Author Topic: Gas Tacho / Revcounter Conversion to Diesel W terminal  (Read 142147 times)

Reply #45December 05, 2008, 04:27:21 am

Smokey Eddy

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #45 on: December 05, 2008, 04:27:21 am »
Well that's the thing vince.

Latches will do, but only to an extent right. A micro controller would be "perfect" but latches would be a good guess.  haha ... so ... when i get it going and it says im idling at 200 rpm i'll know it won't work :P  but if its like 50rpm out i won't care.
Ed
Blacked out mk2 AAZ Jetta RIP. You will be are missed.
White 1999.5 ALH Golf 2dr. 2" wider. 2.5" lower.

Reply #46December 05, 2008, 03:48:20 pm

jimbote

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inductive pickup part number.....
« Reply #46 on: December 05, 2008, 03:48:20 pm »
OK....at the behest of others interested....here is the part number of the Ford inductive pickup I used for my tacho conversion........................... XR3Z-7H103AB ....retails for $23.90 stateside....as far as I know this pickup can be found on all 99' and newer T5's, T45's, and 3650 manual transmissions used in Ford Mustangs....have fun!!

Reply #47December 05, 2008, 05:13:31 pm

saurkraut

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Re: inductive pickup part number.....
« Reply #47 on: December 05, 2008, 05:13:31 pm »
Quote from: "jimbote"
OK....at the behest of others interested....here is the part number of the Ford inductive pickup I used for my tacho conversion........................... XR3Z-7H103AB ....retails for $23.90 stateside....as far as I know this pickup can be found on all 99' and newer T5's, T45's, and 3650 manual transmissions used in Ford Mustangs....have fun!!


Thanks!

So this puppy can drive a standard VW gas tach with no calibration?

I'd rather measure the real RPM then read "a rpm" that comes from the alternator.
'79 1.6TD RABBIT
'84 1.5TD RABBIT
'83 Diesel Westy
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92 Audi 100
'93 Eurovan
'82 Porsche 930

Reply #48December 05, 2008, 06:37:46 pm

Smokey Eddy

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Re: inductive pickup part number.....
« Reply #48 on: December 05, 2008, 06:37:46 pm »
Quote from: "saurkraut"
Quote from: "jimbote"
OK....at the behest of others interested....here is the part number of the Ford inductive pickup I used for my tacho conversion........................... XR3Z-7H103AB ....retails for $23.90 stateside....as far as I know this pickup can be found on all 99' and newer T5's, T45's, and 3650 manual transmissions used in Ford Mustangs....have fun!!


Thanks!

So this puppy can drive a standard VW gas tach with no calibration?

I'd rather measure the real RPM then read "a rpm" that comes from the alternator.


The alt. could slip and all sorts of stuff. Jimbotes method is the superior for sure. Mine is just dirt cheap. :wink:
Ed
Blacked out mk2 AAZ Jetta RIP. You will be are missed.
White 1999.5 ALH Golf 2dr. 2" wider. 2.5" lower.

Reply #49December 05, 2008, 06:58:54 pm

jimbote

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Re: inductive pickup part number.....
« Reply #49 on: December 05, 2008, 06:58:54 pm »
Quote from: "Smokey Eddy"
Quote from: "saurkraut"
Quote from: "jimbote"
OK....at the behest of others interested....here is the part number of the Ford inductive pickup I used for my tacho conversion........................... XR3Z-7H103AB ....retails for $23.90 stateside....as far as I know this pickup can be found on all 99' and newer T5's, T45's, and 3650 manual transmissions used in Ford Mustangs....have fun!!


Thanks!

So this puppy can drive a standard VW gas tach with no calibration?

I'd rather measure the real RPM then read "a rpm" that comes from the alternator.


The alt. could slip and all sorts of stuff. Jimbotes method is the superior for sure. Mine is just dirt cheap. :wink:


Yep...my next one will be the nastiest most dirt cheap conversion on the planet!!!....super rat rod  InVolvo 122s wagon!!!.....dirt cheap rules!! 8)

Reply #50December 05, 2008, 07:16:00 pm

jimbote

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #50 on: December 05, 2008, 07:16:00 pm »
Quote from: "Smokey Eddy"
Well that's the thing vince.

