Today I finally got a chance to hit the dyno room again. On the stand a 2010 VMax that just finished it's initial break-in. Safe to hit it hard on the dyno.

We brought several K&N filters to the test to see if there are any gains to be made just from swapping filters. In our recent filter writeup we discussed several options from K&N that fit the new VMax more or less perfect. 

Several hours later and an entire tank and then some used for testing we gathered well over 100 runs with tons of data about the filters and various airbox modifications. With and without restrictor, with and without rear top cover, stock filter, three different K&N filter - all on an otherwise stock 2010 VMax.

Same day, same dyno it should give us a good idea what is real about some of these filter claims out there.

While we still have to go through hundreds of charts and tons of data here are some of the facts we saw today:

First of all that 2010 VMax was either very well broken in, had a great engine build or something else to it (or all of the above). It base lined at 177 SAE rwhps. By far the best numbers for any stock VMax we have tested to date.

The restrictor removal gains 2-3 rwhps on a stock exhaust (more on better exhausts as we saw last year on the x-pipe), the top rear cover is good for up to 1 rwhps and the K&N's are about 1 rwhps better than the stock filter. 

So except for the up to 1 hps you gain from a K&N filter, the rest has nothing todo with the filter but with modifications to the airbox like the removal of the restrictor.

The CM-9908 is clearly the best fitting K&N option for the VMax and can be run with or without the rear top cover. All K&N filters are virtually identical in performance. 

We will work through all the charts over the coming days and will post detailed numbers and figures by then.

For now, don't expect any magic from just a filter change. the majority of improvements comes from very simple air box modifications that can be performed without the need to purchase anything. With just the restrictor removed and running the stock filter, that 2010 put out a touch over 180 SAE rwhps - or about 3 rwhps more than stock.

That's with the stock exhaust.

Hope this helps! Ride safe!