Air Box Mod - Read this first before attempting!!!

O

OB_Zarniwoop

Registered
Well I did the air box mod and while I was at it I reconnected the Pink wire.

Outcome. Lousy performance especially in low/mid range, so I had my race tuners richen up the bike to it's max which is +10 low +10 mid and +10 high, this is the maximum you can go with the Yoshi box. Although greatly improved it is still not as fast as before as I have only managed to clock 210 since the mod.

My race tuner said that if I'd spoken to him before I had done the mod, he would have advised strongly against doing it saying that it is notoriously difficult to dial in FI and ICU without some sort of regulation valve to even out air flow.

He has now ordered a Power Commander II and the pressure regulator and will spend many many hours working out optimum fuel and Ignition maps.

This is gonna cost heaps guys, but once I get the maps I'll post them here. They should be a good starting point for anyone wishing to carry out the air box mod but WILL NOT BE A PERFECT MATCH. Altitude and temp MUST also be taken into consideration, but as I say they will be a good starting point which should save you guys hundreds of $'s in Dyno time.

Fraternal Greetings

Z
 
ZARNIWOOP: I'm sorry you've had such a miserable experience with the airbox mod.

I presume that your disappointing top speed of only 210 (kph) is a typo, but if it's not then suicide may be the only option for you.

Others have had very good results...check Lee Shierts' site...he got 10 dyno horse power and it was his first mod.

Maybe your Yosh box has a problem compensating for this mod? If so, buying a new airbox to reverse your mod may be a cheaper option than pursuing a solution involving more expensive aftermarket hardware and tuning sessions.

As you probably know it's real easy to get into a vicious circle when a major mod doesn't produce for you.

I am dynoing my Busa tomorrow, weather permitting, for the first time since doing the full-hole airbox mod.

I'll post the results here.
 
Pete,

Sorry read 210 as mph not kph. I have seen 220 on the dial once and 215 on several occasions. Believe it or not, but it's true :-)

Fraternal Greetings


Z
 
Are we running nitrous?

Or have we got major internal engine work happening.

Or a joyously happy speedo?

Or a 12 tooth front sprocket and no rev limiter?

Are your reading glasses OK?

If none of the above, I hereby offer you $25,000 for your Busa.
 
Indicated speed on the speedo is always much more flattering than actual. References to speed as seen on the speedometer should be prefaced with "indicated 200 mph" not to be confused with the guy who's working his butt off to go an "actual 200 mph".
 
Todd & Zarniwoop: 25 large plus shipping plus a free night's pints at that interesting pub on the mainstreets corner in Esher, Surrey.

Red and black's OK. I'm going to paint it all flat black anyway.

[This message has been edited by Dirty Pete (edited 13 September 1999).]
 
Viol8r: There's a big difference between 195 and 220 mph.

Vast even. Like double the horsepower or more.

I'm pretty sure at this point that Zarniwoop's speedo was subcontracted in the UK by Suz to Lucas...The Prince of Darkness.

[This message has been edited by Dirty Pete (edited 13 September 1999).]
 
Speedo is generous by 12%.
The airbox mod will sightly effect 1800-2500 rpm even using the yosh. The PC2 eliminates the problem entirely.
The flapper is primarily regulated by the ECM between 2000-2500 rpm/idle, otherwise its open. Your speed issue is your imagination or you fuel delivery is incorrect --rich/lean at the high end.
Bob
New airbox is $220.




[This message has been edited by Bob (edited 13 September 1999).]
 
hey peter, do you have a red and black bike?
if you do and your planning on painting it then why don't you trade your red stuff with someone in the usa for the black or copper?
 
My Busa read 205 but my Brother officer Clocked me with "Laser" at 191. Speedo is a bit optimistic. Needless to say keep tucked at these speeds. (((((((>>>>>>>>>>>>

161 ®
 
Way to go FalconCop! I personally appreciate you using your position and equipment to work on improving the Busa. You set the benchmark, now please do the airbox mod and do it again so we can all see the top-end results. If you dont like it I'll buy you a new airbox. Or here's another idea. Since I also live in NJ & the only mod I have done is the air-box mod, I bring my bike & we do a comparison. :)


No dice huh Falcon? :(

[This message has been edited by JohnnyB (edited 16 September 1999).]
 
Of course my speedo is out. I know that, they all are but it looks good all the same. When the bike was released, it was written that the speedo was a tad optimistic.

Fraternal Greetings

The WOOP with the RED Scoot!!!
 
ZARNIWOOP: Just dynoed a couple of hours ago for the first time since I cut the entire bottom out of the airbox.

All my bike has is Yosh RS-3 slip ons and the airbox mod.

The mapping for this dyno test was previously returned to dead nuts factory settings.

160.2 RWHP is today's result, compared to 154.2 prior to any modifications. With the slip ons alone, I got no power improvement, and no power loss.

More importantly, there was absolutely no remapping needed. The horsepower curve is perfectly smooth, with NO waves at all.

In the words of the Dynojet technician (Jeff at Brampton Cycle in Toronto), "It's perfect and there's nothing I can do to improve it with remapping."

Jeff does a lot of Hayabusas, both stock and highly modified, and sees a lot of power delivery variations from stock unit to stock unit.

For my unit, the airbox mod in combination with the Yosh slip ons deliver 6 horsepower not including ram air effect, plus smooth power deliver in all ranges...on bone stock mapping.

I hope this helps you deal with your airbox situation.
 
Pete,

Does your bike hesitate between 1,500 and 2,500 rpm. This is when the flapper valve is completely closed so I expect that it must hesitate there. I am +10 +10 +10 but am still worried what sustained high speed cruising will do to the mill.

If your running with stock fuel settings and this major mod to the airbox, your pistons will be burnt out in no time at all as the EFI cannot cope with the added air flow.

The ICU is retarded in 2nd and 3rd gear in Europe to make sure that the bike passes it noise tests. The power Commander II (so I'm told) will allow the user to map out these power dips.

Frats

Z
 
Zarniwoop, I have no hestitation in the low end, no stumble, not even the slightest dip in horsepower delivery on my dyno graph at the low, middle or high end.

My graph line is exactly the same as stock but higher in horsepower at every point on the curve.

The bike runs smoothly and responds instantly at any RPM.

In addition, my exhaust gas analysis was right on spec.

Your comment about burning pistons worries me a little. Since I don't know bobo about stuff like that I'll speak to my tuner.

But given that I'm neither rich nor lean in any rev range, I doubt that anything untoward will happen.



[This message has been edited by Dirty Pete (edited 15 September 1999).]
 
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