Nietzsche

So when the air is hotter or humidity is up how does it effect the motor. Do you have to decrease timing, add fuel, I'm kind of lost on this and today my car was running like a dog. It was about 95 and fairly humid, it reminded me of before I started modding it. What can I do to adjust these problems out.

Barzten1

iTrader: (18)

Id definately add a radiator and even a oil cooler. Just installed my oil cooler tonight so Im not sure how much it helps performance but I noticed a good difference in performance while daytime driving here in the desert after adding my Koyo radiator.

nofeardude87

iTrader: (11)

when temps get high, the ecu will detect this and limit fuel so that you can have a proper air/fuel mixture since hot air means less dense air

It's nothing to worry about. It's a known fact that high temperature will decrease performance in engines

Nietzsche

Yes, but how can I adjust it? Should I dump more fuel into the system? I haven't used it but the UTEC has a temp adjustment.

Cube

iTrader: (7)

Old topic with a dumb question that never went answered... dumping more fuel in would drop even more power. Lean = more power, but also more likely to detonate.

You can't compensate for the weather (aka, hot air will have less density and thus less oxygen required for combustion) other than water/meth injection, so basically, go FI and the intercooler combined with a positive pressure of air (more dense than freezing cold air) will help with your hot air problems

Q45tech

Always make sure that the coolant temperature doesn't exceed 199F as the ecu [oem designs] and most aftermarkets start the summer overheat PROTECTION [decrease advance and enrichen AF] even 1F above than number.

zluver

My cool air tune was already a little rich, so when it hit 90 degrees here in Oklahoma the car just felt slow. I took one to two percent of fuel out from 5500rpm to my redline and pulled 1/2 to 1 degree of timing from 5K up and the car felt much better. I was picking up knock above 6K in the hot weather, but that was fixed by those small changes.

Q45tech

Summer gasoline is blended differently from May- Sept usually less btu per gallon and changes in flame speed [ignition advance].

Sharif@Forged

iTrader: (92)

Cube is right. As air temp goes up, air density goes down, and there will be less molecules of oxygen to burn. So your butt dyno is highly accurate. Hotter temps mean less power...period.

Humidty alone has a negligable impact on power production, which is why even the most expensive stand alone ECU do not have a humidity sensor.

TTRANK

iTrader: (25)

Here in Phoenix the high summer temps make my car mad so I pull a little timing out every ~month from late spring to peak summer time and then start putting it back in once fall comes.

Q45tech

From air density changes alone [11F per 1%] it is usally hard to feel a 33F [3%] change.............look to other additional factors which additively reduce engine output.

gothchick

iTrader: (12)

UTEC allows for global map temp corrections (I was tweaking my settings this weekend). So as air temp goes up (or down), you can set the UTEC to automatically adjust timing & fuel to your desired specs in the form of % increase or decrease.