Airbox mods tested with dyno.

[OB_Dirty Pete]

Bob, have you got pipes or slip-ons so that the newly found extra intake volume has a way to get out?

If so, get out there and wail that thing!

If not, you're wasting your airbox mod.

 

[OB_Dirty Pete]

Bob, I noticed that thing you called a reed too. Seems like a crude pressure release valve that would release air if the pressure got "too high" in the air box.

On the belief that there can be no such thing as too much pressure in the airbox, I'm going to plug that sucker off next time I pull the airbox.

What was that comment about a pressure release hose to the fuel pump? Could you elaborate?

 

[OB_hayabusa]

I thought it was a positive crankcase release. Piss it off and put it into a small puke can.

 

[OB_jeffw]

On our race bike, this vent it is blocked off. I think it's a fluid drain.

I did make the airbox mod, cut out around the inside of the air filter lip. I do have 2-bros slipons, and I did see a performance gain. I did not have any low end stumble, midrange (5k rpm) and up my bike accelerated harder than before. 9-10k rpm the bike screams.

I had 160 rwhp before, I'll see if I can get back to the factory dyno at Pikes Peak to see if I have had an increase.

I do have pictures of the modification that I will put on my web site soon (yeah I know, it might take 2-3 days)

 

[OB_Dirty Pete]

Hayabusa: About this reedy thing in the airbox bottom,I don't think it's for blowby (positive crankcase release). Crankcase blowby goes north past the rings and valves. It doesn't burp out the carbs or injectors. The best place to siphon blowby off from is from under the valve covers. Then from there into a puke tank.

My way of seeing puke, anyway.

Maybe that reedy thing in the airbox is a water drain. In a heavy rain at higher speeds, rain would be forced into the ram air intakes. The rain would end up on the bottom of the airbox. Maybe that thing would let the rain out slowly while preventing too much air pressure differential?

Understand right now that I know bobo about physics.

[This message has been edited by Dirty Pete (edited 19 August 1999).]

 

[Guest]

Hi Cisco, hows the "Busa? (it's me, Roman)

With cutting the airbox plastic, I did mine like Dirty Pete suggested with an electric soldering iron, use one with a pointy tip guys! Not a big crude car iron.

The problem with that is the melted plastic "oozes" out of the fine slot where you are cutting and just gets in the way.

When I did the plastic on my TL1000R I used a fine tip soldering iron, about a 2mm tip (less than 1/8") and it still was a bit of a mess. Fortunately I work with this plastic in VCRs and stuff at my work so I knew to cut the plastic slightly BIGGER than needed, then use a good (metal handle) "stanley" knife (you might call them exacto knives??) to trim the melted edge away and get it down to exact neat edges.

Once the soldering iron had made the main cut, the knife cut neat plastic strips that curled up and I cut them off in 2" lengths for convenience. I didn't need to sand anything, which only makes more mess, was able to shape very nicely with the knife (with a new blade).

Oh, and about performance, I must echo Pete's experience, no troubles down low, more power everywhere, had to re-learn throttle and gear changes as front wheel coming up a lot on my favourite roads. Motor just seems so much more "happy" now. What were those flappers supposed to do anyway?

 

[Guest]

I saw Bob's concern about $200 for an airbox, and the possibility of not getting much gain.

I can only speak from the experience of doing the mod on a TL1000R, which is slightly different from a 'busa, even though it shares a lot of similarities.

With the TLR, the airbox is in 3 pieces, the top lid, the bottom "box", and the thin frame thingy that holds the filter.

Fortunately for TLR owners, we only need to cut the frame thingy, which is much cheaper than a whole new airbox - and easier to fit. I think that may be why the TLR guys were more keen to "hack and slash" to see what the gains were. And, I can't speak about the 'Busa, but there are very definite gains in the order of 5 to 10hp on the TLR from doing this mod.

I hope that before any 'busa owners start hacking at their bikes they are quite sure about what they are doing and I hope that you guys get the gains from the mod that TLR guys do!

After I modded my TLR airbox, the difference was that good that I wished I had done it from day one!

Measure the "flapper" opening (in sq inches etc) with the flap at full open position, and you might find that it is LESS than the throttle body diameter total, ie the MAIN flow restriction in the entire system...

 

[OB_Bob]

After scary riding last night I have come to the conclusion again--that this bike is faster than sane people need.
I was trying too hard to evaluate the airbox mod. I wheelied at one point pure power wheelie--lifts at about 5500 rpm, then i hit a BIG pot hole, which drove my front wheel down fast at which time I freaked and left the seat, my tail bone landed on the hump (Oww!!) then fully opened the throttle again which scared the poop out of me. I didn,t mean to, it happened. I looked like "Normy new guy" during this bonehead move. Fortunately no damage to anything but my pride. I was doing this on long industrial park streets where there are few cars after hours.
Anyway, My DynoJet ass can not detect the difference. Maybe quicker at 5K up, but we need to be more scientific--1/4 mi, or dyno.
I definitely believe the 1800 rpm-2500 rpm is suffering. I will try to remap today to cure this. I assume its now too lean, or the flapper had purpose at low speed.
I know some of you will say who cares as long as the upper rpm is there. Not Me! I like to cruise from time to time and I liked the Busa because it could be driven in different ways with little compromise. The Dyno will tell next week albeit without ramair.
I will take digital pictures of this mod. and post.
Anyone have additional DYNO numners berfore and after airbox mods? or strip times?
D. Pete--Yes I have the full Micron System and Power Commander. My BMC filter should arrive today.
Bob

 

[OB_Cisco San Jose]

Question about the airbox mods,will this affect my riding in the mountains,High Serria Lake Tahoe area and second since this is my commute bike will the rainy weather cause any water to enter the intake area after the mods?I know this would be a stupid question but need to know,hate to have poor performace in the mountains or stuck on the side of the road in a rain storm.Any responce would be welcome.

