[aszorc]

I have a '00 Passat with the APR chip. I've noticed a significant reduction in boost in colder weather. According to APR, the OEM maps reduce boost in colder weather for consistant performance. Does anybody notice the same with their APR chip. In the summer time, I used to hold boost at 16 psi. Now only 12-13 psi.
Does the UPSolute or GIAC chip do the same?
BTW, I have a Forge valve so the DV going bad is probably not the answer.
Thanks


[Modified by aszorc, 6:01 AM 11-29-2001]

 

[mrkrad]

Re: Lower boost with APR chip in colder weather ?!? (aszorc)

basically what your saying is the car makes the same amount of power at 12psi in the cold as 16psi in the blistering heat. Makes sense, since the 4psi is probably a result of heat expansion (insufficient intercooling, too small of turbo) during hot hard days.
Boost doesn't make power, the density of air makes power. In theory it is possible that a cold charge temp of 12psi could make more power than 16psi of hot (less dense) air.

 

[scotty_passat]

Re: Lower boost with APR chip in colder weather ?!? (mrkrad)

yeah, gotta wonder how the MAF readings look WRT temp....
-scott

 

[drm916]

Re: Lower boost with APR chip in colder weather ?!? (scotty_passat)

My GIAC chip makes the same amount of boost in all temps...If anything I think my GIAC makes more boost in the cost because the air is benser.....

 

[Electron Man]

Re: Lower boost with APR chip in colder weather ?!? (drm916)

Yep, air density (mass/volume) is a strong function (inverse relation) of temperature...as temp. decreases, the mass of air per unit volume (lbs/cu ft) increases.
Looking at it another way, the compressor doesn't have to work as hard (lower boost reading) to pull the same mass of air through the MAF when the temp. is lower.