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),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 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