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Alpha-n or speed density ??

Posted: Mon Apr 16, 2012 1:36 pm
by wargen
Hi everybody,

I have some issue, i have been running my bike for a year with a good tuned Alpha-n ve table and ignition table. Now i have added turbo and what i can read in manual i should change to speed density, should i use my old tables or should i make new ones from start?

Tryed to use the ones that Tunerstudio generates from start but the bike hardly start when use them. When i start the fuel load on idle is about 70 % then it stops direct, when i use fixed advance i can start the bike.

Would be wery wery nice if somebody could help me out to understand or if i have some setup problem and point me in right direction and/or if somebody have a base tune to start with

Thanks /Jonny
vfr800_TB.msq
Some data for my bike

Honda 800cc RC46 engine Vfour 90 degres 180 degres cranc MS3 with MSX 1,1 beta, 255 cc injectors, Garret turbo, -0.2 Bar at idle, full bost right now is 0,5 bar, max Vacuum is -0.6 bar when i go from WOT to close, 15degres ignition at 1200 rpm and about 38 degres at 10 000 rpm(without turbo) Max rpm 12000 , 200 HP crancHP is goal. I have connect all 4 inlet vacuum house(4 mm) to a vacuum collection box with size of 1/5 of liter to ensure there is a stable vacuum for the MS3,

Re: Alpha-n or speed density ??

Posted: Mon Apr 16, 2012 5:10 pm
by Eaallred
Someone may correct me but I would start out taking your line of fuel at 100% throttle at your Alpah-n map, and paste that on where your ambient Kpa is (Here in SLC i'm at 84Kpa) in your Speed Density map. Then in theory, you should be close to the same fuel at that point. Start increasing fuel above that pressure of course, but should get you started.

I just switched from SD to AN and it was close enough to run, but I still had to re-tune the whole map quite a bit. But it did get my WOT close enough to run it and tune it.

Re: Alpha-n or speed density ??

Posted: Tue Apr 17, 2012 9:09 am
by wargen
Ok thanks, there is god to start with.

Is there somebody that nows what is normal fuelload at idle? mine is about 70-80 %

Thanks a lot.