RESULT OF AIR BOX MOD

G

Guest

Has anyone ever obtained before and after dyno results on the same day indicating the difference of an air box mod alone? This would be the difference of just the airbox mod - not different exhaust, different tuning (unless tuning for box mod only), different weather, different operator, different filter, different fuel etc in conjuction with the air box mod. In other words: Before and after dyno results taken close together timewise of the air box mod alone PERIOD. This would [should] also have been performed only on a dyno capable of providing simulated RAM AIR for both before and after results. I've had my eyes open for such results since last summer and I've not seen anyone post to this. Only a small handful have ever provided results of any kind from a ram air simulated dyno and those were after multiple mods.

[This message has been edited by Todd (edited 25 February 2000).]
 
TODD, I DID THE AIR BOX MOD, FLAPPER VALVE AND THE RESULTS WERE RW150, TORQUE 96 LBS. THIS IS THE OTHER AIR BOX MOD I DID. RW154 AND TORQUE 101 THEY WERE DONE AT DIFFERENT DAYS AND DYNOED ON DIFFERENT DAYS BUT THE TEMP WAS THE SAME. NOT SURE ON THE BARO. PRESSURE. THERE IS NOT A WAY TO DO THE RAM AIR AROUND HERE. SO ITS HARD TO TAKE THAT INTO CONSIDERATION. THE DYNO RUNS WERE ON THE SAME DYNO WITH THE SAME OPERATOR. AND BOTH WERE TUNED JUST FOR THE BOX MODS.
 
What were the torque CURVE's like after the airbox mod ?? Flat or peaky? What changes did you see between 1100 and 2500 RPM ?
 
This is a good illustration of the convoluted results obtained from a dyno with no ram air simulation when it comes to the air box mod on a Busa. First and foremost we need the ram air imput. Secondly we must know the results taken BEFORE any air box mods were made. The design of the stock air box flapper valve is purpose built to RESTRICT air flow at low rpm which also INCREASES it's velocity in order to gain an increase in torque versus what would normally be seen if the flapper was wide open. On a regular non ram air dyno with no air input to simulate what would normally be seen at speed - increases of PEAK hp over a stock box should be seen. This is due the the fact that no ram air is available and access to what little air is available on the choking Busa has been increased by the elimination of the flapper valve. The stock box was built and designed to compliment ram air at speed. Hacking up the air box for better results while sitting still may be great for a bike with no ram air but what about those of us who actually ride at speed? I feel certain a loss of torque at low rpm is to be expected and will be indicated on a proper (for a ram air bike) dyno. The question is how much low end torque is lost and what if any gain in peak hp is acheived from the airbox mod alone? Also where I live a proper filter is a must if any kind of real longevity is desired for the motor. High winds and dusty conditions are common here. Also as has been discussed in the past how can one properly tune a ram air bike when adding a mod that increases access to available airflow without simulating the actual (or near actual) airflow that will really be seen when riding the bike on the street? On a non ram air simulated dyno the air [and the air density] the Busa will have available will always be less than what is seen on the street regardless of whether it has an airbox mod or not. To me this [proving/tuning airbox mod increases on a ram air bike without adequate airflow] seems akin to trying to replace the jets on a FI bike since it always worked on carbs. Things are different now. Comments, suggestions, ram air experts and air simulated dynocharts[with hp&torque] welcome!
 
TODD I UNDERSTAND WHAT U ARE SAYING AND I HAVE DONE DYNO RUNS SINCE STOCK. EACH MOD THAT I HAVE DONE HAS INCREASED HP AND TORQUE. TRUE NO AIR WAS FORCED IN THE BOX. IT WAS RUN AS A CARBORATED MOTOR, BUT WOULDNT MORE AIR DO NOTHING BUT INCREASE YOUR HP AND TORQUE IF THE MAPPING IS CLOSE? I DONT KNOW A LOT ABOUT FI BUT I CAN TELL YOU I CAN FEEL THE DIFFERENCE IN THE BIKE. IT FEELS STRONGER AND RESPONSIVE.
 
I guess my biggest concern with not tuning for the extra/actual air seen from the ram air on the road is that it's potentially a lean out disaster waiting to happen. Some Busas are slightly lean totally stock and there doesn't appear to be a lot of room for error. The factory ECU does NOT automatically compensate which keeps Yosh [Yosh box] and Dynojet[PC2] in business but unless you can simulate the ram air you may either be too lean [POOF goes your motor] or too rich. [decreased performance] This is of course provided you are attempting to alter the mapping from stock at all. I've seen some owners add the airbox (and other) mods with no remapping whatsoever.

