See link: http://www.la4x4.com/gearcalc.html

I used the tire diameter as 23.6” (the loaded radius * 2) NOT 25.4” (the tire with no load on it)

<pre>
<font size=+1>

Manual Auto (MPH@7200rpm)
--------------------------------------

1st 3.933(29) 2.563(45)

2nd 2.478(46) 1.551(73)

3rd 1.700(67) 1.021(112)

4th 1.250(91) 0.653(174)

5th 0.976(117) 0.470(242)

6th 0.771(148)


</font>
</pre>


Final Ratio:
4.428


Can someone confirm the final ratio?

 

Are those the top speeds in ()? Holy Shit! Those are some short gears. Esp 1-2. Watch out for the rev limiter.

 

The manual's final drive is 3.286

 

I used the tire diameter as 23.6” (the loaded radius * 2) NOT 25.4” (the tire with no load on it)

Ok – now updated with the diff ratio of 3.286 (courtesy of bioyuki – thanks)

<pre>
<font size=+1>

Manual Auto (MPH@7200rpm)
--------------------------------------

1st 3.933(39) 2.563(45)

2nd 2.478(62) 1.551(73)

3rd 1.700(91) 1.021(112)

4th 1.250(123) 0.653(174)

5th 0.976(158) 0.470(242)

6th 0.771(200)


</font>
</pre>


Final Ratio:
4.428 Auto
3.285 Manual


Well, the quarter mile guys will have to shift quick, but that now looks much better!

 

Every time I look at that 4th gear ratio on the auto, it makes me say... WTF... 174 MPH ????

I wonder how many people would have complained about hitting the 7200 RPM limit -- with the top speed cut-off removed -- at 155 MPH (or less) ????

 

Can you compute the rpm's for 6th gear at 80 mph?

 

2884 RPM @ 80 mph in 6th gear.

 

have you noticed the 62 MPH at the 7200 rpm of the 2nd gear?....

Classical text book design of gear ratio for the second!

I read in some car mag that ALL manual gear boxes of ALL makers have the gear ratio of the second gear tops at 62 MPH!

just to make 0-60 MP and 0-100 KMH numbers look good.

 

I think the 5AT runs about 2500 rpm @ 80. I wonder what mpg the new one will get on the highway. Anyone seen the epa numbers?

 

I think its 19/28 for the manual and 19/29 for automatic...

The 28 figure might reflect the higher rpm in 6th gear...

 

Yea, it's just that last 3-4 shift required in the 1/4 mile that some people will end up bitching about (can't please everyone)

 

I guess in he 1/4 mile you would shift 4 times. Out of the 3d you would be a 90 MPH 2 sec later you are doing 100 MPH and finishing the 1/4 miles. I expect 1/4 miles in 14.2s at 100MPH with decent tires... those michelin should go!

 

Er, eh... you fell for the "how many fence posts do you need question..."


1 to 2 shift = shift #1
2 to 3 shift = shift #2
3 to 4 shift = shift #3

3 shifts in manual vs. 2 in the auto


(ok, I know what you mean... I'm having some fun 'wid 'ya...)

And they should send those MXM4s to a racetrack for use as a tire wall/barrier!

 

Close guess! The calc says 2370RPM in the auto's 5th (that presumes the converter is fully locked-up (not in brain damage mode)...


BTW -- Zapata mentioned that the "new" specs are on the Acura web site -- does anyone have the "exact" steps to get at the data @ www.acura.com?

 

Oh boy!---I can just see it now--someone is going to start bitching about why the 6th gear isn't taller than it is in the 6 speed!


How do these ratios compare to those of the NSX?


Here are the ratios of the 2002 Ruf Turbo 911:
3.82
2.05
1.41
1.12
0.92
0.75
Final 3.44

Compared to the 2003 CLS
3.933
2.478
1.700
1.250
0.976
0.771
Final 3.285

 

I think this is what he was refering to:
http://hondanews.com/Forms/acura/CL/...s(r)_text.html

http://hondanews.com/forms/acura/
Click on CL then Specs on the left side.

 

I also do such calculations. What information do you use to assume a diameter of 23.6 for the tire loaded? Is there a rule of thumb?

 

I looked up the "loaded" raidus (the radius of the tire with a load on it). The diameter of the tire -- 25.4 - 25.5 inches is the diameter without a load. The info is in the tire tables on some of the manufacturers' web sites. I went to www.toyo.com and used the 215/50-17 tire to get the info (the 235/45-17) had almost identical info.


There is going to be some "expansion" in the tire with speed, but with modern tires, this can probably be ignored on a "first cut".


So, if you look up a Toyo T1S Proxy @ www.toyo.com and search the specs for the 215/50-17, you will find a loaded radius of 11.8 inches. To get the “loaded diameter” is multiply by 2: (2 * 11.8”) = 23.6 inch loaded diameter. I would be full of it if the contact patch of the tire (from front-to-rear) was near 0!