so once the weather started to get really cold my gas mileage dropped drastically, so i took some scrap metal and slapped together an air cleaner lid to try to keep the air coming into the filter a little warmer so i could try to get a little better gas mileage. performance isn't a real big deal for me right now, because i can't afford any speeding tickets.

here's the setup i had before,

and here's what i put together,




so what do you think?
i figure the shield around the filter will help to keep warmer air from the engine and more specifically from the intake around the filterand the thicker metal will also hold heat and heat the air. maybe it's just crazy thinking. but i have noticed a little more mileage and a cleaner sound too.

 

Why didnt you hook up the stock air cleaner and use the heat stove? Which was Stock...

 

the car didn't have the stock air cleaner on it when i bought it, and i wasn't gonna rummage through a jy to find one

 

Eh, you Prob wont find one in a JY anyway..

Well, I dunno, I suppose it might work..

 

Maybe not enough room for the air to slip in through real well, but I really like the work you've done. More pics/details would be appreciated, since I need something somewhat similar for when I put my Z28 hood on (tomorrow).

 

shouldn't you get better gas milage in cold weather, i know i do, in 110 degree temps "summer" i got like 16-18 mpg at best. now that it gets cold at night 50 degrees i get 20-25, when i keep my foot of the gass

 

no, not really, when the air gets colder your intake is a colder denser charge of air and as it heats up the air expands and you take in more air than you do when it's cold. and your computer compensates for all that air by adding more fuel. so you get worse gas mileage. but the weather is different in ny, i'm talking about like 30 degrees cold during the day
50 is warm.

 

ummm .... TBI has a MAP sensor, not a MAF. The fuel and spark tables are set, there is no "adjustment" for the temperature or density of air. My car get the same mileage, year round, and always has.

You can get icing in your throttle body when the air temp gets really cold, but that makes it run like crap. I'm sure it hurts the mileage, too, but that is from the car running like crap, not the a/f ratio.

 

Yep, that is the problem with Speed Density in general. No compensation for varying weather. The density changes and so do the fuel requirements, and timing requirements.

 

I'm no expert, but density is in the name of the system. Now, the density of the air will change with tempreture change, right? Anyway, SD also has an IAT sensor to feed tempreture readings to the ecm anyway.

I might be completely off the wall, but your statement was confusing.

 

The density DOES change with temperature, but it is not really compensated for it. Even the IAT doesn't do much IIRC. I know that the IAT used in the CPI trucks has alot more functionality in it as I am running the IAT with my TBI setup and a MAF sensor.

The 7747 used in the trucks is the worse offender, it does not even have an IAT in stock form.

 

But if the density changes, wouldn't the reading at the MAP change? That would effectively change your end PW, right?

I've got the upmost respect for you, Fast355, and have no doubt you know what your talking about. Tell me where I've gone wrong in the above logic, please.

 

The baro (and MAP) is constant across the range of intake air temps. There is a small ammount of compensation based on IATs, but its a small, rather useless 5 line table in the stock ECMs. The later TBI/CPI computers had the ability to blend the IAT and CTS to get a true temperature term for the density calcs, but it wasnt used with TBI. GMs solution was to make the intake air temps close to the engine temps through the air cleaner and intake manifold design. Works quite well, but when you start getting into things like CAI's and air gap manifolds, the fueling is all over the place with a stock type TBI system, or any speed density TBI system for that matter. There are alot of dynamics involved with wetflow systems.

 

Does this mean that IAT placement on a TPI CAI on an LO3 is unimportant? This sounds like the IAT is almost useless, however, I noticed a real difference when I moved the IAT sensor to the TPI plenum.