I have a stock 09 crew cab with mostly cosmetic mods. Looking at some threads, seen both sides of the 180 thermostat discussions. For the record, I don't have a tuner and don't plan on getting one, ie. wife/kid/wallet. Do plan on other mods to do in the future such as CAI, tb, bbk shorty headers, y-pipe, 14" Mufflex. I know it's a bit contradictory to get all this but no tuner but that's how it is. Wandering if 180 thermostat is worth it or will I lose mpg due to ECM overcompensating for fuel/richness? Not planning on running E-fan either. All thoughts/suggestions are welcome.

 

With out a tuner to adjust your high/low speed fans coming on then
once the radiator gets heat soaked say in traffic your really not getting
any benefits from a colder thermostat. Although with sufficient air moving
say highway driving yes it will help keep temps down a few degrees.

 

The only reason to use a 180 thermostat is so you can run the different tunes with a tuner. It will cost you some gas because the lower temperature thermostat will cause your engine to run slightly rich, and your exhaust pipes will look sooty. If not buying a tuner, your engine will run more efficiently with the 203 degree that they come with. My advice is to leave it alone until you get a tuner. My second advice is to get a tuner first and not all those other mods, because even in stock form, a tuner will be helpful. All those mods without a tuner will be disappointing .

 

X2. It will not offer any improvement over a stock t-stat if that is all you do. Your engine's stock tuning is maximized at the temperature it runs out now. A tuner is the easiest way to get more power when you decide to make the investment. And don't waste your money on a Cold Air Induction. Plenty of threads explain that they at best will give you 1HP.

 

I have to disagree with what you have said about a CAI. They are a very integral part of bolt on power. Once you have your headers on your engine it can move more air through it, that is if it has more air to move. The stock airboxes are fine for stock engines, but as soon as you start to mod...The CAI would be on my list right after the headers go on, but they both will rely upon a good programmer to make any noticeable HP gains. These HEMI engines are terribly detuned in stock form, therefore a good programmer is your best bang for the buck. The CAI also shows vastly improved throttle response over the stock airbox

 

Removing the stock airbox and replacing it with straighter, smoother and larger tubing can provide more airflow to the engine. No argument there. But without a way to get more air in (Larger throttle body) and more air out (Headers, less restrictive exhaust) they will do nothing. Dyno tests prove this. My buddy put an AIRRAID system with high flow filter on his 08' Ram which was otherwise stock. Chassis dyno tests before and after showed an increase of 1HP at WOT over stock.

However, all these "Cold air Induction" systems that are still keeping the filter IN the engine compartment are not true CAI's. It's a complete sham in advertising. Engine compartment air is hot, period. Because you put a large smooth tube between the engine and the air filter and then use a larger free flow air filter does not miraculously make the air colder. Nor does putting a plastic or metal shield around part of the filter to block some of the heat from the engine. The only TRUE CAI is a system that draws air from completely OUTSIDE the engine compartment. Under the front bumper of the fenderwell are the two most common places for such a system to draw air. And i did tests myself with this by using Inlet Air Temp gauges.

 

In your original post you just stated that CAI's weren't any good period. You are getting mighty picky as to your interpretation of CAI. If the filter is isolated from the vast amount of hot air from the engine compartment, then it is probably flowing colder air than if it was solely engine compartment air. How much colder...I don't know, but I do know that your statement about them being basically worthless as a mod to a hemi engine or any engine, is very subjective at best. If your TESTS were done at MIT I might consider them, but I seriously doubt you have the knowledge or precise testing equipment to make such a claim. A system that draws air from completely outside the engine compartment is not only a CAI, but it is a ram air system also, and sometimes systems ramming cold air into an engine, needs different tuning to gain any benefits from such a system. These CAI manufacturers are giving the general public a system that replaces their stock restrictive air boxes and at the same time probably slightly lower intake temperatures. You want to sue them over your claim....you will lose, because I guarantee you that they will have their own tests done by professional testing companies to prove that their claim of Cold air induction is truthful and documented. How cold doesn't matter, just that their system introduces somewhat colder air than a stock system

 

If they are drawing air from inside the engine compartment they are NOT CAI's, period. Sure, they might flow better then stock but they are not cooling the air any farther over a stock system. That vast majority of these systems while being touted as CAI's are simply not. Because the source of air is still in the engine compartment. Therefore it's not cold. So the title is misleading and is fact false. One of the other issues many (many, not all) of these systems have is they use metal tubing which rapidly transfers heat from the engine compartment to the air passing through it. Plastic tubing offers better insulating properties over metal. Especially since these tubes have to pass over the exhaust manifolds. When i replaced my stock airbox and associated piping with an Airraid "CAI" system i saw an INCREASE in temperature when reading off the factory IAT sensor. Because now i was sucking in more air from the hot engine compartment vs pulling cooler air in from the hole in the fenderwell Dodge already has.

When i put the stock airbox back in but kept the Airraid tube my IAT temps went down to what they were stock. When i wrapped the inlet tube with an insulation kit from Summit racing i saw a 14-17 degree drop in temperature. That was simply by keeping heat away from the intake tube.

I never said anything about suing anyone. I am just pointing out a simple fact that these companies are engaging in deceitful advertising. And anybody with the ability to see the IAT's on their vehicle can do this. You don't need to have MIT involved to read temperatures.

As for a system that draws air from outside the engine compartment? They are not all "ram air systems" as you state. Drawing air from inside the fenderwell is not a ram air system. I had a true CAI on my 96' Impala SS that drew in cold air from the fenderwell. I saw huge drops in temperature over the stock system but their is no ram air effect without some type of scoop or baffle to push a larger volume of air towards the filter to increase positive pressure in that portion of the fenderwell.