[This message has been edited by Todd (edited 25 February 2000).]
 
I will be doing the test for all of you guys. I am waiting for an 18 tooth front sprocket for my bike. I have a yosh pipe, pc-2, and the air-box mod. with these mods the bike hits the limiter in sixth (196.3 MPH) with a head wind, a hot day it does not matter. i am going to install the 18 tooth and go back out with the radar gun. once ihave gotten max mph with my current set-up. i will try a stock air-box with stock filter, a stock box with a bmc filter and a mod-box with the stock filter. once i figure out what works best i will let you know.
 
Todd,

Your point is well made. Seems like everyone is caught up with Dyno numbers nowadays. What people need to realize is that tuning a bike on a dyno(especially one without eddy current load) is NOT perfect. Many times I have tuned a machine on dyno, only to find it lean on track/street. WHY? Because the 'load' of a typical dyno is not as much as real world, i.e. street/track @ 180mph. So on the dyno it pulls that load OK.

The newer style dyno's(eddy current) are much better at simulating the real world load. Add to this the ram air concern...and I wonder exactly how many of this forums bikes are actually FASTER than before...because the dyno said so...NOT!!! Show me a timeslip or radar confirm, thats the bottom line to me.

Oh, and beware of your local dyno jockey playing with the temp sensor....I can make my 'stock' busa put out over 200rwhp if I want to.


Dave
 
Other disadvantages besides the potential loss of low end torque and questionable hp increase could include:

Loss of warranty coverage since Suzuki does have the right to refuse warranty claims upon discovery of such mod.

Higher noise level duing open throttle conditions.

Possible catastrophic lean out condition due to inadequate fuel due to higher air flow.

Some have complained of problems with idle after performing the mod.

Possible legal implications due to those that block off/remove emmission controls when performing said mod.

$200+ dollars to replace box if unsatisfied.

Ram air simulation dyno needed for proper tuning. Increases on non ram air simulated dyno can show inflated hp increases after removal of stock box flapper due to lack of true actual air seen on the road and perhaps (probably IMO) at the expense of low rpm torque. If we were tuning a non ram air carb bike would we want to add restrictor plates during our dynotesting and tuning only to remove them when finished to go ride?

Some of these reasons are probably insignificant to some but they should be noted and realized before performing this mod. I've been considering this mod myself since last summer but never have been able to get past all that's been discussed under this topic.




[This message has been edited by Todd (edited 25 February 2000).]
 
Thats pretty much the same way I did My mod except I used fiber glass screen & plastic welding bond. Also I was able to get all filter and metal out from the bottom of the lid.
Right now Orient Express is the only Place I know of in the U.S.A that can dyno a ramair fuel injected bikes. They can simulate everything including forced air.
Dyno-Jet just came out with a new program and "O E" has it.

Call them and they can tell ya more....

800-645-6521
 
And if this isn't confusing enough, my mph in 1/4 mile track was higher at finish line with "stock" setting. Dyno liked 1 or 2 notches richer, no fan. Track about 600' above sea level, same as dyno. Air temp was 7 deg cooler than dyno, but may have had slightly higher humidity.
 
Although it is possible to debate the merits of airbox modifications to no end, one thing if certain. Any attempt to replace a commercial non-woven paper or fabric, or (professionally manufactured)oiled foam filter with metal screeen, regardless of the number of layers, is bound for major problems. The porosity of a homebrew screen filter is substantially higher than the abrasive particles coming through the intake track. There are (many) reasons why everyone isn't seen running around with open velocity stacks on their bikes. There is no amount of performance advantage that justifies jeopardizing the lifespan of your engine unless it has a time-between-rebuild expectancy measured in hours or runs rather than years.
 
Well, it's like this....I bought My bike as a Toy...not an investment. With that in mind, I like to get all I can out of it.

Yea, if I had to break the penny jar open just to buy it....then maybe I would think twice about doing mods like this one and others.

Remember, "wants" and "gives"....in most cases, if you want gains....your probably going to have to give something some where else.

If dependability was My concern, then I wouldn't be doing mods in the first place.

Duh?
 
I pondered the airbox cut for quite some time and questioned those who I believe to be the most knowledgable around the country. The verdict? No cutting for me. BMC is back ordered or it would be in there now. Thats it for the box other than sealing up the ram air ducts. I am NOT willing to lose ANY low end or mid to gain it back on top. If the a-tech proves to be a superior design then I wouldnt hesitate to install it. Till then, no cutting here. BTW, the BMC always gives a 3hp average increase. Thats from dynojet. Also from Dusty at dynojet is the statement that there is NO gain at all only losses from airbox cuts on the busa's they've tested. Also Lee Shierts looked through all his busa charts to date and was unable to find a single one with the airbox cut that did NOT lose HP in the lower end. A guy like the above who will put an 18 tooth on to achieve 200mph might benefit from this mod, I wont.
 
