I've been tinkering with my car lately trying to get it more efficient. For some reason car manufacturers don't really care to make cars more efficient, even though the cars get more complecated, they really haven't improved vehicles that much in my opinion. I still can't figure out why there aren't any diesel hybrids. Diesel 1.9 vw gets 40-50mpg, 1.9 dohc gas motor is in 30s mpg wise, and gas electric is about the same as diesel, so wouldn't you think if you combine diesel and electric you'd get somewhere in the 60-70mpg zone??

Anyways, the project car that I have is a 2000 v6 mustang. So far with a better tune I got 4-5 more miles per gallon out of it, but there are so many other things that I see that can be improved with the car, and I wanted to hear your opinions about this.

First air dynamic. The only thing that I can improve is the underneath of the vehicle. I would think that at least 30% air goes under the car, so I am thinking about making skid plates and rear defuser for the car, to make it more slick underneath, hoping it would net me less drag. Also replacing the side view mirrors with cameras and putting monitors on the inside of a car instead, I know it's not a lot, but every little bit counts.
I also thought about making some sort of device to give it more exhaust pressure when just cruising around to improve bottom end torque, not sure if it'll work or not.
I wish I could install direct fuel injection on the car, but it's not going to happen, so I want to improve efi that I have on the car now. For some odd reason I was thinking about heating up the fuel before it gets to the injectors so far I've had mixed opinions about this, but I want to try it and see what it does, I might have to retard the timing, but I am hoping that it would lead to more complete combustion, and maybe loss of power, but not much.
Next thing that I want to do is decrease the amount of current that the car has to use. Replace all the light bulbs with leds and go to hid in the headlights ( 30w hid vs 55w halogen), less work for the alternator, less drag on the motor.
I also want to lessen the drag on the motor buy going away with belt ( except for the alternator) and going to electric water pump, electric ps and electric a/c.


To sum it all up, my goals are to decrease air drag, decrease drag on the motor, and improve efficiency of the efi.

I'd love to hear all the feedback from you guys.

 

• Raise the compression ratio 13:1 - you will need some alcohol injection if you ever feel the need to go WOT again
• Cut power supply to fuel injectors on one bank when cruising - this would be a poor mans displacement on demand but should help due to less throttling
• Custom cam grind to hold the intake valve open very late - google Atkinson Cycle
• ceramic coat the pistons and cylinder head to keep heat in the cylinder
• Reduce vehicle weight if you drive in the city a lot
• Reduce drag if you drive on the interstate a lot
• push the tyre pressure as high as you dare
• Fit a hot ignition system to ensure any fuel you put in the cylinders gets fully combusted
• You want the most free flowing exhaust possible to minimize the pumping loop

 

Crower cycle - 6 stroke with water injection.

 

My goal with this car is to find out what works and will work on any other car, simple stuff first, and more complected second.

One more question, what the difference between 40lb injectors and 40psi and 20lb injectors at 80psi?

 

Cut power supply to fuel injectors on one bank when cruising - this would be a poor mans displacement on demand but should help due to less throttling

On a second note, I don't think that it'll work, because of frictional losses and excess amount of O2 in the exhaust will cause computer to add more fuel to the 3 inj that will be working.

I am more after some things that have been used in the past with good success like in 92 vx or cx civics they used lean burn to get great gas mileage on the highway, that's what I am after.

 

Are you using a standalone and wideband? You can lean it out at cruise quite a bit and get some mileage there.

 

I don't think increasing the bottom end torque will help, that would increase fuel consumption.

 

Unless I am way off base, your engine doesn't use the o2 sensor to adjust fuel while driving.

Also, at least in my eagle, a disconnected fuel injector will throw a code and turn on the CEL.

One last thing, in order to double the flow of a liquid, you have to increase the pressure by four times. A gas, like air, can be compressed, so more can be forced though with much less force than a liquid.

Don't forget high compression with water injection.

 

I'll find out for sure, but in theory with more bottom end torque the car should be able to reach or stay at a certain speed with less load, with would mean it'll use less gas. On my 1000mi trip I was able to get 30mpg at 60mph and the load stayed around 28%, and at 70mph it was around 36% and the gas mileage dropped to 28mpg.

 

I am using predator for now and looking into getting a wideband.

 

I am pretty sure that your engine uses O2 sensors to adjust fuel while driving, but it doesn't use them at wot.

