Car seems faster when cold- Am i imagining it?

[live2themaxuk]

Hey all

 

if my car has been sat over night, or maybe couple of hours after going to the gym, for the first 3-4 minutes, it seems to accelerate harder and im SURE im not imagining it.

 

When i accelerate say it second, there seems to be ALOT more induction'y v-tecy sound to it,, the whole acceleration noise is alot more inductiony compared to when its warmed up and alot more raspy and roary from the exhaust.

 

Obviously if its got 'cold' then the ECU is gonna be implementing some choke or some different map to help the car warm up and get up to operating temperature, but i dont understand why it seems more torquey especially after the magic 3k rpm mark.

 

There no way its do to with the airfilter sucking in 'hot' air, as it only seems faster for the first 3-4 minutes until its warmed up, then the inductiony raw dies off.

 

does anyone else notice this?

 

 

JWT pop charger

Fujitsubo cat back

decat pipes

 

Jamie

[Beavis]

But maybe it is to do with sucking in warm air. I think that the zed's engine warms pretty quick and remember cold air is more dense than warm air........could that be the reason for the different noise.? Do you have the heat shield in place?

[GC350z]

The MY07 roars when started from cold. Incredible sound. Lasts between 30secs and a minute.

 

The MY04 was never as loud.

 

 

Guy

[Guest prescience]

The ECU will run in open loop mode when you start the engine until the O2 sensors have heated up sufficiently to provide a useable signal. The ECU then switches to closed loop and pretty much always operates in closed loop unless you are at or near wide open throttle. Closed loop can be thought of as 'ECU dialling out my mods mode' - it's not really that simple but a good enough analogy.

 

So when you start up, you are actually getting the benefit from your breathing mods (decats, exhaust and popcharger) until the car goes into closed loop mode. So it is probably a genuine effect you are experiencing

[sinbad]

The ECU will run in open loop mode when you start the engine until the O2 sensors have heated up sufficiently to provide a useable signal. The ECU then switches to closed loop and pretty much always operates in closed loop unless you are at or near wide open throttle. Closed loop can be thought of as 'ECU dialling out my mods mode' - it's not really that simple but a good enough analogy.

 

So when you start up, you are actually getting the benefit from your breathing mods (decats, exhaust and popcharger) until the car goes into closed loop mode. So it is probably a genuine effect you are experiencing

 

Yeah what he says...

Until the car is warmed up you'll have that effect.

[live2themaxuk]

Thanks prescience and Sinbad

 

Its weird i kinda figured that in a way as the eagerness i got from it and the induction sound was not unlike the effect i had when i put and induction kit on a previous car, though, the effect didnt go away as such.

 

Froma technical perspective what actually makes the induction noise more just after startup as that is evident there is no doubt. . . .? Just the increased air flow?

 

Now. . . what can i do to keep it . .? Chip? Uni, F-con, UTEC etc? i guess

 

Jamie

[Guest prescience]

Reset the ECU regularly (the pedal procedure in FAQs), a reset delays the 'recovery' to full closed loop equilibrium since it resets short and long-term fuel trims - which take some miles to return to equilibrium values

[Kev946]

No need to get too technical. Simply pu cold air is more dense which = more oxygen. Fuel needs oxygen to burn.

 

This is why turbo cars have enormous intercoolers often bigger than the radiator.

[Kennydies]

I dont ever put my foot down when the engine is cold, I always wait until the oil is up to temperature.