Airbox mod



SLEEPERBUSA

Registered
I don't need a dyno to tell me that a small box mod makes HP!
I made back to back test passes. The same day, the same distance, and the same rollons.
I went 182 and 183mph on the first 2 baseline passes, went home, cut the box and went 187 and 188 mph with the box mod as the ONLY difference, an hour later.
THAT'S MY dyno.
5 MPH difference in a 1 mile pass is MAJOR!

The bike only had Yosh dropin cams. Not even a header.

The cams obviously wanted the motor to breath better, when I let it, it liked it!

1st baseline was from second gear at 70 mph, for 1 mile, going thru the gears. 182 to 187.
Second baseline was from 110 mph in 6th gear for the same mile. 183 to 188.
Had it NOT been an exact match between the 2 passes, I may have done more, but those 4 passes convinced me!

This is NOT hearsay...........I DID IT Myself.
I was using my GPS, not the speedo.
I could HEAR the motor reving faster and I could SEE the tack moving faster.
Suzuki makes a fine product, it's up yo US to make it better.
 

SierraFlyer

Registered
I would debate your assertion of the engineers at Suzuki being the "right" way. They have design goals to meet that may be different than I need. Almost all of them involve a compromise to meet the other goals. For example, The engineers detuned 1st thru 3rd in the RPM ranges idle to 4500 RPM to improve driveability and traction control. That compromise introduced the low RPM jerkiness. They tried to smooth out the jerks by improving airflow at low RPM through the airbox. The airbox is designed for top end airflow and has flat response in the low end. The flap is a compromise in itself. The air flow to the filter is necked down to an opening much smaller than the filter even if the flap is wide open. This chokes off top end airflow. HP is made at higher RPMs and not lower RPM. The Torque peak is well over 6500 RPM and the HP peak is over 10500 RPM. So why would you even care about the torque or HP loss at the 2000-4000 range? That is just a transition RPM until you get into the real power band. The only draw back is the highway cruise RPM are in that range and it might reduce fuel efficiency by a couple %. That doesn't interest me at all. The burning valve issue would be a major lean condition caused by more air than my little AB mod would produce. I also have the ability to remap the ECU and would increase the fuel mixture to compensate for the extra air. So for all these reasons I would say the Suzuki engineers have not design the optimal airbox for MY DESIGN GOALS. For all we know, the flap is there to improve the efficiency of the fuel burn to reduce part throttle exhaust emmissions?

I am sorry if you thought I meant the flap is linked directly to throtle position. I left out the part about RPM being linked directly to the throttle position. Then the flap is linked directly to the RPM. I just made the jump. As for the TRE, I would partially agree with you. Gears 1,2 and 3 are timing retarded in lower RPMs. the TRE uses an advance curve (5th) that is more timing advanced over the entire range of RPMs. I don't have a programmer that can remap timing so the TRE is a compromise that improves over stock in the lower gears, and has no affect on the upper gears. I would prefer to map each gear seperately but can't. The stock ECU is also too lean in the lower RPMs. Idle and lower throttle position smoothness and response are greatly improved by fattening up the mixture at those RPMs. I even got better gas mileage! Where were the Suzuki engineers on that one?? Obviously they had different goals to meet.

Please don't think I am slamming the Suzuki engineers, They are clearly tallented and designed a bike to go really fast but also be a great touring bike at the same time. If they had pruned 60 lbs more out of it, it could be a great race bike? That wasn't a design goal.

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laugh.gif
 

SierraFlyer

Registered
I would debate your assertion of the engineers at Suzuki being the "right" way. They have design goals to meet that may be different than I need. Almost all of them involve a compromise to meet the other goals. For example, The engineers detuned 1st thru 3rd in the RPM ranges idle to 4500 RPM to improve driveability and traction control. That compromise introduced the low RPM jerkiness. They tried to smooth out the jerks by improving airflow at low RPM through the airbox. The airbox is designed for top end airflow and has flat response in the low end. The flap is a compromise in itself. The air flow to the filter is necked down to an opening much smaller than the filter even if the flap is wide open. This chokes off top end airflow. HP is made at higher RPMs and not lower RPM. The Torque peak is well over 6500 RPM and the HP peak is over 10500 RPM. So why would you even care about the torque or HP loss at the 2000-4000 range? That is just a transition RPM until you get into the real power band. The only draw back is the highway cruise RPM are in that range and it might reduce fuel efficiency by a couple %. That doesn't interest me at all. The burning valve issue would be a major lean condition caused by more air than my little AB mod would produce. I also have the ability to remap the ECU and would increase the fuel mixture to compensate for the extra air. So for all these reasons I would say the Suzuki engineers have not design the optimal airbox for MY DESIGN GOALS. For all we know, the flap is there to improve the efficiency of the fuel burn to reduce part throttle exhaust emmissions?

I am sorry if you thought I meant the flap is linked directly to throtle position. I left out the part about RPM being linked directly to the throttle position. Then the flap is linked directly to the RPM. I just made the jump. As for the TRE, I would partially agree with you. Gears 1,2 and 3 are timing retarded in lower RPMs. the TRE uses an advance curve (5th) that is more timing advanced over the entire range of RPMs. I don't have a programmer that can remap timing so the TRE is a compromise that improves over stock in the lower gears, and has no affect on the upper gears. I would prefer to map each gear seperately but can't. The stock ECU is also too lean in the lower RPMs. Idle and lower throttle position smoothness and response are greatly improved by fattening up the mixture at those RPMs. I even got better gas mileage! Where were the Suzuki engineers on that one?? Obviously they had different goals to meet.

