First of all...yes I searched, so don't recomend that please. I just want to know how to burn a little richer, not at idle, but accross the board, how do I put more fuel in my engine? All the search results say is get an apexi SAFC, but I was thinking it was just a matter of a faster fuel pump and what bigger injectors? Oh, it's a stock 90 NA, slightly advance timing. If anybody knows, please hook a brotha up. Thanks.

 

why have you dyno'ed it yet are you lean???? you need a fuel controler like the afc. what you are trying to do sounds stupid sorry man. if you are running lean is one thing but just trying to run rich that is only killing your horse power and cardon fauling the plugs and shortening the life of your motor.

 

I'm pretty sure I'm running lean, but I never said I was doing it...now did I? I just wanted to know HOW to do it. So, if anyone knows HOW to do it, let me know. I mean I know the apexi will do it right, but is there an alternative?

 

there is no alturnative. you either need a fuel controler, a fuel regulater, fuel injectors. those are the ways to richen the car but make sure you dyno it to make sure your not hurting your performance.

ps sorry I am having a bad day didn't meen to take it out on you. sorry

 

A bigger fuel pump will help a little. it takes alot to make a N/A run lean though... I'm sure you are fine.

 

he is right ya know?

the computer uses the readings from the O2 sensor in your exhaust to place your fuel mixture as close to Stoichiometric as possible, and then rich when you stomp on it.

i only know of a trick that works on the 86-88 Airflow meters, i dont know how the 89-91s are set up. but basically, you pop off the cover of the meter, and advance the toothed wheel on the potentiometer, so that it tells the computer that the Airflow meter is flowing a tad more air thn it really is, and its a linear effect. which means, if you make the meter say its flowing 5% more air at idle than it really is, itll say its flowin 5% more air at ANY given moment.

but again, this is only been tried on the 86-88s.

sorry for my lack of help.

wait till you open up your intake and exhaust (header, gutted cats, canister muffler), then you might need to add more fuel.

chris

 

it's all good bro Don't sweat it. Hope your day gets better in a hurry, sometimes melting a few miles off your tires helps

 

well, yeah it's not all stock I have a straight pipe inplace of the cats and an N1 cat back. And while I have your attention, I've a quick question about air filters... If I have the stock airbox should I go with a cone K&N inside the box, or just the stock looking flat K&N filter?

 

oh yeah if I wasn't past the radials already I like drifting and burnouts, good thing nitto's are on there way.

 

untill you have a full exhaust with headers, intake, and some porting you shouldn't need any more fuel. as for the intake, get a cone, but it replaces the box, it doesn't go inside...

 

Oh....hehehe, I was wondering about that, like why put a cone in that tiny box? Riiiight. Anyway, My fuel is prolly good, I was just wondering. So the cone comes next...but without the box wouldn't that suck in lots of HOT air from the engine bay, unless I actually built a new box for it? Seems to me a flat filter inside the stock airbox would only pull in cold air and would be better. What think you?

 

I just put on the K&N cone intake and haven't done the cold air box yet. I have noticed absolutely no difference in engine temp or power loss... actually, I gained quite a bit (no dyno... yet). It's up to you.

I did leave on the black air tube that goes over the fan cowl. My guess is that is still feeding cold air to the motor quite nicely.

K&N does make a drop-in replacement for the FC, but the actual intake that's part of the box is where the air restriction comes into play.

- JB

 

i like Taranis' idea. leave the front pipe on, and fabricate a panel to isolate your new cone filter into that little corner where the Air box currently resides. so youll have cool air fed into this chamber, and save 100 some odd bucks by not buying a "Fresh Air headlight cover" from RX7.com.

btw, an Adaptor and cone from a 90s MR2 turbo fits PERFECTLY, and its HUGE since its meant for a turbo car. *Shhh, dont tell anybody, its my little secret

 

The power gain is from the drop in restriction, but you are making less power than you could because you're sucking hot air. You won't notice a change in coolant temp, you'll see a huge change in intake air temp. I have a temp meter on my pod filter and haven't fitted a heat shield yet (I'm working on it!) and it regularly exceeds 140degF!
That thing relys entirely on a sealed path from the engine, so it sucks cold air in. Hardly any cold air will be pushed in, and it'll be making stuff all difference to the intake temps.
Correct, drop in filters make stuff all difference in cars will good airboxes, let alone bad ones like the FC's.

 

Getting back to the original question installing larger fuel pumps and injectors are to allow to to supply more fuel to the engine, but that's not tuning. Precise amounts of fuel must be added under the varied conditions the engine experiences; if you make major changes to the engines hardware, the fuel delivery must be tuned to suit this. Something like an S-AFC or aftermarket ECU must be used for this tuning. You can't make random changes to hardware and just expect mixtures to be OK, that's a recipe for disaster!

 

If you are running lean- it could only be due to a problem somwehere.
The big question- Why do you think you are running lean???
Are the exuast pipes gray? Are you making the manfold glow red? Are your spark plugs white/tan?
You will get more power running lean anyways, unless you are extremely so. Unless they are NUTSO ported, N/A's DO NOT NEED bigger fuel pumps and injectors- Myself, and a lot of other people here that have actually done it, know that you don't need to!

If you want a rough estimate- take the voltage off your 02 sensor- if, while under full throttle, it stays above .80v, you aren't running lean, and your car is normal.
Don't rely on this sensor for tuning though, it's useless- not accurate at all.

 

right, I know. But yes my plugs have a yellowish tan tinge to them. At anyrate, I got my answer, and thats cool. Thanks guys. I'm out