Atomic EFI vs. FAST EZ-EFI 2.0

We deal primarily with efi conversions and tuning at the shop and have experience with both of these units. I am sorry to say that neither system has impressed me very much. On the Atomic unit we lost a fair amount of power on the conversion and the unit leaves very little ability to change much of anything to any fine amount. The owner also complains of driveability issues such as surging at cruise and such. Being there is no direct adjustment for timing or fueling and they are self tuning there was nothing we could do. The Fast EZ 2.0 is much the same. We had fueling issues on the dyno as well as some weird system resets and shutdowns. Fast took the unit back for repair and the owner decided to go with the sportsman unit so we could have a bit more adjustment. I strongly urge anyone to get a unit that is end user tuneable as I have been unimpressed with the so called "self tuning" engine management systems out there. They work ok on a fairly mild setup for a simple plug it in and get it running but from what I have seen I would not expect perfection. Sorry if this isn't what you want to hear but I feel people should know what they are getting into with these systems. Best of luck with your decision. Done right EFI can be absolutely amazing.

Scott,

I've heard the new Holley EFI systems are amazing (https://www.holley.com/products/fuel_systems/fuel_injection/terminator_efi/) and make the F.A.S.T. system look "old school". As someone who took the EFI plunge a long time ago, my best advice is; resist the temptation to buy it from Summit or Jeg's because there will be times when you need a real expert on the other end of the phone. Besides, the experts will always match prices.

Call or send an e-mail to "Dave" at Autotrend EFI (www.autotrendefi.com). I was referred to Dave by the Head of Kinsler's Tech Dept. They told me he's the best EFI guy they know of. That's pretty high praise coming from Kinsler.

I have been running an MSD Atomic FI for about 9 months now and I am pretty pleased about the results. I have no experience of other 3rd party EFI systems so I cannot compare results.
The Atomic is controlling timing and running a return fuel system with regulator, I would recommend you strongly consider both options for drivability and reliability. Some Atomic users complained of low speed stumble until they went to a return system, prevents hot-soak issues, etc. With timing control no more messing with springs, stops or moving vac hookup or amount.
My engine is a 393ci with a 248/252 @ 0.050 mechanical roller camshaft with 626 crank hp, so I am at the limit at what the Atomic recommends.
My cold and warm starts are great, idle is really good, I get ~16mpg on a run, no issues with reliability, acceleration is fantastic.
The one issue I do have is a slight bucking when driving at low rpm. At less than about 2,000rpm on a constant throttle, the car feels like it is missing and you feel the car jerking a bit, not violent. Anything less than ~40mph in 5th requires a lower gear. I have tried different settings which have made it better but it might just be a characteristic of my aggressive cam and getting reversion. Atomic are working on an update which is supposed to be coming out soon and will give that a try. If parts fail, i.e. o2 sensor, idle control etc, generic parts are available but if you want them covered under warranty you need to send the complete unit in to MSD.
The ability to change timing, vac advance, pump squirt etc while driving via the little handset is great, you also get a nice accurate reading of your water temp..
When Kuntz & co dyno'd my engine they also put on the Atomic with my old Hall Pantera GTS headers, 552hp @ 6,200rpm, 505lb-ft @ 4,800rpm, instead of 626hp @ 6,700rpm, 556lb-ft @ 4,900rpm with dyno carb & headers, quite a drop. Kuntz were not familiar with the Atomic so the stock Atomic fuel pump I sent them would not have been big enough so maybe some setup issues, rotor phasing etc. Now running a high hp pump return system with Pat Mical's headers and my butt dyno is happy.

I do agree i think the ability of the user to tune the system (whatever it is) is of great importance.

Many "self tune" systems rely on oxygen sensor information to adjust fuel/air ratios to achieve a almost constant 14.7:1 ratio.

This may allow the car to "run" but it is probably not going to run as well as it could.

Also these systems are designed by engineers that have the 350 Chev mindset and so fuel curves and spark curves, for those systems that control both, are tailored to "fit" the characteristics of the more common smallblock Chev and not the 351C.

You must have the ability to adjust the system to compensate for this.

I also do recommend a fuel return line fuel system with a pressure relief valve style fuel regulator.

This can be a pain to put in but once it's done it's there and can prevent all manner of vapour lock issues by supplying cool fuel from the tank all the time.

