If I tune my car a certain way it'll get this wierd smell at idle.I do notice the blms go lean.I can't understand what would cause this.So I posted it here for you to take a stab at it.My ideas are too much/little timing,too lean,too big of injectors for the ecm to handle(30lbhr) or the catalayic converter overheating??

 

if it smells like a lit match then yr in toruble. it means yr cooking the catalytic converter. in the abscence of excess feul to convert
nox2 into water the noble metals will catalize themselves. running lean with a cat is bad news. this might be yr smell. fatten up the idle a bit.

 

i guess it would depend on the smell. If its lean enough to get a lean miss, you would get a bad smell out of it also, almost like being to rich. Too much idle timing will also make it stink, esp if lean.

 

It kind of smells like when exhaust is new and has a coating on it.The exhaust is not new though.It's only after I change something in the chip.I can't pinpoint the cause.My intake is painted but it does'nt smell even in 100F temps.I'll figure it out but help helps.Would the catalayic converter breakup if it was exposed to a prolong lean condition?

 

I dont get how a 400 sbc would get a slower time than a stock 305/350,with an optimised prom

 

anybody?

 

Well it all comes down to air flow,A engine is just an air pump.
The more air it can pump the more power it can make .
With the stock intake and runners on a larger displacment
engine is going to lower peak power even more ,you should have plenty of torque - if you can gear and hook to take full advantage of that torque than you should not have a problem running
mid to lower 13's.
Your mph is a true indicator of what a car is capable of,HP calculators like the one at mustang corral are very accurate
of possible ET - both of my vehicals are with in 1 tenth of
corrals estimate .
It come down to if you can 60ft what your HP is capable of and gear to take advantage of peak power in all 3 gears with out over rev in top crossing the line.

 

So, I want a clean- smelling idle. Suggestions?

 

huh?

 

been here-check your a/c evaporator housing. are you running headers? with mine, the plastic would get hot enough to never really melt but the frickin thing gave off the burning smell i think you are describing. then i grabbed an evap.housing heat shield off a phord ranger and it fit t!ts. and the smell went away. then i took the whole thing off and replaced it with a real metal heater only box. hope this helps.

 

Thanks grumpygreaseape, did figure it out a while ago.It was the cooling fan switch plastic plug.I put some header wrap on and it never burns now.I guess when the headders heated up more than usual the plastic burned.

I would like to know how that car(in poll) would go slower than stock,anybody?

 

sounds like at least a 13high second ride