Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

mossman · 01-31-2009, 10:21 PM

Hi, All. I just finished building my MPGuino and it came out and works great! I will post some pictures soon. The problem I am having Is that my '94 Ford Ranger has a variable reluctance VSS . This, as near as I can understand, produces an AC sine wave with frequency proportional to speed. The upshot is my 'guino doesn't start to register until I hit about 12MPH and it's a bit dodgy until 20MPH. Above that speed it's rock steady and right on. I gather variable reluctance sensors are not as accurate as hall effect and and other pulse type sensors especially at low speeds. Do you think the low frequency signal could be processed (Rectifier?) to produce a better digital signal? I would prefer not to have to retro another sensor on the drive shaft, but if I must then I will Modd away! I have played with pulses/mile and vss delay to no avail. 16000 pulses/mile seems right on though it's double what the VSS is supposed to put out. Thanks for your ideas!

01-31-2009, 10:21 PM	#1 (permalink)
mossman EcoModding Lurker Join Date: Jan 2009 Location: Monterey Bay, CA Posts: 7 Shadow Fox - '94 Ford Ranger 90 day: 22.08 mpg (US) Silver FoX - '00 Honda Civic EX 90 day: 36.31 mpg (US) Thanks: 0 Thanked 0 Times in 0 Posts	Variable reluctance VSS Hi, All. I just finished building my MPGuino and it came out and works great! I will post some pictures soon. The problem I am having Is that my '94 Ford Ranger has a variable reluctance VSS . This, as near as I can understand, produces an AC sine wave with frequency proportional to speed. The upshot is my 'guino doesn't start to register until I hit about 12MPH and it's a bit dodgy until 20MPH. Above that speed it's rock steady and right on. I gather variable reluctance sensors are not as accurate as hall effect and and other pulse type sensors especially at low speeds. Do you think the low frequency signal could be processed (Rectifier?) to produce a better digital signal? I would prefer not to have to retro another sensor on the drive shaft, but if I must then I will Modd away! I have played with pulses/mile and vss delay to no avail. 16000 pulses/mile seems right on though it's double what the VSS is supposed to put out. Thanks for your ideas!