I dont know if you guys will be able to answer this, but when its hot and muggy my truck really has a preformance hit. even with a turbo and a comp, i'm lucky to get the tires to spin. this is my first summer with a vehical with all these mods getting a problem like this. i checked, no water is getting into any of the replaced computer parts. the turbo has enough lube to run right. my 300 doesnt have any (noticable) preformence difference on these types of day. is it natural, or did i mess something up.

Edit: At night it runs with more power, also it runs best right before a thunderstorm.

 

Check for air intake cleanliness, or proper air/fuel mix.

 

i notice this problem when i fly too so, it doesn't have me too worried, mostly i drive the 300 on day like that. the only reason it has me concered is i went up to up-state a 4 hour drive away, and with the loss of power came crappy gas mileage. the intake is fine, how do i check the mix ratio? this is why i like carbs.

 

Every body looses power on hot muggy days compared to cool crisp days, I'm sure one of our scientist will chime in to explain, Bob, where are you at.

 

Also i want to try a new oil, synthetic. what is recomended by yall, with what oil fliter, fram?

 

Mobil 1 oil, and motorcraft oil filters, k&n makes agood oil filter, it has a drain back valve, and a nut on the end for easy removal, I am currently using the k&n, I'm just not sure thier worth the ten bucks they cost, I might be going back to motorcraft.

 

thx wendell. leavening for the local autozone (a 35 minute drive) going to change the oil and filter. as for the k&n, i actually am getting one as we speak.

 

" YEAH", the k&N SEEMS TO BE A GOOD OIL FILTER, THE NUT SURE HELPS FOR TIGHTING AND LOOSING, IT'S JUST THAT THE TEN BUCKS BUMPS ME OUT,I DON'T KNOW WHY, I SPEND MORE THAN THAT ON JUNK FOOD IN A WEEK.

 

Not a scientist, but I figure a mech engineer is close enough...

Theoretically, engines produce more power on hot muggy days since the air contains more energy than that of cool dry air. However, no real engine runs theoretically due to several factors, such as detonation. In the case of the Ranger(Im assuming you have a 3.0), perhaps due to the age of the design, it seems to always be running on the edge of detonation. Add factors like the build up of carbon deposits in the combustion chamber, use of a turbo, and hot intake air, it pushes your engine closer to detonation. The detonation might not be bad enough to produce an audible "ping", but it is still reducing the overall performance of the engine. I also find that performance is the absolute worst in hot, non-humid days. The reason for this is because when water vapor is present in the air, it allows the air to absorb more heat from the combustion and surrounding material, thus reducing the temperature of the combustion chamber and allowing the engine to run at the optimum performance.

This is just a brief explanation...Ive taken classes in Thermodynamics, Heat transfer, and Internal Combustion Engines and there are MANY factors that effect performance. Im sure everything is fine in your rig.

Ive always had the best luck with Mobil 1 Full Syn. Using that oil gives my truck a smoother idle and perhaps even a slight mpg increase. It is the most expensive oil on the market, but I think its well worth the price.

 

This is natural is stated above. Your intake, while stated to be a cold air intake, is pulling more air than stock so you'll see more of a performance fluxuation with hot muggy weather. Add a/c and all the rest and it's all natural. K&N filters are a great product and mellow on the growing landfills: http://motorhaven.autoanything.com/a...A2090A0A0.aspx

 

Perhaps flush the fuel tank with some Red to get rid of gunk buildup too

 

I was doing some in-depth research on the subject. The hot air is less dense, that means less O2 comming in, and a less powerfull explosion. also the moisture impeeds the combustion process too. the best temp/humidity for my engine is 68 deg F at 30% Humidity.

 

Anyway changed oil put what Wendell recomended, engine seems to like will continue with mobile one. was using schell 10-w 30.

 

If you have too much O2 within the combustion, it will have a negative effect on performance, which is one of the reasons an EGR system is used.

How did you determine the best temp/hum. for your engine?

 

becuase, it runs best at those conditions. i keep a log of preformance so i can tune it. every time i drive it (EVERY TIME) i log my data.