So what you're trying to say is that if I raise my fuel pressure to 80psi I'd have to replace 40lb injectors to 30lb injectors instead of 20lb like I thought before?

 

Yeah, to 27.6lb/hr to be precise, but I am not 100% sure that this could help you, you could adjust the pulse width of the 40lb injectors to lean out as much as you " like to".
I would not think that turning off 3 injectors (of 1 side) could help with fuel consumption, even at idle, besides of having an interesting problem of balancing because in order to keep running the engine (inertia) extra fuel would be needed to those 3 cylinder, if you could disengage half of the engine cylinders at idle or cruising it would be different but rather impossible in your application.
About aerodynamics... well lowering the vehicle A LOT and using a spoiler to avoid all the air you can from going under the car could help reduce the drag. Those skid plates could add some weight, you will have to do the test of what is better, the reduce in drag or moving the extra weight all the time, you could (if its a sunny day) remove the windshield wipers, i don not know how far are you willing to go?
I do not think that heating up the fuel could help in any way, besides how are you planning to heat it up? thats more energy wasted, increasing the comp ratio would surely help in the efficiency you got to improve the VE all you can.

 

warm fuel atomizes better. I have thought about this too. Bad for performance, but should be good for efficiency.

 

Air under the vehicle banging around consumes a bunch of hp at higher speeds, not as big of a deal at city (35 mph) speeds but would still help to have a "chin spoiler" very low to the ground to move the majority of the frontal air to the sides of the vehicle.

Second issue is the air coming into the grill/ radiator. Normally goes inside the engine compartment, bangs around the firewall for a while, and then exits under the vehicle (banging around there too). The old Pontiac "Trans Am" air vents on the TAs or Camaro helped get rid of the air BUT a rear facing "Cowl" type wide hood will allow a lot of air out of the engine compartment and over the roof of the vehicle, especially if the opening is several inches forward of the windshield. The cowl hood also might allow a straighter shot of inlet plumbing to the boosting device vs a 180 degree pipe on a "blow thru car"

Might be hot in the summer time with the windows down though on the occupants but would look cool.

Tom Vaught

 

I believe your fuel economy decreased due to the increase in speed, (and therefore drag), not engine load. From what I've read, gas engines make best economy when either at WOT and rpm near peak torque, or when idling. A buddy and I tested this with his car (91 notch with stock engine, full exhaust,) and were able to get over 30mpg with an average speed of about 50mph. We basically accelerated hard up to 60 then coasted down to 40. RPM was between 2500 and 3500 when accelerating. Normally the car wouldn't have done better than about 20mpg.

The easiest ways to improve aerodynamics are to lower it as far as is reasonably possible, and to put a a large 'apron' on the front to get air moving around and over the vehicle. Think pre-COT NASCAR. Removing the mirrors usually works too, but the camera thing seems like a lot of work, lol.

 

I am going to pass on the shutting off injector idea. And I also thought about lowering the car as much as possible, but it won't be practical, at least for me. The skid plates will be mostly out of plastic ( except for around exhaust), so it shouldn't add a lot of weight.

My head telling me that hotter fuel will burn more complete ( at the faster rate though which might cause detonation , so I'll have to see how much I am going to have to retard the timing, or use higher octane fuel maybe), I am planning on using the engine's wasted energy to heat up the fuel, so it won't waste any more energy than the engine already does. Higher comp ratio might be in the future, but at the very end though.

 

That's what I was thinking, I already know plenty of ways for getting more power, so I am doing this for the efficiency, because I drive my car normal 99% of the time.

 

the fuel economy decrease due to both the drag and the engine load. Drag actually caused higher engine load, so if I'll lower the drag, the engine load will decrease as well, and I'll get better gas mileage as a bonus.

Lowering the car and putting an apron around the front of the car is a great idea, just not practical for a regular street car for obvious reasons ( crappy roads), and I think your idea will improve the aerodynamics, but it will also produce vacuum state under the car which will provide more downforce, and more downforce will lead to more drag. But I can use your idea as well, 1st I'll make sure the air goes smoothly under the car as much as I can, then I can either come up with the same suspension set up as mark 8th ( lowering the car at speeds higher than 60 miles per hour, thus providing less drag), or make a chin spoiler that will be operated by hydrolics to change its angle at 60mph or so for less drag as well. I'll have to see which set up end up being most weight/$/aerodynamic efficient and I'll go from there.

 

Btw I really appreciate everybody's feedback , cause 2 heads is always better than 1