Latches will do, but only to an extent right. A micro controller would be "perfect" but latches would be a good guess.  haha ... so ... when i get it going and it says im idling at 200 rpm i'll know it won't work :P  but if its like 50rpm out i won't care.


Curious as to what a "latch" is....I'm pretty electronics ignorant (would almost like to stay that way) sounds like it may be something that divides the signal?.... :?

Reply #51December 06, 2008, 03:56:23 pm

Smokey Eddy

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #51 on: December 06, 2008, 03:56:23 pm »
Can be used for many many many many things.

A signal divider is one of them. Each latch can divide a signal by two, so wire a few in series and there you go.
http://en.wikipedia.org/wiki/Flip-flop_(electronics)


^^^
why that isn't a link i have no idea...



Edit: ahh thanks Andrew
Ed
Blacked out mk2 AAZ Jetta RIP. You will be are missed.
White 1999.5 ALH Golf 2dr. 2" wider. 2.5" lower.

Reply #52December 07, 2008, 07:53:47 am

jimbote

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #52 on: December 07, 2008, 07:53:47 am »
using smokey eddies idea of a latch may work with the inductive crank position sensor already installed in the block of  1Z/AHU/ALH blocks....they read a wheel with four slots so they give four pulses per rev. if you used a "latch" (not sure how they wire in) which divides by two you would get the two pulses needed to drive the tach?....maybe eddie will chime in....

Reply #53December 07, 2008, 01:21:36 pm

Vincent Waldon

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #53 on: December 07, 2008, 01:21:36 pm »
Yup... you got it... a latch (at least the way Eddie's usin' 'em) divides by two.  Put two of them in a row and you get divide by 4, etc etc etc.

So perfect for what you're thinking.

Not so hot when you need to divide by something other than an exact multiple of two... which is why boxes like the Dakota Digital use a microprocessor to do the math.

Eddie: I'll re-do the calculations sometime soon (gotta head out the door)... the "7.456" was just a random number to make a point that it's not an exact multiple of two... but as discussed recalibrating the tach will likely compensate just fine.
Vince

Edmonton, Alberta, Canada
2001 silver TDI Jetta Malone Stage 1.5 , 2001 blue TDI Jetta SBIII 216s Malone Stage 3, 1970 Bay Window bus

Gone but not forgotten: 1969/1971 Beetles, 1969/1974 Westies, 1979 Rabbit, 1986 TD Jetta, 1992 gas Jetta, 1994 TD Jetta

Reply #54December 07, 2008, 03:49:02 pm

Smokey Eddy

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #54 on: December 07, 2008, 03:49:02 pm »
Quote from: "Vincent Waldon"
Yup... you got it... a latch (at least the way Eddie's usin' 'em) divides by two.  Put two of them in a row and you get divide by 4, etc etc etc.

So perfect for what you're thinking.

Not so hot when you need to divide by something other than an exact multiple of two... which is why boxes like the Dakota Digital use a microprocessor to do the math.

Eddie: I'll re-do the calculations sometime soon (gotta head out the door)... the "7.456" was just a random number to make a point that it's not an exact multiple of two... but as discussed recalibrating the tach will likely compensate just fine.



Ahh Genius!
I'm thinking of making a microcontroller later on. Making the flip flop was kinda fun  :D
Ed
Blacked out mk2 AAZ Jetta RIP. You will be are missed.
White 1999.5 ALH Golf 2dr. 2" wider. 2.5" lower.

Reply #55December 07, 2008, 03:51:48 pm

Smokey Eddy

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #55 on: December 07, 2008, 03:51:48 pm »
Quote from: "jimbote"
using smokey eddies idea of a latch may work with the inductive crank position sensor already installed in the block of  1Z/AHU/ALH blocks....they read a wheel with four slots so they give four pulses per rev. if you used a "latch" (not sure how they wire in) which divides by two you would get the two pulses needed to drive the tach?....maybe eddie will chime in....


