Power drop in warmer weather

[cyclist112]

I recently bought a 91 eclipse turbo, and am unfamiliar with turbo cars(main experience with small block V-8 that are NA). I notice that in winter my car seemed to hit a higher boost, and run better all around. I moved from Illinois to Houston Texas and the high heat here(90-105 every day) seems to be taking away power. Boost when it was below 50 would peak at about 14psi(according to the factory gauge) and when above around the 50 mark would go down to about 12psi. The biggest thing I notice is the power loss, and im not sure if that is directly related to the boost change or not. when the water temp is below about 190 degrees it seems to have more power and once it is at full temp it responds slower and feels a bit more sluggish(before anyone scolds me for driving cold, I allow the car to sit before driving off and give it a minute or so before hard throttle). The car is completely stock. I am wondering if the intercooler could be going bad or need replaced, as almost all parts on the car are original with just hitting 100k miles.
Like I said, I am not familiar with turbo cars, so any help or advice would be appreciated.

 

[Colt4G63 also]

That happens; cooler air is more dense, so you can get more in there. Plus the ECU gives more agressive timing when the engine is cooler, and the air charge is cooler.

 

[97gst_spyder]

Exactly what he said, more heat less timing, less performance.

Maybe a larger IC, or IC sprayer would help. Also, the factory gauge is not very accurate either.

 

[TexasTurbo]

The less timing doesn't make the boost lower, the less dense air makes the boost lower. What AFR is your car at when it is in boost? Has that changed at all?

 

[tron2119]

Cold air=more oxygen =more power
Hot air= less oxygen=less power

 

[hoby0316]

Upgrading IC would help.

 

[DJ23GSX]

Welcome to the world of turbo cars. They love nice cool weather. There is nothing wrong with your car thats just the way heat affects a turbo car. I've owned 3 dsm's from stock to heavily modded and they all felt slower in the hot summer heat. Cold air is more dense so the turbo can suck in more of it with less effort hence why you see more boost in the colder weather. Cooler intake temps make more hp as well. A bigger intercooler or meth injection will help with the intake temps in that hot Texas weather. This is the main reason I turn my boost all the way down (9psi) in the winter so when the summer heat rolls in and I'm running 20psi it doesn't feel like a slug compared to the winter if I left the boost at 20psi. Hell even on cool mornings on my way to work she rips but by the time I get out of work its hot outside and I can def feel the difference in power.

 

[mByron]

Like everyone else said, upgrade the intercooler. A nice big front mount intercooler would help keep your incoming air cooler. I've seen a big improvement in my horsepower after installing a fmic especially in summer when the car doesn't seem to have that "umph" anymore.

 

[DJ23GSX]

Considering your in a very warm climate a giant front mount might raise your coolant temps a lot and cause overheating problems because it restricts airflow through the radiator especially if you plan on keeping your a/c. Your best bet might be meth injection. One thing you should do is pull off the stock intercooler and clean the inside of it out with some sort of degreasing solution. Some people use gasoline but I've had good luck with straight simple green without mixing it with water or even seafoam in a pinch. Let the solution sit inside the intercooler and allow it to break up all the oil inside. I like to fill it almost half way up with solution and cover the ends and give it a good shake every couple of minutes while its soaking to make sure you get it inside all the tubes. Depending how much oil is in there you might have to do it a few times till the solution stops coming out gray or oily colored. After the solution comes out clean give it a good rinse with some water and let it sit out in the sun and bake till its completely dry inside. On a stock car that still vents the crankcase back into the intake pipe will build up oil inside the intercooler causing it to lose its efficiency. In other words a dirty/oily intercooler will not cool the intake charge nearly as well as a nice clean intercooler.