Guitar Tuner Speedometer

I cannot imagine why your plan would not work provided the guitar tuner can “hear” the whine from a location where you can see the output. I think this is brilliant!

In the key of G-flat (Gb) you need a Cb, you can’t call it B because there’s already Bb.
Back on topic: follow someone in another vehicle and have them go 35, 50, 60 etc., then note the pitch.

Or you could do it the easy way and just stick a GPS unit on the dash.

@circuitsmith‌ precisely what I was thinking. That’s what I’ll do. I’ll run the test and share the results. Wish me luck.

@PvtPublic‌ see that would be the easiest. That would require $$$. I already have the tuner. And I just don’t think the GPS is sporting enough. Doing this one for Tom.

Stick a magnet on the wheel rim and a pickup for a “bicycle” speedo within measuring distance. Heck, it can be anywhere on the driveshaft. GPS is sub-optimal because there is (IMO) unacceptable measurement lag.

Also, a tach can be mounted using a plug wire…this will be proportional to speed in a given gear IF this is a stick-shift (or a reasonable approximation for an automatic). You could super-impose the MPH on top of the RPM readings. I think I’ve even seen a bus that had a combo tach/speedo…with different possible MPHs for different possible gears (i.e. if you’re in 3rd, you must be doing 35 MPH…)

I don’t know any specific location for a radar gun, but I do know they’re as common as dandelions in the sports world.

@the_same_mountainbike would that not be as common as dandelions in the sports FIELD? Now I do not know if you have experienced different pavement noises but my concept for the future, grooves in the pavement that emit a slow down voice from the tires on the pavement, like a needle in a record groove if you are going too fast.

Barky, I accept your correction! {:slight_smile:

^Rumble strips designed to play the William Tell Overture?https://youtube.com/watch?v=0BcznTZzoec

I was thinking the same idea earlier in the year, but not for speed, for measuring rpm for tuning up my Corolla. My plan was to connect the rpm signal straight into the guitar tuner audio port, only with a couple resisters to lower the voltage. What I remember, I did some back of the envelope calculations and decided it probably wouldn’t work b/c the rpm signal is too low of frequency.

A tach would seem simpler… {:slight_smile:

With all due respect, OP…you specifically ask us a question that juxtaposes speed-dependent motor frequencies AND musical scales…as you put in your screen name, “GuitarCar1991.”

YOU then “ding” me for “off topic” by pointing out a link, regarding–GASP!–speed-dependent rumble strips that make noise via utilization of musical scales! How is that NOT germane to the topic raised??? That is EXACTLY what you proposed in your first post! You could even use your guitar tuner there: if the notes go sharp, you’re speeding.
(I guess you ain’t a fan of Willie Tell: fine! Go get a long driveway and some road equipment…make yourself a “Stairway to Heaven” musical driveway. I thought that was a pretty cool link, myself. )

Notice that we already solved your problem for you. While it is truly admirable that a site exists where people–for free and of their own good nature–help answer car questions for complete strangers, it exists at least partly for the recreation of regular members, and that, as such, it is entirely reasonable that we should enjoy the occasional meandering of thought…once the stated problem has been put to bed, as yours was. (And for reference, have you actually listened to the show this site is derived from? T+R ran a pretty loose ship, at times…an hour’s show often was 15 minutes of advice…and 45 minutes of mirthful meanderings off the original train of thought. And it was GREAT fun, too.)

(If you suffered from “chubby fingers syndrome,” my apologies, as a fellow sufferer. Otherwise, please revisit your critique, and consider revision…)

@meanjoe75fan‌ I believe this would fall under the category of: woah man: relax. I’m on my phone and it’s touch screen. I watched the link and all. And you actually question whether I ever listened to the show? Come on man dope slap - a guy accidentally presses an off topic (which I have no idea what it does) and you write that little bit. Sheesh. Cannibalize your own. This is the kind of stuff Melissa Peterson would love to see. This is what she wants: we can’t fight our own.

Fat thumbs: touch screen:iPhone please mellow

there is no guarantee that as the system wears, that the frequency source is stable and predictable. so idea is fun, but not reliable.

Okay, mea culpa, then. That’s a liability of how the feedback is incorporated in this site–lots of “clumsy finger” feedback when using a phone.

I over-reacted. To my defense, we’ve had a few new posters that wanted you to answer their question, and were quick to flag ANYONE who “branched off,” regardless of whether the question had been answered or not. I’m glad you’re not that way.

@gdawgs‌ would it work if I tuned it up every 6 months?

@meanjoe75fan‌ not a problem. When I tried to like your comment I accidentally flagged it again: that would have kicked it off again. Ha. I appreciate the attempt to preserve the spirit of the community. It’s about people not cars.

I say go for it!! A guitar tuner is like 15-20 bucks. Follow a friend who does exactly the speedlimit on several different rated roads and record what pitch each speed is.

My 1950 cadillac’s speedometer doesnt work either. I usually just go with the flow of traffic as I’m generally much more worried about stalling out or breaking down and the old tired starter not getting me back up and running.

BUT I do use the iphone speedometer app. Theres several to download for free and they work fine.

@wesw‌

“I am looking for a used Cherokee tho…”

What happened to your current/previous one!?! She bit the dust?!?

not yet, but I m planning ahead!!!

old blue may need to ride again soon. I have him jacked up and am waiting for another 50 degree day…

I’m not going to bother with the tuner idea but if you think that would be good do then go for it. If you want to fix the speedometer itself it seems that would be easier than trying to do something else.

Looking at some data it shows that power from fuse 17 is needed on pin A8 (WHT/BLK wire) of the connector to the cluster. Running a new wire between those points may possibly fix the whole problem. I don’t know how bad the “melt down” is. Pin A5 (WHT/ORG wire) ties to pin 47 of the PCM for the speed sensor if that wire connection is bad. The return might be made inside the cluster. I can’t tell with the data I have available. The fuel sensor wire is on pin B1 (dark blue). It seems to me that it would be pretty nice to have it working also.