engineering question, about tach reading vs vehicle speed
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Joined: Jun 2002
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From: San Diego, CA
engineering question, about tach reading vs vehicle speed
Ok, I have a theory question for all of us true tech dorks out there.
I noticed that, in my 91 CRX Si, certain speeds, like 35mph, 55mph, 65mph, and 90mph (that's not all, but those are the most apparent), all hit the tachometer exactly on a white notch in a corresponding gear. Has anyone else noticed this on any other Hondas? My question is, could that be planned into the design of the tach? Perhaps it's intended as just another visual checkpoint for those key speeds that you see most often while driving (well, except 90 :naughty: ).
It's more of a curiousity thing that anything, it may just be coincidence. What do yall think?
I noticed that, in my 91 CRX Si, certain speeds, like 35mph, 55mph, 65mph, and 90mph (that's not all, but those are the most apparent), all hit the tachometer exactly on a white notch in a corresponding gear. Has anyone else noticed this on any other Hondas? My question is, could that be planned into the design of the tach? Perhaps it's intended as just another visual checkpoint for those key speeds that you see most often while driving (well, except 90 :naughty: ).
It's more of a curiousity thing that anything, it may just be coincidence. What do yall think?
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Joined: Mar 2003
Posts: 1,412
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From: Tucson AZ
umm if u really want to think about all of this then figure out the specific gear ratios ur tranny is using and do the math, i bet that the gear ratios places all of these speeds at about the same rpm, probably not done on purpose or nething just ended up being the most efficient way of gearing ur particular engine, my crx hf d15b6 engine literally holds the same level of acceleration of rpms and speed in 2nd gear from 30 mph-50mph as the rpms kinda weird watching ur tach go up exactly the same as ur speedo... just weird coincidences i guess.
