Situation: I have a '94 Ranger with the 5.0L out of a '97 (or '98) Explorer in it. Everything works flawlessly, including the OBD-2 system, with the check engine light fully functioning just as it should. But, I want more power out of it.

Of everywhere I've looked, supercharging is by far the best bang for the buck. I could go with the aftermarket supercharging route, or, I have access to a free supercharger out of one of the 3.8 Bonneville's. Building an adapterplate for it to mount to the factory Ford manifold isn't a problem, we have many machinist friends with more than enough capability, and a little bit smaller pulley on it should compensate for the displacement. The problem I've run into is compensating for the boost of the supercharger with extra fuel.

Now unless I've thought this out wrong, being that it uses the MAF system instead of a MAP, it shouldn't see the boost numbers in the manifold instead of the vacuum and freak itself out, correct? It should read before it enters the manifold, and thus not see the boost (where it's actually supposed to see vacuum) and not go all crazy. I don't know what the computer would do... I know with cams I've done in the fuely's that the extra vacuum it sees causes the computer to just keep adding more fuel, but what would it do in a positive boost situation?

Also, in overcoming the fuel issue, would simply running a larger injector be the simplest way to add fuel, given that at full duty cycle it was putting out enough fuel to beat the knocking? Or, like in a Cadillac, could I use a boost pump in the fuel system to change the fuel pressure from say, 30psi up to 60psi and effectively change the amount of fuel put out by the injectors per cycle?

Or, if worst came to worst, where would I go to get a chip burned/built/bought that would have the right parameters in it for the supercharger...?

I absolutely love my truck and want more out of it, and in ponies/dollar this seems like the absolute best way to go. Any thoughts on where I could find the air/fuel ratio's for given boost anywhere? I know the motor has the knock sensor, so it technically shouldn't detonate itself to death if it was lean, but I don't want it to have to operate on really wild timing all the time, either, obviously. Having a starting point for air/fuel ratio's under boost would save alot of headaches, so if anyone has any experience with this kind of 'problem', it would be HUGELY appreciated!

Thanks, Matt

 

If you're looking for the originality factor, then the Bonneville blower would be interesting.

An air meter can compensate for increased airflow, but only if the air meter was designed/calibrated for a boosted application. Sometimes you can do a low boost kit (like 6psi) and be ok. Not much past that and air meter's output will be above the range of the ECU, and it causes a lean conditions when this happens. An aftermarket air meter, chip and larger injectors is definately a better option. The other fuel issue you may run into, is the pressure dropping off with larger injectors and more airflow. An FMU (prefferably a fully adjustable unit) can help, and/or a larger volume fuel pump.
I personally prefer going with more volume than pressure. The fuel pressure will be more consistant and the fuel wont heat up as much as it does with the pressure is increased. However, an FMU is easier to install, and works well for most street applications.

 

Matt
Pretend you have a 5.0 mustang. Lots of Supercharged 5.0 mustangs in the world. The explorer 5.0 is the same roller cam block as a stang with a different intake. If I were you I wouldn't try to reinvent the wheel.

 

That would work, except that the Explorer computers and Mustang computers are nowhere near similiar. The supercharger unit might work for a little bit but it would detonate to death due to lack of fuel. My pickup uses the OBD-II setup perfectly, and runs exactly as it should even though it technically would fail the evap. tests, solenoid checks, and everything else, we worked around that to make it function correctly. Sadly throwing a Mustang blower at it wouldn't work out in the long run; there's just no way to logically and accurately remap the fuel curve and overall computer function to work with the blower.

We've had ALOT of people come through our shop looking for a solution for their lopey cams in their EFI 351's in Bronco's and whatnot, and there's no real feasible and economical solution that we've ever found. The extra vaccuum from the cam and boost from the blower would theoretically create the same effect, a confused computer, and then we're back to square one.

Thanks though.

 

No, they're not programmed the same, but both will accept aftermarket tuning of some kind to work with a blower. I think what sguy1 is saying is that the Mustang kit itself, with some minor modifications, can work on a V8 Explorer being that both are 302's

As far as the air meter goes; you are correct, it will not sense any vacuum or boost pressure, and it wasn't designed to either. It is designed to measure the air flowing through it. A properly calibrated air meter, and aftermarket tuning, will help support the use of a blower. Basically, the air meter will send a signal (voltage) back to the ECU so it knows how much air is going into the motor and adjust the fuel and timing accordingly (with the help of a few other sensors as well).

 

Thank you blurry94. As I have said in other posts about my project finding a good tuner guy is key. No big power increase can be had without a proper tune

sguy1

 

I have a Powerdyne kit on my 99 Mountaineer 5L...runs great!

Easy install...mild gains