desking101

Hi guys,

Not sure if this is a problem or not. I'm seeing conflicting answers so would like to see if anybody has experienced this and it turned out be either normal, or a problem that they fixed. My car is not seeing more than 10psi under WOT no matter the RPM nor the gear. This is on 91 octane in 60 degree weather. It simply maxes out at 10psi. From what I've been reading, these are supposed to be 12-13psi at WOT but can drop depending on weather and other factors. I don't seem to be experiencing any drivability issues (no surging, misfiring, etc), car runs fine. As far as acceleration, I've only had it a couple weeks so I have nothing to compare it to. Seems to run fine. Is this an issue I should address before I go out and get a tune etc. or does it seem normal given the conditions? The car is all stock.

Thanks

polobai

Normal imo for the cool weather. When it warms up chances are you will see the boost pressure rise 1-2psi.

quattroboy

I'm seeing 10 psi maximum on my base 991.2. I took it to the dealer and had them check and they saw 11 psi.

See my post here: Low Boost Post

As a reference point, the ambient temperature was about 20 C or about 68 F and with 94 octane.

My cars seems to run fine, but I swear I saw more boost before.

desking101

It did warm up a bit today to 70 degrees and I finally saw 11psi, so I'm thinking it may actually be the temperature

ClassJ

Keep in mind. As far as I know the 991.2 does not have boost targets. It has torque targets and limits on things like boost etc. When it is cold out, and the air is nice and dense, you don't need the same boost to make equivalent torque.

AlexZTuned

This. When I installed TiAL M660’s and all of the bolt-ons, my boost was reduced by 1-2 psi because the ECU is now able to target and hit the requested torque with less boost. Prior when I was stock, I would consistently see 12-13 psi. Now, on the stock ECU (not tuned), I see 11-12 psi max.

Boost will be dependent on density altitude (temp, humidity, elevation, etc) and the ECU will adjust boost to hit the requested torque.