Old School 350 EFI Conversion

64nailhead

G-Body Guru
Dec 1, 2014
668
375
63
Upstate NY
#11
This is dead on. If you're on an extremely tight budget, you can cobble together a factory-like TBI setup. However, these things will give up a lot of power and performance compared to any of the aftermarket options you are considering.



This is a bit misleading. If you think you might want to force induct down the road, buy an EFI system up front that can handle it. FiTech makes some systems that don't do FI and some systems that do. Problem solved. And as for non-FI upgrades (such as installing better heads, a hotter cam, etc) then any of the self-learning EFI setups can handle that change and adjust accordingly.



I think FiTech got a bad rep out of the gate. They were the first truly affordable EFI conversion, and thus they drew a lot of first-time EFI customers who had no idea what they were doing. When they got confused, or did something wrong, they would all flock to the customer support people and, quite frankly, the support people got tired of teaching people about EFI and how it works. That's not their job. But no matter what you think of their customer support, FiTech ought to be honored for redefining the bolt-on EFI market. Were it not for them, you still would have to pay at least $2000 for any sort of performance system.



The FiTech systems (and others, I am certain) use a lot of GM-style OEM components. They do this on purpose, for two reasons: these devices tend to be pretty reliable, and they are readily available at any parts store in the nation should you need a replacement. As far as paranoia about underhood heat and vibration ruining electronics, have you ever noticed where most manufacturers mount their stock computers on their EFI engines? ;)



Then you are the perfect candidate for a self-learning EFI conversion. I am right there with you, as I have a FiTech Go EFI 4 kit sitting in my garage, awaiting install. I just purchased a new fuel tank and pump assembly, so I am finally getting close to my conversion. (I will need to wait until after Easter Jeep Safari; I need to devote my current free time to finishing maintenance and prep on my Wrangler.)

I've been studying and researching EFI conversion s since before I installed by V8. Let me share the three best pieces of advice I have.

#1: read the best internet feedback available

From what I've seen, if you want to hear about experiences and get help from others who are doing the same upgrade, there is only one forum you should visit: the Team Chevelle EFI subforum (http://www.chevelles.com/forums/89-efi/). Here you will find hundreds of car guys who are happy to share their experiences, their failures, their successes, and so on. You can learn what not to do, and also plan your upgrade via methods that work successfully for many others. Reading threads in that forum can be time well spent.

#2: install a proper fuel delivery system

Every EFI conversion system's instructions will tell you to build a proper fuel delivery system. Every magazine review I have read will also tell you this. But despite all that, I've seen dozens of idiots (in the Chevelle forum and elsewhere) who drop a grand for their EFI system but then refuse to spend another $500 on a proper fuel delivery system to make it work... and when it doesn't work right, they loudly blame the EFI manufacturer. Don't be that guy. Yes, FiTech makes a "fuel command center" which is sort of a go-between so you don't need to alter your stock carbureted fuel tank and pump... but don't fall for it--it is often problematic. Instead, look to the factory and replicate what they did: install a baffled fuel tank with an in-tank high-output pump. Dozens and dozens of guys in the Chevelle forum report good FiTech results with a Tanks Inc tank and pump, so that's what I bought.

#3: use an acceptable intake manifold

Many guys in the forum report bizarre behavior and unsolvable issues with their self-learning EFI conversion. This generally never happens with a single plane intake, but is often seen when using a dual plane intake. For this reason, some people will say a dual plane cannot work and should be avoided. That's bad news for those of us whose engines don't need/want a single plane intake (indeed, my engine would give up a lot of low-end torque if I had to switch to a single plane). Thankfully, it isn't true. It turns out the issue is usually only seen on a dual plane intake which is fully divided, like this one:



Notice how the plenum divider comes all the way to the carb mating surface? For some reason, the EFI systems don't like it when the left side and right side throttle bodies cannot 'see' each other's signal. The solution is easy: use a dual plane manifold whose plenum divider is ground down in that area, such as my Performer RPM AirGap:



An intake like this typically sees none of the bizarre issues mentioned above. If your current dual plane intake does not have a cutout area like this on its divider but you want to continue using that intake, you can grind down the divider yourself. Numerous forum members have done this to fix their issues.