Please don't think I am slamming the Suzuki engineers, They are clearly tallented and designed a bike to go really fast but also be a great touring bike at the same time. If they had pruned 60 lbs more out of it, it could be a great race bike? That wasn't a design goal.

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Busashot

Registered
If you get server errors go back and edit the last duplicated post by just putting in a period(.). That way this Post isn't longer. Just a tip.
 

L4G4RT0

Registered
Yeah... I just bought the Ivan's TRE and I wuz told to make changes on Exhaust system, on Airbox and if possible to install the PC II... With all this discussion now i really don't get it:
- is the TRE enough to improve response by itself?
- can I damage my bike if I don't use the PC II to make some remaping?
- and how about the exhaust system...? it's a gr8 idea, but may i skip it by now ($$$ related)
- last (and the topic's issue): should i buy a NEW airbox, since the mod seems to be under heavy discussion?!

Tkz guyz
 

SLEEPERBUSA

Registered
Yeah... I just bought the Ivan's TRE and I wuz told to make changes on Exhaust system, on Airbox and if possible to install the PC II... With all this discussion now i really don't get it:
- is the TRE enough to improve response by itself?
- can I damage my bike if I don't use the PC II to make some remaping?
- and how about the exhaust system...? it's a gr8 idea, but may i skip it by now ($$$ related)
- last (and the topic's issue): should i buy a NEW airbox, since the mod seems to be under heavy discussion?!

Tkz guyz
A TRE DOES help smooth out the slight blip when ya roll the throttle, IF the bike has one. Some don't.

You won't damage the bike by not having a PCII.

Get the exhaust when you can afford it, it WILL help, but the bike is great in it's stock form.

The box mod doesn't need to be under heavy discussion.
A stock bike likes the "stock" box, a "flapper removed" box, OR and "small" box mod.
Alot of guys just reach in and remove the flapper, it gives a little more air flow, yet retains the low end torque.

A "big" box mod should be saved for a modified motor.

Your bike will be fine, ride and enjoy!
beerchug.gif
 

monsterspeedfreak

Donating Member
Registered
I would debate your assertion of the engineers at Suzuki being the "right" way. They have design goals to meet that may be different than I need. Almost all of them involve a compromise to meet the other goals. For example, The engineers detuned 1st thru 3rd in the RPM ranges idle to 4500 RPM to improve driveability and traction control. That compromise introduced the low RPM jerkiness. They tried to smooth out the jerks by improving airflow at low RPM through the airbox. The airbox is designed for top end airflow and has flat response in the low end. The flap is a compromise in itself. The air flow to the filter is necked down to an opening much smaller than the filter even if the flap is wide open. This chokes off top end airflow. HP is made at higher RPMs and not lower RPM. The Torque peak is well over 6500 RPM and the HP peak is over 10500 RPM. So why would you even care about the torque or HP loss at the 2000-4000 range? That is just a transition RPM until you get into the real power band. The only draw back is the highway cruise RPM are in that range and it might reduce fuel efficiency by a couple %. That doesn't interest me at all. The burning valve issue would be a major lean condition caused by more air than my little AB mod would produce. I also have the ability to remap the ECU and would increase the fuel mixture to compensate for the extra air. So for all these reasons I would say the Suzuki engineers have not design the optimal airbox for MY DESIGN GOALS. For all we know, the flap is there to improve the efficiency of the fuel burn to reduce part throttle  exhaust emmissions?

I am sorry if you thought I meant the flap is linked directly to throtle position. I left out the part about RPM being linked directly to the throttle position. Then the flap is linked directly to the RPM. I just made the jump. As for the TRE, I would partially agree with you. Gears 1,2 and 3 are timing retarded in lower RPMs. the TRE uses an advance curve (5th) that is more timing advanced over the entire range of RPMs. I don't have a programmer that can remap timing so the TRE is a compromise that improves over stock in the lower gears, and has no affect on the upper gears. I would prefer to map each gear seperately but can't. The stock ECU is also too lean in the lower RPMs. Idle and lower throttle position smoothness and response are greatly improved by fattening up the mixture at those RPMs. I even got better gas mileage! Where were the Suzuki engineers on that one?? Obviously they had different goals to meet.

Please don't think I am slamming the Suzuki engineers, They are clearly tallented and designed a bike to go really fast but also be a great touring bike at the same time. If they had pruned 60 lbs more out of it, it could be a great race bike? That wasn't a design goal.

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Great read Sierra, very well worded!!!!
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200hp

Registered
What is the best air filter to put on a stock 02 Busa?  Thanks!

Postal.  
cool.gif
When you are done gutting your air box then gut your old air filter. Rip it clean off the lid and put the lid back on. I don't care about peoples openions on this topic, I care what the Dyno says. For anything other than a stock bike the flapper and filter are in the way.
Matt
 

L4G4RT0

Registered
Thanks SleeperBusa. I'll try to make some tests before and after the TRE's installation. If I don't find big differences, then I'll proceed to the exhaust system change... i don't know what brands people usually prefer, but it has to be one that exists here in Europe. I'll check it out in other posts maybe.

:cool:
 


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