Also use a Bosch fuel injector pump. The pumps that come with these EFI setups are cheap trash and they fail in short order leaving you stranded.

Bosch make a stack of pumps and there will be one that is spot on for your use.

0 580 254 044 is the part number of the pump i've used for MPEFI, it flows up to 200 litres per hour and working pressure of 5 bar (approx 73 psi). The regulator will of course drop the pressure to whatever is required for the injectors you are using.



The issue of altitude may be a ongoing problem for you. Selection of the right type of control will be a big consideration in your circumstances.

Here in Australia it's not a issue as Australia is almost completely flat and there is little altitude change on any road you can drive on.

The systems i've used would not compensate for the 10,000 ft altitude change that you have and would require manual adjustment as your car climbed up from sea level, just like the engineer in a pre-computer aircraft would have to do constantly adjusting the fuel mixtures as the planes altitude changed.

Curiously carburettors being a device that uses air flow and air density to initiate fuel flow tend to compensate for altitude change more easily than EFI systems. That is not to say automotive EFI systems can't do it but it is necessary to factor that feature in when designing the system and as most cars don't fly the designers tend not to worry about it.

You may notice that many automotive EFI systems come with a warning "not to be used on aircraft" this is because altitude change can be a problem for them.

Something to look into......

I put a Holley system on a Pantera a few years back. I really liked it.

NO LAPTOP NEEDED.

It's a weekend project.
There's a little more to it than bolt up, plug in then go.
But for the most part it was pretty easy to install.
Everything needed was in the kit.

Self learning Or you can add CAM specs and other engine info though the hand held control.
I just set it for self learn and drove the car for a few hours.

HOLLEY 550-401

quote:

Originally posted by agustaboy:
I put a Holley system on a Pantera a few years back. I really liked it.

HOLLEY 550-401

I've used them too. They're a pretty simple system and can work really well. Use the 900cfm or 950cfm versions, the 700cfm on a 351C doesn't cut the mustard.

I don't know how they will go with the altitude issue.

The full Kit
About $2,100.00

quote:

Originally posted by smeadphoto:
Aloha Gang!

Now that the brakes on my car are thoroughly sorted (many mahalos to Scott Bell for saving my okole), I'm looking into Major Project #2: Converting to EFI.

Since most of the runs we do over here take us up Haleakala (at a touch over 10K feet), the car nearly refuses to run at the summit. I've been doing some research, and I've narrowed it down to two systems: MSD's Atomic EFI and Fuel Air Spark Technology's EZ-EFI 2.0.

I'm leaning towards the MDS system, as it interfaces with my 6AL control box and distributor, plus it's a returnless design (no need to plumb a return fuel line to the tank).

One thing I do like about the EZ-EFI system, is that it's E85 capable (not that I want to run it, but could in a pinch).

Has anyone had any experience with these two systems? Recommendations?

Mahalo,

Scott

I have seen the MSD Atomic system and it seems to be pretty good. I seem to recall that for the best performance a return line should be used. I was going to help a friend set one up and he did use a return line on his car. Running a return line to the gas tank is very simple on a Pantera since the tank is next to the engine.

I used the F.A.S.T XFI 2.0 system which is port injected and allows for full tuning. It is a bit more expensive than the throttle body units, but it is self tuning. They also offer a dash mounted monitor that allows for some adjustment to the system and you have several different tuning set ups that you can switch to with just the press of a button.

I understand the desire to use a simpler less expensive system, but in the long run I believe port injection is the way to go. I have had my car up to a little over 9000 feet and it runs fine with the XFI 2.0 system.

Most modern systems will have a MAP sensor so altitude should not be a problem. Coolant temp, air inlet temp, fuel pressure, throttle position, o2 sensor are pretty standard also. The ability to control ignition timing also helps with the tune ability.
With the Atomic you can set idle, cruise and wot afr, pump squirt, power valve, cam type and engine cui, idle & total timing, when timing comes in and total, vac amount, if ported or unported, all which have an impact. The other systems I am sure have pretty much the same options. Not the same as setting a map for ultimate tune ability but I don't want to go there.
I am not sure what pump is with the stock Atomic kit but the regulator is a Bosch. I am using a 044 pump.

Thanks for all the great info, guys!

