Ghirt944T

I jsut installed Authority stage 2 chips, and ever since it smells like im running alittle rich? Think its jsut a simple tune up problem like sparks and wires? Dont know when the last tune up was, jsut bought it.

poormans9fitty1

Yes, it could be the chips. The authority chips run rich through low rpms and lean through high rpms.

Danno

"The authority chips run rich through low rpms and lean through high rpms."

Do a search here for "autothority chips" and you'll get numerous dyno-charts showing the types of air-fuel ratios you'll get. What kind of boost-controller do you have? Make sure you're only using the banjo-bolt restrictor as that's the boost-curve those chips were mapped for.

Peckster

You can tell the difference by smelling the exhaust? You must know a lot about cars. What's the difference?

You can tell a lot more by checking your plugs, even more by doing a plug chop at different rpms.

I'm running APE chips and never noticed any difference in smell from any other car.

And by the way, everyone knows APE chips run rich at higher rpms, not lean. They say it's for engine protection reasons. My car runs great with them.

HoBoJoe

You can smell more fuel in the exhaust when a car is running rich... it's not really noticable unless the car is running so rich that it's detuned by too much fuel... or you can pull the spark plugs and look at the diode(?) and if it's white it's rich, black it's lean... I'm pretty sure that's how it goes...

facboy

no it's the other way around. white = lean, black = rich.

HoBoJoe

Thanks for catching that facboy... I'm still a newb, so i get things mixed up sometimes....

APKhaos

Most race techs will tell you that its next to impossible to get a reliable plug readings from engines running unleaded gas. The characteristic signs [grey/white, light brown, etc] are specific to leaded gas.

Gross cases are probably still OK - if the plug is dead white its lean, dead black and sooty its rich. Dont trust much beyond that with unleaded gas.

FSAEracer03

Telling the mixture from exhaust smell is pretty simple actually and can be used to tune 2-strokes in about 10 seconds!

Richness is evident by a smell of unburnt fuel while leanness (is that a word? lol.. it is now!) smells like burnt pans.. that pungent smell you get when you leave water on to boil too long and it fries the pan.

rhesus

I think it's the other way around sir. Lean up top, rich down below.

Charlotte944

I don't know haw the APE chips are programmed, but I can definately tell when one of these engines is running either rich or lean by looking at the plugs. The ceramic on lean plugs will have a bright yellow to white color, "Stoich" plugs will have a soft darker yellow to tan color, and rich plugs will be dark brown to black.

As for smelling the exhaust, that works too, but there are a lot more things to look at.

First off, a rich engine will tend to "bog" with sudden throttle applications, and a lean engine will tend to "wind up" much quicker. A rich engine will tend to return to idle slightly quicker that a lean engine. A rich engine will have a deeper exhaust note, while a lean engine will sound "tinny".

Final note: Back in the days before unleaded fuel, you could spot a properly tuned engine by looking at the deposits in the exhaust pipe. "Sick" engines would have dark deposits, while "healthy" engines would have light brown to tan deposits. Once unleaded hit the pumps, all exhausts turned black.