Speedo Re-calibration

[ozute]

G'day guys,

Someone mentioned to me earlier that if i got some non stock tyres/rims for my VR that I would have to get the speedo recalibrated. I was given the impression that it's just a matter of a techy plugging in to the onboard compa and telling the car the new sized shoes. Is this the case, and does anyone know if it's costly please?

 

[Macca177]

at a guess, it would only make 2 or 3ks differnce in a commodore. give or take depending on diamatter

but when i had my 4wd i was near 30- 40 k out due to very large tyres(37")
i see ur in syndey, theres a bloke out beverly hills way, he works out the diffencer(dont ask me how) and works out the gears on the cog to correct it.

i never had mien done but my mates have and hes very good. I can try get his number for u if u like.

dont know if its computer controlled on the commodores, if its a senscor or geared for the car to get the speed.


hope this helps a bit
cheers
hayden

 

[chicb8t]

I changed my stock 15inch wheels for 17 inch rims on my VR and it made no difference at all. just check ure speed agaist a friend in their car when u get the rims if you get parnoid. probably wont be out by enough to bother with

 

[ozute]

Excellent, sounds good.. Thanks guys

 

[michaelw]

Am I missing something (most likely) but even in the rims are different sizes the outside of the tyre is still the same isn't it?

I thought it was just the sidewalls were smaller on a 17' vs 15'?

Mike

 

[ozute]

That's true mate, but sometimes the combinations are not equal to the original dimentions

 

[semmi]

check out http://www.1010tires.com/TireSizeCalculator.asp - this is a tyre size calculator which allows you to compare different tyre sizes and what the speedo difference will be.

it's a good way to determine if the difference is worth worrying about or not!!

 

[ozute]

EXCELLENT, just what I was looking for.. Thanks heaps semmi!

 

[semmi]

cheers mate :thumbsup:

 

[burnz]

i see ur in syndey, theres a bloke out beverly hills way, he works out the diffencer(dont ask me how) and works out the gears on the cog to correct it.




hope this helps a bit
cheers
hayden

dia x pi x rpm keep gearbox in direct not 1,2,o/d x 60 divide diff