 

[OB_hayabusa]

Cisco, the mods retain the standard retention of water because the airfilter is not being bypassed.

 

[OB_Dirty Pete]

Bob: Whoa!!!!!!!!!! Glad you're still with us! You must feel like you've just spent a week in Mike Tyson's jail cell.

Your description of your short hop flight was totally graphic. Don't you hate it when the situation just gets so out of control and you can't reel it in and it seems to last forever?

You're a good rider to have kept it together.

If your DynoAss can't feel the difference from the airbox mod, then that's to be trusted. I wonder if you might get better results by returning your Power Commander to dead stock settings, if it's possible to do so.

Reliable people are reporting measured gains of 10 horse power for the airbox mod i.e. Lee Shierts, when it's the first mod done. And 99TLR and others have had the same DynoAss results.

Sometimes, riders will get a false DynoAss reading because other sensory indicators of speed result from the mod. Like a noisier exhaust system, or extra intake noise, or even a firmer suspension setting can fool you.

But with the airbox mod there are no such false indicators (some guys say they get more intake roar, but I can't hear it). Also, I completely trust my instinctive management of the bike's throttle and tranny, and when the airbox mod screwed up those instincts temporarily, I knew I had significantly more power.



[This message has been edited by Dirty Pete (edited 20 August 1999).]

 

[OB_Bob]

I am really not getting any work done, but D.Pete I will try different settings, and I can place them anywhere including to stock using the P Commander--mainly at low rpm. I did not say its slower, just can't tell. I probably was making more HP to begin with the full pipe and P commander vs. slipons. Maybe the difference isn't as dramatic with this combo. given where I started?
Lees perf. modified his bike at 26 MILES on the clock! This is not great news because the bike will break in on the DYNO. Ask any Dyno shop, ask DynoJet. Maybe loading the bike Lee also saw an increase in power due to this? Just a thought.
Bob

 

[OB_cbxchris]

Bob, do you plan to dyno your bike with and without airbox mods...would be very interested in results! By the way ...Micheal at dyno-jet had me send my commander back to see if he could find out what was wrong with it. I rode this bike last night without commander and the starting problem is definetly in the commander. They were extremely helpful and I`ll let you know what comes of it. Later....

 

[Frank Adams]

i guess it's time i jump into this topic.
if you want to do something that is simple and that will just blow you away!
then first make the dission if you what to run in the real high mph.
if you don't, 170 or lower.
then quit messing with the airbox and put on a set of stacks. you'll be freaked out! of what you'll be about to experince in this no cutting/hacking test...

 

[OB_Dirty Pete]

Frank: Thanks for the response.

I have a hard time understanding why any one other than Hell's Angels would want increased horsepower at the low end.

Hill climbing with the Busa? Boulevard cruising? Trailer towing on a "Busas for Christ Motor Cavalcade"?

Busas were made to wail and suck and spew air. I love the Screamin Demon!

 

[OB_Dirty Pete]

Frank!!! Tell more!!!!!!!!

Pant pant drool drool.......

What stacks? Do they work with the airbox mod already done? Is it only for 170 mph plus? Any dyno evidence of effectiveness? Where do you get them?

Speak man, speak! We need more ponies!

NOTE: If you've got a good horsepower mod, I suggest you start a new subject for it, like "Velocity Stacks" or something, so we don't have to download this large "Airbox" post every time.

[This message has been edited by Dirty Pete (edited 21 August 1999).]

 

[viol8r]

tell me more about the h.a.'s.

 

[OB_Bob]

Stacks will eliminate ramair because will not have a box to pressurize.
I would also expect to remap, but maybe not. Again, lets see the Dyno for a stack bike or perf.
CBX-I was going to compare the stock box with modified, but my dealer just told me that guess what-the air box is on back order. So it will be with the mod. airbox. Pisses me off too because i asked the dealer for availability before i cut the box. he said it was avail.
I made some map changes yest/last night --still low rpm cruise affected, i feel. Although a little better.
Bob

 

[OB_Malcolm]

Alrighty then! I don't want to do over 170mph. 160 in the quarter will do just fine!Who has but the stacks on (Frank), what size are they, where did you get them from, how much. Thanks

 

[Frank Adams]

pete, this is all heresay, i've been told that the stock air box with no mods restricts alot of air flow. a guy told me he took his airbox off and put on a set of stacks and saw a 6 to 7 hp gain on the bottom end. yes you'll lose your ram air on the top end. the best you can do is try to improve your box to respond at a lower rpm. your most gains for the low end will be with out any airbox. thats why i said to make that dission weather you want one or the other. topend or lowend power.