Apollo

We pretty much drive ours everywhere just as you describe and use the red key for the most part. Living near Vegas it does get really hot in the summer. We did a lot of hard testing with Kendall's oil cooler both on and off the track.
We use 91,or 93 when I have access. Usually mix in some 100 when tracking just for extra margin in the heat. Unless you are really wringing it out on a really hot day, 91 will be fine. On a hot DD day using 91, just switch to the black key if you are concerned and drive a little more conservatively.

boss man

any up-dates on the CEL problems with the kooks catted or is that still an issuie.

ace72ace

http://bossmustangsonline.com/index.php?topic=3583.0 Post #19

nota4re

You have 4 choices on the Boss regarding Long Tube Headers (any manufacturer);

1. Don't do the Long Tube Headers
2. Do the headers, keep OEM Track Key, and live with the light (our 2012 LS)
3. Do the headers and install a custom tune which also turns off the rear O2's
4. Do the headers and have a shop simese two cats per side together. Expensive (4 cats) but this works (our 2013 LS is running this set-up)

twr437

ace72ace

The youtube clip that cloud9 posted over at BMO sounds wicked! If I had the money I would get these w/no cats in a heart beat, CEL be damned. Would be great to see more Dyno results of just the upgraded exhaust w/o a tune with or without a CAI so we have an idea of what 'consistent' gains you can get just by replacing the stock headers and H pipe w/Kooks setup.

IIRC we are talking 25-30hp w/o a tune and 30+ with a tune and CAI?

boss man

I believe most of your gains are with the removal of the cats and mid pipe and a tune if I remember correctly. Headers dont play a huge part in the HP gains. i read that the factory headers do a pretty good job with flow. I guess it all depends on what your plans are in building your roadrunner 5.0.