Tach Conversion - Mechanical to Electric
#22
Race Director
Thread Starter
I bought the tach used from a member on the forum. As a matter of fact, he was doing an LS swap and was going with aftermarket gauges. Seems like it was around $70 shipped or so.
#24
Race Director
Thread Starter
I got the tach from member catchme76. It says he has a 76.
Looking at Wilcox's webpage, the 75-77 tach boards are the same so, yeah I would hazard to guess the tachometers themselves are the same also. Good luck and be sure to yell at me if you have any questions.
Looking at Wilcox's webpage, the 75-77 tach boards are the same so, yeah I would hazard to guess the tachometers themselves are the same also. Good luck and be sure to yell at me if you have any questions.
#26
Race Director
Thread Starter
#27
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No LS conversion. My front was badly crunched and I'm having the rest stripped and all painted fresh. In the process I began thinking about the drivetrain. Not too old right now, but I figured the time may be right. Leaning toward a FastBurn 385 and a T-56 modified by Keisler. Almost any engine option other than rebuilding mine again is going to involve an HEI distributor, so need to think about converting the tach.
#28
Got to revive this thread for one more question.
If I use a 75-77 tach on an LT1 conversion and have the signal coming from the coil in my wire harness, will the gauge read correctly?
I thought power for the tach came from the signal wire? If no then where did you guys pull power and how did you splice in? I'm no really comfortable with splicing or cutting ignition wires.
Thanks!
If I use a 75-77 tach on an LT1 conversion and have the signal coming from the coil in my wire harness, will the gauge read correctly?
I thought power for the tach came from the signal wire? If no then where did you guys pull power and how did you splice in? I'm no really comfortable with splicing or cutting ignition wires.
Thanks!
#29
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Got to revive this thread for one more question.
If I use a 75-77 tach on an LT1 conversion and have the signal coming from the coil in my wire harness, will the gauge read correctly?
I thought power for the tach came from the signal wire? If no then where did you guys pull power and how did you splice in? I'm no really comfortable with splicing or cutting ignition wires.
Thanks!
If I use a 75-77 tach on an LT1 conversion and have the signal coming from the coil in my wire harness, will the gauge read correctly?
I thought power for the tach came from the signal wire? If no then where did you guys pull power and how did you splice in? I'm no really comfortable with splicing or cutting ignition wires.
Thanks!
No idea if the tach will read correctly. For a LS1 the ECU has to be re-programmed to change the pulse count. I think most newer engines use a 4-cylinder pulse count - probably so the tach driver could be used in many vehicles. If the LT1 signal is coming out of the ECU then you might be able to change the pulse count if necessary.
Check over on ls1tech.com - there is a LT-1 section there that might have some info.
Rick B.
#31
Pro
Back from the dead again. I just acquired a 76 tach that I want to put together to work in my 73. I went to a HEI in the 73 not knowing I would sacrifice the tach.
So my question is where will I need to hookup to get the tach to read out. I know where to get power and ground, but not where to get the feed. Will it be on the HEI? Will this swap even work for me?
TIA
Matt
So my question is where will I need to hookup to get the tach to read out. I know where to get power and ground, but not where to get the feed. Will it be on the HEI? Will this swap even work for me?
TIA
Matt
#32
Melting Slicks
Back from the dead again. I just acquired a 76 tach that I want to put together to work in my 73. I went to a HEI in the 73 not knowing I would sacrifice the tach.
So my question is where will I need to hookup to get the tach to read out. I know where to get power and ground, but not where to get the feed. Will it be on the HEI? Will this swap even work for me?
TIA
Matt
So my question is where will I need to hookup to get the tach to read out. I know where to get power and ground, but not where to get the feed. Will it be on the HEI? Will this swap even work for me?
TIA
Matt
When you installed the HEI, did you run a new 12V wire to it? The existing wire is some type of resistor wire for the points style distributor and needs to be bypassed for proper HEI operation.
DC
#33
Burning Brakes
Your HEI distributor should have at least 2 connections: +12v power, and tach output. You will need a tach output filter between your HEI distributor and the board on back of the new tach.
You may find my two threads about this useful:
my-mechanical-71-to-electronic-75-tach-conversion-process.html
tachometer-gauge-pointer-size-differences-mech-elec.html
It's not very difficult to make the switch.
Jeff
You may find my two threads about this useful:
my-mechanical-71-to-electronic-75-tach-conversion-process.html
tachometer-gauge-pointer-size-differences-mech-elec.html
It's not very difficult to make the switch.
