Jump to content
Sign in to follow this  
radness

Cold Start Performance

Recommended Posts

Hey,

 

When i start my car up and it's cold , i notice a significant performance difference (obviously i dont floor it but even gentle pressure on the pedal gives a lot more response., why is this?

 

Is it because;

 

a. the engine block/bay is cold and so much more cold air is getting in it?

 

b. The cold start is giving the engine more fueling

 

c. the cat is not warmed up yet and so isn't so restrictive (i read that your Cat needs to be at working tempature before it can start removing the pollutants. Is this true?

 

Sorry if this is a bit of a dumb question !

Share this post


Link to post
Share on other sites

You don't say which engine?

But it's down to how rich the engine is running, fuel doesn't vapourise and so mix with air as well at cold temps, so the engine runs richer to compensate, often over-doing it a bit.

Share this post


Link to post
Share on other sites
The fuel atomises alot better in cold/damp consitions !

I think you mean air is more dense at cold temps (more dense = more power potential), VW's are designed to run pretty hot as that makes the engine run more efficiently, fuel definitely doesn't atomise better when and engine is cold, why do you think carb engines have a choke?

Share this post


Link to post
Share on other sites
The fuel atomises alot better in cold/damp consitions !

I think you mean air is more dense at cold temps (more dense = more power potential), VW's are designed to run pretty hot as that makes the engine run more efficiently, fuel definitely doesn't atomise better when and engine is cold, why do you think carb engines have a choke?

 

yeh sorry the air is more dense sorry ! :bonk:

Share this post


Link to post
Share on other sites
You don't say which engine?

But it's down to how rich the engine is running, fuel doesn't vapourise and so mix with air as well at cold temps, so the engine runs richer to compensate, often over-doing it a bit.

 

 

Sorry, it's the 9a. Always thought it was a bit weird as soon as it reaches tempature it seems not to rev as well. (about 10-20% difference - i suspect) :(

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...