Those of you who is using stock boost solenoid to control boost, have you noticed an increased in boost during the colder season?

My car was dyno-tuned via ECUflash to 26.5psi just two weeks ago. Nothing has been altered since, except our weather changed and became colder since. I was triggering ASC light at peak boost and my mode23 datalogs showed I was boosting at 31psi!? In other words, I was overboosting.

I brought the car back to the tuner to check for possible vaccum leak, he checked every vacuum hoses and confimed everything were intact. I have been running the JUN wga and he wondered whether if it was set too tight for the cooler weather, so he disconnected the stock boost solenoid vacuum hose, boosting solely using the JUN wga. I did several pulls to see whether I would still trigger the ASC light. Datalog shows 19psi at peak with this test, with no overboosting issue.

He said that it is not unusual for the boost to increase due to colder weather, especially when using stock boost solenoid. He recommends getting aftermarket boost controller to avoid this from happening. Do you guys agree with his comment?

Our temperature is now 10 degress celcius, compared to two weeks ago about 20 degrees celcius. But I'm still surprised by how much boost I am seeing now compared to two weeks ago due to this change (31psi vs 26.5psi!). Has anyone else notice the same issue?

 

Something isnt right there. You shouldn't be boosting to 31 if your tuned to 26.5, unless its a spike on shifting, which the mrs do. Mine is less modded than yours, but my boost is set to 25, and I have seen spikes to 28 when its in the 50s. (Im in Houston, so thats cool here).

I wonder if the tcu is killing you because of the boost spike? I have heard that the Perrin and Grimmspeed boost control solonoids help, but Im not sure to what extent. I know they will cut down on boost flutter.

 

I had this issue with the stock BOV. It would spike to 29-30psi with OEM BOV. I was tuned for 25-26 PSI. I switched to a GFB BOV and it spikes to 25-26 psi and then slowly decreases towards redline. I have a 3 port solenoid as well.

 

The OEM boost control is just as good (if not better) than any aftermarket boost control, if properly tuned.

Sounds like the load-target and error correction tables aren't tuned as well as they can be...

- Bryan

 

i would say YES weather does affect the problem you are having (from previous experience), the car is still new and the parts too (which are greatly improved). get a re-tune with the boost , load and corrections.

just my 2 cents