I swapped my BOV (from an uncrushed 1G DV to a Forge VTA BOV) and the AFR has changed from 10.9:1 to 11.9:1 on a WOT 3rd gear pull. Once full boost hits it's ramping up from around 11.6:1 to 11.9:1, which seems to be a full point leaner than it was before with the same tune. I also noticed the EGTs get over 970^C on a WOT 1-4 gear pull. (19 degrees timing up top on 22psi boost.)

I drove the car around for 2 days (200 miles) like this before I noticed it. My best guess is that 11.9:1 is WAY too lean for 91 octane... What has me mostly concerned (and what I noticed before the leaner AFR) is that the EGTs are WAY higher than normal. Even in the dead of summer, boosting 22psi, I was not breaking 920^C on a WOT 1-4 gear pull.

I had my AEM EMS tuned last summer for 91 octane, and again in January for 101 octane but I haven't driven the car hardly at all since January and have probably 340 miles on the car with the new BOV. (140 of those miles on 101 octane and a 101 octane EMS tune.)

BUT, it looks to me like the new BOV fixed a SERIOUS boost leak on my car!

I'm thinking I should either:
1) Put the leaky 1G valve back in for any daily driving;
2) Drop the boost down to ~14psi;
3) Mix in some 101 octane with 91 to bump up the octane on my tune; or
4) Leave the car parked and don't drive it until it's retuned.

*sigh* Fixed one problem, caused another.

-D