speedometer gear question......

[abodyjoe]

does this chart look good?

when i put the 2.76 gears in the car i changed the speedo gear to a 28 tooth.. speedo is about 2 to 2.5 mpg fast now.. tires are a 225/60-15 which is around 25.5" tall.. with the 3.23 and a 33 tooth gear it was dead on. would a 29 tooth slow the speedo down or speed it up? i'm having a major brain fart over this...lol i know 2 mph off isn't much but it annoys me..

 

[CFD244]

I'll take slow it down Alex for $200?

 

[WV64Signet]

This is like one of those ASVAB questions.



Same diameter gear with fewer teeth would slow the speed given the same output shaft speed....

 

[abodyjoe]

Same diameter gear with fewer teeth would slow the speed given the same output shaft speed....

well the gear on the shaft of the trans stays the same.. the gear that goes to the speedo will get larger. so i guess the speedo will slow down.

 

[WV64Signet]

well the gear on the shaft of the trans stays the same.. the gear that goes to the speedo will get larger. so i guess the speedo will slow down.

I just went to 15" wheels. Haven't played the game yet. I have 3 different gears to work with.

 

[abodyjoe]

I just went to 15" wheels. Haven't played the game yet. I have 3 different gears to work with.

if the tires are the same height you'll stay the same.

 

[WV64Signet]

if the tires are the same height you'll stay the same.

I stayed as close as I could. 64, not a ton of options in the back with wheel opening clearance

 

[Lefty71]

Put more air in the tires....

 

[abodyjoe]

lol

 

[toolmanmike]

does this chart look good?

when i put the 2.76 gears in the car i changed the speedo gear to a 28 tooth.. speedo is about 2 to 2.5 mpg fast now.. tires are a 225/60-15 which is around 25.5" tall.. with the 3.23 and a 33 tooth gear it was dead on. would a 29 tooth slow the speedo down or speed it up? i'm having a major brain fart over this...lol i know 2 mph off isn't much but it annoys me..




View attachment 1716421060

You usually have to dink around to get it closer to perfect than the charts can get you. 1 tooth is usually 2-3 mph. You are close.

 

[oldkimmer]

More teeth slow the speedo down. 29 will do it 4 ya. Kim

 

[abodyjoe]

I'll move it to a 29 and see if that gets it.

 

[mopowers]

If the 33 tooth gear was dead on, I'd go with a 28.

(2.76/3.23) * 33 = 28.2

 

[oldkimmer]

If the 33 tooth gear was dead on, I'd go with a 28.

(2.76/3.23) * 33 = 28.2

He already using a 28 tooth gear. Kim

 

[mopowers]

He already using a 28 tooth gear. Kim

28 will be closer than a 29. Unless the 33 wasn't dead on.

 

[RustyRatRod]

well the gear on the shaft of the trans stays the same.. the gear that goes to the speedo will get larger. so i guess the speedo will slow down.

That's correct. Larger driven gear will slow the speedo down.

 

[abodyjoe]

If the 33 tooth gear was dead on, I'd go with a 28.

(2.76/3.23) * 33 = 28.2

28 reads 2mph fast.. the 33 was dead balls on which is why i went 28. i'll throw the 29 in there and should be good..

 

[Kern Dog]

28 reads 2mph fast.. the 33 was dead balls on which is why i went 28. i'll throw the 29 in there and should be good..

Dead balls seems more like a reference to being sterile rather than accurate.

 

[mopowers]

28 reads 2mph fast.. the 33 was dead balls on which is why i went 28. i'll throw the 29 in there and should be good..

Certainly doesn't hurt to try.

2 mph off at what speed though? 2 mph off at 20 is very different than 2 mph off at 75. If it's the latter, you may just have to live with it.

 

[abodyjoe]

Certainly doesn't hurt to try.

2 mph off at what speed though? 2 mph off at 20 is very different than 2 mph off at 75. If it's the latter, you may just have to live with it.

seems to be 2mph everywhere.

 

[MoparLeo]

 

[abodyjoe]

View attachment 1716421204

what a crappy chart. i like the brewers chart better. it says 28 tooth , thats what i have and its off 2mph., the brewers chart says one for a 25" tire and one for a 26" tire. a 225/60 (atleast mine) are 25.5".

 

[mopowers]

If your speedometer is off 2 mph at every speed, your current speedometer gear is probably the correct one and either the speedometer or whatever you're using to measure actual speed needs to be recalibrated. If your speedometer gear was wrong, the mph difference would increase as speed increases.

 

[abodyjoe]

i ordered a 29 tooth and will throw that imn.. will probably fix it for me..