I am getting a lot of questions about which exhaust is the 'BEST' for the new VMax (2009++).

While in general it can get tricky to say which one is THE BEST, for the 2009/2010 VMax it seems to be pretty clear at this moment. Of the available contenders we had the chance to test the Stock System, our own member's (blueta71) designed X-Type Cat Eliminator which uses stock mufflers, the Akrapovic midpipe+mufflers and a 4-1 full system.

Naturally one would expect the best numbers coming from the full system.

It does not help that there are so many different numbers flying around, each with different configurations. Changes between configurations are not always highlighted or put next to each other for direct comparison.

In order to give you ONE point of view, we have tested these setups on the very same bike, with the same aftermarket changes applied to all pipes. That starts with a stock Bridgestone 200 tire, Yamalube full synthetic oil, TopSpeed Governor eliminator, EXUP eliminator, Power Commander 5 w/ Auto Tune (although only used on the dyno - due to the tuning challenges when used on the street) but also our very own Monster Big Air.

Same configuration for all runs. Only difference: The pipes.

For all runs we ALWAYS run with the K&N air filters. We don't feel that numbers without filter should ever get published as no one should run a high tech motorcycle like the brand new VMax without filters - NEVER - EVER - not even on the track.

So this is the closest Apples 2 Apples comparison between the top 3 contenders on the market that we could come up with. Same Dynojet 250 Dyno, with high flow cooling system (3 turbo blowers that keep even the VMax cool during extended load tests) and eddy current brake for custom map tuning.

All pipes got a custom map, done with the help of the Autotune, so that in each configuration, the AF ratio is as close to optimal as possible.

There are new exhaust systems in development from various manufacturers and we will add their numbers to the comparison as soon as the manufacturers make their systems available to us.

Lets have a look at the charts. Since different dyno shops continue to use different scales we provide you the charts in the most common formats: SAE (the official US standard), STD (the old US standard) and uncorrected. Caution about uncorrected results - they should not be used to compare the systems, since each system was tested on a different day. We only show them so you can see what the bike truly made that day with that exhaust. 

One final word of caution - different dynos around the world WILL give different numbers. While the absolute numbers are nice to look at you should always look at the delta between the stock bike on that dyno and the modified one. Its the difference that counts. There are no magic stock VMaxes out there that make 10 hps more. We have had 4 stock 2009 VMaxes on the same dyno and when run with the same oil, they make within 1/2 hps of each other - a rounding error.

Lets start bottoms up. The stock bike on our Dynojet 250 at pretty much sea level makes about 173 rwhps (SAE) and 110.7 ftlbs (SAE) in 4th gear. In fifth the number would be about 15hps less due to the speed governor. Equipped with the TopSpeed the stock bike will make about the same 173 rwhps (SAE) in 4th as well as in 5th gear.

Again all these configurations have been run with the Monster Big Air installed. It is not about its performance, different filter options will produce different results - its about the identical setup. Over stock airbox, the Big Air adds about 7hps on top.

3rd place in our current comparison takes the only full system on the market at this point in time. 190.5 rwhps (SAE) and 120.6 ftlbs (SAE) of torque. Only place it shines it at 3k rpm, where it performs better than any other configuration tested. So low rpm roll ons will feel strong, but as soon as the tach hits 3.5k all other pipes have caught up and will start to run away. It seems that the stock headers do a pretty good job, since both other options run with them and deliver quite a bit more torque and power across the rest of the power band.

In relative terms the full system in combination with the Big Air gets you a gain of 17.5 rwhps.

2nd place goes to the X-type cat eliminator from our own member blueta71 (aka Mike). His design has fascinated us from the very beginning. Simple, with stock mufflers, yet amongst the top performers we have seen to date. I made my very own custom exhausts, but did not manage to squeeze more out of the Vmax than Mike did. At 193 rwhps (SAE) and 122.5 ftlbs (SAE) of torque, the extreme low cost mid-pipe outruns the full system by 2.5 rwhps on top, even more at 8.5k.

Again, when compared to the stock setup, the x-type cat eliminator with stock mufflers in combination with the Big Air gains about 20 rwhps over stock.

1st place to this date goes clearly to the Akrapovic mid-pipe/muffler combination. While we have not tested the setup with the stock mufflers, we expect from prior tests and different runs, that the vast majority of gains comes from the Akrapovic midpipe. running this setup with stock mufflers should result in very similar if not identical results.

At 196 rwhps (SAE) and 124 ftlbs (SAE) of torque this combination is the current king of the hill. Straight bolt on, easy to install, the best installation instructions of all, the best hardware kit and by the way the BY FAR lightest configuration. Loose an extra 5 lbs of dead weight over other configurations.

In relative terms the Akrapovic in combination with the Big Air gains  about 23 rwhps. That's 23% more gain than the full system and 13% more than the x-type cat eliminator.

In terms of quality the Akrapovic system is also clearly the leader of the pack. The welds are superior, the mounting hardware is top notch, it even comes with anti seize and gasket paste tubes. I really likes the copper based gasket paste. It makes it SUPER easy to slide the midpipe over the rear headers.

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