JFFR: I'm guessing you've got a Windsor in your car, as FAST only offers the XFI 2.0 Port system in a 351W config. I wonder if the XFI Sportsman with the EZ-EFI 2.0 would offer a suitable solution?

Blane: As you've done several EFI conversions, what are your thoughts on the Holley system, and are there any other alternatives you'd recommend that would work well on a 351C, and fit under the stock engine cover?

I have not used the tbi style Avenger units from Holley but we have done several of the HP and Dominator units. We have used Holley EFI stuff in the past and have never liked them all that much but with the new units they have really hit the ball out of the park. They tune easily and can be bought with all sorts of different wiring options. They are also quite versatile allowing them to be used with newer motors as well. We are also big fans of the Haltech and Vi-Pec ecu's however these require considerably more time input as they must be wired in for most engines. The throttle body units themselves can be bought from FAST separately, have most sensors built in and can be used with just about any aftermarket system.

I have the XFI 2.0 system on my cleveland. XFI can be used for any motor, as far as I know.
Self tuning? Not my XFI system. Im about 95% tuned. Takes a lot of tweaking by a knowledgable tuner.
I ran mine in the rocky's at altitude. Ran like shit. I found out later that I should've changed a setting in the software that would've checked the altitude/pressure every time I started the car and it would've compensated.
FAST Easy EFI is self tuning, not XFI. Apples and oranges.Night and day difference.
Once you get it tuned its incredible.
Will

quote:

Originally posted by 4NHOTROD:
I have the XFI 2.0 system on my cleveland. XFI can be used for any motor, as far as I know.
Self tuning? Not my XFI system. Im about 95% tuned. Takes a lot of tweaking by a knowledgable tuner.
I ran mine in the rocky's at altitude. Ran like shit. I found out later that I should've changed a setting in the software that would've checked the altitude/pressure every time I started the car and it would've compensated.
FAST Easy EFI is self tuning, not XFI. Apples and oranges.Night and day difference.
Once you get it tuned its incredible.
Will

I am not sure about the older F.A.S.T XFI 2.0 systems, but my model can self tune. You can also select to not use the self tuning mode. It still needs a good base tune set up to start with, but any good tuner can do that. I have had my Pantera from 9k feet above sea level to about 100 feet below sea level. It runs good and it keeps the fuel air ratio right where I want it to be.

any multi-port adventures out there?

quote:

Originally posted by 73 l:
any multi-port adventures out there?

Like this ?

quote:

Originally posted by Aus Ford:

quote:

Originally posted by 73 l:
any multi-port adventures out there?

Like this ?

Port injected bank fired. The next set up may be sequential, but I will need a crank and cam sensor for that.

This is the most recent Holley system we did. The owner opted for the Dominator ECU. It was a conversion on a blow through carbed 572ci Pontiac. The owner cannot rave enough about how much better the car drives. When the car is dead cold you can reach in through the window,turn the key and it fires right up and settles into a nice idle. This thing also makes in excess of 800 ft/lbs at the tire.

Hi Guys.... I think I can chime in here.
I am in the process of installing an MSD Atomic EFI into my Pantera. Its going on a new 427 Crate motor (535hp) with an aggressive cam, which is basically at the maximum ability of the Atomic.
So far installation has been straight forward. I have plumbed the lines for the fuel return, installed the fuel regulator and MSD 6AL. I was surprised to find that I had a Mallory distributor, so I am going to change it to an MSD to allow the Atomic to control timing.
I'm just waiting for a Steel timing gear to arrive and then I'll update again.
G

Dr. Olds. Make sure that gear is compatible with the cam.
W

I run a Mass-Flo system. Works great...
http://www.promracing.com/massfloefi
http://www.promracing.com/pro-...ete-efi-systems.html

4NHOTROD...... Thanks. The 'manual' that came with the 427 says that it needs the steel Mustang 5.0 EFI distributor gear to go with the cam. The distributor that Ford Racing recommends (MSD85840) is too big and it hits the back glass, so I have had to put a steel gear on to a MSD8478 distributor.

Dr Oldsmobile, you could have used the MSD 8578 distributor which also the small cap but without the vacuum advance and saved yourself ~$80.
Hopefully you also ordered the adjustable rotor if you want the Atomic to control the timing.
The Atomic FI is rated for 650hp with the correct fuel pump.