82 FB with renesis engine

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Sib West
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82 FB with renesis engine

Post by Sib West » Mon Oct 12, 2020 5:33 pm

Hello to all.
i have followed the forum for a while but unfortunately my computer skills are so poor it has put me off from joining in.

I could do with some help and advice with a few jobs on a 82 FB s2 with a renesis engine fitted.

I would like to use the original tacho but with the loss of the coils and with the new engine management fitted it doesn't read correctly.
Apparently the ecu has rpm output but the fb tacho has a high voltage spike tacho.
Does anybody have a instrument cluster to sell? I can try fitting the back of a electronic tacho to the original tacho?

I would like to fit a 24 Spline Torsen lsd. Does anybody knows of one?
Thanks
Dave

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gt_james
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Re: 82 FB with renesis engine

Post by gt_james » Tue Oct 13, 2020 10:20 am

can't you tap into the negative of a coil to work the tacho rather than using an ecu output?

Don't think theres such thing as a 24 spline torsen, your only option is an 81-83 GSL clutch type diff.

Sib West
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Re: 82 FB with renesis engine

Post by Sib West » Tue Oct 13, 2020 11:36 am

From what i understand!
it doesn't create a high enough spike for the FB tacho and the renesis has four coils as opposed to two so the rpm would be half.
I'm thinking i will have to fit the guts of a modern tacho onto the face of the FB tacho!
Thanks for the reply

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Re: 82 FB with renesis engine

Post by gt_james » Tue Oct 13, 2020 1:32 pm

I'm sure there's an easier way to feed the existing tach, basically your rx8 ecu outputs say a 5v square wave tach signal, or 12V or something, there will probably be a converter to replicate the output from the negative of a coil.

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Re: 82 FB with renesis engine

Post by gt_james » Tue Oct 13, 2020 1:37 pm


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Re: 82 FB with renesis engine

Post by gt_james » Tue Oct 13, 2020 1:42 pm

or maybe greddy rpm adapter

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Re: 82 FB with renesis engine

Post by spirit r » Tue Oct 13, 2020 6:27 pm

Sib West wrote:
Mon Oct 12, 2020 5:33 pm
Hello to all.
i have followed the forum for a while but unfortunately my computer skills are so poor it has put me off from joining in.

I could do with some help and advice with a few jobs on a 82 FB s2 with a renesis engine fitted.

I would like to use the original tacho but with the loss of the coils and with the new engine management fitted it doesn't read correctly.
Apparently the ecu has rpm output but the fb tacho has a high voltage spike tacho.
Does anybody have a instrument cluster to sell? I can try fitting the back of a electronic tacho to the original tacho?

I would like to fit a 24 spline Torsen lsd. Does anybody knows of one?
Thanks
Dave
Try this http://www.abbott-tach.com/cablex.htm and search Mx 5 24 spline torsen 1. The torsen 2 with 26 spline working good and quiet in my car.

viewtopic.php?f=4&t=1118&start=150

http://www.ausrotary.com/viewtopic.php? ... 8#p2825227

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