My Air Box Door Mod

Just thought I would share my air box door mod. I did not want to alter the stock air box configuration underneath the seat and I did not want to ride with the door completely off so I came up with another solution. I gutted out the center the of the air box door and used air conditioner sponge filter (washable-reuseable), the door acts as a bracket to seal in the filter. This will allow more air flow while keeping dirt out (and light splats of water). I'm going to get a dyno custom map for the set-up and will add a 2 map PC switch to toggle between 2 maps, one stock air box and one modded air box door map. I ordered another stock air box door ($17 shipped partzilla) which I will carry and change on the fly if I'm going to hit some streams or ride in the rain.

Parts:
Sponge filter: http://amzn.to/1WS2GO5
Stock air box door: http://www.partzilla.com/parts/detail/yamaha/YP-3D7-1441A-00-00.html
Power Commander 2 Map Switch: http://amzn.to/1rgIg5q

My video on this mod:

https://youtu.be/voWNTa5jhwQ

For your needs this will work well.

I don't care about going back to stock so I cut holes lol.

Lots of guys leave the air box door off when offroading, just be careful when in deep water and honestly with the door off the air box is just as water tight as some mx bikes and the old gasgas I had and I never drowned it but its filter was filthy after rides when the WRR's is still clean.

Biglake wrote:

For your needs this will work well.

I don't care about going back to stock so I cut holes lol.

Lots of guys leave the air box door off when offroading, just be careful when in deep water and honestly with the door off the air box is just as water tight as some mx bikes and the old gasgas I had and I never drowned it but its filter was filthy after rides when the WRR's is still clean.

Yeah definitely will put the stock door and switch maps if crossing water. I just wish my warp 9 wheels would get here already!

So I took my bike to get dyno tuned with this air box door mod and he said he could not tune it, said it was maxed out and brought in too much air that couldn't be matched with enough fuel. He said I would actually be losing performance, so I brought him my other unmolested stock door to tune the bike. This sucks. I think I will just drill a hole and use frogzskin mesh on the air box door but a much smaller opening and see if he can tune the bike. How are people saying they get better performance with the air box door off and this dyno tune expert says it's bs, says it loses performance with the door off or cut out like I did?

That does seem strange to me...you are using a power commander right? I am going to call BS that a door mod alone would cause that issue....

CRFan1 wrote:

That does seem strange to me...you are using a power commander right?  I am going to call BS that a door mod alone would cause that issue....

Yes, I have the power commander v module installed (fuel + ignition). This place has been dyno tuning bikes for over 15 years. He said most guys on the forums and on the internet don't know what their talking about and have not had their bike dyno with the air box door removed. The guy even said any air box mod, flapper or ultimate air box mod, is a waste and won't achieve much and could actually be losing performance. I explained to him that Dynojet has a map on their website for the air box mod so it must be beneficial, he really didn't know what to say other than he is the expert and everybody else is full of shit.

Should I just have them put on the auto tune? He says a custom map is better than auto tune. However, I like to travel to the mountains in high elevations. Also, I figure the auto tune could accommodate any changes I make to the air box door to bring in a little more air.

I would try another tuner.....the WR is pretty corked up so some type of airbox mod would definitely be a help. You may lose some low end but you should gain in the mid and top. I have no experience with auto tune so not sure on that. I will be curious if other members here have some real world experience they can share....

CRFan1 wrote:

I would try another tuner.....the WR is pretty corked up so some type of airbox mod would definitely be a help.  You may lose some low end but you should gain in the mid and top. I have no experience with auto tune so not sure on that.  I will be curious if other members here have some real world experience they can share....

I would like to see someone post a dyno chart with the air flapper mod, ultimate air box mod or air box door removed to see any real gains.

I don't follow the fuel programmer mods on here too closely as I haven't done any myself but you'll notice a lot of people here never have their bike professionally tuned but simply do it by "butt-dyno". So I would be careful when people claim big power gain by removing the door just by feel. Fact is it is difficult to tell, and the increased sound may often give the impression of more power while in reality there is none.

