Air Box Mod, Small or Large

[gjklm]

I've looked through several threads and could not find this answer, maybe somebody can help me out.

I have an 02 with Yosh RS3 slipons and TRE, no other mods have been done performance wise.

Is the small air box mod worth doing or is the full better with my current setup.

Or should I just leave it alone ??

Any info would be greatly appreciated

[gjklm]

Also if either one is worth doing, does anyone have any pics of what they did or know where I can get some instructions on completing this.........Thanks

[BADZXELEVEN]

I had the same thing, except with yosh, stage 1 cams.
Did the small box mod and picked up <span style='font-size:15pt;line-height:100%'>5</span>mph on the top end!

I would just remove the flapper in the box for now, if I were you.
Remove the filter, it's right there.

[BADZXELEVEN]

Check out this link.

[gjklm]

Hey Thanks alot BAD............Man that was fast and that is why I love this website

[BADZXELEVEN]

Glad to help!!

[Doc_Busa]

Until you get a Power Commander, I would hesitate to do much more modifications. You do not want a lean condition that could potentially burn you pistons and valves... Just my opinion....

[gjklm]

I appreciate the opinion, this may sound like a dumb question but here go's. I dont quite get what the PCIII will do for me or even what it does I read on these boards that alot of people have them , so what do they do? Also where is a good place to get one and should I get PCII or PCIII and is it easy to install and (yes one more question)what is a good price for one........Thanks again

[SierraFlyer]

The PC3 is a unit that plugs in between the wiring harness and and the ECU. Its purpose is to allow owner access to the mixture and timing (at least on the PC2) for tuning purposes. The way it does it is to take the signals from the engine sensors and tweak them enough so the ECU compensates and changes the timing of the injector duration and the timing phase and duration. The "tweaking" is just signal offsets. Just as the TRE mod fools the ECU into thinking it is in 5th gear all of the time, the PC2/3 fools the ECU into thinking it is at a different air temp, air density, engine RPM, cam position, etc. so that it chooses a fuel/timing curve that is better for performance than say smog reduction. The benfit is that you can unplug the PC and return the Busa to stock and the ECU will never know. Otherwise you would have to remap the ECU memory to get it back to stock. The PCs can be changed as many times as you wish and at any time too. Thats nice for when you add other performance parts like race air filters, air box mods, ported heads, cams, exhaust, etc.

[Doc_Busa]

I appreciate the opinion, this may sound like a dumb question but here go's.  I dont quite get what  the PCIII will do for me or even what it does I read on these boards that alot of people have them , so what do they do?  Also where is a good place to get one and should I get PCII or PCIII and is it easy to install and (yes one more question)what is a good price for one........Thanks again

Sierra did a good job with the technical, so let me provide some basics. How you ever modded a carb. motorcycle? If so, what three things do you do with a stage one build?
1. high flow air filter (i.e., BMC, K&N, etc.)
2. high flow exhaust (i.e., Muzzy, Yosh, etc.)
3. CHANGE THE JETTING!!!

Number 3 is critical, why, because you need to get more fuel into that beast to compensate for the extra air (high flow filter) and extra exhaust flow.

Now, you are dealing with a fuel injected bike, the same thing applies, more air, more exhaust, means more fuel, otherwise you begin to lean the bike out, which is bad. It may run faster and more powerful, but you may be running lean. Some say "lean is mean", but those people enjoy changing pistons, valves, etc.

See what I mean? The PowerCommander can compensate for the higher air and exhaust flows by adding in more (or less) fuel when needed during any part of the RPM curve (it is way more complex than this, but this is the basic scenario).