09 FLHTCU Slip-on Question

[maldetete]

What is Nightrider's opinion on installing V&H Monster Oval slip-on's on a 09 FLHTCU without changing A/C, installing SERT, and dyno? I've been informed so many different ways it's mind boggleing!

[spmullen]

The March 2009 CycleWorld Magazine article where they installed a set of V&H Monster Ovals on an 09 Ultra pretty much sums it up.
Per CycleWorld "Peak hp went up almost 5% and peak torque more than 9%, a level of increase that continued across the entire RPM band"
All without REMAPPING. CycleWorld is not known for doing Harley an favors.

If you go back to the Fall 2006 Enthusiast Magazine, published by Harley-Davidson, they published that you will get improved HP/Torque if you add performance mufflers and air cleaner, all without remapping the ECM for the closed loop bikes. You can be very sure that this was produced by the Technical people, but the Legal and Marketing people were very unhappy with the info getting out. That is why you see the Stage 1 kits listed in the HD catalogs.

All this goes to show is what Nightrider has been telling riders for a long time is accurate; the closed loop ECM will compensate for changes in exhaust/air cleaner. Your engine will not "go lean" by making the typical upgrades that riders do. The closed loop ECM's will keep the AFR at the OEM 14.6:1 fuel ratio. Technically, this is not a lean fuel mixture and the engine does not have a problem with this.

I think you will find Nightrider is not the only source of "closed loop" compensating for exhaust/air cleaner changes. American Iron Magazine had published an article on this some time ago, some of the exhaust manufacturers are telling riders this. Ever wonder about V&H's Fuel Pak? How about the EPA/CARB legal version of the PowerCommander? Do not confuse issues with the 06 and earlier bikes with the closed loop (07>later) bikes.

But there is a difference between a technical issue and a rider comfort issues. Technically, the engine is fine with the OEM fuel mixtures. But many riders are uncomfortable with the heat of the exhaust/cylinder head temperatures the late model bikes have. The ability to richen the closed loop AFR is a way to improve rider comfort.

But you can put the slip-on mufflers/air cleaner upgrades on your 07>later bikes. The sky will not fall, your engine will not 'go lean' contrary to what many Dealers, shops and vendors try to tell you.