Alpha 1-4
NAXJA Forum User
- Location
- Ontario, So Cal
Looking for a 39 or 40 tooth speedometer gear. Just upgraded to 4.56 on 33'' BFG AT's.
Thanks
Thanks
Wanted
- Thread starter Alpha 1-4
- Start date
Producer_Shawn
NAXJA Forum User
- Location
- Burbank, CA
Did you go from stock gears to 4.56s? tires how do you like it? is it a noticeable difference?
- Location
- Westminster, SoCal
I might - I'll check later on today.
Alpha 1-4
NAXJA Forum User
- Location
- Ontario, So Cal
Shawn,
Yes I was running stock 3.55 before and I have only done the first 15 min drive, no hard accelerations, with the 4.56. With having the wrong speedo gear and the shift points being WAY off, there was still a noticeable change in throttle response.
Kejtar,
Thanks.
Yes I was running stock 3.55 before and I have only done the first 15 min drive, no hard accelerations, with the 4.56. With having the wrong speedo gear and the shift points being WAY off, there was still a noticeable change in throttle response.
Kejtar,
Thanks.
- Location
- Westminster, SoCal
two things - I don't have that speedo.
Also I double checked my chart that I worked out a while ago and I believe that you really need a 38 tooth gear (btw, I don't have that one either
).
Also I double checked my chart that I worked out a while ago and I believe that you really need a 38 tooth gear (btw, I don't have that one either
).Alpha 1-4
NAXJA Forum User
- Location
- Ontario, So Cal
Every chart I have looked at says 39 tooth for a 33" tire. I measured the actual size and it was 32.8 diameter and the tooth count for a 32" tire was 40. What brings you to a 38 tooth gear?
- Location
- Westminster, SoCal
The chart that I have was "home grown" by myself and couple other folks and verified with GPS. It has been many years since I touched it but if I recall correctly the issue was that if you went with the tooth info and tire size from the factory setup and built a chart based on that you were close but not 100% accurate and most charts that I have seen were built based on that.
Now for all intents and purposes the variation was about 2% (if not less - again I'm reaching back in my memory to something that was created in 2006 ) and that does not take into account the tire wear and the actual tire size differences (not all 33" tires are really 33") which on larger tires could have more of an impact.... anyways 
To expand on that - if you have a chart that is built with a 33" tire in mind the distance traveled on a rotation is 207". If your tire is really 32.8" then your distance is 205" and change making the difference less then 1%. Now when you wear out the tread and drop to 32.5" then you are already off by 1.5% and so on.....
Now for all intents and purposes the variation was about 2% (if not less - again I'm reaching back in my memory to something that was created in 2006
) and that does not take into account the tire wear and the actual tire size differences (not all 33" tires are really 33") which on larger tires could have more of an impact.... anyways To expand on that - if you have a chart that is built with a 33" tire in mind the distance traveled on a rotation is 207". If your tire is really 32.8" then your distance is 205" and change making the difference less then 1%. Now when you wear out the tread and drop to 32.5" then you are already off by 1.5% and so on.....
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