hello, anyone know if there is a way to make the spedometer on my '94 2.2L 5spd. read accurately for 16" rims? the car came with stock 14" rims, didnt like them lol. i've never switched rims on a car before but someone mentioned something to me that there is something in the transmission that can be adjusted so the spedometer reads correctly with the 16" rims? or if there is any way to do this please post back to me!
thank you all for the help..
http://www.cardomain.com/memberpage/682845/ <=== my '91 Sunbird LE 2.0 4cyl
COMING SOON.. '94 Cavalier 2.2L Z-Wannabee (in progress)
there are shops that deal with speedometer adjustments and they can do it but if i remember correctly there is a gear in the transmission that has to be changed
Just go to this site
http://www.miata.net/garage/tirecalc.html
It will tell you what tire size to use so your spedo wont be screwed. Bassically you get the same tire diameter but with a diffrent rim size so your tranny gearing will still be the same.
i didn't have to and i went from 13s to 16s, i had 3 different police officers clock me for reference and it was dead on
One way would be to modify the calibration in the ecm to change the speedometer output pulses per mile. This is what GM would have done if they changed tire sizes.
Like a couple of people have said, you may not need to make any changes. If the outside of the 14" tire is very close to the same size around as the outside of the 16" tire, you will be ok.
-->Slow
slowolej wrote:
If the outside of the 14" tire is very close to the same size around as the outside of the 16" tire, you will be ok.
-->Slow
within 1", give or take.. i just put them up against one another quickly when i first bought them... will get an accurate difference for tomorrow
the stock tires are 185/75/14 i believe and the new tires on the rims are 205/55/16. but they are within 1" in diameter.
will get back to you all and see what you all think!
Thanks
http://www.cardomain.com/memberpage/682845/ <=== my '91 Sunbird LE 2.0 4cyl
COMING SOON.. '94 Cavalier 2.2L Z-Wannabee (in progress)
If the new tires stand 1" taller (larger diameter) that's a whole different thing than being 1" larger around.
When the "pros" do a speedo recal, they like to get the rolling circumference of the tires. Install the tire on the car, mark a line on the bottom of the tire in the middle of the bulge where it touches the ground. Continue to draw the mark on the ground. The roll the car straight ahead until the mark is on the ground again and make another mark on the pavement again. Measure between the 2 marks to get the rolling circumference. I that distance is close between the 2 tires, your speedo will be close to correct.
You might be surprised at how far the car goes with one turn of the tire. It's usually 6 feet or more.
-->Slow
oh.. ok i see what you mean now. aw well, i am going to call around and see if anyone can do this locally. will be at least a week or two, i was just curious about what i would be getting into. is this a common thing for mechanics to do... or would i need to go to a specialty shop for this?
Thanks
http://www.cardomain.com/memberpage/682845/ <=== my '91 Sunbird LE 2.0 4cyl
COMING SOON.. '94 Cavalier 2.2L Z-Wannabee (in progress)
um...
at the risk of sounding like an ass, you'll only be gaining two revolutions of the tires per mile. your speedometer will be off by approx 0.1 mph. somehow i don't see this as justification for recalibration.
hey, at least your speedo works; mine shows about 10% of actual speed. be happy with whatcha got, ya' know?
Have you seen the turbo wagon?
14.069 @ 98.91mph
229.1hp & 261.7ft/lbs @ 6psi
no tuning time
ok cool.. so 0.1mph = ___ km/h? LOL. yeah i'm gonna take off one of the stock rims, and check the distance of the stock 14 and rim on 1 revolution compared to that of the 16" tire and rim, then i will post my info and see what you all think.
thank you all for the input
http://www.cardomain.com/memberpage/682845/ <=== my '91 Sunbird LE 2.0 4cyl
COMING SOON.. '94 Cavalier 2.2L Z-Wannabee (in progress)
Quote:
hey, at least your speedo works; mine shows about 10% of actual speed.
Your can be corrected easier than the stock 94 j. You just need to say something.
-->Slow
?
http://www.cardomain.com/memberpage/682845/ <=== my '91 Sunbird LE 2.0 4cyl
COMING SOON.. '94 Cavalier 2.2L Z-Wannabee (in progress)
that calculator makes things pretty easy! Thanks sharkey. soo yeah, the "spedometer difference" is 0.203% too fast, and at 60mph on the stock 185/75/14's the 205/55/16's are around 60.1mph.. so i think this is going to work. the tires on the '94 Cavalier coupe right now are 185/75/14's... but maybe the guy didnt keep the exact size, anyone know if this is the size the cavalier would have actually came with??
http://www.cardomain.com/memberpage/682845/ <=== my '91 Sunbird LE 2.0 4cyl
COMING SOON.. '94 Cavalier 2.2L Z-Wannabee (in progress)
not sure if its safe or not but when i got 18's i think my car was like 5mph off.. when i put my white face gauges on i had to remove the needles.. i got someone to tell me how fast the car went in a certain gear ect.. 3rd gear at 4k rpm like 40.. just an example i then put th speedo on like 40 when the rpm was at 4k in 3rd gear.. ive had people drive right next to me its pretty dead on now.. and i did it a couple times
yes, my speedo is easy to fix. just have to wire in that vss buffer from the cadi j car. easy enough, just haven't gotten to it.
Have you seen the turbo wagon?
14.069 @ 98.91mph
229.1hp & 261.7ft/lbs @ 6psi
no tuning time
