DFI Tacho output

Holden/Delco Tuning. ALDL, OBD 1.5. Circa 1989 to 2004.
Skullator
Posts: 45
Joined: Sat Jul 12, 2014 10:31 am
cars: HJ Holden with supercharged v6

DFI Tacho output

Post by Skullator »

Hi all not sure if this is the right forum but here goes
Without trying to start a flame war
I have a S/C V6 out of VX Commodore and am trying to connect it to a TS Magna dashboard
The issue i have is the tacho output on the E terminal of the DFI is not strong enough to run the the tacho which in the original car ran off the coil via a signal conditioner.....basiclly a normal tacho
What i am after is a simple transistor circuit to boost the signal to mae it work
I know you can buy the converters, but for the couple of dollars of parts in them i d like to make my own
I have tried a 1W audio amplifier but this didn't work .
All help appreciated
Skull
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Jayme
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Location: North Coast, NSW

Re: DFI Tacho output

Post by Jayme »

its not really an amplifier.... what you need is a transistor and a relay coil.... the transistor uses the square wave from the DFI unit to drive the relay coil like an actual ignition coil. the voltage spike from the collapsing magnetic field of the relay coil is what the tacho reads. obviously you need to remove the relay bar or itll buzz :P ive used it on 2 different cars now, a VK and a nissan patrol. one relay coil that I tried to use, worked fine in the relay but wouldnt drive the tacho for some reason. maybe too small or something, no idea. I just swapped it for a different one and it worked.

there is a diagram on here somewhere in another thread if I remember correctly.
Skullator
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Joined: Sat Jul 12, 2014 10:31 am
cars: HJ Holden with supercharged v6

Re: DFI Tacho output

Post by Skullator »

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Just found the diagram
Cheers for the speedy reply
off to town..............................................................
Skullator
Posts: 45
Joined: Sat Jul 12, 2014 10:31 am
cars: HJ Holden with supercharged v6

Re: DFI Tacho output

Post by Skullator »

well that worked a treat
had to substitute bc337 for transistor
but otherwise no pain

thanks Gurus
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Jayme
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Re: DFI Tacho output

Post by Jayme »

a magna?? time to post an engine bay pic man. I have no business flaming when ive done a v6 into a ford escort hahahaha

:worthless:
Skullator
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Joined: Sat Jul 12, 2014 10:31 am
cars: HJ Holden with supercharged v6

Re: DFI Tacho output

Post by Skullator »

TS Magna Dash in HJ Holden
TS Magna Dash in HJ Holden
IMAG0451[2].jpg (1 MiB) Viewed 3692 times
Skullator
Posts: 45
Joined: Sat Jul 12, 2014 10:31 am
cars: HJ Holden with supercharged v6

Re: DFI Tacho output

Post by Skullator »

20140904_114325[1].jpg
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Holden202T
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Re: DFI Tacho output

Post by Holden202T »

is that a hz front end ?
HQ355
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Joined: Sun Nov 17, 2013 6:53 am
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Re: DFI Tacho output

Post by HQ355 »

Love the engine bay, but magna dash in a holden ?
Dylan
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Re: DFI Tacho output

Post by Dylan »

Good work, is there a build thread anywhere?
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