I'll post pics of the latches on my other test thread and try and explain how they work. Just trying to make my wiring on the bread board a little more .. visually pleasing. Vince would have my head if he saw crossed wires and other such electronics blaspheme.
Ed
Blacked out mk2 AAZ Jetta RIP. You will be are missed.
White 1999.5 ALH Golf 2dr. 2" wider. 2.5" lower.

Reply #56January 14, 2009, 11:28:24 pm

Rabbit TD

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #56 on: January 14, 2009, 11:28:24 pm »
Quote from: "jimbote"
Okydokes,

The Ford probe (with no voltage applied) can drive the VW 4 cylinder gas engine tach and produce an accurate RPM if it sees two chunks of steel every rotation of the crank shaft.

True or no

does the Ford probe have only two wires (signal and ground)?


True.....the ford probe and "most" magnetic inductive sensors (found in automotive applications) have only two wires that are interchangeable signal or ground as in it does not matter which wire goes to ground and which wire goes to signal....the two leads or pins in "most" sensors are only the termination of a coil of copper windings around a magnet....now all "inductive" sensors do not have a "magnet" some are merely a coil of windings around a laminated core and the moving poles are magnets ie the magneto on a lawn mower.....but for this application it would probably be easiest to source and use a "magnetic inductive" pickup ....being as how it can be difficult to attach magnets to the crank pulley....[/quote]


I really like this method of driving a tach.  I was looking at one where somebody put an optical pickup sensor in the timing belt cover and it read off the pump sprocket but this seems beter to me and even less complicated.  I guess the ford probe will work with other tachometers besides VW too won't it {please say yes}.  I just got a mig welder for Christmas and this will probably be my first project :D

Reply #57January 15, 2009, 03:43:20 pm

jimbote

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #57 on: January 15, 2009, 03:43:20 pm »
Quote from: "Rabbit TD"
Quote from: "jimbote"
Okydokes,

The Ford probe (with no voltage applied) can drive the VW 4 cylinder gas engine tach and produce an accurate RPM if it sees two chunks of steel every rotation of the crank shaft.

True or no

does the Ford probe have only two wires (signal and ground)?


True.....the ford probe and "most" magnetic inductive sensors (found in automotive applications) have only two wires that are interchangeable signal or ground as in it does not matter which wire goes to ground and which wire goes to signal....the two leads or pins in "most" sensors are only the termination of a coil of copper windings around a magnet....now all "inductive" sensors do not have a "magnet" some are merely a coil of windings around a laminated core and the moving poles are magnets ie the magneto on a lawn mower.....but for this application it would probably be easiest to source and use a "magnetic inductive" pickup ....being as how it can be difficult to attach magnets to the crank pulley....



I really like this method of driving a tach.  I was looking at one where somebody put an optical pickup sensor in the timing belt cover and it read off the pump sprocket but this seems beter to me and even less complicated.  I guess the ford probe will work with other tachometers besides VW too won't it {please say yes}.  I just got a mig welder for Christmas and this will probably be my first project :D[/quote]

the answer would be yes!!....We (my pop and I) did some testing on an old ford ranger tach also and it worked just as well....good luck!!! :D  :D

Reply #58January 17, 2009, 12:18:55 am

jimfoo

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #58 on: January 17, 2009, 12:18:55 am »
I noticed the Dodge at work has an interesting pickup. It is a coil in the middle of an m shaped piece of steel. It is just clamped on the outside of the alternator with a very large hose clamp, over the windings.
Jim
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Reply #59February 25, 2009, 09:10:04 am

jimbote

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Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #59 on: February 25, 2009, 09:10:04 am »
Just wondering if anyone else has tried my "ford inductive" tach driver method.....also wanted to report I have put over 2k miles on this mod and its working flawlessly still....please let me know what successes/failures you have had :D