-CON-

Hi, does any one know any tricks or ways to make rotary eat less gas, so far I tried the swirling system (tornado) inside my air intake line, it didn't work, as a mater affect I think it made it worst.

So if any one knows anything about fuel economy mods, please punch a line!

mdkrause

Hey I know exactly what you are talking about. I have tried everything.
The other night I was watching a show about corvettes and was kinda shocked to find out that one of the original engine ideas for the vette was a turbo rotary engine but scraped the idea because they were fuel gusslers. When I heard that I laughed and said your not kidding. I didn't mind it so much when I got mine in 86 but today it's not so much fun. Gas prices are 4 times what I started out with. Even thought maybe rebuilding the carb would help NOPE.
I guess we just have to face it, if we are going to own one of the coolest cars in the world, we are going to have to live with crummy fuel economy.

Good luck

MDK

old_skool

the "tornado intake system" is nothing but a scam. the best way to keep your fuel economy up would be to make sure you are properly tuned, run some seafoam through the tank to clean the fuel system, make sure your tires are properly inflated, etc. what kind of car do you have? those are just a start. if you do a search, you'll be able to find much info on the subject.

rotorhead_fc

Yeah those tornado's are a plain rip off sorry to say. Generally given the nature of a Rotary engine they consume a lot of gas mainly because the combustion chamber is so large. More so than that of a regular piston engine. Like old_skool said, you can have it run about as economically possible for a rotary but it will never compare to a 4 banger.

Its a price im willing to pay to drive such a sick car!

Turbo II

iTrader: (1)

60K tuneup, correct tire pressure, shift before 3800.

Jpk3200

And shave some lead off your foot.

old_skool

Lots of things that you can do, but question is, are they worth the effort. If you're getting really bad fuel economy right now (defined as <12 city, <15 highway), then you might try looking into one or more of the following;

Brakes - are your brakes in good shape? Do they drag at all, or do you notice that one brake seems to get hotter than the rest when you stop driving? Brake dragging can dramatically reduce total mpg. Change your brakes and lube the pivot pins to keep things in good working order.

Intake/Exhaust - a restrictive intake/exhaust system, clogged by long passages and/or debris on your air filter can cause poor mpg - get a new air filter element, fix that leaky fuel injector, or retune your carb for a leaner mixture.

Wheel bearings - do you hear squeeks and/or groans from the wheels under light braking or turning? Could be that you need new wheel bearings and grease seals. If yours are worn out, not only will they cause toe problems, but will wear your tires more quickly and increase front-end drag. Get an alignment, replace wearing parts, and set it for minimum toe-in for better mileage.

OMP pump running well? Premixing? Having plenty of oil for internal seal lubrication will decrease internal engine resistance which is a big determinant of mpg. Change your oil and go to a lighter weight (10/40 instead of 20/50) to decrease internal friction.

Tire pressure - 28 may have a nice, comfy ride, but 32-34 (based on tire size and manuf. recommendations) will definitely net you as much as 1-2 more mpg. Less rolling resistance means better efficiency, AND performance.

fuel filter - having a dirty fuel filter will cause the ECU to think that you are running lean, and will open the injectors longer

By far, the biggest contributing factor to poor mpg is your own driving style. Stay out of the secondaries, drive highways when you can, and keep it below 65 on the highway. Use your cruise-control more, and don't drive like a 'rabbit' - drive like the 'tortoise'. Slow and steady wins the race (and pays less at the pump). HTH,

n20zuki

its funny bc for years i figured the lil 1.3litre would get decent gas milage but the more i read the more i see not.

Sol5t1c3

its not like we purchased a bike. motors smaller than a four cylinder but make the power of a v8 and up, yeah fuel's gonna bite. all i know is shift at 3k, ease on the gas, and listen to the other members.

Aaron Cake

iTrader: (1)

In the FC FAQ, there are links to a few detailed mileage topics.

Anything sold to improve fuel economy is generally a scam. If a 3 cent piece of sheet metal shoved into the intake could improve fuel economy, don't you think the manufacturer would have already installed it? This goes for ridiculous things like the Fitch Fuel Catalyst, HHO systems, fuel pills and additives, as well as any other miracle device.

