Why do we have, cold start?

[Starry]

What are the benefits of the cold start? On my Rs4 I had it mapped out. I’m sure there is a reason for it but I wondered what it was and could it be disabled on the S3?

 

[Lehn]

You mean where the idle revs are higher than normal?

 

[Starry]

You mean where the idle revs are higher than normal?

Yes, runs faster and noisier for about a minute.

 

[TYb]

I don’t know the technicalities but isn’t it something to do with emissions, getting the engine up to temperature as quickly as possible?

 

[Ron240]

Ive noticed this and wondered why it does it....but my car sounds mean as **** for about a minute or so after starting from cold.

 

[TYb]

https://www.google.co.uk/amp/s/www.carthrottle.com/post/amp/why-are-cold-starts-so-loud/

 

[ZipZap01]

This is due to emissions.

During a cold start the ECU operates the engine at high throttle, but runs the ignition timing extremely retarded to limit torque to control the engine speed.

This results in combustion being incomplete by the time the exhaust valves open, giving a meaty sound. The idea is to get lots of still burning fuel into the catalytic converter to warm it up quick.

 

[Tej13]

I thought this was a good article on secondary air injection - as you expect from PH

https://www.pistonheads.com/regulars/ph-explains/what-is-secondary-air-injection-ph-explains/38694