Even on most custom tunes it's rarely the tune and more the fuel people put in their cars, lack of monitoring, and the way they drive that causes issues. These upgrades result in a unique exhaust note that provide awesome power potential. It's worth noting that Cobb is also a boilerplate tune that is geared to being excessively conservative in the name of safety and rightly so. COBB Tuning exhaust components for the Focus ST use 3 304 Stainless Steel and are a direct replacement for factory components. I've also begun monitoring oil temperature instead of boost, as boost is a pretty linear and predictable parameter (OTS is like 21 psi?), but oil temp will let me know when the car is truly ready for a good drive. You really want to make sure you're in the 11's or better for WOT, though.Īlso don't go WOT under a 1/4 tank of gas or you risk fuel starving and grenading your shit. During normal driving you should hover around 14-15 points with some dips into the 40s when you throttle off briefly or change gears. Some people see 10 points in AFR and that's kind of rich, but better than being lean at 12 points and above too frequently. At WOT, you want to see mid-11's as your ratio. I also think it's worth talking about AFR a bit here.
![focus st cobb stage 1 v 312 dyno focus st cobb stage 1 v 312 dyno](https://www.stratifiedauto.com/images/Website%20Images/Customers/Dyno%20Results/Focus%20ST%20GTX2867%20Dyno%2093oct%20344whp.jpg)
I might be paranoid but I don't believe in being TOO careful. When on boost, the Stage 2 tune consistently registering a ratio of 10.3 on my AEM wideband gauge.
![focus st cobb stage 1 v 312 dyno focus st cobb stage 1 v 312 dyno](https://i.ytimg.com/vi/z5_NcsRb9fw/maxresdefault.jpg)
However, based on my AEM wideband readings, it seems clear that COBB are running conservative fuel mapping. It's worth mentioning I think that once he hits -1.00 OAR he should swap the gauge for Ign. On the topic of day-to-day drivability, COBB have done a great job of maintaining the smooth idle and glitch-free powerband of Stage 1.