My reason for installing the 18 toth is not to achieve 200 mph, but to load the motor so i can see what differences the airboxes and filters make. i expect the top end to be lower. you can not tune with a lap-top when your on the rev-limiter. i will keep you posted.
 
Do Lee or dyno-jet have ram-air on thier dyno`s....NO......Lee had the box cut on his 200mph bike...there`s no way a uncut box is going to outperform a properly cut box ...I proved it on the street with two busa`s. And I`ll add dyno-jets maps are at best a starting point for jetting. Just cut third busa`s box tonight. To each his own.
 
WELL, THE RESULTS ARE IN. THIS IS GOING TO BE A LONG ONE. FIRST LET ME TELL YOU WHAT I DID. I TOOK OUT THE AIR FILTER AND CUT THE LITTLE LIPS OFF THE BOX (WHERE THE BOTTOM OF THE FILTER GOES ON). FLAPPER VALVE WAS ALREADY TAKEN OFF. I THEN SANDED IT SMOOTH. I BOUGHT METAL SCREEN AND LAYERED IT SIX TIMES TO WHERE YOU COULD NOT SEE THROUGH IT BUT AIR WOULD FLOW SMOOTHLY. I CUT THE SCREEN TO WHERE THERE WAS ABOUT TWO INCHES EXTRA WHEN IT LAYED ON TOP OF THE HOLE IN THE BOX (BY THIS I MEAN THE HOLE INSIDE OF THE BOX). I APPLIED HOT GLUE TO EVER LAYER OF THE SCREEN (GOOD STUFF, WORKS WELL). I THEN SEALED THE SCREEN ONTO THE BOX WHERE THE BOTTOM OF THE FILTER USE TO LAY. CAULT WORKED WELL FOR ME. I THEN STRATEGICALLY PLACED FIVE SCREWS IN THE BOX AND THROUGH THE SCREEN TO SECURE THE SCREEN DUE TO HIGH WIND AND PRESSURE. MAKE SURE ALL PLASTIC CHIPS ARE OUT OF THE BOX BEFORE YOU REPLACE IT BACK ON THE BIKE. LET THE CAULK DRY. TO SEAL THE BOX I CUT OFF MY STOCK AIR FILTER TOP AND TRIMMED IT DOWN TO WHERE THERE WAS ONLY A LITTLE FILTER LEFT AND A LITTLE METAL FROM THE FILTER. I PRESSED THE REMAINING METAL OVER THE REMAINING PAPER FILTER AND BURNED IT TO WHERE THERE WOULD BE NO CHANCE OF LENT FALLING INTO THE STACKS. THIS WORKED VERY WELL. NOW, MY MODS ARE A HINDLE PIPE AND THE AIRBOX MOD EVERYTHING ELSE IS STOCK. TOOK IT UP TO THE DYNO TODAY AND AFTER PLAYING WITH THE MAPPING CAME UP WITH THESE RESULTS... I GAINED 4 HP AND 5 POUNDS OF TORGUE. FINAL RESUTLS WERE 154 RWHP AND 101 LBS TORQUE. I THOUGHT GOING IN THERE THAT I HAD 154 RWHP AND 98 TORQUE. BUT IT TURNS OUT THAT THAT WAS NOT CORRECTED. SO, IN CONCLUSION, THIS BENIFITED ME. I SPENT $5 ON THE SUPPLIES AND $60 ON THE DYNO AND HAD GOOD GAINS. THE ONLY DOWN FALL I SEE IS I MAY HAVE TO CLEAN OUT MY AIRBOX ABOUT EVERYOTHER RIDE TO GET THE JUNK OUT OF IT. THE PROCEDURE TAKES ABOUT 45-60 MINUTES. LET ME KLNOW WHAT YOU THINK. I WILL HAVE THE DYNO SHEET IN A COUPLE OF DAYS. THE PRINTER WAS NOT WORKING TO PRINT OUT THE RESULTS.
 
Cutting the Busa's pink wire was popular for a while too (it always worked in the past right?) until people figured out what really happens when this mod is performed. I still hear about the pink wire being cut even today. I'm open to the box mod - just want to see some documented proof of the results, repercussions and drawbacks first. At least one owner has been dissatisfied enough to repurchase a new stock box after the mod.

[This message has been edited by Todd (edited 25 February 2000).]
 
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