Cold cause low boost

[krummel21]

I was tuning today and it was about 90 degrees out. As you can see in run 16 and 17, I was pretty much done with my tune just wanted to try and get rid of the knock in 17. Then rain came right after run 17 and dropped the temps a lot as you can see in run 18. Now look at that run and tell me why my boost dropped so much and my a/f got screwed up. I got a/f back to normal in run 23 but my boost was still down.

I came home and the first thing I did was check for boost leaks and there wasn't any. Would the drop in temp cause these two things to happen?

thanks,
Krummel21

 

[alex99gst]

I was tuning today and it was about 90 degrees out. As you can see in run 16 and 17, I was pretty much done with my tune just wanted to try and get rid of the knock in 17. Then rain came right after run 17 and dropped the temps a lot as you can see in run 18. Now look at that run and tell me why my boost dropped so much and my a/f got screwed up. I got a/f back to normal in run 23 but my boost was still down.

I came home and the first thing I did was check for boost leaks and there wasn't any. Would the drop in temp cause these two things to happen?

thanks,
Krummel21

The cooler air is more dense and usually people see more boost. I can't see any logs or anything if you were trying to post them.

 

[andymoraitis]

In warmer and less oxygen rich air, I often see a maximum boost reading of 25 psi. If I go out on a cool morning, I'll usually see up to 26. The reasoning behind this is that cool and dry air is more densely packed with oxygen and as such has the ability to make more power than warm humid air (as Alex mentioned). Humidity, or water grains also have their own effect outside of ambient air temp since water in the air displaces oxygen.

I wouldn't worry a bit as this is completely normal.

Enjoy,

Andy

 

[krummel21]

sorry heres the runs.

 

[krummel21]

This log is from a dyno tune I had done a while back. Check the psi and intake temps. I just noticed this and I haven't touched the MBC since then. Has anybody heard of this happening?

 

[andymoraitis]

Unfortunately, I don't use a PC or Link so I can't read those.

Sorry!