Does changing the diff size and wheels through the speedo out by much??

 

If so how do you get round this?

do u mean the internals of the diff ?? id so do u mean for the n/a ratio ?? if so then yes knocks it our alot and you need an N/A speed sensor.

 

If u mean the wheels on the car , then as long as u change the tyre size to match the same circumference then no. For e.g : 16" wheels using 225 x 60 x 16 . then u put 18" on , u would have to use 225 x 40 x 18 to make up for the extra size if you get what i mean. so the surface area is still the same size.

If you can be arsed, you can recalibrate the speedo, but it involves dismantling the binnacle and for the sake of convenience drilling a couple of holes in the speedo housing to access the adjustment potentiometers.

 

Note that your odometer will also be out, which wouldn't be corrected even if you did recalibrate the speedo.

you can increase your wheel size to 18" without having to worry about it, makes virually no difference.

So what about 19's

So what about 19's

 

as long as u get correct tyre size should be fine , few people on here running 19's like ya5een but i heard the ride is dam hard !!

as long as u get correct tyre size should be fine , few people on here running 19's like ya5een but i heard the ride is dam hard !!

'tis true karl, but thats mainly due to the coilovers. there isnt a huge difference in the ride between stock and 19s but its definately noticable

'tis true karl, but thats mainly due to the coilovers. there isnt a huge difference in the ride between stock and 19s but its definately noticable

 

I agree, i am still on stock shocks and springs and the ride change from stock wheels to 19" isnt that different.

It's a richmond gears, gear kit for the diff.

 

So no it's not a N/A diff.

 

I'm just worried if i changed both my diff and wheels it could put my speedo out so i end up getting a speeding ticket.

 

That would just be great.

the speedo will be off by about +10% by changing the TT for a NA/leader diff gear.

(so the speedo will show a higher speed then you are actually driving)

 

larger wheels will have a negative effect, eg going from 16" to 18" will result in approx -6% (depends on tire size)...

 

so in other words.. your speedo will most likely still indicate a 5% higher speed then that you are actually doing...best is to check with a GPS.

I'm running 18's with 265/35 and my speedo is surprisingly accurate when comparing to GPS, usually only 2-3 mph out at motorway speeds

the speedo will be off by about +10% by changing the TT for a NA/leader diff gear.

(so the speedo will show a higher speed then you are actually driving)

 

larger wheels will have a negative effect, eg going from 16" to 18" will result in approx -6% (depends on tire size)...

 

so in other words.. your speedo will most likely still indicate a 5% higher speed then that you are actually doing...best is to check with a GPS.

 

Cool well there is no need for me to worry if my speedo is reading higher it will mean i'll be doing under the speed limit and no speeding tickets yeay :dance:

I'm running 18's with 265/35 and my speedo is surprisingly accurate when comparing to GPS, usually only 2-3 mph out at motorway speeds

 

that's probably because most standard speedos usually have a positive deviation from the factory.

By installing larger wheels this deviation will decrease and make the speedo more accurate.