3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

less fuel use

Thread Tools
 
Search this Thread
 
Old Mar 21, 2004 | 08:41 PM
  #1  
austinsFD's Avatar
Thread Starter
Ahhhh Motherland!
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 715
Likes: 0
From: CA: Van Nuys
less fuel use

i have a 1994 fd3s and i was wondering if i lowered the fuel inj. CCs in the PFC would i get better gas milage or would it just screw up my engine and turbos?
Old Mar 21, 2004 | 08:43 PM
  #2  
Hyperite's Avatar
Vagina Junction
Tenured Member 20 Years
 
Joined: Mar 2001
Posts: 1,838
Likes: 0
From: Seattle, WA
lowering the fuel injector size in the computer would cause it to dump MORE fuel, since it think you have smaller injectors and has to open them wider. Anyway, this isn't stuff you want to do regardless, in either direction. Proper tuning will give you the best compromise between power and fuel efficiency. I say don't mess with it.
Old Mar 21, 2004 | 08:51 PM
  #3  
austinsFD's Avatar
Thread Starter
Ahhhh Motherland!
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 715
Likes: 0
From: CA: Van Nuys
thanks hyperite
Old Mar 21, 2004 | 09:13 PM
  #4  
mad_7tist's Avatar
Rotary Freak
Tenured Member 05 Years
 
Joined: Jan 2004
Posts: 1,899
Likes: 0
From: tampa
550cc and 850cc injectors not exactly fuel efficent. fast though.

what kind of mileage are any single guys with upgraded injectors getting?
Old Mar 21, 2004 | 09:13 PM
  #5  
ijneb's Avatar
FOR SALE
Tenured Member 10 Years
 
Joined: Jun 2002
Posts: 738
Likes: 0
From: Central Florida
better gasmilage?
www.autotrader.com search for honda.
get an old, ugly beat up one if thats all your budget will allow.

You'll be glad you did.
Old Mar 21, 2004 | 09:22 PM
  #6  
rynberg's Avatar
Lives on the Forum
Tenured Member: 20 Years
 
Joined: Dec 2001
Posts: 14,716
Likes: 10
From: San Lorenzo, California
Oh my god. That's all I have to say about your PFC idea. Do yourself a favor -- DON'T CHANGE ANY SETTINGS ON THE PFC.

You want fuel efficiency, buy a Civic.
Old Mar 21, 2004 | 10:26 PM
  #7  
austinsFD's Avatar
Thread Starter
Ahhhh Motherland!
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 715
Likes: 0
From: CA: Van Nuys
why are some rotary guys such a**holes when people ask questions "rynberg" im sure you had questions when you got interested in the rotary engine i guess people gave you alot of sh*t when you started in this fourm!
Old Mar 21, 2004 | 10:26 PM
  #8  
austinsFD's Avatar
Thread Starter
Ahhhh Motherland!
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 715
Likes: 0
From: CA: Van Nuys
why are some rotary guys such a**holes when people ask questions "rynberg" im sure you had questions when you got interested in the rotary engine i guess people gave you alot of sh*t when you started in this fourm!
Old Mar 21, 2004 | 10:40 PM
  #9  
Broken09's Avatar
I am becoming...
Tenured Member 10 Years
iTrader: (1)
 
Joined: Jan 2003
Posts: 1,507
Likes: 0
From: Montgomery, AL
I think it's the fact that you bought a sports car and now you want better gas mileage. It's just one of those things that if you buy a car like this you have to be aware of the fact your gas mileage will suck. You pay to play. I'm not trying to be an ******* here just stating the facts.
-Nic
Old Mar 21, 2004 | 10:58 PM
  #10  
pomanferrari's Avatar
Rotary Freak
Tenured Member 15 Years
iTrader: (1)
 
Joined: Feb 2002
Posts: 1,650
Likes: 2
From: San Jose
Originally posted by austinsFD
why are some rotary guys such a**holes when people ask questions "rynberg" im sure you had questions when you got interested in the rotary engine i guess people gave you alot of sh*t when you started in this fourm!
Rynberg isn't an a$$hole telling you not to mess with the PFC settings. And Rynberg educates himself before asking questions. You obviously have no clue. Nor did you bother to educate yourself.

You might as well ask if you can get better gas mileage if you change the "cc" setting to zero. That way, you'll never have to pay for gas.
Old Mar 21, 2004 | 11:11 PM
  #11  
Sesshoumaru's Avatar
Tenseiga
iTrader: (1)
 
Joined: Apr 2003
Posts: 2,252
Likes: 0
From: Iowa
there are other ways to squeze gas milage out of a rotary safely

I'm in the 20's all day with my TII with a street port and no 5th gear senor.

Change your 02
Reduce backpressure
Increase intake
High compression numbers help
clean injectors

not sure if the fd's do this or not - but in fifth gear it retards timing and fuel for FC's.

