Poor performance in the heat

[mattpearce]

Hi Guys,

As many of you would know it was 40c in Sydney today.

I noticed on my normal drive home in peak traffic (14km) that by about the 8th km that the performance of my Euro (6MY05) was considerably poorer, much slower off the mark and much more laboured.

It wouldn't rev that much in first and when it did rev it felt like it was surging / pumping.

Has anyone else experienced this during quite hot conditions?

I am running Optimax Extreme (third tank) and I wonder if that has anything to do with it.

Matt

[incoming]

engines tend to run better in cooler weather...
hence CAI was made for the cold air

[EuroAccord13]

The colder the air, the more combustible the molecules are and hence more power, hot weather with warmer air affects the performance of all vehicles...


Moving it to the Tech Section as this problem doesn't just affect only the Accords....

[DjRob]

mayb u got ur A/C blasting away........

[Spunkymonkey]

also add using air con as well, which makes the engine work a bit harder too. My car was struggling today in the heat, with air con on, and crappy gearbox lol.

[EuroAccord13]

To add to the Aircon Part... I dynoed my car with and without aircon, I lost 8hp @ the wheels with the aircon on and half a second slower down the 1/4 mile...

[mattpearce]

[QUOTE=EuroAccord13]The colder the air, the more combustible the molecules are and hence more power, hot weather with warmer air affects the performance of all vehicles...

Well I've certainly never experienced it in all the vehicles I've owned.

Holden VN Berlina '98
Holden VS Calais '95
Holden VT S2 Acclaim '2000
Mitsubishi Magna TF Executive '98

Matt

[aleksandrov]

Every time I tried to rev my MY05MT today it was choking. It felt almost like there was a rev limiter kicking in. I thought it was because the air con needs to work a lot harder in extreme heat.

[Domokun SPL]

Aircon doesnt work any harder or less in different external temperatures. It a mechanical generator either on/off which compresses a gas which cools like an intercooler some air.

Could find its not just the heat, but the humidity in the air causing the combustion to be worse.

In reality, the density difference between 20 degree and 40 degrees isnt that great, its all the other crap in the air. Dont forget in peak hour traffic that the CO2, NOx etc all go up because of the exhaust of all the cars.

[eurotrash]

A common rule of thumb is that decreasing the air intake temperature by 10 degrees F will increase horsepower and torque by 1%. The converse is also true.

[JasonGilholme]

i experience this same problem in my 2001 holden barina. I think the computer in the newer cars are programmed to retard the timing alot sooner and more severly then the older cars. Alot of my mates that own astra's also have this problem. Obviously your going to get poorer performance in the heat but with a newer car they tend to kick in some sort of safety protocol to protect the engine

[MoDCoN]

[QUOTE=EuroAccord13]The colder the air, the more combustible the molecules are and hence more power, hot weather with warmer air affects the performance of all vehicles...

Well I've certainly never experienced it in all the vehicles I've owned.

Holden VN Berlina '98
Holden VS Calais '95
Holden VT S2 Acclaim '2000
Mitsubishi Magna TF Executive '98

Matt

these are all running fairly large and torquey engines all 3.0L and above? (magna?) so you will find that they are less effected by heat increase. smaller engines seem to labour more....

[Terry]

hot weather sucks:thumbdwn:

[crx_boy7]

ok why do u think that hot air rises? because its lighter than cold air!!! why is it lighter?
because the air moleculs stay closer together when they are cold(higher densitiy) and when they are hot they spread out(lower density)
what dose this have to do with performance?
if i grab some hot air in a box and some cold air in a same sized box which would have more air moleculs??? COLD
obviously the more air u get into ur engine the more burning will occour inside thus more performance

anyone who disagerees can buy a bannana, peal it and stick it where the sun dont shine then take it out and eat their choc topped banana spit!!! LOL(i am not liable for food poisoning!!)

[crx_boy7]

Terry i really really love ur EP pic

man i wish i had one