Sol5t1c3

^ this man's a genius

Jam_98

i used to own a honda prelude 2.2 h22a costs just as much to drive it as a rx7 maybe a little more but not a hole lot correct tire pressure helps.. and how you drive your car if u drive the hell out of it your gunna burn the gas real fast just drive it nice

hamsto24

try taking some unnecessary weight out too, i think every 100 lbs is about 1 or 2 mpg, better than nothing. also dont drive like a racer when you dont need to.

-CON-

Thanks guys for all your advise! I appreciate that even though it doesn't cheers me up, doe to the fact that I just have to compromise.

But there was one thing I was gonna ask, > what if somehow I could increase the temperature in a gasoline supply line ( heat it up or what ever ). The idea here is that if the gasoline will be hot or warm it'll evaporate better when it is sprayed in the combustion chamber than cold gasoline, so I am thinking if it will evaporate better then it may burn better and may give better low rpm torque, witch may increase the fuel economy.

What do you guys think of that idea? Does it makes sense or it's just stupid?

old_skool

no. just no.

jmazda73

MY DAD sugests to run the car lean but performance is going to be a little shatty but more economic, or retard the timing a little on crank angle...

dgeesaman

iTrader: (7)

There is nothing that you can do with your RX-7 that will pay for itself in gas savings. That especially includes the free stuff.

arob82gsl

Agreed agreed. The best way to save gas money is to move to south carolina. 1.29 a gal is pretty good hunh?

Ruston

Please Oh Please don't run lean, unless you wanna lessen the amount of money paid for gas by not have a car to put it in >_<

Rx-7Doctor

iTrader: (13)

That depends on your set up.

My Se with mild mods such as RB exhaust, 2nd gen leading coil, electric fan, 2nd gen trans with very tall 5th has yielded a best of 33.5 MPG.

Peejay's 12a carbureted model has yielded more than that.

The 2nd gen leading coil mod on my SE produced a 1.5 MPG increase and was verified 3 times by switching back and forth from the stock to the 2nd gen coil pack. When I went to the electric fan I gained 1 MPG.

A lot has to do with driving style also.
Increasing your tires pressures 5-7 PSI will make a difference without compromising tire wear.

ogreshooter

As with the 4x4 world that I am a big member of, the best things you can do to help mileage have already been listed.

Tire pressure
Tune up (pugs, wires, oil - check your viscosity and run a lower level to reduce internal engine friction)
driving style
Keep your speed low (less than 65 mph)

The only point I will argue is cruise control. I have done several tests with a wide variety of vehicles and the best method I have is to keep a constant foot pressure on your pedal. That may mean going slower up hill and faster down hill, but in the end your economy can and will go up.
Case i n point: 1996 Ford Bronco with 351 (5.8 liter) engine.

Driving too and from Albany Oregon along Highway 97, 58 and I-5 (I do this trip a lot) I have seen increases as much as 3 mpg when not using cruise control. I think that this is a battle that will never see the end, but that is my stand on it.

Thanks,

Wally

hamsto24

one thing i do with my car can add up to 15 mpg if used whenever possible. if u have a manual (which i assume) whenever you casually get up to a good speed and u know ur gonna stop soon just press on the clutch and coast, if ur on a flat surface, you can usually make about 1/8th of a mile from 40 mph just coasting, since the engine goes to idle rpms with the clutch in, this saves a LOT of gas. my car gets around 30 mpg, but with this method, around 42 mpg. i would suggest the same with automatics but just let go of the gas. you can also do this if u know there's slower moving traffic up ahead just coast all the way up to them and apply the brake until u match their speed and coast and gas from there.

Jpk3200

Modern EFI systems completely shut off the injectors when RPMs are above around 1500 with high engine vacuum.

ALUMINUMOWL (SUFH)

wouldnt it turn off then? haha i dont see how thats possible...

Jpk3200

It's simple.

During acceleration, the engine drives the transmission, which drives the rear wheels.

During decel, and if the TPS is closed, and above say 1500 RPM, the turning rear wheels drive the transmission, which connected to the engine turns the engine.