who said that AP2 have 4.3 final gear?

I just learned from hyper-rev that ap1 and ap2 have same final gear ratio. only difference between ap1 & ap2 is 5th and 6th gear ratio.

 

gears 1-4 are the same and 5 and 6 are different. however, there is also a secondary gear in the transmission that affects all 6 gears so that gears 1-4 have a shorter gear ratio, 5th gear is a bit taller so that the overall is almost the same and 6 is even taller so its still taller than the ap1 6th overall. this is all in the tranny.

the final drive in the differential is the same.

theres a chart somewhere...

 

The secondary gear in the transmission is 5% lower (IIRC) on 1-5 and 6th is 5% higher for less revs when cruising.

It would make sense that 5th and 6th are both 5% higher since they are on the same shaft, but I read that 5th was also lower.

I thought rear gears were the same.

4.30s are in most of the Miatas and can be had cheaply.

 

here's that chart.

http://www.vtec.net/articles/view-ar...icle_id=146907

Transmission Gear Ratios

Gear 2004 2003 Net Change*
1st 3.133 3.133 4% lower
2nd 2.045 2.045 4% lower
3rd 1.481 1.481 4% lower
4th 1.161 1.161 4% lower
5th 0.943 0.970 1% lower
6th 0.763 0.810 2% higher
Reverse 2.800 2.800 No change
Secondary
Gear Reduction 1.208 1.160 4% lower
Final Drive 4.100 4.100 No change
*Net gear ratio change occurs through modification of the
secondary gear reduction ratio inside the transmission.

Source: Honda PR

 

I think you may have misunderstood.

By the information given by others, the first 4 gears are "like" having 4.3s in the FD. The FD is still 4.10

 

Well I was sorta-kinda right. I had the concept right, just not the right numbers.

Why don't 5th and 6th have the same percentage of change if they are on the same shaft and only the secondary gear has been changed?

So if you put 4.30s in a car with the AP2 transmission it would almost be like 4.44s in a car with the AP1 tranny - cool.

 

do you not understand that 5th and 6th were changed as well?

 

It was my understanding that the gears are all the same, only the secondary reduction gear was changed.

"*Net gear ratio change occurs through modification of the
secondary gear reduction ratio inside the transmission. "

 

If you take a look at the gear calculator and compare AP1 and AP2 trannies, gears 1 to 4 stayed the same and the secondary reduction gear ratio changed. To ensure that the AP2 car had very similar cruising rpm on the hiway, gears 5 and 6 was changed so that rpm stayed almost the same as in an AP1 car.

 

So, can I buy the secondary reduction gear for the AP2 and install it in my AP1 tranny? Looks like it's about $300 for both gears. It looks a damn site easier than rebuilding a diff.