Has anyone move from a carbureted system to a FAST EZ EFI and noticed any difference in their HP/Torque and/or fuel economy? Was wondering if it was worth the $2,245.55 price tag.

While I have the older FAST, 1st Gen system, I have been to EFI classes and observed the EZ system working on a dyno at the Westech Facility in Southern CA.

From my perspective EFI is very good at improving general drive-ability, starting up cold or hot, lower fuel consumption, lower emissions but at the cost of more than double a carburetor system.

With the EZ system the tuning issue is lessened a lot compared to older EFI or carburetors.

Ron

While I have the older FAST, 1st Gen system, I have been to EFI classes and observed the EZ system working on a dyno at the Westech Facility in Southern CA.

From my perspective EFI is very good at improving general drive-ability, starting up cold or hot, lower fuel consumption, lower emissions but at the cost of more than double a carburetor system.

With the EZ system the tuning issue is lessened a lot compared to older EFI or carburetors.

Ron

With respect to the gains you saw do you think it's worth the money? If it gets me an extra 5-8 mpg then I would probably consider it.

I think it's worth the money. I went from 12-13 mpg hiway to 18 to 20 mpg.

Keep in mind there are gas tank and fuel pump issues with changing to EFI. Electric fans, while not mandatory, work toward the improved mileage and are easy to control form the ECU. This can lead to the need for a better alternator and wiring.

All this adds more cost than just the basic EFI.

I would still recommend it, all things considered.

Ron

I have a first injections efi setup and I get 17 mpg with 383 700r4 and 3:73 gears. Mileage and drivability definitely improved over the holley 670 carb that I had. I believe it was a little faster overall with the carb.

I think it's worth the money. I went from 12-13 mpg hiway to 18 to 20 mpg.

Keep in mind there are gas tank and fuel pump issues with changing to EFI. Electric fans, while not mandatory, work toward the improved mileage and are easy to control form the ECU. This can lead to the need for a better alternator and wiring.

All this adds more cost than just the basic EFI.

I would still recommend it, all things considered.

Ron

That's a decent improvement considering the price of gas these days. I have no problems going to a bigger alternator and electric fan but would like to stay away from having to do any major electrical upgrades. You saying that an eletric fuel pump is absolutely needed for the EFI and it will not work with a mechanical pump?

That's a decent improvement considering the price of gas these days. I have no problems going to a bigger alternator and electric fan but would like to stay away from having to do any major electrical upgrades. You saying that an eletric fuel pump is absolutely needed for the EFI and it will not work with a mechanical pump?

I don't know of any modern EFI that works with a mechanical pump. All that I have seen are electric. The pump does not take much current though and is normally buried in the fuel tank.

Ron

I have a first injections efi setup and I get 17 mpg with 383 700r4 and 3:73 gears. Mileage and drivability definitely improved over the holley 670 carb that I had. I believe it was a little faster overall with the carb.

How much was your final cost with the First Injections unit if you don't mind me asking? Any idea what your mpg was before the changeover?

I don't know of any modern EFI that works with a mechanical pump. All that I have seen are electric. The pump does not take much current though and is normally buried in the fuel tank.

Ron

I haven't seen any either that use a mechanical pump but wasn't sure if it was possible or not. I guess an electric pump keeps the constant pressure there for the EFI system to work properly as opposed to a mechanical unit would be applying pressure erratically as the engine RPM's changed.

Wow.....didn't see there was an exact same post as this one. My bad!!!!!!!!!:clonk:

How much was your final cost with the First Injections unit if you don't mind me asking? Any idea what your mpg was before the changeover?

I believe mine was around 1500 at the time I bought it but looks like it has gone up.. I got the kit with the gm ecm...
Dont' know that I checked my mpg before the changeover but it was considerable better...

http://www.firstfuelinjection.com/index.html

It is a bit shaky to attempt to justify EFI on the basis of improved HP or Tq or MPG because YMMV.

First looking at the MPG point... An EFI system is much more tuneable than a carb for all the different operating conditions the engine sees. However a carb CAN be tuned very closely for certain conditions, and if it has been tuned well an EFI system by definition is not going to beat it under those conditions. This means you will get the same MPG either way. But you might consider the odds there that most carbs are not really tuned well and so give an advantage to EFI since most modern EFI systems will self tune to an optimal operation. This means you will get better MPG with EFI. So how well tuned is your carb? YMMV.

Looking at the HP point... this tends to be high RPM operation and depends on getting air into the engine. That depends on intake manifold mostly rather than how the fuel is delivered. Since many of the EFI systems use a converted carb intake design there is not much difference. However an EFI system is not dependent on manifold vacuum for fuel atomization so you can run a bit more aggressive intake and throttle bore than a carb while maintaining driveability. So you can tweak things for more HP with EFI without losing street manners. But some carb setups are already tweaked so YMMV.

On the point of TQ... again depends on airflow and intake. Many modern designs can really bias the intake design for more Tq with EFI with long individual intake runners. Most aftermarket EFI conversions use converted carb intakes and do not get this benefit. So this really is a wash either way too.

Where EFI really shines though is in instant response in any condition. An engine does not run without atomized fuel. Remove the fuel or muck up the atomization and you will have no power. A carb setup being dependent on vacuum and airflow to deliver fuel and atomize it will sometimes just not deliver fuel (which we band-aid with an accelerator pump). Likewise without some intake manifold vacuum or heat or whatever atomization can easily get mucked up. The EFI system in contrast always has pressurized fuel to deliver under all conditions. The transition from pressurized to not across the injector nozzle accomplishes most atomization. So the EFI system always has fuel and always has atomization so the EFI engine is always running and producing power.

*THAT* is why you spend the extra $$$ on EFI.