Now, opening the air box in moderate ways, like removing the flapper, surely can bring some more performance coupled with a good tuning. However removing the door completely increases the volume flow so much that the physical limit of the injection system may very well be reached. So I'd be more inclined to believe your tuner.

Searching for dyno on this forum gives some good results, here's a couple:

https://wr250rforum.forumotion.com/t7793-dyno-fmf-megabomb-powercore-4-tuner?highlight=dyno
https://wr250rforum.forumotion.com/t10321-dyno-results-fron-session-at-jett-tune?highlight=dyno

I would stick with the flapper mod. Seems from those dyno results people are getting good results with that. Opening the airbox too much will do you no good

Check out this guy on youtube, your tunner is full of shit.
mrduhfactor
WR250R DYNO TEST - Lindsay Machine Racing

Sorry I cant figure out how to make it a link.

Guys the bottom line is without dyno proof we are talking out of our asses but I will say this......I find it really hard to believe that you reach the limit of the injectors and FI system by opening your air box door.  Is it possible?  Sure I guess.  If that is the case they put too small of an injector in our bikes.  The fact is when you open the air box the next thing in the chain to be an air restriction will be the Throttle body....that will only flow so much air no matter WHAT you do to the airbox.  Also, there is a guy on youtube that has a WR called daisy chain or whatever.  It's a 290 with a stroked crank (310cc), head work and other things and it makes about 34HP if I remember....i saw nothing regarding any sort of aftermarket FI system other then a PC.

https://www.youtube.com/watch?v=Lmp1EvTt7pA

We can all argue until we are blue but until I see actual dyno proof I won't say what will work or won't but I am pretty sure you could tune your bike with the door off, lol.

bigg wrote:

I don't follow the fuel programmer mods on here too closely as I haven't done any myself but you'll notice a lot of people here never have their bike professionally tuned but simply do it by "butt-dyno". So I would be careful when people claim big power gain by removing the door just by feel. Fact is it is difficult to tell, and the increased sound may often give the impression of more power while in reality there is none.

Now, opening the air box in moderate ways, like removing the flapper, surely can bring some more performance coupled with a good tuning. However removing the door completely increases the volume flow so much that the physical limit of the injection system may very well be reached. So I'd be more inclined to believe your tuner.

Searching for dyno on this forum gives some good results, here's a couple:

https://wr250rforum.forumotion.com/t7793-dyno-fmf-megabomb-powercore-4-tuner?highlight=dyno
https://wr250rforum.forumotion.com/t10321-dyno-results-fron-session-at-jett-tune?highlight=dyno

I would stick with the flapper mod. Seems from those dyno results people are getting good results with that. Opening the airbox too much will do you no good

The dyno guy said the flapper mod is pointless because it opens up when you need it anyways and won't make much a difference on this lil 250. I talked to a guy who owns a wr250r and x, he did the flapper mod on the x but not the r, he said he could not tell a difference.

Biglake wrote:

Check out this guy on youtube, your tunner is full of shit.
mrduhfactor
WR250R DYNO TEST - Lindsay Machine Racing

Sorry I cant figure out how to make it a link.

I just watched that video before I read your post. I was pissed off at first and then I watched it again, pay attention to the end of the video. The tuner says he gained an extra 2 hp BUT then laughed at how LEAN the bike was with that 2 hp gain (with the air filter removed and no door). I believe he said "14 to 1" or said 14.1, as though that was a ridiculously LEAN reading. The last thing I want to do is run the bike ultra lean and damage the engine. The tuner said running a bike super lean for extended periods will ultimately damage the engine.

It's tough to argue with a dyno tuner that is a former AMA Superbike racer and team owner, who has been dyno tuning bikes for nearly two decades.

