Tuning With Ram-Air?

fastblackblur said:
It does. Think about it. The pressure in the intake manifold is constantly changing as the RPMs change and the throttle opens and closes. The argument would be is the change from the ram air even large enough for ecu to care about?

How do you tune for your ram air? Well it's easy, you get a data logger with wideband O2 sensor capability and log what your sensors are telling you. If the engine's AFR is too far off adjust the corresponding cells in the fuel map.

Has anybody ever blew up a bike because they didn't account for ram air?
Click to expand...

Ahhh I see now... Yeah so essentially altitude changes are large enough for the ECU to adjust, but the ram air doesnt cause a big enough change for it to care... That makes a lot of sense...


And no, I doubt there is a "problem" with not taking the ram air into account, I just figured for those nit-picky people out there who like to squeeze every last drop of power out of their bike that they can, one could really dial it in...
 
That's what I was trying to tell you earlier...TPS, GPS, and rpm's...ECU has different fuel maps for different gears and engine speed + load.

That's why a TRE is such a problem depending on what you are trying to do with the bike...it tells the ECU that you are in 5th gear all the time so you get full advance on the timing...well you also get the 5th gear fuel map which is richer than gears 1-4.

Tuners go in and build a custom map and add or subtract fuel at throttle percentages to get a smooth power curve. It may take a few hrs and many pulls to get it right...once they build up a good inventory of different maps for bikes with similar mods...then they have a better starting point.
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Yeah, a lot of cars and trucks use a MAF...I think because the power to weight ratio is so good on sport bikes...plus the higher rpm range...they need multiple fuel maps .

Gen2 Busa has a 12.5 to 1 compression ratio...runs on pump gas and puts approximately 175hp to the ground. Wet weight stock is about 570 lbs...to get that kind of power to weight ratio on a 3000 lb car...you would need almost 1000 RWHP.

Modern sport bikes are amazing!
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moosestang said:
sport rider did a test of different ram air setups. I believe they hooked some large blowers directly to the ram air.

Sport Rider-Ram Air Test of sport bikes on the motorcycle dyno
Click to expand...

Methinks that was posted on page 1 of this thread already. Good read though!


fastblackblur said:
Well did some searching and the busa ecu does not run like my ol'turbo camaro lol.

low throttle/low rpm it runs speed density using a MAP sensor to calculate fuel needs. Then it switches over to an Alpha-N mode where it calculates fuel needs from a pre determined table using throttle position and rpm.

hear is some neat info i dug up...

Tuning the FUEL maps - initial thoughts and concepts - ECU hacking

Learn something new everyday:beerchug::thumbsup:
Click to expand...


Ahh ok, so it only adjusts for varying pressure at low rpms, essentially when you are cruising... So tooling around town, taking easy touring rides, etc will be nice and smooth. But beyond that is where it has to be pre-programmed based on what mods you have and what altitude you are at...

Would there be a performance loss to go with a system thats constantly adjusting, throughout the RPM range?
 
danath 34 said:
So I am a complete newbie when it comes to tuning... I have only ever adjusted jetting on a carb, and have never done any kind of tuning in any way/shape/or form on a fuel injected bike... But I was thinking today, and have a question...

How do you accurately tune a bike with a ram-air intake, like the busa? Because to my knowledge, when a tuner does his magic on the bike, it is on the dyno, and thus the air pressure at the intake is just ambient pressure. Now you can tune it and get great numbers on the dyno, but when you actually take off down the road, you are going to get more air pressure (and thus more airflow) at the ram air intake. Now even if you perfectly tuned the bike on a dyno, wouldnt the nature of the ram-air make it go lean when you get up to speed?

Is there any accurate method of tuning so that you account for this extra air, short of setting it up in a wind tunnel?

Someone please educate me :bowdown:
Click to expand...

You go into ECU editor, turn the ram air compensation OFF, tune the bike on the dyno, go back into ECU editor, and turn the ram air compensation back ON . . .:cheerleader:
 
danath 34 said:
Would there be a performance loss to go with a system thats constantly adjusting, throughout the RPM range?
Click to expand...

I'm sure there is a reason why suzuki chose the tunning strategy that they did.

When reading about alpha-n mode tunning this phrase comes up frequently, "Alpha-N mode is often used on naturally aspirated racing engines" It would be cool to sit down and talk to one of their engineers and see why they made the choices they did.

found some cool info in google books.

Motorcycle Fuel Injection Handbook - Google Books


talks specificly about alpha-n tuning on page 76.
 
+1000 :thumbsup: the algorithm for ram air compensation is already built into the stock ECU.
POWERHOUSE said:
You go into ECU editor, turn the ram air compensation OFF, tune the bike on the dyno, go back into ECU editor, and turn the ram air compensation back ON . . .:cheerleader:
Click to expand...

oh yea, someone mentioned a blower in front to mimic ram air... there's was a guy trying that. It's not that easy. Not even close. :laugh:
 
Commuta_Busa said:
+1000 :thumbsup: the algorithm for ram air compensation is already built into the stock ECU.

oh yea, someone mentioned a blower in front to mimic ram air... there's was a guy trying that. It's not that easy. Not even close. :laugh:
Click to expand...

Not necessary :laugh:
 
Commuta_Busa said:
+1000 :thumbsup: the algorithm for ram air compensation is already built into the stock ECU.

oh yea, someone mentioned a blower in front to mimic ram air... there's was a guy trying that. It's not that easy. Not even close. :laugh:
Click to expand...

Yes, it is built into the stock ECU, and can be changed to accomodate different gearing as well, if other than stock . . .:laugh:
 
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