1st, I would like to thank Dino from DNA for sending me one of the 1st DNA stage 3 filters for the XT660Z and allowing me to test the filter on an actually running bike.

Initial impressions:

I like what DNA did with this filter. The quality is as always great, plus they added an extra metal plate to help hold the filter in place. It fitted real easy and can be installed by just about anyone.

Testing:

As always Jon was ecstatic to receive the filter and was only too happy to let me play with his XT660Z on the dyno. Just a note. I operate my dyno at around 5000ft above sea level and as a result seem to be reading very low compared to other similar dynos. You can roughly add about 10 to 12% to my readings to get a good idea of how much power other low altitude dynos will read. Don't worry too much about the actually HP and torque amounts, rather look at the gains from before and after. The best is to work out the gains as a percentage and that will give you a good idea of how much you will be gaining over a stock setup.

The 1st Dyno run we did was with Jon's bike in stock form. Nothing removed or added. See blue line. The bike produced peak power at around 5800 RPM and gave just over 37HP at the rear wheel.

The red line shows what happened when the DNA's Stage 1 and 2 filters, plus a powercommander with a custom made fuel map was added. Exhaust is still stock. The powercommander and fuel map by itself adds a few HP and is well worth the investment. This combination resulted in some impressive gains. Midrange power increased by as much as 10 to 12% over stock. Peak power was increased by around 8%. Jon said it felt like a different bike. He loved the improved low end grunt and crisper performance.

The last run, green line, was done with the DNA stage 1, 2 and 3 filter, plus a powercommander. A custom fuel map was specially made for this combination. This setup resulted in some low RPM power losses when compared to the stage 1 and 2 filter only setup, but the good news is that it still made more power than stock. I don't believe pone can blame the stage 3 filter for this, as we got the same result when we run a open airbox without any filters. It seems that the airbox harmonics is affected at low RPM, but adding an aftermarket exhaust should restore the midrange power gains. One interesting thing Jon mentioned is that he did not notice the slight HP and torque losses of the stage 3 setup versus the stage 1 and 2 setup. It felt to him as if the bike ran way better than before, so don�t read too much into this.

Saying that, this combination really came to life at around 4600 RPM and from 5200 RPM it made the stage 1 and 2 filter gains look like minor gains. Peak HP jumped up by 15% over stock plus peak RPM is now at 6100 RPM. The power output also gained massively over stock, all the way to the RPM limiter, which should result in much quick acceleration times and top speed gains. On the open road and for those thinking about taking some nice long trips, these top end gains are most welcome.



Overall impressions.

As with the XT660R/X, the DNA side cover filter make a massive difference in power. The same goes for the XT660Z's DNA stage 3 filter. I have tested various aftermarket exhaust system on both the XT660R/X and the XT660Z and the DNA filter upgrades alone make by far more power than any of the exhaust systems I have tested. The DNA filter upgrade, even when combined with a powercommander, is still a cheaper upgrade than adding a good set of aftermarket exhausts. The other advantage I like is that you can gain all that extra performance, and not having to deal with a loud exhaust system.

It is my own personal opinion that the DNA filter upgrades are the best bolt on performance upgrade you can do to the XTZ. Hands down!

PS, I highly recommend a powercommander and custom fuel map with the DNA stage 1,2 and 3 filter setup. I forwarded Kev a copy of the map I made for Jon's Tenere, so please keep an eye out for it in the fuel maps section. (Only available to XT660.com member)

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Disclaimer: any mod undertaken, are carried out at owners risk