Fueling question!!

[Nickf10]

Anyone running 100 octane? I have jb4 + bcm with downpipes. If so how much in a tank? And which map for jb4 + Bcm. Thanks guys!!

[Msizzle]

i use race fuel or octane booster on map 2 which is 22psi, unfortunatley we are out of fuel after that and the clutch can't really hold any more power so the higher boost maps can't be used. If you have a non competition package car I wouldn't run 22psi on pump gas even though it says you can, you are just about maxing your fuel trims and the car can get very lean. Pump is fine for your 18-20psi, then on map2 i use the higher octane

[ur20v]

Some can get away on map 2, do some logs and send to Terry to see if your fuel trims are maxed or not.

As mentioned above 22psi is the max on OEM clutchs even then some get slip at low rpm.

[erm324]

Map 2 (22lbs) on rev 1.4 is fine on competition package cars. Fuel trims will be maxed but AFR will still be in check so it's ok (fwiw I've never ran anything but map 2 since install). Competition package cars run very rich and can get away with a more a more aggressive map on the JB4 using pump fuel.

If your car is non-competition package, then either use map 1 (19lbs) on rev 1.4, or map 1 (4-5lbs over stock) on rev 1.5.

For more info check the M5/M6 thread on N54tech.