Open Pod Filters

[ficklepickle]

Hi guys, can anyone enlighten me as to what the advantages and disadvantages of having a open pod air filter. Using it on a Honda NSR150SP. Thanks!

[Pandoras Kitten 3]

Getting rid of your airbox and using an open pod or 'cone' filter gives your engine direct air intake from your surroundings.

 

Without going into all the scientific stuff like using an airbox for things like Hemholz resonance, an open filter will give you increased top end performance but lousy torque on the low end. If you ripped out the stock intake system you may lose the benefits of the airbox giving a stable, pressurised clean air supply to the engine, and if it's a closed intake system with ram air, well you lose that nice high speed boost too.

 

Without the airbox it can be very difficult to tune the carburettor because there is no airbox giving a steady air supply.

 

Thusly, stock can work best, because the NSR SP legend says is named after a certain racetrack in Japan (it was built to conquer that, I guess!).

 

And that means Honda has spent a lot of time and money on the best engineers to make a street legal 150cc racer for you.

 

I would prefer to use cone filter on Phantom because the stock airbox is not built for performance and is very restrictive. But I didn't need to spend so much to enjoy performance and throttle response gains - drill a few holes in the right place will do.

[Orleng]

Airboxes are also helmholtz resonators. Those things give free 10-15% extra air at a certain a certain rpm, likely your peak torque rpm range. Removing your airbox can remove this effect.

 

End result, lowered torque at this former peak. Will give you more high-end power IF tuned correctly.

 

Simply put, unless you rev the t*ts off your ride, not much point messing around with open pods.