Hi Kev,
Nice to see you are back again,
Yes it is amazing how the data show what is happening in the real world!
The stock air box and filter configuration has a Volumetric Efficiency of 0.539 @ 7400 rpm,
Compared to the completely open air box without anything inside and 4mm plus throttle body that has a VE of 1.027( almost impossible for a naturally aspirated engine) , gives us a theoretical power of 85.75 hp!
Ok this can only happen in a perfect world, but 80 hp is very close!!
Can you please give me the following info concerning the raptor mods:
1. RPM the the motor rev to, will it be 7400 or more?
2. The cfm that you mentioned is what the head flows? And if yes at what pressure? (inches of water or millibars, would do).
3. The stage 3 DNA air box will have interchangeable aluminum trumpets(velocity stacks) to help tune the length, could you please specify the internal diameters that could be useful and cover the Raptor etc. mods?

We are already working on the DNA Stage 3 air box, as soon as we will have the complete prototype I will start a new thread and post details, photos etc.
Regards,
Dino

Raptor hits 9000rpm at the rev limiter thats why with their mods gain more hp than the xt660 motor

Hi Dino I will try to get the answers for you.

This was the build I was talking about. Quote taken for the Raptor forum.

We had the opportunity to do some dyno tests the other day.
The machine we were had the opportunity to test on was a 869 cc 11:1 compression Rocket Factory kit with a T-rex +1mm head, Megacycle X2 cam, KDS bored TB (47), Dynatek Fuel controller, RCI 650 injector, Dynatek Ignition (all runs done on curve 2 as it comes on the box), Monster Dual Drag pipes, and a Velocity Intake.
It made a baseline of 74 hp and 62 ft/lbs.
We pulled the head off and swapped it out for the new KDS race head. We put the same cam, rocker arms, even valve springs in the new head. The only thing we changed besides the actual head and valves was the throttle body and the intake boot (which had been port matched my Kenny at KDS to match the flow of the new head).
We immediately dyno tested it (the Raptor never left the dyno, straps were tight the whole time).
It made a base line of 79.9 hp and 62 ft/lbs.
I feel like it was a great improvement from an already good running head, at over 5 hp and no significant loss in tq with a full race head.
To give you guys some perspective on the numbers compared to something else….
Jade had his machine dynoed at Rocket Factory and made 82 and came here and tested it right after and made 72. This might be able to help make better comparisons to some of the larger build numbers from their dyno. We also had another customer who did something very similar and had similar numbers and results.
I want to take the opportunity to thank Jade and Kenny from KDS for their help and for trusting us to be the ones to test this head on our dyno and trusting us with their work. The opportunity is greatly appreciated. It means a lot to us to be in the position to do this for these guys.
Please leave the shop bashing and internet loyalty fighting stuff somewhere else.
Please see our other thread on the intake testing.

The first dyno sheet is the aboves build, the second is what can be done with a lot of money.

I will find the head flow tests for you from the Raptor forum as they are a good read. As you can see the Raptor can rev to 9000RPM with a modified ignition device. Volicity stacks can work, many of the V twins run this set up to get more torque.

DNA STAGE 3 XTX/R complete air box MOD
 

Hi Kev,
Nice thread, the Raptor one, so now it makes even more sense.
From my calculations, if the head on the flowbench can flow 133cfm, and the engine revs to 9000 rpm the volumetric efficiency will be VE=0.96, a very high number for naturally aspirated engine, but yes it is possible.
So we have stock 660cc engine revving @ 7400rpm with VE=0,539 produces 45 hp
Highly modified 869cc engine revving @ 9000rpm with VE=0,96 produces?.... 80.15 hp
We can see now that 80.15 hp, the theoretical power, is what these guys have actually achieved..! Bravo that is very good!
Conclusion the Highly modified XT 660 X /R definitely needs a very well designed air box!
And here DNA steps in…..
Stay tuned.
Thanks
Dino

What did I say to you guys? Seeing is believing, and with Dino on board in collaboration with Kev I can see in my crystal ball a lot of good things coming your way for your XT's.

Stay tuned

:hae18:

CaptMoto could you translate Kev's and Dino's funny words? they look like english but i didn't have a clue:YellowCrazy_J8GDC6:
Dose it mean that if we twist the thingy on the bars the round things turn quicker and we smile more and more?
Guys all i can say is that "GOD YOU KNOW YOUR STUFF RUDDY WELL" lol, well done.

pretty much so... i.e. the more you put in the more you get out :dink:

Thought you might like to see what the inside of the airbox looks like after the stock filter has done 12,000 miles, followed by three days looning around with other riders in Death Valley...

http://i492.photobucket.com/albums/r...x/DSCF2554.jpg

Guess I should have checked it each evening... (but was too busy drinking wine and eating barbecue beef... x)

xxx

ps. don't worry, I've cleaned it out and fitted a new filter now x

Hi Jmo,
As I can see from the photo�..very bad news for you engine. It is also necessary to strip down and clean your �throttle body�.
Mainly this condition will occur if you keep running with a very dirty paper filter or the filter is not sealing properly.
The paper filters called also as �mechanical filters' or �go no go� filters are made out of a paper media that has small holes, for example 10 or 15 microns, all the dirt that is bigger than 10 or 15 microns will stay on the surface of the filter, all dirt that is exactly 10 to 15 microns will block the holes and all dirt smaller will go thru. All this happens in a perfect world and if you change the filter in time.
Now what happens in reality, users remove the filter and blow it with compressed air..! thinking that the filter is cleaned, NO in reality the filter media holes are forced to open and finally you end up with a �clean filter� that has very large holes 30 to 50 microns or larger, that will allow all the new dirt to enter your valuable engine.
With the XT 660 Z we also have another issue, with stock filter not being made in the proper tolerance or the �soft frame� material not soft enough to seal correctly against the top cover and resulting in conditions as the photo you have posted.
Maybe it will seem like advertizing, but I would recommend to use a DNA filter and solve the problem.
Regards,
Dino

Yes, it needs a big (24,000 mile) service when I get home, and I will get them to clean out the throttle body as you suggest (reckon a new fuel filter will be required too, US gas isn't the cleanest - and certainly not the highest octane!)...

I may well be giving you a call re a filter and airbox top too... x

xxx