hi lads, lately my zed has felt slightly underpowered (tt auto) when you boot it from a standing start the wheels used to spin and away you go... but lately it seems a bit flat low down.

 

but today in the sweltering heat i put my aircon on, and the car is

totaly different , its real powerful low down and i can spin the wheels

 

why is this?

 

can any one help?

 

many thanks

 

Jim:confused:

air con should sap power slightly :confused:

Hmmm, can't explain that, Jim, but no Nelly, I don't think so...

 

I believe that it should have no net effect, since the Z is endowed with some clever gadget to disengage the air con when you want maximum welly.

 

It does have a special valve though, that increases the idle when you switch it on (can't remember the name) presumably this increases the fuelling, so maybe this is related after all.

 

CheerZ,

JB.

Cant be a positive effect - only negatives.

 

Aircon saps power via compressor except at full throttle when it disengages.

 

saps more power via electric fan

increases underbonnet temp due to condenser heat getting pushed under the bonnet. Causes engine fan to lock up its clutch using even more power to shove hot air away.

 

If you get in traffic this will then heat soak to the intercoolers and boost pipes and plenum causing further power drop.

 

So its either your imagination or something loose just fixed itself - just wait and see what some cold damp air will do!!

thanks for replie lads, i know it does seem a bit strange but i can atually light the back tires up with it on???? but when i turn it off i just get a sort off hesitation / lag????

 

thanks very much anyway lads

 

JIm:)

Originally posted by WillieO

Cant be a positive effect - only negatives.

 

Aircon saps power via compressor except at full throttle when it disengages.

 

saps more power via electric fan

increases underbonnet temp due to condenser heat getting pushed under the bonnet. Causes engine fan to lock up its clutch using even more power to shove hot air away.

 

If you get in traffic this will then heat soak to the intercoolers and boost pipes and plenum causing further power drop.

 

So its either your imagination or something loose just fixed itself - just wait and see what some cold damp air will do!!

 

If i have my aircon on the temp goes up by 8-10 degrees within a couple of minutes of turning it off it drops again by 8-10 degrees,

quite a big difference

Something Bagins just added made me think again.

 

 

If you had a stuck open engine thermostat (or no thermostat even fitted) the engine could be running so cool its stayed on safety boost even in this weather! Stuck in traffic would always warm it right up though.

 

By switching on the aircon the extra heat from the aircon condenser onto the engine radiator could be enough to warm the engine right up and let the ECU enable normal boost.

 

Trust your temp sensor connections are good and clean?

 

Could give a similar effect and the extra temp caused by aircon pushes the sensor reading up enough to kick in normal boost.

mmmm thats interesting mate thanks!!!

 

:D

 

Jim