Hi guys,

I just swapped my speedometer to one with a tachometer. After putting it all back together, I drove around to discover that my speedometer is off(according to my phone's GPS). I'm using 175/70R13 tires which is within specs. I was wondering if there is a way to correct it.

Any help would be greatly appreciated.

PS: random question, does anyone know if oxyacetylene welding would work/hold exhaust hangers?

Thanks!

 

what car, transmission, and cluster are you using? how far off is the speedo to gps?

 

Totally forgot to mention in my original post.

It's a 1991 Civic HB DX. 5 speed manual. With a cluster swap from a 1990 Si, but I kept the part that connect to the speedometer cable, therefore keeping my original Km. Speed difference is:
Gps/speedometer (km)
35/40
100/107
120/135

Roughly like that. Hope this helps.

 

Is it faster or slower?
My 91 si reads 67 when gps says ~65. It gets worse the faster I go.
This with 195/50/15

I also have some 205/50/15 and these read slower.
65 when gps says I'm going ~68

It's not off by too much to worry about imo.
Just get different size tires next time.

At least your speeder doesn't go 360 degrees like a friend of mines did.

Doh!

 

My civic thinks it's going faster than it is. So speedometer reads 135km/h but Gps say 120km/h.

 

I am wondering if the speedo is calibrated to the Si transmission/final drive which would lead to the incorrect reading.

 

I forget, but I think speedo cables, trannys and speedometers are unique to one another.

 

That's the thing, I kept the part that connect to the speedometer cable when swapping the dash clustef. So in a way, the speedometer haven't changed. Since the speedometer is a machically operated, it shouldn't be effected by the electrical side of the dash cluster...

 

It's a cable driven speedo. Plugs in on both ends cable shouldn't matter when u swap trans. Assuming the tires are what's reading wrong. Isn't it supposed to be a 14'