Help-Runs poor below Boost

M

madpersian

Registered
Any one have a Busa with Hahn kit that runs right? I have a 99, run about 9 lbs. Runs crappy under 4k or 90mph on highway. Have PC and tried 3 different maps, still too rich off boost. I guess it's my map, that's what the tuner says. Fouls plugs, exhaust all sooty black. what kinda plugs/gap you guys run?
Any help desperately needed and appreciated!
 
I gapped my plugs at 20...

It is probably your map... If you are running like #### before boost, your map is more then likely not tuned right for below boost... You should invest in getting her dyno tuned... It will be worth your money... When you do get it tuned, it may take some time to get it right and multiple times at the dyno... I remember one person on this forum claimed they had their bike on the dyno for 90+ runs before they got her running real smooth... Not saying that will happen to ya, but chances are good you need to adjust the map...

An idea... Use the buttons ont eh PC to kick up or down the low band of the PC. The buttons on teh PC will adjust the low, mid, high rpm areas and they get adjusted by a percentage when you use hte buttons instead of fine tuning with the computer... I will warn you, one bar makes a big difference... Decide wheather its running lean or rich and then tune it one bar at a time accordingly and see if that helps a bit...

Careful with your map, if you go lean, you are going to go boom under boost...

CLoud
 
Thanks Guys. I really appreciate the help. Gary could you please send my a map to madpersian@att.net Where can I get water injection? Anybody familiar the stand alone EMS for a Busa? Read about it online sells for about $1600. Turbo cars run perfect, can a turbo car EMS be used on a Busa? I think Mitsubishi turbo Eclipse's use a similar fuel press reg. Just a thought. Thanks again.
 
What's your A/F ratio? If you don't know then any changes is nothing more than a crapshoot at best.
Crapshoot change #1. If your running a rising rate FMU then open up the air bleed a half turn at a time.
You really gotta know the A/F before you can do anything worthwhile. At least if you are way rich you probably won't fry anything.
Without knowing the A/F ratio, I'd be more concerned and scared if the bike was running really good.
Mad`
 
I've E-mailed you the map. It is for use with a PCII. The fuel pressure regulator change that I linked you to MUST be made or this map will be worthless.
 
im having the same problem with my bike, except its a velocity stage 1 kit. runs like **** at cruising range (idle-3500rpm) had it mapped numerous times but still never gets better. i have no idea what it is.
 
Check your 2 way check valve that goes to your map sensor. The stock one will defently not work.It is a one way.Mke sure all vacume lines are ware thay should be.
 
03HAYABOOSTA
I just moved my dyno up to NC and if you can't find anyone up there to get it straightened out and need the help, i'm sure i can down here. I've setup a lot of em.


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I had frank from powerhouse in NY map this thing more times than i cant count. the problem never goes away and from what ive been told hes the man with turbo bikes.
 
There are a lot of good turbo tuner guys out there, but it probably doesn't need more mapping. It could be something in the setup or combo of either turbo system or motor. No offense and I don't know them up there but i would be weary if his cure is to keep mapping it instead of trying figure out why it has the problem??


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Yea im bringing it back to him sat and telling him i dont want it back till its fixed cause he built the motor from scratch himself and installed everything. im wasting my time trying to fix it in my garage. i shouldnt have to!!
crazy.gif
 
iap sensor is bad or the vac line is off or the bleed/check valve is in wrong and the sensor is not seeing vac.
 
I have a 99 as well. Mine ran like yours until I discovered the voltage regulator was shot. The pc2 was never seeing stable voltage so it would get confused and the bikes map would jump around.
I also called Teri Keiser at Mr. Turbo to see what he thought. Apparently the 99's sometimes get this mysterious unmappable problem that is exactly as you described and I experienced. Anyways, the voltage is easy to check. Good luck--JT
 
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