Anyway, those are three best tips I would share with anyone who wants to install an EFI conversion on their V8 car.
I agree and disagree with all of this - RESPECTFULLY.

For most people the 'self learning' systems are idiot proof if you are looking for a bump in performance with a mild cam or head upgrade. After that - they all stink until you get into the MS and Holley HP/Dominator systems. This excludes the Big Stuff, Haltech, etc. that are in the $3-8K area which are drag race only systems. The HP/Dominator stiff is great with great support, but the MS stuff has support that is better than Holley's. But the MS support expects that you know a little more than the basics.

I disagree with your comment about fuel systems. The cheapest and easiest system out there for 400-450HP is a Walbro 255 with a $20 Summit pre-filter and TPI Vette or Camaro post filter. It can be run with rubber lines capable of handling factory fuel injection. You can buy and plumb the the entire system for a little under $200. And if your HP needs go over that, then drop another $100 for a second pump or $160 for 044 Bosch that will handle 600 NA HP. The only issue with this type of setup is that the pump is not a factory part and not readily available. Personally, I setup all of our builds with two pumps and if one craps out, then run the the one that is good, but I'm yet to have this occur - but I attempt to always think ahead for the inevitability of a failure.

Regarding the Fitech, if you want to add power or boost, then you need another unit. Try to change a part on that china junk - good luck. If you have an issue, then they send you a new unit because it is pretty much non-serviceable - seen this in action. And guess what, when this occurs you're towing it and waiting for another batch of parts from china.


Old 307 and 403 - I understand your concern about EFI reliability issues. I'l give you a short story. The MS2 that been in our Cutty for over 2 years was previously in a Pontiac Astre. The reason it got moved was that the Astre rolled between 2 and 3 times and was totaled. I swapped the ECM, relay board and harness to the Cutty and fired it up with no repairs needed. Every sensor and electronic component from the dizzy to injector was transferred as well - no repairs needed. I would refer to that as relatively reliable and hardy.





In closing, if you cannot use a multimeter and do not want to read a manual, and want to buy a quality, self tuning, North American made product, then buy the Sniper. AGAIN, I mean no disrespect with my comments or thoughts.

p.s. - I have 3 MS systems in the driveway and am building the 4th as we speak. I've never had a hardware or software issue in 5 years of using them. I wish my wife's Ford could compare - lol.

Sincerely and respectfully - Jim
 

DoubleV

Royal Smart Person
Feb 25, 2011
1,957
60
48
Cleveland, aka 'The Factory of Sadness'
#12
Factory designed EFI is engineered specifically for that particular car and are built to last. Aftermarket units are a one size fits all design that are made in China. Only time will tell if any of these aftermarket EFI units can consistently last as long as they should. Hopefully they are better than I believe them to be. If it is proven they are, I may go that route too someday though I've never had any issues with my Qjet.
 

ssn696

Comic Book Super Hero
Jul 19, 2009
3,027
954
113
New Mexico
#13
I am appreciating this constructive dialogue. I'm in armchair engineering mode. I look forward to reading further posts in this thread.
 

Wageslave

G-Body Guru
Jan 25, 2017
698
441
63
#14
p.s. - I have 3 MS systems in the driveway and am building the 4th as we speak. I've never had a hardware or software issue in 5 years of using them. I wish my wife's Ford could compare - lol.

Sincerely and respectfully - Jim
As someone looking to eventually set up a MS system, what are your setups like on your cars?
 

ssn696

Comic Book Super Hero
Jul 19, 2009
3,027
954
113
New Mexico
#15
Yes, do tell. Sounds like the start of a Sticky...
 

