Fuelling Turbo Bike With ITB's
Posted: Sat Apr 19, 2008 10:23 am
Fellow MS'rs, I aplogise in advance for the length of the post but it'll hopefully set the scene & level of my understanding (obviously not too good!!)
As the title suggests am building a Microsquirted Gsxr 1100 Turbo. The question I have is regarding SD or Alpha-N or Blended Alpha-N. I've read plenty on the subject but have no definative answers. I know most prefer the SD setup but I have doubts on it's suitability for my install.
Systems I have used from other manufacturers use Alpha-N for the base load measurement (this dictates the Fuelling & Ignition from the lookup tables) then apply a correction for the MAP either positive (boost) or negative (vacuum). This MAP corrction table is pretty much constant for all engines as the delta remains the same. I can understand this & it fits in with my understanding of the use of individual TB's.
I know my inlet vacuum will be reasonable on idle but as soon as the throttle is cracked it will fall hence the need to go for Alpha-N, at least at low speed / no boost. The MAP will also saturate at higher throttle openings hence the need for Alpha-N there too. I will need the MAP compensation once the engine starts to see 0 vacuum / positive boost.
The bike will see mostly road use so needs to be as crisp as possible.
Question I have is if MS 2 can do the MAP corrected Alpha-N or will it have to be an Alpha-N to SD switch over?
I know this question has been asked in many different ways by many different people & I apologise if I have missed something somewhere. If anybody else has experience using the SD/blended Alpha-N in a similar install with success then I'm happy to take it on board! Just trying to get it all straight in my mind before I try starting / mapping.
Thanks,
Stewart
As the title suggests am building a Microsquirted Gsxr 1100 Turbo. The question I have is regarding SD or Alpha-N or Blended Alpha-N. I've read plenty on the subject but have no definative answers. I know most prefer the SD setup but I have doubts on it's suitability for my install.
Systems I have used from other manufacturers use Alpha-N for the base load measurement (this dictates the Fuelling & Ignition from the lookup tables) then apply a correction for the MAP either positive (boost) or negative (vacuum). This MAP corrction table is pretty much constant for all engines as the delta remains the same. I can understand this & it fits in with my understanding of the use of individual TB's.
I know my inlet vacuum will be reasonable on idle but as soon as the throttle is cracked it will fall hence the need to go for Alpha-N, at least at low speed / no boost. The MAP will also saturate at higher throttle openings hence the need for Alpha-N there too. I will need the MAP compensation once the engine starts to see 0 vacuum / positive boost.
The bike will see mostly road use so needs to be as crisp as possible.
Question I have is if MS 2 can do the MAP corrected Alpha-N or will it have to be an Alpha-N to SD switch over?
I know this question has been asked in many different ways by many different people & I apologise if I have missed something somewhere. If anybody else has experience using the SD/blended Alpha-N in a similar install with success then I'm happy to take it on board! Just trying to get it all straight in my mind before I try starting / mapping.
Thanks,
Stewart