I'm gonna shoot for about 22-25 on my FD
Old Mar 21, 2004 | 11:33 PM
  #12  
XSTransAm's Avatar
Ee / Cpe
Tenured Member 05 Years
 
Joined: Jan 2003
Posts: 2,843
Likes: 2
From: Gaithersburg, MD / WVU
Originally posted by Sesshoumaru
I'm gonna shoot for about 22-25 on my FD
not to discourage you, but i get about 14 on my FD... I dont think you can get 22-25

sorry
Old Mar 21, 2004 | 11:49 PM
  #13  
ijneb's Avatar
FOR SALE
Tenured Member 10 Years
 
Joined: Jun 2002
Posts: 738
Likes: 0
From: Central Florida
Originally posted by XSTransAm
not to discourage you, but i get about 14 on my FD... I dont think you can get 22-25

sorry
Maybe he can... going down the side of a mountain with the engine off
Old Mar 22, 2004 | 12:48 AM
  #14  
scotty305's Avatar
~17 MPG
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jan 2004
Posts: 3,478
Likes: 334
From: Bend, OR
A cheap, effective way to prevent detonation is to run rich. If you choose to lean out the fuel mixture, be aware that you run a high risk of damage to your motor.

If you want better mileage for some kind of endurance racing or something, look into decreasing the weight of the car, lowering the drag coefficient, or maybe lowering the boost somehow (but I'm not too familiar with boost control).


If you absolutely feel you must run lean, buy a J&S Safeguard so you can curb the detonation that you're very likely to run into. If you think a full tank of premium is expensive, look into the price of a rebuild...


-s-
Old Mar 22, 2004 | 12:53 AM
  #15  
Kevin T. Wyum's Avatar
None
Tenured Member 05 Years
 
Joined: Mar 2002
Posts: 1,318
Likes: 1
From: Minneapolis
Hrmm? I got 25mpg on the transit sections (read lots of highway time) of the One Lap. I don't think I really ever went past 45% throttle position doing that though.

Kevin T. Wyum
Old Mar 22, 2004 | 02:00 AM
  #16  
rynberg's Avatar
Lives on the Forum
Tenured Member: 20 Years
 
Joined: Dec 2001
Posts: 14,716
Likes: 10
From: San Lorenzo, California
Originally posted by austinsFD
why are some rotary guys such a**holes when people ask questions
Why do so many ignorant kids think they can afford to properly own this car?

Originally posted by austinsFD
"rynberg" im sure you had questions when you got interested in the rotary engine i guess people gave you alot of sh*t when you started in this fourm!
No, people didn't give me ****, because I didn't ask a bunch of questions without doing a little (or a lot) of research first.

Please explain how I was an *******? You obviously have absolutely no clue about engine management systems or how a fuel injected car works. That's not an insult, it's just an observation. Since that's the case, it would be best not to change any settings on the PFC, as you could blow the motor.

As far as my comment regarding gas mileage, read my first reply above. This is a hard core sports car. If you can't afford to put gas in it, sell it and move on to something else more practical. For some reason, your generation seems to think they have to have the best of everything RIGHT NOW. I waited until I was in a position to properly afford a car like this, it's obvious that a large majority of the current FD owners don't.
Old Mar 22, 2004 | 02:14 AM
  #17  
jimlab's Avatar
Super Snuggles
Tenured Member 20 Years
 
Joined: Feb 2001
Posts: 10,091
Likes: 34
From: Redmond, WA
Originally posted by rynberg
Why do so many ignorant kids think they can afford to properly own this car?
Because they don't look any farther than the purchase price.

If a few extra gallons of gas a week are causing you any financial hardship, you bought the wrong ******* car.
Old Mar 22, 2004 | 04:43 AM
  #18  
scotty305's Avatar
~17 MPG
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jan 2004
Posts: 3,478
Likes: 334
From: Bend, OR
AustinsFD kinda sorta almost brings up a good point though; I've noticed that lots of old-school rx7club members are pretty vicious when it comes to answering dumb questions. On the Subaru forums I used to frequent, when someone asked a question that was deemed ignorant or noobish, the attitude was a little more laid-back compared to this forum. We would still mess with them, but in a more friendly joking manner, not as blunt and confrontational.

I guess my point is that if you discourage the ignorant person because you deem that his question is dumb, he's likely to stop seeking knowledge, and the end result is one more mistreated RX7.

-s-
Old Mar 22, 2004 | 04:54 AM
  #19  
AREITU's Avatar
cool story bro
Tenured Member 10 Years
 
Joined: Aug 2001
Posts: 158
Likes: 0
From: Berkeley
Originally posted by scotty305
AustinsFD kinda sorta almost brings up a good point though; I've noticed that lots of old-school rx7club members are pretty vicious when it comes to answering dumb questions.