454GrandPrix

Master Mechanic
Jul 27, 2016
353
462
63
Lehi, Utah
#16
I agree and disagree with all of this - RESPECTFULLY.
Not a problem. No feathers were ruffled when reading your post. ;)

For most people the 'self learning' systems are idiot proof if you are looking for a bump in performance with a mild cam or head upgrade.
From everything I've seen, these 'self learning' systems will work very well up to at least 600 HP, and often a bit beyond (depending which kit you select). That will cover the vast majority of members of this forum, myself included.

I disagree with your comment about fuel systems. The cheapest and easiest system out there for 400-450HP is a Walbro 255 with a $20 Summit pre-filter and TPI Vette or Camaro post filter. It can be run with rubber lines capable of handling factory fuel injection. You can buy and plumb the the entire system for a little under $200.
I have used Walbro pumps very successfully in the past. That's what I installed on my turbo Caravan back in the day, and it always worked perfectly. However, part of my success may have been because I perfectly replicated the OEM stock setup: I mounted the Walbro inside the tank, and maintained all hoses and filtration like the OEM setup. This is yet another reason I suggest anybody who wants to convert/upgrade from a carburetor to EFI ought to pattern their fuel system after an OEM high-pressure EFI layout. If you cobble together the right pieces in just the right way, it might work... but if you recreate a proven, well-engineered system then your odds of success increase significantly. I am only encouraging others to be successful.

Regarding the Fitech, if you want to add power or boost, then you need another unit. Try to change a part on that china junk - good luck. If you have an issue, then they send you a new unit because it is pretty much non-serviceable - seen this in action.
My co-worker Mike converted to FiTech over a year ago. When he bought his system, he thought he might someday add a little boost... so he chose a "Power Adder" system that is boost capable and put that on his El Camino. To this day, he is still running n/a... but if he does decide to add a turbo, his current EFI system is ready and able to handle it.


To anyone else reading along: do not take any of my posts in this thread as some sort of an anti-Holley statement. The Holley Sniper and the FiTech Go EFI 4 systems offer comparable performance potential. If you prefer the Holley over the FiTech for any reason whatsoever, great! Choose that system and run with it. Install it properly and I'm sure you'll be delighted.
 

64nailhead

G-Body Guru
Dec 1, 2014
668
375
63
Upstate NY
#17
As someone looking to eventually set up a MS system, what are your setups like on your cars?

The Cutty has been running a pre-assembled MS2 and relay board. It was originally on a turbo'd 327 with TPI. Las winter we swapped in a Motown LS and fired the ignition with a small cap GM 8 pin dizzy with remote coil (same as what's found on every TBI & TPI motor except Vette's.) The MS2 won't run coil near plug and and a 4 wire IAC - doesn't have the circuitry. We are swapping to an MS3X that he bought used that came with JB Perf I/O box. This will allow for coil near plug plus oodles of other neat stuff - launch control, boost control, traction control via ABS sensors (thank you Blazer brake upgrade), table switching, datalogging via flipping a switch, etc.. Pretty much everything a Holley Dominator will do. The MS3X will run 8 more injectors if needed or wanted. The big advantage is the coil near plug though - firing a coil once every two rpm's give silly hot spark. I've been trying to document most of it through my build thread.

He has '78 280Z that he swapped in a factory '82 280ZX turbo motor. It's running an MS1 with pre-assembled relay board. This one was a little tricky for the spark as it is running a remote coil with a GM 4 pin HEI module. The ignition and tach requires a couple of pullup resistors be installed to get the ignition to work. We are going to install a boost controller so he can turn boost up via flipping a switch or rheostat to overcome the factory 8 psi. What a fun little cat to drive. Absolutely night and day compared to what was pulled out of it. I'll come back to this set up.

We have a 90 Formula Firebird with a well built 355 with an Accel Super Ram on top. I wired this one in parallel (piggybacked) with the factory ECM so that all of the gauges, AC, cruise, etc. still function as original. Someone had chipped the ECM previously and it ran great at WOT, but wouldn't run worth a crap anywhere below WOT. This is running an assembled MS2 and relay board. I mounted them in the rear in behind the wheel well. The only item in site is a loomed cable running from the front to rear - it can be seen behind the driver seat next to the rear seat. This thing is an absolute tire burner (no traction) and I have a ticket to prove it.

