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vanonimous
Samba Member
Joined: October 19, 2013
Posts: 362
Location: Burien, Center of the Universe
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 Posted: Sat Jun 25, 2022 11:33 pm Post subject: SVX Conversion Tachometer Question |
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I swapped an SVX engine (EG33) into a 1990 Vanagon L plus 5 speed 094 transaxle and I love it, it rips. L model has a clock instead of tachometer.
I had an extra tachometer I had modified for use on a 4 cylinder Subaru engine, went and installed it using tach signal directly from the ECU.
Used trim pot on the back of the tach to make it work but it reads a bit too fast.
I searched for what others are doing to make a late tach work on SVX conversion but couldn't find much info.
Yahoo Vanagon/Subaru group was shut down a while back when Yahoo closed groups feature.
Any ideas?
_________________
If happiness is being a mechanic, owning a Vanagon is nirvana.
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Last edited by vanonimous on Sun Jun 26, 2022 8:38 pm; edited 1 time in total |
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djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32634
Location: Reading Pennsylvania
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wesitarz
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Joined: August 20, 2012
Posts: 1491
Location: Victoria,B.C.Canada
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ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 6361
Location: Honolulu,Hawaii and France
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| Posted: Sun Jun 26, 2022 11:25 am Post subject: Re: SVX Conversion Tachometer Question |
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| vanonimous wrote: |
I swapped an SVX engine into a 1990 Vanagon L plus 5 speed 094 transaxle and I love it, it rips. L model has a clock instead of tachometer.
I had an extra tachometer I had modified for use on a 4 cylinder Subaru engine, went and installed it using tach signal directly from the ECU.
Used trim pot on the back of the tach to make it work but it reads a bit too fast.
I searched for what others are doing to make a late tach work on SVX conversion but couldn't find much info.
Yahoo Vanagon/Subaru group was shut down a while back when Yahoo closed groups feature.
Any ideas? |
There's a couple resistors to replace in the tach to make it work with the ECU signal. I'm not sure the exact procedure, SmallCar does it. I posted pics a long time ago of the circuit board before and after modification.
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget |
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Crankey
Samba Member
Joined: July 11, 2004
Posts: 2659
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| Posted: Sun Jun 26, 2022 2:30 pm Post subject: Re: SVX Conversion Tachometer Question |
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I have a scan guage dash display and it's correct on the rpms,
the stock tach is working but about 500r's off, slower.
I don't know the brand but it's wired into the ECU and it's a 2011 Impreza engine/ECU. So...may not translate anyway. |
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vanonimous
Samba Member
Joined: October 19, 2013
Posts: 362
Location: Burien, Center of the Universe
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| Posted: Sun Jun 26, 2022 9:04 pm Post subject: Re: SVX Conversion Tachometer Question |
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Thanks for this life saver, I followed the link and found some optional solutions:
1) To make the original late (1986+) tach work with original faceplate, connect two of the 6 primary ignitor wires (using in line diode for each wire) to the green tachometer signal wire in the engine bay's electrical distribution box. This generates a 4 cylinder pulse and displays correctly on the original 6000 RPM plate.
2) If you have a new 8000 RPM faceplate, connect 3 of the 6 primary ignition wires to the green signal wire mentioned above. This can be a sequence 1-3-5 or 2-4-6 respective of the firing order and generates a 6 cylinder pulse for which new face plate is needed.
3) This solution option would entail modifying the original tach to make use of the tach signal coming from the Subaru ECU. I was not able to find the details on what resistor(s) to replace to achieve this. If anyone knows please add.
| djkeev wrote: |
But am I correct to find that the SVX engine really is a Subaru car model designation and not an engine designation? |
Edited OP to reflect the engine type, thanks for pointing it out.
| ALIKA T3 wrote: |
| There's a couple resistors to replace in the tach to make it work with the ECU signal. I'm not sure the exact procedure, SmallCar does it. I posted pics a long time ago of the circuit board before and after modification. |
I went tough your pictures, didn't see it but found many other interesting pics like Skodilac 120 transaxle! 
_________________
If happiness is being a mechanic, owning a Vanagon is nirvana.
Lighting upgrades: https://www.thesamba.com/vw/forum/viewtopic.php?t=578291
Last edited by vanonimous on Fri Jul 01, 2022 12:48 am; edited 1 time in total |
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ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 6361
Location: Honolulu,Hawaii and France
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| Posted: Sun Jun 26, 2022 10:07 pm Post subject: Re: SVX Conversion Tachometer Question |
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| vanonimous wrote: |
| ALIKA T3 wrote: |
| There's a couple resistors to replace in the tach to make it work with the ECU signal. I'm not sure the exact procedure, SmallCar does it. I posted pics a long time ago of the circuit board before and after modification. |
I went tough your pictures, didn't see it but found many other interesting pics like Skodilac 120 transaxle! |
I was probably using an outside host than Thesamba back then, I ruined a lot of my posts 
Here they are, back from 2009 
Left tachometer is stock model, 1987, Right model is modified one
This is a stock tacho from 1984, it is said to work as is
AutoVentures has or had a separate circuit board you could install to use the stock tacho without modifying it.
Now it's integrated in the harness, not sure it can be sold or installed separately.
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget |
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wesitarz
Samba Member
Joined: August 20, 2012
Posts: 1491
Location: Victoria,B.C.Canada
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vanonimous
Samba Member
Joined: October 19, 2013
Posts: 362
Location: Burien, Center of the Universe
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| Posted: Tue Jun 28, 2022 11:59 pm Post subject: Re: SVX Conversion Tachometer Question |
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| ALIKA T3 wrote: |
Left tachometer is stock model, 1987, Right model is modified one[/b]
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Thanks, this is solid gold. Looks like modified tach has 1k Ohm resistor over the hole removed. I might try that to see if it will work.
Thanks, above video shows the mod for a 4 cylinder Subaru engine ECU signal. I tried a tach modified like that and it was displaying about 1/3 too many revs using EG33's ECU signal.
I wasn't able to open linked file since I haven't registered, is the file specific to utilizing EG33 engine's ECU tach signal? If so I'll register to look at it.
_________________
If happiness is being a mechanic, owning a Vanagon is nirvana.
Lighting upgrades: https://www.thesamba.com/vw/forum/viewtopic.php?t=578291 |
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