35's or 39's

[Coastie]

FIXED

Multiply what?

His speedometer is 6 MPH over what it should be...

 

[kastein]

it is 6mph over... at 79mph.

The difference it is off by is going to be linearly dependent on the speed he is going since this is based on the diameter of the tires being different. All the speedo does is crank the dial up more a little bit for each tick it sees on the VSS signal line, which is why you change the speedo gear to have fewer teeth when you use bigger tires without changing the axle ratios. The fewer teeth results in the VSS input shaft spinning faster too.

 

[1990heepxj]

or you know how much its off by and guage ur speed accordingly

 

[austinaubinoe]

just be happy you can go 75! But you should definitely get 39's! My speedo being 10 miles over has saved me from a couple speed cameras!!!

 

[ScienceguyXJ]

Changing the speedo gear to correct for the problem is simple. Takes only a few minutes to change it out. Only hard part is figuring out how which gear with how many teeth you need...

 

[rweaver138]

your all wrong, he needs 42x8.5's

 

[CherBear]

it is 6mph over... at 79mph.

The difference it is off by is going to be linearly dependent on the speed he is going since this is based on the diameter of the tires being different. All the speedo does is crank the dial up more a little bit for each tick it sees on the VSS signal line, which is why you change the speedo gear to have fewer teeth when you use bigger tires without changing the axle ratios. The fewer teeth results in the VSS input shaft spinning faster too.

Thank you

 

[austinaubinoe]

your all wrong, he needs 42x8.5's

Thats what I meant to say , wait, did you really mean 8.5 inches wide?? That would be crazy! would look like that "yeti" concept thing on youtube!

 

[Dest]

I run 54 inch boggers with a budget boost and a D35 with 3.07s (front and rear!, people tell me its a D30 but i know better.) No fender trimming also. But my speedo is spot on.

Your sig says otherwise. :eeks1:

just be happy you can go 75! But you should definitely get 39's! My speedo being 10 miles over has saved me from a couple speed cameras!!!

Have you really gotten out of tickets because your speedo was wrong due to adjustments you've made to your vehicle? Don't get me wrong, I'm happy for you, but I can't think of anywhere that would actually fly.

 

[Darky]

Your sig says otherwise. :eeks1:



Have you really gotten out of tickets because your speedo was wrong due to adjustments you've made to your vehicle? Don't get me wrong, I'm happy for you, but I can't think of anywhere that would actually fly.

He was saved from the ticket because his speedometer read 10 mph faster than he was actually going, therefore, his speedo may have said speeding, his actual speed was not speeding.