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Speedo fix for oversized tires


88HatchMonster
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Here's one way to "recalibrate" your speedo for larger tire sizes. I scanned the face panel of my speedo, and using an online tire size/speedo calculator for reference, remade the face with Adobe Illustrator so the needle would show the correct speed with my larger tires. I printed it out with my laser printer and attatched it to the old face with double-sided tape. Should do the trick...

 

6078speedoweb1.jpg

 

6078speedoweb2.jpg

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meh... milage may vary... this is only a band aid, your odometer will still be way off. as far as I know you can get differant spedo gearing, or I'd start yankin parts from other vehicles till I got something accurate... but I swear theres probably a way to calibrate everything right, someone just needs to get really into the electronics and figure it out... but then again I might also be full of ************ and not know what the hell I am talking bout :brow:

 

edit: you can buy aftermarket speedometers that come with an electrical sending unit and some of them are totally customizeable...

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That's awesome!

 

Might be another product for you to sell, if they're cheap to make. You could produce them with the proper correction for a few different popular tire sizes. I've never had my EA82 gauge cluster apart, so I don't know how hard it would be to do on those cars, but if it's not much of a hassle to install, and you could produce them for a reasonable cost, I'd probably buy one.

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meh... milage may vary... this is only a band aid, your odometer will still be way off. as far as I know you can get differant spedo gearing, or I'd start yankin parts from other vehicles till I got something accurate... but I swear theres probably a way to calibrate everything right, someone just needs to get really into the electronics and figure it out... but then again I might also be full of ************ and not know what the hell I am talking bout :brow:

 

edit: you can buy aftermarket speedometers that come with an electrical sending unit and some of them are totally customizeable...

 

it's a completely mechanical speedo, so there's no 'reprogramming' available...and there aren't any aftermarket speedo gears available for our cars....maybe something else would work....I'm not sure if anyone's tried.

 

I've got one of those aftermarket ones, little metal sensors on the driveshaft, little sensor mounted near it...fully reprogrammable speedo. I haven't hooked it up yet though....other things need to be taken care of first.

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that is a great idea. To calibrate your new face to your rig I can only offer the following: it takes exactly 60 seconds to travel one mile at 60mph. I use the yard sticks on the interstate. I know you can figure out other speeds and the elapsed times, but high school was sooo long ago I have forgotten how.

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I attempted the same thing with my EA82 and ended up with a broken guage cluster. :( Had a hard time getting the needles off and then they broke. :(

 

I am going to try again and I will make the file available for download when I am done.

 

I had the same thing on my jeep cherokee, but I did them in white face style :) the light behind them made them glow a cool green color.

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  • 4 months later...

Hi everyone, here's an update on this little project. It's all done and I'm pretty happy with the results.

 

Yes, keeping the backlighting was the big challenge and it didn't take much head scratching to realize my original approach wasn't going to work. Taping a printout over the old face would result in a mess of overlapping numbers when the backlight was on. Also, the white of the paper was translucent enough, but the black printed area was not opaque enough to fully black out the backlight like it should.

 

I solved these problems by running one sheet of self-adhesive label paper through the laser printer 3 times, this built up a totally opaque layer of toner. To match the thickness of the original face, I cut out the exact shape from a clamshell CD case. The plastic was plyable and easy to cut with scissors and a razor blade. I simply peeled and stuck the new printed face to the plastic cutout.

 

Probably because I'm certified compulsive, I went and made a new face for the tachometer that upped the redline to 6500 (this hatch has a '93 EJ22 :grin:). This was kind of pointless, but at least this way the faces matched. One other thing I did since the first rev. was to put on Km/H marks (I'm only 1 1/2 hours from Canada so why not?)

 

I know a few people were interested in doing this mod... If anyone wants a sticker (just the sticker you do the rest) they can send me a SASE. Just PM me for my address. No charge... the hard part is done, it's no big deal to run off a couple more copies. The speedo face will work on EA81s with the ODO between the guages and is calibrated for tires with an actual diameter of 27.5".

 

guages1.jpg

 

Guages2.jpg

 

Guages3.jpg

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The way to fix the guages is to have the speedo cable cut and an adjustable gear reduction unit spliced into the cable. It's not cheap, but will allow you to change your tire size by simply changeing the gear set in the reduction unit. There are places that specialize in this for big lifted trucks ect. I think the service is around $100.... definately not as cheap as your solution, but if you plan to change tires sizes later.... and it's definately as cheap or cheaper than a full programable guage and electric sender setup.

 

Looks good tho - you have a lot of time on your hands.

 

Personally I just used an online tire size/speed calulator, and figured the percentage increase in the speed, and made a simple chart that I taped to my dash. 47 MPH is 55 for me... I've trained myself to know this when in the wagon. It's an off-road dirt and rock machine and fixing the speedo is the least of my worries. But that's me. This would be a neat trick for my Brat when I lower it tho... definately might consider that.

 

*edit* could you post the image file perhaps?

 

GD

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The way to fix the guages is to have the speedo cable cut and an adjustable gear reduction unit spliced into the cable. It's not cheap, but will allow you to change your tire size by simply changeing the gear set in the reduction unit. There are places that specialize in this for big lifted trucks ect. I think the service is around $100.... definately not as cheap as your solution, but if you plan to change tires sizes later.... and it's definately as cheap or cheaper than a full programable guage and electric sender setup.

 

Has anyone ever done this? When you take your cable in to the 4x4 shop don't tell them it's for a Subaru... :)

 

I'm not putting up an image file cause the printing is the critical part (not gonna work on an inkjet, has to be color laser.. there's a couple other tricks...). That's why I offered to send copies to anyone who wants. But if you know what your doing and want to modify it or print it yourself PM me your email address and I'll send you the EPS file.

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I have seen GD's suggestion done before - but not in a Sube. This suggestion might have a slight advantage coz the odometer/trip meter will be correct as well.

 

But again - I am very impressed with your effort.

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  • 3 weeks later...

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