My advice to you is this:

1) DNA stage 1 & stage 2 is the way to go for top HP gain.
2) your snorkel is off already so you're ok
3) Worry Brother's cover is optional but it will stop a nosey copper say: "aye aye what have we got here?, not suitable for road use?"
4) You've got the cans covered

Now this is the crucial choice that you wil have to take: you are adding more air intake and quicker exhaust gas dispersion via the after market cans which do not have catalizers or resrictions, sp what do you think you are going to need next? more fuel intake is the answer. Adjusting CO2 will only work on part throttle and at the lower regime, what you need is a fuelling device.

And your choices are Kev Mod or Power Commander, the Kev Mod will keep you honest but it is a fix that works uniformely over the whole rev range whereas the power commander is the ultimate because a qualified Dynojet tester can fine tune every area to adjust the fuelling as required, adequately to your bike's response and for that there is no substitute but the PCIII and mapping is the most expensive solution. So it all depends on how much you are willing to spend.

To answer your question in a nutshell your best bet is both filters and the Kev Mod.

Willing to spend and 'allowed by the bank manager' are two very different figures :)

Power Commander is not an option for me at the moment.

So i guess it's either buying or making the Kev Mod. Well, one of the lads who's a whizzkid on this stuff may be asked about it.

Thanks for the advice :)

Damnit!! It was you who won it!!

I thought I had that ****** and in the last 3 seconds there were a few more bids.

3 bloody seconds!!!!!!!!!!!!!!!


Nice job though... guess ill have to keep looking...:wub:

http://www.motorcycle-exhausts.co.uk...oducts_id=7562

Just found that... Nice little find I think, free delivery too.

stage 2 �43.56

I only paid �3 less than you can buy it for mate. You can get the Stage 1 on Ebay for �29.97

By the time i won that and paid postage it was �26.01

I've just paid a LOT more than that from e-DNA shop

:(

http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT

another one there.

Do yourself a favour get a DNA stage1 filter, the DNA stage 1 filter flows more air then a K&N stage 1 filter.

The results are very impressive and enlightening.
All the air flow tests took place the same day on DNA’s Rotronics Computerized FlowBench, the test pressure was 1,5” inches of water and the results corrected to 25� celcius.
1.Presentation of the air filters:

a) Stock Yamaha air filter, single layer paper non-reusable air filter
b) K&N YA-6604 air filter, 4 layer cotton oil impregnated reusable air filter
c) DNA P-Y6E04-01 air filter, 4 layer cotton oil impregnated reusable air filter

2.Air Filter Design (see attached files)

a) The K&N YA-6604 air filter:
Media material 4 layers of K&N cotton
Number of pleats 11
Pleat Height 21 mm
Active Pleat length 115mm*
Pleat Pitch 6,36mm*
Oil volume 7ml
Total active filtering surface 53.130�mm*
� * as measured from the K&N sample filter we purchased.

b) The DNA P-Y6E04-01 air filter:
Media material 4 layers of DNA cotton
Number of pleats 9
Pleat Height 31 mm
Active Pleat length 124mm
Pleat Pitch 10mm
Oil volume 16,3ml
Total active filtering surface 69.192�mm

As we can see the DNA filter has larger pleat height 31mm(K&N 21mm), the pleat pitch is 10mm(K&N 6.36mm), the amount of oil DNA uses is more than double, and the most important +30.23% more active filtering surface..! for the same application.

At this point I must explain that the pitch of the DNA material is calculated taking under consideration many different variables; we use a specially developed algorithm and the final design varies from application to application. Even 0.1 of a mm can make a very big difference in airflow, speed of the air stream at the surface of the filter, turbulence and many more details that we can’t mention for obvious reasons.

So already from the start we have2 very different air filters!

Let’s continue with the tests.

3. Absolute AIR FLOW tests: the filters are tested out of the air box on a custom made plenum; nothing causes turbulence or restrictions to the air flow
(see attachments).
The result is solely what the filter can give.

a) Stock Yamaha Paper Air filter
70.42 CFM @ 1.5” of H�O

b) K&N YA-6604
92.18 CFM @ 1.5” of H�O
+30.9% over stock

c) DNA P-Y6E04-01
122.4 CFM @ 1.5” of H�O
+73.81% over stock
+32.78% over K&N…?

4. Air Box AIR FLOW tests: the filters are tested inside the stock Yamaha air box,
To eliminate the losses (restriction) that the stock throttle body could cause we used a 48.6mm throttle body without the butterfly; the absolute largest that could be connected to the XT 660 Rubber trumpet.
Air box restrictions, shape, resonance, position of the air filter, if the design of the air filter suits the design of the air box and many more variables play an important role now.
Also I have added the Volumetric Efficiency (VE), of the XT 660 Engine, that occurs for every configuration, if the tuner takes 100% advantage of the extra flow.

a)Test 1:
Air box & std filter & snorkel
46.53 CFM (1318 lit/min) VE=0.539

b)Test 2:
Air box & K&N filter & snorkel
52.51 CFM (1486 lit/min) VE=0.608

c)Test 3:
Air box & DNA filter & snorkel
57.19 CFM (1619 lit/min) VE=0.663

d)Test 4:
Air box & DNA filter & Without snorkel
59.52 CFM (1685 lit/min) VE=0.690

e)Test 5:
Air box & DNA filter & DNA Stage 2 filter & snorkel
79.19 CFM (2242 lit/min) VE=0.918

f)Test 6:
Air box & DNA filter & DNA Stage 2 filter Without snorkel
79.89 CFM (2262 lit/min) VE=0.926

g)Test 7:
Air box all open Without filters, side cover, snorkel
(this test is for reference only the bike can’t be used on the road in this state)
88.6 CFM (2509 lit/min) VE=1.027

Finishing our detailed tests clearly the conclusion is That the DNA stage 1 filter is NOT the same filter as the K&N as the overall difference is Massive.

Now he tells me LOL.

Read the mod section all the answers are there. Not all is lost a K&N stage 1 filter is still better then standard one.