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.
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help.
RIP Bob Parks.
1967 Burban the WMB,1991 S(stink)-10 Blazer,1969 GTO, 1970 Javelin, 1952 F2 Ford 4X4, 29 Model A, 72 Firebird. 85 Alfa Romeo
If it breaks I didn't want it in the first place
The WMB repair thread
http://67-72chevytrucks.com/vboard/s...d.php?t=698377