Can I run TOO rich?
 

I currently only have a dp and a custom cold air intake, but was thinking about getting a Pettit Unlimited ecu. Most that are used are set up for dp, mp, cb, intake and usually an IC. I'm going to be getting a cb probably sometime this winter, and I would be probably make a mp to put on also at that time. My question is that with just a intake and dp, would the upgraded ecu run TOO rich that it could do more harm than good? Thanks for any input.

Justin

there's no such thing as "too rich" if you own a FD.......just too poor. :(

im in the exact same situation, nerx PM me when u decide on what to do. what intake u got. im running the pettir intake and a 3"dp with the 99spec turbos and i was looking to do ecu CB and IC b4 next summer when things start heating up again.
-Mike

too rich = bad gas mileage...

...not that FD owners should complain about gas mileage:)

too rich also = less power

I read some where that if you have too much fuel, it could possibly up the risk of detonating... anyone got any info on this?

REALLY too rich and you car will also kick, buck, spudder and barely accelerate. I'm talkin 7:1 rich here though...

K

what's 7:1? (I'm an idiot, help me out)

your not an idiot... but you may have done too much ex......

To much gas will cause missing and poor performance but even worse the gas can wash the oil away from the rotor seals and housing which is not to good . metal to metal is not what I need to hear.

Too rich is just as bad as too lean, so yes, you can run too rich. Too rich can cause detonation, but also increases wear, causes carbon buildup, clogs your cats, causes extremely high EGTs, and it hurts power. If you keep boost at 10psi, tests show the stock ecu is best (ie closest to the ideal A/F ratio) even with several bolt-ons. A Pettit or similar ECU will be richer than needed, although it will be programmed for up to 14.7lbs, so if you overboost you will be safe, thats the main advantage imho.

so what is considered "too" rich?

anything under 11:1 is rich

contary to the above post about a car sputtering at running too rich (7:1)....Ive finished tuning my car and it ran like junk at 9:1-10:1.

talk to the tuners....there are guys who have lost motors from running too rich...contrary to what the guys above have said.

lots more from lean...but rich is bad too. you need to run an 11.2:1 afr through the power band...leaner during vacuum....if you are on the street...you can run
12:1 on race gas at the track.

if you get an upgraded ecu then you should get a dyno pull and see what your fuel numbers are. that is the only way to be safe. If you are modifying your car then you need to know what it is doing. TRUST ME ON THIS.

NO UPGRADED ECU WILL BE PERFECTLY TUNED FOR YOUR CAR. each car is different and needs to be tuned on its own as you upgrade it. each car needs to be tuned for its own needs using a wideband O2 sensor either on the street or on the dyno.

getting chip upgrades will help but your car will be running rich and lean in different areas that you wont be aware of.

your best bet is a programmable ecu like the pfc or the haltech or the aem...or like i said...get it dynoed after you get the chip upgrades.

good luck boys...


j