cheap/easy mpg boosters?

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KramerSwinger70

KramerSwinger70

70 Dart Swinger360
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Sep 17, 2009
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so my 70 dart currently has a 225 /6 in it. i intend on swappin in a 360/904 down thge road, but that wont be for quite some time..so i was curious if anyone knows of any ways to improve mileage? i do want to put on dual exhaust, by splitting the single pipe into a Y but thats all i have planned really.
 
JMO, Go to a 2 1/4 exhaust and remove the small system, start at the exhaust manifold 8)
Change over to electronic ignition.
 
Lose as much weight as you can (Car not you:) ) and-aerodynamics. Front air dam and side dams will help. And a flat pan for the under carriage. spoiler in back will not help. Make sure you use a soft air dam to stop it from breaking on curb stops/parking. Get it as close to the ground as you can. Helps with cooling and handling at speed by making a low pressure air pocket under the car, Pulls cooling air through better and "glues" the car to the road. Yes it acts like you added weight to the car but the inertia will not increase and the lower air drag more than makes up for the downward force.
 
Don't remember when they went to hydraulic lifters but if you have solids the tune-up includes making sure they're adjusted correctly.
 
Hotter thermostat,free flowing air filter,yes open up the exhaust,coast when ya see the red light ahead of you or traffic slowing,accelerate gradually if traffic permits,viscious fan or electric fan,maybe a gear change a lot of this stuff sounds like it will make the car faster...it will but it will also increase the mileage if you keep your foot out of it
 
What kind of mileage are you getting right now?

First adjust your valves. If you don't know how there is a ton of info on the slantsix.org board

Do the HEI swap and then get the NGK ZFR5N plugs. Cut the washers off them and gap to .040

195 thermostat

2 1/4" exhaust helps a lot but isn't cheap. I don't know if you'd need bigger with a 360 or not so it might be best to not even mess with that.

Make sure you have no vacuum leaks and are pulling more than 20hg on your vacuum gauge.

Air up your tires, get rid of any pointless weight in the car and see how you do by rolling in and out of the throttle for a month.
 
I've never had any luck with the slant, but, an engine is an engine and it should respond the same no matter, unless it is allready at it's max potential. Starting from top to bottom, front to rear, drivetrain to running gear;

Free flowing air cleaner with a K&N or equal filter. Open element or a MP air cleaner adapted on top, you get the idea...

Clean the carb up!

Being you want to change the slant out for a V8, I'll skip the intake and other parts for a "On the cheap" reply and suggestion(s).

The exhaust can just be enlarged. Going dual isn't going to help and I would be, it would actualy hurt. At 2-1/2 inch pipe size, it is plenty for the engine size and HP level of the engine.

An MSD or equal ignition with a careful look at the distributors timing is a good spot to find a few miles to the gallon.

IDK if a set of taller tires is up your alley, but it wold lower the Hwy. operating RPM of the engine. Inflate what ya got correctly, slightly more to oval the tires will also help.
 
look at raising the initial timing as high as you can get it and still be able to start it when fully warmed up.

On the exhaust pipe diameter, bigger is not always better, so consult a professional exhaust/header fabricator when it comes to appropriate diameter, cause yes restrictive pipes hurt flow=hp/mpg but a necessary diameter is needed to keep thing moving fast out of the engine-velocity.
oh and no exhaust leaks! lol

Multi spark, like MSD as menetioned, will help out a lot 2-3 mpg 'guesstimate'

Aired up tires to the max rating when COLD, they expand when hot and will fool you into thinking they filled enough.

Smallest fan diameter you can use and still cool efficiently as well as good belt/pulley alignment.

valve lash on the looser side may help sum.

A tight convertor, or a lock up trans would be very nice and an easy bolt in for a 'driver' or mild build.

GOOD ALIGNMENT too.
 
You've already received many suggestions. The most important (and cheapest) are the tuneup, air up the tires, and drive slower, Another thing that can improve mileage dramatically is to go with a higher gear ratio in the rear end. If you have a 3-something or lower gear now, going to a 2.76 or higher can get you several MPG.
 
Aside from what's been offered... Check you tire pressures. If they are below max, reset them to max pressure. That will get you a ton if your tires are low to begin with.
 
1wild&crazyguy said:
so run an open header then? no...
oh but then the power under the cam go's away and you find yourself tuning a lil richer and using more throttle to get up to speed...
I'm talking mpg, not ultimate power...
why do you think that way?
Click to expand...

Uh, because you are incorrect. An open header, PROPERLY JETTED will not require "more throttle" and will in fact give you better mileage.

This thing is not a two stroke.

The only reason cars have exhaust systems made the way they are is for cost, noise, and emissions.


EDIT I see you are already talking about OPEN headers, and I was thinking the OP was talking about the MUFFLED EXHAUST SYSTEM, IE from the header/ manifold and back.

You are right about an OPEN header, low end torque will go away if too big. I doubt this is possible with a system clear back to the bumper, unless it's literally dragging the ground.
 
With all of the above, keep it washed and waxed. It works both physically and mentally. Physically, less wind resistance (ask the NASCAR guys), and mentally a clean car always seems to run and drive better.
 
1wild&crazyguy said:
On the exhaust pipe diameter, bigger is not always better, so consult a professional exhaust/header fabricator when it comes to appropriate diameter, cause yes restrictive pipes hurt flow=hp/mpg but a necessary diameter is needed to keep thing moving fast out of the engine-velocity.
oh and no exhaust leaks! lol
Click to expand...

:read2:

67Dart273 said:
Uh, because you are incorrect. An open header, PROPERLY JETTED will not require "more throttle" and will in fact give you better mileage.

This thing is not a two stroke.:hello2:

The only reason cars have exhaust systems made the way they are is for cost, noise, and emissions.


EDIT I see you are already talking about OPEN headers, and I was thinking the OP was talking about the MUFFLED EXHAUST SYSTEM, IE from the header/ manifold and back.

You are right about an OPEN header, low end torque will go away if too big. I doubt this is possible with a system clear back to the bumper, unless it's literally dragging the ground.
Click to expand...

Yeah I know I'm right, and you can fit 3''+ pipes in a 67&up a body, so are you gonna stick a 3'' pipe on your slant??

1st you're not quoting what I entirely said, and 2nd you prove me right by mentioning collector diameter and it's effect on low end ...therfore the reaction of most would be to step on it to mask it till into the power band.
btw at the same throttle position, richer means more gas used.

I already said small can restrict but that there is a usable size limit per app.
Race cars can use the gains from an open header, on't get me wrong, but thats at a way higher rpm-higher exhaust speeds/faster pulses.
so rpm range is another factor, whats this guys range?
velocity with exhaust is like an open water spicket blowin water a 1' 1/2 out, then stick a hose on it and it flows 3 ft and a solid narrow fast moving stream.

don't confuse what I said, I'm not the one whos wrong.
Click to expand...
 
rumblefish360 said:
The exhaust can just be enlarged. Going dual isn't going to help and I would be, it would actualy hurt. At 2-1/2 inch pipe size, it is plenty for the engine size and HP level of the engine.
Click to expand...

well the idea bhind doin the Y pipe was that when the 360 goes in, i would reuse the pipes, mufflers, tips, and just cut the pipes where it straightens out an run new pipes from the 360 manifolds/header(dunno yet) to meet the rest of the exhaust
 
So in conclusion, there are only a couple things you can do that are cheap or free. Everything else is going to cost you $100+
 
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