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Has anyone done a FI conversion , how well does it work, thinking of doing it to my BBC but looking at the expense vs reward factor. And hopefully someone has already done it and will be able to take the guess work out of it.:no:
 

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Great White North
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I have been thinking about it too, but to run a closed loop type system, you have to run dry headers for the O2 sensor. A friend has converted a couple of Enderle injection units for 8-71 blowers to aftermarket EFI controller (accel I think), and has offered to build one up for me. Still have to figure out how to make johny law happy with the sound, maybe Borla X-1 muffled dragster headers ( they may not make it very quiete, but it looks like you are trying and we do not have db legislation, only that you must have a functioning silencing device).
 

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I just installed a Holley Avenger self-tuning system on an old Impala the other day. I was blown away that the car fired right up and within a few minutes of driving it, it was running every bit as well as the carb that was on it. The jury is out on whether the fuel economy improved but so far its snappy, idles well, and runs smooth.
 

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a properly tuned efi setup should never need an O2 sensor. now don't get me wrong, to get it properly tuned you must have a wideband O2 sensor, but once tuned correctly it can be run perfectly fine without one. Computers are calculation devices, you give it inputs such as rpm and load, then factor in air temp, coolant temp, altitude, etc. and it will calculate how much fuel to give based on the VE table which YOU tune. It has only been in the more recent years that aftermarket setups have been going to a full closed loop operation where the O2 acts as a constant COMPENSATION device (it is not used to determine fuel that needs to be delivered, simply a reading to adjust slightly from the VE table you tune and your desired A/F ratio at a given load and rpm) The even newer stuff like what cyclone is talking about has a self tune feature. it operates the same, just that it records the difference between desired A/F (which you set) and actual A/F. It then will auto correct the VE table to get the desired A/F in line with the actual A/F. It is just performing the task that you would normally do for tuning the VE table.

I have done many efi swaps, and have more in the works. I personally have had a lot of success with megasquirt units which are a much more raw form of efi. But many people on here use FAST, Holley, Motec, Big Stuff.......and the list goes on and on. I also had a mefi unit with a ram jet style manifold on my old engine, which did not run an O2 sensor. I never once had an issue with it and it only got me more hooked on EFI. The difference between a well tuned efi setup and a carb is night and day in my opinion. I just bought an old 64 ford F100 that is all original (and beat) and its the first carb setup i've had in years!......I hate it! its soon going to be torn apart and will never see anything related to mechanical fuel control ever again.

The costs are extremely reasonable for the swap and its just a matter of how involved you want to get. if you plan to do everything yourself and are determined to keep it as affordable as possible, then it can be done for under $2000 quite easily. But if you start finding "must have parts" and bling or just want to pay someone else to do it....well the price can goes as high as the moon, but that's with all things I suppose.

If I ran an over the transom header setup, I'd tune dry, then once I got it set, I'd pull the O2 and run the water again. Even better is to dyno it, get the tune roughed in. then you would only need a small amount of seat time with the dry headers to fine tune it on the water and go back to injected without O2. Keep the tune on the conservative side and you will never have any issues. Mine ran for many years never once leaving me stranded.

Andrew
 

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Has anyone done a FI conversion , how well does it work, thinking of doing it to my BBC but looking at the expense vs reward factor. And hopefully someone has already done it and will be able to take the guess work out of it.:no:
FWIW & MHO...put a set of stack injectors or a T/R with a hat & port injectors...alot easier to tune & i think they make more HP...ask some of the guys who are running those kind of systems & see what they say :)...just sayin' my .02 cents
 

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EFI Costs

Accel super Ram $775
Edelbrock fuel rails $120
Trick flow 120# injectors $433
Fuelab pump $585
Megasquirt computer $425
Fuelab regulator $140
Harness home built $164
Sensors $160
2X innovate widebands $270
Fuelab Fuel filter $160
BBK throttlebody $360

$3592
Everything new

This is what my EFI has cost so far.
This does not include any fuel lines or fittings. I have also purchased the AN fittings to be welded to the tank.

I made the jump with my twin turbo street car. After choking down the cost, every other aspect is worth it! But choking down the cost is a little tough.

Blow through carbs can be tuned VERY effectively, a wideband is a must!

The EFI gain is: altitude variance, instant boost changes 10psi 15psi 20psi correct AFR instantly after setting your boost level, timing control, datalogging, constant AFR monitoring with instant corrections, monitoring charging system.
Then outside the EFI functions, you can monitor pump pressures, a paddle wheel speedometer, G meter, input from your GPS (some models)........and what ever else you can think of, heart monitor? Blood pressure?

Everything has a cost. If you do not intend to fully utilize the functions, then the cost is greater than the benefit.

In my opinion;
Naturally aspirated or roots type blown, the minimal gains over a well tuned carb are not worth the effort or cost.
Turbo'd, the gains are priceless.

I have an accel VI computer if someone wants to get in on the cheap. The features are a bit limited with this version.
 

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Highaboosta
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3,431 Posts
...alot easier to tune
I would be interested in how your tune is.
What is your A/F ratio at idle ? cruising speed ? WOT ?

I never found a MFI user yet who could tell me WHAT their fuel curve was so you can be the first.

Isn't that the whole purpose of a fuel injection system,
How accurate of a fuel curve can it produce at various load points and RPM ranges ?
 
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