Originally Posted by Duhfactor
Just an update related to the modified shootis map I installed on my 07' with akro's. After riding it around town, the bottom end seems to be getting better (more smooth), but the mid range is not going to work for me. It's just too weak compared to the standard akro map. I have found that it feels lean from about 3000-4500 RPM, really having a pause or delay until it hits 4500-5000 RPM, then the fueling, in combination with my 200 throttle tube, and she wants to throw me off the back.....
I'm going to change the secondary throttles like my modified shootis map on a regular 07' akro map for starters. I think opening up the secondaries must lean the fueling down just a bit, although it seems odd that changing those would make that much of a difference. I did have some deceleration popping with this map compared to the akro map too.
To be continued this weekend..........
Opening the secondaries makes perfect since because that slows down the fuel charge velocities. Irregardless of the fact of the A/F ratio it still is getting less of a charge in there(think like a small supercharger with them closed more). The engine is going to create x vacuum at any RPM. If you close the secondaries you increase velocity because x vacuum has to go thru a smaller area. This is how a ported cylinder head can sometimes only make another 2 hp. Big holes look nice but can sometimes hurt true performance.