I'm just beginning the process of taking our original MS2 and relay board and putting it back onto the TPI 327 with a turbo and putting it in my son's '67 C20. The chassis needs a bit of body work.

He has a buddy that has a 90ish Miata that he turbo'd and bought a Plug-N-Play for the Miata and base tuned that for him. They installed the turbo setup, bigger injectors, pump, and the piggyback ECM in about 20 hours.



Regarding support, the 280Z build is a well documented system that has been done a 1000 times. There is a forum that is dedicated to MegaSquirting everything from land speed record holders to lawn mowers (no kidding). If you can't find a previous thread answering your question, then start a thread and you will end up with someone that built the boards and wrote the software - unlike FB or alot of the garb from self proclaiming experts found in many arenas. If that's not enough, then track down one of the guys at DIYAutotune.

Keep a couple of things in mind - the MS2 was designed around the GM TBI/TPI platform. It is almost a plug and play setup. And there are many MS3 setups designed for the GM LS platform. This isn't saying you can't use it on a Ford, Chrysler, etc. It's a matter of finding out how to control the spark and calibrating your MAP, CLT, IAT sensors. It will handle any fuel system that has an injector - the MS1 works so good for that it'll make you ask why upgrade to anything else.

DIYAutotune has three videos going through how to hookup an MS2 to a SBC from start to finish. The 3 videos total over an hour, but it is step by step on the fuel system, wiring, testing, mounting, grounding (yes grounding), etc. They are easy to watch and to learn from. Those 3 videos were my bible for my 1st build. I was initially intimidated and worried that I spent about $800 and this wasn't going to work, but just like in the video, I had the car running and idling in less than 2 minutes via making timing and fueling adjustments in a matter of seconds.

https://www.diyautotune.com/

There other places to buy MS systems such as EFIsource. The sloppy mechanics guys swear by EFIsource. I've had great support from DIYautotune so why change.
 

Wageslave

G-Body Guru
Jan 25, 2017
698
441
63
#18
I have a shelf full of TBI parts waiting on me to splurge on a MS2 or a Microsquirt. I was planning on doing a fuel only setup at first, but eventually going to set up ignition also. Thanks for the insight and info!
 

CWPottenger

G-Body Guru
Oct 9, 2012
852
202
43
#19
I have had great success with my F.A.S.T. Ez-EFI ver1 (Now EZ-Fuel) and I just upgraded to the XFI Street ECU. This system has been extremely reliable, economical, and great improvement over the carb. I went this route because I already had spent money on my igniotion system when I had a carb so I only needed fuel control. I have an 84 T-type so I already had a baffled tank and efi pump. I did upgrade my pump to the Racetronix assembly
 

olds307 and 403

Comic Book Super Hero
Oct 14, 2008
3,286
706
113
Melville,Saskatchewan
#20
I believe Cutlassefi will be doing Dyno sessions this week on an Olds 350 with the new Mahle 10cc pistons and a 422 ci Olds 350 stroker with his new 4" stroker crank. Both are early iron SBO heads with big valves and the stroker is a very pump gas friendly 9 to 1 compression. The Holley Sniper will be compared to a Quickfuel carb. I will post a link when it comes up.
This motor pulled 18" of vacuum with a mild custom roller cam. The Holley Sniper did make identical 408 hp as the Quickfuel 750 cfm carb. Where it really shined was the extra low end torque, to the tune of 12 ft/lbs and the 516 ft/lbs! was at the start of the 3200 RPM curve, you know darn well it was higher. By the way, these new Olds stroker cranks are lighter, 58# vs 64# for the 330 crank and much stronger in 5140 and 4340 material. Here is the Sniper Dyno sheet, done with a stock divided RPM intake.
dyno_sheet_1c0f5b444c12f3da6bb193a98efff0a279e7b6d6.jpg
 

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