-s-
Because they've been around long enough to where they've heard the questions a million times. Subarus weren't popular until Subaru brought the WRX over so everything is still all good. Check back in a few years then you'll get a few pessimists. I get vicious at newbie questions because it only takes a simple click of the FAQ or five minutes with google.com to figure out what they're asking...
Old Mar 22, 2004 | 11:31 AM
  #20  
Sesshoumaru's Avatar
Tenseiga
iTrader: (1)
 
Joined: Apr 2003
Posts: 2,252
Likes: 0
From: Iowa
Maybe he can... going down the side of a mountain with the engine off
was that really necessary?

it's been done

https://www.rx7club.com/showthread.p...hreadid=186070

this is same thing you see in the 2nd gens too

people range from 10mpg to 20mpg and up

It has to do with how you drive and what is hwy and street. Other half is engine condition/mods

I think 20's are a realistic and obtainable goal.

Stock hwy is about 20 if i remember and with a opening up the intake/exhaust i think i can get 1-2 more mpg.


Last edited by Sesshoumaru; Mar 22, 2004 at 11:44 AM.
Old Mar 22, 2004 | 12:26 PM
  #21  
Hyperite's Avatar
Vagina Junction
Tenured Member 20 Years
 
Joined: Mar 2001
Posts: 1,838
Likes: 0
From: Seattle, WA
I get 22 in 5th when it's hot out, A/C off, rarely boosting. You'll get better gas mileage in warmer temperatures, but with the less-power tradeoff. My first tank of the season, I got 12.2 MPG (but it was a fun ride ). I have the feeling w/ the high gas prices, this'll be an expensive summer.

Everybody posting about increased mileage with mods, it doesn't exactly work like that. Decreasing backpressure will require more fuel. Don't believe me? Go drive with a cat for a tank, then swap in a midpipe. Watch the fuel level drop when you floor it. It's almost visible!

Basically, don't expect anything better than a max of 17. If you get it, congrats, if not, too bad. It's a 10 year old car with a thermally inefficient engine. But that's why we love them
Old Mar 22, 2004 | 12:35 PM
  #22  
rex u.k's Avatar
Senior Member
Tenured Member 10 Years
 
Joined: Jun 2003
Posts: 322
Likes: 0
From: England,u.k
You US people should never complain about fuel consumption, the pittance you pay for it.
Old Mar 22, 2004 | 12:40 PM
  #23  
P'cola FD's Avatar
Hamado things my way!
Tenured Member 10 Years
 
Joined: Oct 2001
Posts: 1,245
Likes: 0
From: Pensacola, Florida
Let me jump in here for a second. With a pettit unlimited ecu, intake, dp, mp, cb, and ported intake ports, I consistently saw 18mpg in the city (when not beating on the car), and 23-24 on long road trips. It is not hard to get better mileage, just make sure the car is running properly, and keep your foot out of it.

Another thing, I know it seems that people can be total ******** for jumping down someone's throat just for asking a simple question, but what most people don't understand is that a lot of us have been on here for many years. It seems that many questions get asked in threads more than once a day. Other questions only get asked every few months. Either way, they have probably been discussed way beyond thoroughly in more than one thread. Senior members get upset because all a person had to do was go to "search" and type in "fuel efficiency" or "fuel consumption" and had at least one thread where this was previously discussed.

BTW, even with a standalone, and many mods you can still get "decent" mileage. The big thing is using a wideband, and tuning the light load areas to stoich, and setting up a closed loop system.
Old Mar 22, 2004 | 02:01 PM
  #24  
scotty305's Avatar
~17 MPG
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jan 2004
Posts: 3,478
Likes: 334
From: Bend, OR
A better /more accessible FAQ system would help , years ago when I was into computer hardware/overclocking, I helped revamp one of the FAQ's at www.hardocp.com . When noobs would come asking stupid questions, it was possible to just reply "read FAQ, it's in there!" and lock the thread.


Maybe someday when I've got enough rotary knowlege I'll try to do something like that around here.

-s-
Old Mar 22, 2004 | 02:11 PM
  #25  
adam c's Avatar
Cheap Bastard
iTrader: (2)
 
Joined: Sep 2002
Posts: 8,368
Likes: 50
From: San Luis Obispo, Ca
If you open up the intake and exhaust restrictions, you will get better gas mileage at minimal throttle pressure. The system doesn't have to work as hard to move the car. The problem is that most of us don't drive our cars like that. Now that we have the capability to use more fuel, we do.

Back to the original question. You didn't buy this car because it gets good gas mileage. It gets lousy gas mileage. Unless you drive it like an old lady, there isn't anything you can do about it.

At least you can have a big smile on your face when you are not at the gas pump



All times are GMT -5. The time now is 03:26 AM.