John Larkin
Sublime Master of Turbology
- Joined
- May 25, 2001
- Messages
- 5,012
Is there one?
Does anyone know the voltage output scale of the VSS?
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John Larkin
Sublime Master of Turbology
- Joined
- May 25, 2001
- Messages
- 5,012
Thanks Dave. Anyone know how the pulses correlate to speed?
John, call John Spina at Casper's. He sells various VSS signal converters and can give you the pulse specs. I want to say it's a 2 pulse/rev output but I am not sure.
http://www.casperselectronics.com/
http://www.casperselectronics.com/
Hi John,
What kind of problem(s) are you having? There is a speed buffer that is between the VSS and the computer that can cause you trouble. It did me for almost a year before I found it.
My troubles was cruise not working right and the tranny locking up in 2nd with light throttle after the engine warmed up.
Gary
What kind of problem(s) are you having? There is a speed buffer that is between the VSS and the computer that can cause you trouble. It did me for almost a year before I found it.
My troubles was cruise not working right and the tranny locking up in 2nd with light throttle after the engine warmed up.
Gary
John Larkin
Sublime Master of Turbology
- Joined
- May 25, 2001
- Messages
- 5,012
Well, I am collecting information for a project that will likely overwhelm me. But it's fun to talk about!
I'm trying to make a switch that will sense MPH in 3rd gear, possibly activating torque converter lockup. I may drive myself crazy trying to use the VSS as the indicator. It may be better to use RPMs once the 3rd gear pressure switch opens. I did the math and with a 28" tire and 3.42 gear, rpm's at 1:1 transmission ratio in 3rd gear (it is 1:1 in 3rd, right?) should be 3697 @ 90mph. 90 was an arbitrary number. Now this is considering "zero" TC slippage. Real world rpms would probably be higher, maybe not.
However, when you lock the TC, theoretically rpms would drop to that level @ 90mph if for no more than a moment. Taking into account the normal 200-300rpm drop of the lockup, maybe a signal generated at 4000 rpm would basically compensate for it. I'm beginning to decide that the logic circuitry of a system like this for automatic engagement of lockup probably isn't worth the trouble. But using a shift light to signal the rpm only when in 3rd gear might not be a bad idea so I know when to throw the lockup switch manually, correlating the rpm with mph since the speedo only shows 85
.
That's about it for now.
And Gary, from reading gnttype archives, it was stated that the VSS is a 4 pulse system. Apparently rare these days since 2 pulse is more common.
I'm trying to make a switch that will sense MPH in 3rd gear, possibly activating torque converter lockup. I may drive myself crazy trying to use the VSS as the indicator. It may be better to use RPMs once the 3rd gear pressure switch opens. I did the math and with a 28" tire and 3.42 gear, rpm's at 1:1 transmission ratio in 3rd gear (it is 1:1 in 3rd, right?) should be 3697 @ 90mph. 90 was an arbitrary number. Now this is considering "zero" TC slippage. Real world rpms would probably be higher, maybe not.
However, when you lock the TC, theoretically rpms would drop to that level @ 90mph if for no more than a moment. Taking into account the normal 200-300rpm drop of the lockup, maybe a signal generated at 4000 rpm would basically compensate for it. I'm beginning to decide that the logic circuitry of a system like this for automatic engagement of lockup probably isn't worth the trouble. But using a shift light to signal the rpm only when in 3rd gear might not be a bad idea so I know when to throw the lockup switch manually, correlating the rpm with mph since the speedo only shows 85
. That's about it for now.
And Gary, from reading gnttype archives, it was stated that the VSS is a 4 pulse system. Apparently rare these days since 2 pulse is more common.
John,
You do know you can get chips with blinking SES lights for shift indicators at a specified RPM, and WOT TCC lockup at whatever MPH you specify? Red A. is known for these; I am sure others can do it also. Why build extra hardware when the ECM can do it?
You do know you can get chips with blinking SES lights for shift indicators at a specified RPM, and WOT TCC lockup at whatever MPH you specify? Red A. is known for these; I am sure others can do it also.
Why build extra hardware when the ECM can do it?Similar threads
