2nd Generation Specific 1986-1992 Discussion

Aftermarket Tachs

Old 05-27-2004, 08:01 PM
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Anybody recommend a specific tach to work with a rotary? Most allow to compensate for 4,6, or 8 cylinders. What setting do we put it on, or are there special rotary models out there?



Thanks,



Craig
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Old 05-27-2004, 08:55 PM
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we're 4 cylinder. stock tach is bigger than just about anything else
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Old 05-27-2004, 09:34 PM
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More like 6, arent we? Reads off the number of pulses in one rotation. Or does it have to do with spark plugs?
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Old 05-27-2004, 09:46 PM
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The number of sparks on the leading coils is the same as a 4 cylinder.
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Old 05-27-2004, 09:56 PM
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Doesnt each spark plug fire every other revolution, regardless of how many cylinders there are? Isnt that pretty much the definition of a 4 stroke?
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Old 05-27-2004, 10:08 PM
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Originally Posted by CGeek2k' date='May 27 2004, 06:56 PM
Doesnt each spark plug fire every other revolution, regardless of how many cylinders there are? Isnt that pretty much the definition of a 4 stroke?
a 4 cylinder engine fires a spark plug every 180degrees, just like a 2 rotor
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Old 05-27-2004, 10:33 PM
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My friend has one of those huge tachs in his car... He actually pulls it off though and it isn't ricerish at all. It's nicely mounted in a custom aluminum dash next to his steering wheel. He doesn't even have a speedo.
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Old 05-28-2004, 12:30 AM
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Originally Posted by j9fd3s' date='May 27 2004, 07:08 PM
a 4 cylinder engine fires a spark plug every 180degrees, just like a 2 rotor
so what if youre running a non waste-spark ignition? i dont know anything about tachs, honestly.

i saw a race setup on an rx7 that had nice pro-comp (i _think_) auto meter gauges. the tach was smaller, but hell, you can see it just fine. nice big numbers.
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Old 05-28-2004, 12:56 AM
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More than anything if youre racing you just need the shift light.
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Old 05-28-2004, 03:15 AM
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i see the need for it for a certain applications, all factory tachs have a certain miscalibration to them, the higher in rpm you go the worse it gets, they also lag behind what the actual rpm is. If you have an S4 turbo and want to spin it to 8500 or more, you're really only guessing as the tach only goes to 8k, ya know?
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