Quote:
Originally Posted by HO455
Definitely interested in this! I have been playing with an Arduino and a spare speed signal generator from my Gearvendor. Big learning curve for me. 
I have a TH350C transmission in front of the Gearvendor and my earlier attempts to use vaccum switches didn't work out very well. I couldn't stop the detonation caused by having the converter locked up at lower speeds during part throttle acceleration. I feel that keeping the converter unlocked below 45 mph in conjunction with a vaccum switch should solve my pinging issue.
I have experienced poor life span with the TCI style vaccum switches. The diaphragms fail giving me a vaccum leak. So I am interested in the vacuum sensor you have sourced too. Using a sensor should give you the ability to set the hysteresis to what ever you want. Good idea.
I have also thought about installing a ECU from an early TH350C car in the truck as a low cost MPH switch. I just haven't found one in the wrecking yard yet. |
I agree 45 mph would be a good cutoff. I am not sure if I'm going to be able to make the vacuum sensor work to my satisfaction. My impression is that you don't have to press the gas pedal down very far to make the vacuum level go almost completely away. I'd like to have the TCC stay locked maybe all the way to half throttle. Maybe a pedal-mounted switch from a 71-72 truck with a TH400 would be a better way to go. Another approach might be to tap into one of the pressure ports on the side of the 700R4 transmission to read the pressure associated with the TV cable position. I have thought it might work well to base the decision to lock or unlock the TCC on whether the gas pedal has been pressed down slowly vs. quickly.