CRFan1 wrote:

Guys the bottom line is without dyno proof we are talking out of our asses but I will say this......I find it really hard to believe that you reach the limit of the injectors and FI system by opening your air box door.  Is it possible?  Sure I guess.  If that is the case they put too small of an injector in our bikes.  The fact is when you open the air box the next thing in the chain to be an air restriction will be the Throttle body....that will only flow so much air no matter WHAT you do to the airbox.  Also, there is a guy on youtube that has a WR called daisy chain or whatever.  It's a 290 with a stroked crank (310cc), head work and other things and it makes about 34HP if I remember....i saw nothing regarding any sort of aftermarket FI system other then a PC.

https://www.youtube.com/watch?v=Lmp1EvTt7pA

We can all argue until we are blue but until I see actual dyno proof I won't say what will work or won't but I am pretty sure you could tune your bike with the door off, lol.

I agree, without dyno charts for proof we are all just talking. This dyno tuner is a former AMA superbike racer and team owner, exclusively has been tuning bikes for nearly two decades since retirement, it's tough to argue with him. lol
As far as him saying he couldn't tune it, that's because he said he couldn't match enough fuel with all the air that was coming in, it was way too lean. Yes, you will gain hp being more lean like that but riding the bike for extended periods lean could cause damage to the engine. A damaged engine is not worth the extra 2 hp.

Agreed.......very interesting though. It basically means the fuel pump and/or injector is not up to the task. Hard to imagine but if that head will indeed flow more air then the FI system can handle (I still find it hard to believe but I will take that tuners word for it until somebody posts dyno proof), then there is some major power gains to be had with a better fuel pump/larger injector size and some tuning.

Does the super bike tunner have any experience with single cylinder bikes?

I ask this because 4 cylinder sport bikes are totally different animals and modding their air boxes doesn't help power.
Singles need all the air they can get, look at mx bikes they have wide open air boxes, if a smallish air box opening made more hp they'd have one.

Where did the injector is maxed out talk come from? that's a non issue, you can run a big bore stroker with the stock injector but you have to run a programmer to add more fuel.

The youtube vid I had in my last post was just to show that the bike does make more hp and tq with a wide open air box, that wasn't the best vid as they were just doing a before 310 run so they had some thing to compare their 310 kit to.
Highfive also had a dyno run proving more air = more power, he had his a/f ratio dialed in with the opened up air box too.


Im thinking your tunner couldn't be bothered to do two different tunes for you so he lied to you talking you into just one set up making his life easier.

Heres a link to highfives dyno runs, I don't know why my link goes to page 3 the dyno info is on page 1 of that thread.
http://www.thumpertalk.com/topic/634507-highfives-2nd-dyno-test/page-3

Please note the fmf programmer hes running was changed around 2012 to add more fuel on acceleration so run it on 2 or 3 if your buying a new one not 5 like him.

See....good info. My suspicion all along was something was up with this tuner cause I find it hard to believe you couldn't tune the damn bike because of an open air box. I would find a tuner who gives a damn quite honestly.:)

Biglake wrote:

Does the super bike tunner have any experience with single cylinder bikes?

I ask this because 4 cylinder sport bikes are totally different animals and modding their air boxes doesn't help power.
Singles need all the air they can get, look at mx bikes they have wide open air boxes, if a smallish air box opening made more hp they'd have one.

Where did the injector is maxed out talk come from? that's a non issue, you can run a big bore stroker with the stock injector but you have to run a programmer to add more fuel.

The youtube vid I had in my last post was just to show that the bike does make more hp and tq with a wide open air box, that wasn't the best vid as they were just doing a before 310 run so they had some thing to compare their 310 kit to.
Highfive also had a dyno run proving more air = more power, he had his a/f ratio dialed in with the opened up air box too.


Im thinking your tunner couldn't be bothered to do two different tunes for you so he lied to you talking you into just one set up making his life easier.  

