Fuel Economy & Power Boost

[motorman2008]

Anyone ever tried tweaking any of the new 4.0 engines? I know you can tweak the fuel injection on kawasaki streetbikes by installing a variable resistor in-line with the coolant temperature sender which improves both the mileage and power since it leans out the amount of fuel by tricking the main computor into thinking the engine is running a little hot. I wonder if it would work on a ranger or any new vehicle?

 

[motorman2008]

I guess nobody heard about it lol

 

[Ranger 1]

Did it on a 302 Mustang, saw no real improvement. They sell them on ebay for almost every application. My best performance boost came from a ZEX kit.

 

[rocket 5979]

I guess nobody heard about it lol

Everyone had heard of it. Just not a smart mod.

 

[motorman2008]

Did it on a 302 Mustang, saw no real improvement. They sell them on ebay for almost every application. My best performance boost came from a ZEX kit.

Variable resistor on ebay? I never saw anything like that on there. You guys dont think I'm talking about a vortex or something like that do you? I mean just a plain variable resistor that you wire in yourself. And your right that it wont gain much for power but when we were racing bikes any little power gain was useful. and for the price of a $10 resistor and do it yourself I cant see it being that bad of a mod. We used to gain upwards of 4 MPG on the bikes and with gas prices the $10 for the resistopr would probably pay for itself. But I haven't tried it on anything other than a bike so I really dont know what the gains or losses would be.

 

[Maniak]

Here is a post from another thread... As I understand it, you are asking about trying to change the IAT so it changes the mixture. It doesn't help, if anything it makes it worse (making it think its cooler out).. If you made it think it was warmer out to lean the mixture you would still loose power because it would pull the timing back some.

~Mark

This part goes in series with the engine coolant temperature sensor. I think some guys might bypass the sensor altogether to keep this resistor on the system to trick the computer. You could fine tune it if you use a potentiometer instead of a resistor, although you will still need a resistor if you decide to eliminate the ECT. This chart is in # 25 in my list of useful threads:

I made one of those things myself using a POT.. I could move the temperature that the computer saw around.

It just doesn't work.. Never saw any difference in mileage or any SOTPD (seat of the pants dyno) increase. I spent $5 on mine which included a little project box to put it in..

Now I have a spare POT and little project box for some other project down the road.

~Mark

 

[motorman2008]

I see, Well I know of one mechanic out here who did something to his own F-150 with 5.4 engine. He gets 28 MPG with it but I'm not sure what he did. I know it only got 16 MPG before.

 

[rwenzing]

F-150 with 5.4 engine. He gets 28 MPG with it but I'm not sure what he did. I know it only got 16 MPG before.

Sorry but I'll have to raise the flag on this one.

 

[rocket 5979]

Sorry but I'll have to raise the flag on this one.

Now Bob you can't raise the BS flag just yet until you know what mods the guy did. Ya know, like a 4 banger swap! :

 

[motorman2008]

I'm not joking dude. It is feasable to get 28 MPG out of a 5.4. If you know what your doing I'm sure you can do whatever you really want if your willing to invest time into it. He said he had to tweak several sensors and open up the exhaust and intake.

 

[motorman2008]

I dont mean to sound over-optimistic but there has to be ways to tweak fuel injection, it cant be impossible.

 

[rocket 5979]

I dont mean to sound over-optimistic but there has to be ways to tweak fuel injection, it cant be impossible.

There are ways to tweak fuel injection. But it is only to an extent. Go a little more lean in the AFR's and you will gain a little MPG. Go too lean and you will not have proper combustion and which will kill power and mileage will follow. That is why stoich AFR's are so important. A tune itself will not net a large different unless it is combined with allot of other MPG friendly mods.

 

[motorman2008]

Well, from my own experience with modern fuel injection on motorcycles there's quite a bit of room to move to achieve perfect stoich. Unless its a Suzuki lol, which are super lean anyways for emissions. And I would assume a Ford engine would have quite a bit if not more room to lean out for perfect stoich. Now if I could remember the calculations from college would help lol. And I agree that I would have to do more mpg friendly mods to achieve that.

 

[rocket 5979]

Well, from my own experience with modern fuel injection on motorcycles there's quite a bit of room to move to achieve perfect stoich. Unless its a Suzuki lol, which are super lean anyways for emissions. And I would assume a Ford engine would have quite a bit if not more room to lean out for perfect stoich. Now if I could remember the calculations from college would help lol. And I agree that I would have to do more mpg friendly mods to achieve that.

I do allot of Ford, Lincoln, Mercury custom computer tuning. It just is not the case. You are damn near at perfect stoich for gasoline (14.64:1 AFR) when in closed loop (part throttle, idle) anyways. You can lean it a liiiiiiittle further but nowhere near what you seem to think you can do. Once you go so far past stoich you will see results I outlined in my previous post. That is why when people ask for a MPG tune they do not really see a huge difference over any other typical performance tune. There is only so much optimization and tweaking that can be done with AFR's in the tuning before you meet a point of diminishing returns.

I do not have any experience with motorcycles so there may be allot left in the AFR tuning for those. Just like my vehicular knowledge doesn't fully crossover to cycles, the same can be said for the reverse. You seem to come from a cycle background but that application of knowledge isn't an exact crossover.

 

[motorman2008]

Actually most motorcycles are very efficient. The Honda Goldwing would probably be the closest to automotive FI than anything else as it has an automotive style V6 in it. But maybe its easier to notice power and fuel economy gains on them since they are so light.

 

[motorman2008]

With the way fuel prices are going I think I would rather find a way to get better mileage and sacrifice power for the way that I drive, which is mostly highway at about 65mph, or at least find a way for my truck to get more consistent mileage instead of jumping from 28mpg to 22mpg almost overnight. Is there a way to even it out?