RPM's at 80 MPH
#76
12-17-2009, 11:21 AM
Join Date: Apr 2009
Location: Tallahassee, FL (or thereabout)
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I've read some of that before, but I didn't realize it was only affected over 73(ish)
So I'm guessing this is caused by the ECM (or TCM or someotherCM) seeing a different ratio of the VSS in the tailshaft vs the ABS wheel speed sensor? If that is the case, I can setup a microcontroller to multiply the pulses coming from the VSS by the ratio of the differance between a 3.3 and 3.5 and that should fix it yes? Or I'm I all the way in left field again?
#77
12-17-2009, 01:34 PM
Thanks Dave.
I've read some of that before, but I didn't realize it was only affected over 73(ish)
So I'm guessing this is caused by the ECM (or TCM or someotherCM) seeing a different ratio of the VSS in the tailshaft vs the ABS wheel speed sensor? If that is the case, I can setup a microcontroller to multiply the pulses coming from the VSS by the ratio of the differance between a 3.3 and 3.5 and that should fix it yes? Or I'm I all the way in left field again?
I've read some of that before, but I didn't realize it was only affected over 73(ish)
So I'm guessing this is caused by the ECM (or TCM or someotherCM) seeing a different ratio of the VSS in the tailshaft vs the ABS wheel speed sensor? If that is the case, I can setup a microcontroller to multiply the pulses coming from the VSS by the ratio of the differance between a 3.3 and 3.5 and that should fix it yes? Or I'm I all the way in left field again?
#78
12-17-2009, 02:20 PM
Join Date: Apr 2009
Location: Tallahassee, FL (or thereabout)
Posts: 22,160
Received 851 Likes
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639 Posts
^Yeah, 79 is the magic number LOL!
I don't think it will be too hard. I built a digital speedometer for my Trans-Am, so I'm used to dealing with a VSS. Only trick will be generating the 'fake' signal in a way that the ECM/TCM will still read it. I don't know anyone locally that has a swapped diff so I guess it'll just have to wait until I do mine.
I don't think it will be too hard. I built a digital speedometer for my Trans-Am, so I'm used to dealing with a VSS. Only trick will be generating the 'fake' signal in a way that the ECM/TCM will still read it. I don't know anyone locally that has a swapped diff so I guess it'll just have to wait until I do mine.
#80
12-17-2009, 06:54 PM
#81
12-17-2009, 07:01 PM
On page one, there is a lot of confusion regarding OEM FDs. Per Post #17:
I posted up the info to clear this confusion regarding OEM FDs. That was obvious to everyone except yourself. No crap rpms will be different if you've got a non-OEM spec FD. Next time, I'll make it a point to very clear for the automotive noobs like yourself that need a lot of hand holding to get caught up on this stuff
I posted up the info to clear this confusion regarding OEM FDs. That was obvious to everyone except yourself. No crap rpms will be different if you've got a non-OEM spec FD. Next time, I'll make it a point to very clear for the automotive noobs like yourself that need a lot of hand holding to get caught up on this stuff
Minor differences in RWD 5AT rpms in 5th at 80mph can be attributed to the following:
1) Worn tires (ie shorter)
2) Shorter tires than stock
3) Taller tires than stock
4) Torque converter locked
5) Torque converter unlocked
6) Torque converter in slip-lock
7) non-OEM FD was installed
#83
12-17-2009, 07:17 PM
^Yeah, 79 is the magic number LOL!
I don't think it will be too hard. I built a digital speedometer for my Trans-Am, so I'm used to dealing with a VSS. Only trick will be generating the 'fake' signal in a way that the ECM/TCM will still read it. I don't know anyone locally that has a swapped diff so I guess it'll just have to wait until I do mine.
I don't think it will be too hard. I built a digital speedometer for my Trans-Am, so I'm used to dealing with a VSS. Only trick will be generating the 'fake' signal in a way that the ECM/TCM will still read it. I don't know anyone locally that has a swapped diff so I guess it'll just have to wait until I do mine.
#85
12-17-2009, 11:22 PM
On page one, there is a lot of confusion regarding OEM FDs. Per Post #17:
I posted up the info to clear this confusion regarding OEM FDs. That was obvious to everyone except yourself. No crap rpms will be different if you've got a non-OEM spec FD. Next time, I'll make it a point to very clear for the automotive noobs like yourself that need a lot of hand holding to get caught up on this stuff
I posted up the info to clear this confusion regarding OEM FDs. That was obvious to everyone except yourself. No crap rpms will be different if you've got a non-OEM spec FD. Next time, I'll make it a point to very clear for the automotive noobs like yourself that need a lot of hand holding to get caught up on this stuff
You're posted up info is not necessarily correct. There are discrepancies with many people who never changed anything.
Stop regurgitating what you do not know for a fact please. Or go to some other thread to troll.
#88
12-18-2009, 01:18 PM
Just to clear things up.
03-06 RWD 5AT Sedan (open or VLSD) - 3.3 gear
03-07 RWD 5AT coupe (VLSD) - 3.3 gear
04-06 AWD (open) - 3.5 gear
All 6MTs (open or VSLD) - 3.5 gear
Minor differences in RWD 5AT rpms in 5th at 80mph can be attributed to the following:
1) Worn tires (ie shorter)
2) Shorter tires than stock
3) Taller tires than stock
4) Torque converter locked
5) Torque converter unlocked
6) Torque converter in slip-lock
03-06 RWD 5AT Sedan (open or VLSD) - 3.3 gear
03-07 RWD 5AT coupe (VLSD) - 3.3 gear
04-06 AWD (open) - 3.5 gear
All 6MTs (open or VSLD) - 3.5 gear
Minor differences in RWD 5AT rpms in 5th at 80mph can be attributed to the following:
1) Worn tires (ie shorter)
2) Shorter tires than stock
3) Taller tires than stock
4) Torque converter locked
5) Torque converter unlocked
6) Torque converter in slip-lock
#90
12-18-2009, 01:21 PM