am in the process of selling off my carb, LM-1 Wide band, carb tuning parts, I hope to recoup 1/3 of my Atomic expense. You can sell off some parts if you like it and recoup some coin.

Mosey over to the Atomic forum and you'll find that not everybody's installation goes so well.

http://www.atomicefi.com/forum.aspx?g=topics&f=12884901886

I'm holding off for awhile.

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I have been looking at the FAST EZ EFI nad the Atomic and settled on the Atomic EFI because of the Atomic's ability to control timing.

If you read through the forums on any of these systems you will find a broad range of expertise and abilities of the end customer. Many of the problems/complaints are related to user/installer errors. True there are some bad parts, but remember you are not marketing to EFI experts, you are selling to weekend mechanics, and I think the MSD is looking for an even less sophisticated market than even the FAST EZ EFI.

It would be nice if the manufacturers would post information on failure rates of components so that a buyer can make an informed decision. But I dont see that happening.
Scott

It has been my experience that all non-laptop self learning systems have issues with low vacuum engines. The ECUs look at vacuum to determine engine load and when the vacuum is jumping around 3 to 5 inches because of cam durations and low LSAs there's just not much you can do. All non-laptop systems need an idle vacuum of at least 8 inches. Laptop systems can handle this because you can manually do whatever the engine needs.

As far as failure rates - you have to admit that all electronics is pretty good. Barring any customer induced problem, it's not the electronics that fail, it's the mechanical parts. Number 1 failure is the fuel pump. And that's usually because they are installed poorly. Hot fuel can cause cavitation and any electric pump will fail if it's inlet flow is restricted.

Injectors almost never fail unless you get dirt in the system. Then they clog quickly, but that should never happen in a correct installation.

Next is mechanical relays. Sure they're cheap and easy to replace, but they are still mechanical. There are very few relays in a carburated engine. Lose a relay in an EFI engine and it dies.

Next is crank and cam sensors. Separate inductive or hall-Effect sensors (like a crank trigger) are great, but those distributors with multiple sensors are complicated and tend to be a failure mode. That's why all my cars use separate cam and crank sensors and no distributor at all.

Next is TPS and IAC sensors. Their failure rate is very low, well below the distributor level, but they still wear out.

Temp sensors never fail.

Do a good clean installation, pay attention to the instructions, and don't scrimp on the fuel system (good pump, filters and fuel line routing) and these things will run as long as any new car.

I'm very finicky about failures and I don't like distributors so all my cars are coil-on-plug. Now there is nothing left to fail expect the fuel pump which I'm sure it will.