Speedometer for a buggy (step 1 of making a street legal buggy)

Herzog

somewhat damaged
Admin
Location
Wydaho
I want to see what it will take to get my buggy street legal under the new law. So far, its going to be very easy except for the speedometer part.

I currently have a cable port on the tailshaft of my atlas. It's just an older OEM jeep mechanical cable port. Are there such things as a digital conversion for that? I'm guessing if there is, then pretty much any digital speedometer gauge will work...?

Has anybody done this yet? Any recommendations? :cool:
 

Greg

I run a tight ship... wreck
Admin
Do you still have an OBDII port? You could use a ScanGauge II, they have a readout for MPH as well as everything else to monitor your engine as well as check and clean engine codes. You can adjust the percentage of the readout and verify it with a GPS to make it correct. Last I checked, they cost around $115-120 and you can buy them at Auto Zone, etc.
 

Bart

Registered User
Location
Arm Utah
Why not just run a mechanical speedo ans run the cable from the tailshaft to the speedo? I did this on my Willys buggy. Its also what I'm planning with this Jeep.
 

Jinx

when in doubt, upgrade!
Location
So Jordan, Utah
This is a good thread for me. I skipped the speedo option for a shorter drivetrain length on my 4spd atlas. So the gps. ObdII are good options for me.
 

N-Smooth

Smooth Gang Founding Member
Location
UT
Do other atv's or sxs' use gps speedos? That's the direction I would want to go but I'm not sure how detailed that portion of the inspection is.
 
I had a cable speedo from my atlas to an autometer gauge... I changed it to digital driven autometer with the cable to pulse adapter. I like that it can easily be recalibrated for different tires, gears, etc... However, it cuts out intermittently... Not sure why.
 

Herzog

somewhat damaged
Admin
Location
Wydaho
Do you still have an OBDII port? You could use a ScanGauge II, they have a readout for MPH as well as everything else to monitor your engine as well as check and clean engine codes. You can adjust the percentage of the readout and verify it with a GPS to make it correct. Last I checked, they cost around $115-120 and you can buy them at Auto Zone, etc.

You forget how old my engine/trans are. :D They are renix (1989 XJ) But this is a really interesting option!

Why not just run a mechanical speedo ans run the cable from the tailshaft to the speedo? I did this on my Willys buggy. Its also what I'm planning with this Jeep.

I could, but I didn't want to have to play around with the speedo gears to get a correct readout. I'm assuming it would be pretty badly off. It would probably suffice for inspection, but I do want it to be accurate if I'm gonna have it. :D

Do other atv's or sxs' use gps speedos? That's the direction I would want to go but I'm not sure how detailed that portion of the inspection is.

I looked into this. You can actually buy a unit that does your temp, voltage, speed and a couple other things for about $150. But they are made to just plug right into the atv with existing connectors, so I'm not sure about how it would interface well with a different speedometer sender.

I had a cable speedo from my atlas to an autometer gauge... I changed it to digital driven autometer with the cable to pulse adapter. I like that it can easily be recalibrated for different tires, gears, etc... However, it cuts out intermittently... Not sure why.

This is what I want to hear! (sans the cutting out part...) So you can calibrate your digital speed gauge after the fact? :cool:
 
This is what I want to hear! So you can calibrate your digital speed gauge after the fact? :cool:

Yep. The Autometer one has you put it in calibration mode, then drive exactly 2 miles... And done. Worked very well and was simple enough with using the distance on my phones GPS.
I bought the cheaper (I think Summit?) sender... Wondering if the pulse cuts out causing my intermittent inop... I'm going to buy the autometer sender and see if it helps.
 

Herzog

somewhat damaged
Admin
Location
Wydaho
Awesome, thank you!

I guess the next question is whether or not the gps based modules will pass? Reading the descriptions, they appear to start working within a few seconds and are obviously accurate. The tinfoil hat in me doesn't like the idea of the gps speedometer, but that doesn't mean you can't wire up a kill switch when you don't need it.
 

TurboMinivan

Still plays with cars
Location
Lehi, UT
I guess the next question is whether or not the gps based modules will pass?

Yes, they will. In fact, you can still pass the inspection even if the speedometer is not functional. From page 65 of the current safety manual:

M. SPEEDOMETER / ODOMETER

1. Check vehicle to be sure that it is equipped with a properly functioning
speedometer and odometer (41-1a-901 UCA). Although not a cause to
reject, all vehicles are required to have a working odometer in order to be
registered in the state of Utah.

a. ADVISE when:

1) Speedometer or odometer is not functional or is disconnected.

If there is no speedometer/odometer in the vehicle at all, I would think it is up to the inspector to decide if the vehicle is failed or simply advised. But if a speedo/odo is present but is simply not working--even if no wires are connected to it at all--the law spells it out very clearly: this is merely an advise and will not prevent you from being registered.

Any GPS speedo/odo will meet Utah's legal requirement. For that matter, one of my techs pointed out that even a speedo/odo smart phone app would meet the requirement. If you have some sort of cell phone holder somewhere on your dash and the app is running during his inspection, he said he would pass you without batting an eye.

FYI
 

Herzog

somewhat damaged
Admin
Location
Wydaho
Yes, they will. In fact, you can still pass the inspection even if the speedometer is not functional. From page 65 of the current safety manual:



If there is no speedometer/odometer in the vehicle at all, I would think it is up to the inspector to decide if the vehicle is failed or simply advised. But if a speedo/odo is present but is simply not working--even if no wires are connected to it at all--the law spells it out very clearly: this is merely an advise and will not prevent you from being registered.

Any GPS speedo/odo will meet Utah's legal requirement. For that matter, one of my techs pointed out that even a speedo/odo smart phone app would meet the requirement. If you have some sort of cell phone holder somewhere on your dash and the app is running during his inspection, he said he would pass you without batting an eye.

FYI

That is hilarious. Thanks for the info!
 

Bart

Registered User
Location
Arm Utah
Yep. The Autometer one has you put it in calibration mode, then drive exactly 2 miles... And done. Worked very well and was simple enough with using the distance on my phones GPS.
I bought the cheaper (I think Summit?) sender... Wondering if the pulse cuts out causing my intermittent inop... I'm going to buy the autometer sender and see if it helps.

Good to know. Sounds like the way to go.
 

bryson

RME Resident Ninja
Supporting Member
Location
West Jordan
The OBDII options (ScanGauge, etc.) would still require you to have a speed sensor of sorts in the vehicle, even though you wouldn't need a separate speedometer. The OBDII unit needs to get a speed signal from something...
 
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