He tunes all bikes. Actually, a local guy who sells parts for the wr250r and drz400, who has a wr250r and wr250x himself recommended this dyno tuner. He had his wr250x tuned there.
That video you posted, if you pay attention to the end, the a/f ratio was not dialed in, the tuner laughed at how lean the bike was running with that 2 hp gain, he said "14 to 1"

You will get more power with more air flow BUT the bike will almost certainly run too lean. I have a power commander v and the tuner said he was not able to add enough fuel to match the added air that was coming in from the modded air box door. What I should have did is just drilled a small 1/4" to 1/2" hole in the air box door and used a frogzskin screen to cover it and see if he could have tune it like that.

Biglake wrote:

Heres a link to highfives dyno runs, I don't know why my link goes to page 3 the dyno info is on page 1 of that thread.
http://www.thumpertalk.com/topic/634507-highfives-2nd-dyno-test/page-3

Please note the fmf programmer hes running was changed around 2012 to add more fuel on acceleration so run it on 2 or 3 if your buying a new one not 5 like him.

I would like to see a second opinion from another tuner. It just seems like it would run too lean with the air box door off. My tuner has been tuning all kinds of bikes for over 16 years. I'm more inclined to believe him.

nah fishy

Im starting to

You can add tons of fuel to go along with modding the airbox on big bore stroker builds which need more fuel than stock motors with a pc5 or fmf/dobeck programmer, when tuned right it wont be lean.

The first vid I linked wasn't the greatest because they never tuned it, they were simply after a before 310 kit hp # to compare their 310 kit to but it showed you get 2 more hp when you open up the air box, that's a huge and very noticeable amount on a 25 hp bike!


I've dealt with guys like your tuner before, I wish they would come right out and say "Im too busy I don't want to touch your 25 hp bike"

DS123 wrote:

I would like to see a second opinion from another tuner. It just seems like it would run too lean with the air box door off. My tuner has been tuning all kinds of bikes for over 16 years. I'm more inclined to believe him.

Well, I've read this thread, watched your new YouTube vids about it, and read all the comments under the newest airbox vid as well.

One thing is absolutely certain... it's not REALLY settled here, or on your YouTube channel.  Everyone would benefit, and be interested in, seeing a second opinion from another tuner.  I hope you will consider visiting another tuner and posting the results of that.  Easy for me to say, I know, but I don't have a Vlog with over 140,000 followers either.  I advise NOT prepping/skewing the new tuner by telling him the whole back story- just see what he comes up with from his own experience (don't alter the outcome).  If you want to get really fancy, call 3-4 more tuners as well and just ask them.  Not only would we all appreciate it, but the followers of your badass VLOG would dig it as well I think.  It lends an additional level of legitimacy to your Vlog.  Hell, I might even subscribe!

You have a great platform because of your Vlog; this seems like as good a subject as any to make sure and get it right due to the amount of people, including me, who have holes in their airboxes and who watch your vids!  

Let's go for a Riiiide... to another tuner... for a second opinion...  

WR250r update: Dyno Tuner said there was a problem my power commander, one of the pins in the connector was pushed back, was causing it not to communicate properly. He completed the map for the stock door, now he's going to try and tune the bike with my air box door mod again (Door hollowed & covered with filter). So if the second map is successful I'll have two maps on my switch, one for the stock door and one for the modded door. I'll do an unveiling of the modded wr250r next week. Stay tuned!

PS- it seems like Biglake is right, tuner was probably too lazy to take the time to tune it, but has since changed his mind and says he can tune it with my door mod for AN EXTRA $200!

Update: Bike is done! The dyno tuner was able to tune this air box door mod. The air box door mod is legit!  I had him do two custom maps, one for the stock door and one for the modded door and I use a two way switch to access both maps on the fly. $500 for both maps. I also had him custom tune my suspension for my weight and had him mount and balance new tires on the bike. He said he ran into an issue tuning the suspension, something was frozen and he ended up having to replace a spring as well. I bought the bike brand new last year so this makes no sense to me but I did not argue. Total cost for the labor was $922. Subtracting the labor, all the mods ran me about $3,000. I did all of the other mods on the bike.

Thanks for everybody's input on this thread.

So here is the finished product complete with two dyno charts for the custom maps.