Bike was a Stage1 114ci Heritage. Got Stage1 Power Vision map from Fuel Moto. Bike ran great. Added Woods 22X cam and got a map made for the cam from Fuel Moto. Bike runs fine. Today just out of curiosity I compared the Stage1 and Stage2 maps with WinPV. I was surprised to see the VE tables numbers for the Stage2 map were lower in the lower rpm range than the Stage1 map. I expected the cam would require more fuel in the lower rpm range and thus the VE tables numbers would be higher. Can someone explain this? Thanks

 

Might suggest you call Jamie at Fuel Moto and put your questions to him. Likely to get a better answer there than here.

 

How long has it been since you flashed the new tune. Did you do your 3 20 min auto tunes?
like mentioned above best bet is to call fuel moto. I am running fuel moto tune with the 22xE and loving it!

 

Nothing wrong with the tune I have. I'm just trying to understand why a Stage1 map VE tables would be higher than a Stage2 at low rpms. I would have thought a cam change would require more fuel everywhere Just for my understanding of how this stuff works.

 

the reason I asked when you flashed is I do believe I read that it takes some miles for the fuel tables to adjust completely.

 

You are correct. I got some good info from another site. A guy was kind enough to compare his Stage1 and Stage2 maps and his VE tables were similar to mine. The VE tables in the Stage2 map were lower than the Stage1 map at low rpms but higher above 2000 rpms. So sounds like that's typical with a mild cam. I was just surprised it was that way.

 

excellent info, thanks for posting it!

 

Volumetric Efficiency (VE) tables indicate how efficiently your engine pumps air. A value of 100% indicates you are pumping air at full capacity based on engine rpm and displacement. It is possible to go above 100% under certain conditions where intake flow momentum and exhaust scavenging add to flow capacity. A cam that is operating off design (higher rpm cam at lower rpm) will pump less air.

Fuel flow is determine by the Lambda tables (Air Fuel Ratio AFR tables in the old days). At Lambda = 1 the oxygen and fuel are in balance for complete combustion. At high power and high rpm Lambda is reduced (more fuel is added than can be burned completely) this done to reduce combustion temperatures to a level the engine can tolerate.

 

Thanks. I guess that explains why any performance cam will be slightly less efficient at really low rpms. Guess the stock cam is king in that regard