airbox ?

I remember reading a thread somewhere where somebody much smarter than me ran the flow numbers for the WRR engine and concluded that other than the flapper mod the airbox flowed enough air no matter what mods were done. Some math dealing with the throttle body diameter, engine size, valve/port size etc. I have spent the last 20 min trying to find the damn thread but cannot. Anybody? Even better would be dyno results, flapper mod HP vs door off HP?

I can tell you right now, without needing an advanced engineering degree in flow dynamics, that the bike runs noticeably stronger with the airbox door removed completely.

You need a fuel programmer so you can increase the fuel being added so you won't run too lean, and an open aftermarket exhaust too.


So perhaps you're thinking of the flapper mod being enough when everything else is 100% stock?


But it's beyond obvious to those who've done it that the wr250r/x CAN run much stronger with more airflow than just the flapper mod when other mods have been done as well.

Having owned a many modded cars and bikes the whole "seat of the pants" feel means nothing I have done mods that I swore added power but the dyno said it aint so. Sound has a lot to do with perceived speed and acceleration, sound can make something "feel" faster. I was hoping that somebody would have dyno results from back to back runs one with door on one with door off.

Here's something to look at:

http://www.wrrdualsport.com/tech-guide/dynotesting/71-dyno2

To me, it's not whether or not doing something like removing the airbox door increases power (it does if you modify fueling and exhaust), but whether or not you want to put up with the added intake noise.
It honks pretty good.

mpatch wrote:

Having owned a many modded cars and bikes the whole "seat of the pants" feel means nothing I have done mods that I swore added power but the dyno said it aint so. Sound has a lot to do with perceived speed and acceleration, sound can make something "feel" faster. I was hoping that somebody would have dyno results from back to back runs one with door on one with door off.

Feel free to pay for the dyno results and post them for us.

On a bike that struggles to make 25 horsepower - noticeable is noticeable.

It ain't just noise.

I just did "the ulitimate airbox mod". I just had the bike on a dyno on Thursday but the results aren't really that accurate because my clutch was shot from the previous owner. I am going to try to get it back on the dyno next week now that I have put a new clutch and did the airbox mod. I will post the results. Here's my run from thurs. The bike has an EFM auto clutch that wasn't working right as you can see from the results (clutch not engaging properly). The run was made at about 5000 ish feet asl.

After reading the linked page I went out to the garage and pulled off the airbox cover. I'm too senile to notice if its faster but hot damn, now it sounds like I'm on a Moto3 racer. Love it. I'm at 5000' ASL and you can't get too much air here.

I am;

All crap removed
FMF Programmer
Leo Vince Pipe
K & N Filter
52 MPG
Ride like I stole it.