Jeff
#34
Pro
Previous owner of my '73 swapped to HEI and to a later model electronic tach so it can be done. He used the face off of the old tach. Not quite sure where to get the proper feed. Maybe someone with a later model car can post part of the wiring diagram for you.
When you installed the HEI, did you run a new 12V wire to it? The existing wire is some type of resistor wire for the points style distributor and needs to be bypassed for proper HEI operation.
DC
When you installed the HEI, did you run a new 12V wire to it? The existing wire is some type of resistor wire for the points style distributor and needs to be bypassed for proper HEI operation.
DC
#35
Pro
Your HEI distributor should have at least 2 connections: +12v power, and tach output. You will need a tach output filter between your HEI distributor and the board on back of the new tach.
You may find my two threads about this useful:
my-mechanical-71-to-electronic-75-tach-conversion-process.html
tachometer-gauge-pointer-size-differences-mech-elec.html
It's not very difficult to make the switch.
Jeff
You may find my two threads about this useful:
my-mechanical-71-to-electronic-75-tach-conversion-process.html
tachometer-gauge-pointer-size-differences-mech-elec.html
It's not very difficult to make the switch.
Jeff
#36
Former Vendor
Member Since: Aug 2006
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Here are the wires and where they go on the board if you still need this. There is also a video on how to do the zero set on YouTube. If you need that link let me know or I'll bump the thread. When you remove the face you will need to do a zero set on the tach to make sure it knows where zero is located.
Here is the thread link and I just bumped it too! http://forums.corvetteforum.com/c3-t...post1578098801
Willcox
Last edited by Willcox Corvette; 08-12-2011 at 12:07 AM.
#37
Back from the dead again. I just acquired a 76 tach that I want to put together to work in my 73. I went to a HEI in the 73 not knowing I would sacrifice the tach.
So my question is where will I need to hookup to get the tach to read out. I know where to get power and ground, but not where to get the feed. Will it be on the HEI? Will this swap even work for me?
TIA
Matt
So my question is where will I need to hookup to get the tach to read out. I know where to get power and ground, but not where to get the feed. Will it be on the HEI? Will this swap even work for me?
TIA
Matt
#38
Burning Brakes
Eddie,
Boy, you are going all digital. . . I've been buried the past few weeks so I've not been much help. Norm was off on a medical leave and I subsituted for him. Sorry I did not get a chance to respond to your other post before you got this fixed.
You can use the 1975-1977 style tach. Best if you find a 75-76 tach since the face is closer. Once obtained this, go to my site and look up the tach board. The picture there will show you where to place the wires to power up the tachometer.
The 75-77 tach will bolt right up to your dash with out any problems. This really is an easy conversion for you. . .
Willcox
Boy, you are going all digital. . . I've been buried the past few weeks so I've not been much help. Norm was off on a medical leave and I subsituted for him. Sorry I did not get a chance to respond to your other post before you got this fixed.
You can use the 1975-1977 style tach. Best if you find a 75-76 tach since the face is closer. Once obtained this, go to my site and look up the tach board. The picture there will show you where to place the wires to power up the tachometer.
The 75-77 tach will bolt right up to your dash with out any problems. This really is an easy conversion for you. . .
Willcox
What would be great is Wilcox would make a board for the tack that could be wired directly to the ecm.
From what I'm reading the ECM puts out a signal as a 4 cyl Dakota Dig SGi-8D seems to be a fix to make our vets read the signal correctly from the ECM. any one with more input I would enjoy hearing your experiences
Last edited by Tim 1973; 10-17-2013 at 01:08 AM.
#39
You can have the ecu tuned to put out an 8 cylinder signal. Go check for the settings at LS1tech.
I'm using a 75 guts with my 73 face plate for my LSX 454 conversion. It's still not going to wire directly to your ecm, you will need a converter box to convert the signal from the ecm to the tack. I have not purchased it yet but I do have a write up on the procedure somewhere.
What would be great is Wilcox would make a board for the tack that could be wired directly to the ecm.
From what I'm reading the ECM puts out a signal as a 4 cyl Dakota Dig SGi-8D seems to be a fix to make our vets read the signal correctly from the ECM. any one with more input I would enjoy hearing your experiences
What would be great is Wilcox would make a board for the tack that could be wired directly to the ecm.
From what I'm reading the ECM puts out a signal as a 4 cyl Dakota Dig SGi-8D seems to be a fix to make our vets read the signal correctly from the ECM. any one with more input I would enjoy hearing your experiences
1975, 75, c4, conversion, conversions, convert, corvette, electric, instruments, kit, mechanical, sale, tach, tachometers, work