If you want your spreadsheet to be accurate just multiply your FD X the reduction gear (1.206) and use that as your "effective" final drive instead.

Peter

 

Thanks for this info. I don't want to argue with anyone. I don't have any knowledge of an effective drive. I am naive when it comes to that.

 

This "transfer ratio" is the same as the "secondary reduction ratio". It's like another gear that the transmission must spin through before the power goes out to the prop shaft. All gears (1 through 6 and reverse) spin this gear before power leaves the tranny.
We all know that the ring and pinion gear is known as the "final" drive gear or final drive ratio. Think of the 2ndary reduction gear as one more gear just before the rear diff. This would be similar to changing the diameter of your tires and changing the final drive ratio again. It just so happens that this 2ndary gear is at the back end of the tranny. This was the gear that Honda changed in the AP2 to make the tranny work like an AP1 does with "gears" in the rear diff. Then Honda went and altered the ratios for 5th and 6th so that engine rpm at cruising speeds could be "liveable". If you compare the ratios of the first 4 gears of both cars, the numbers are nearly identical. It's gear 5 and 5 that got changed slightly.
For the AP2, changing the 2ndary reduction gear as they did, was "like" going from a 4.10 FD gear to a 4.3 FD gear in an AP1 (for the first 4 gears). Coincidentally enough, it is the 4.3 FD gear (in an AP1) that is very popular in Japan.

 

[QUOTE=xviper,Nov 13 2005, 08:27 PM] This "transfer ratio" is the same as the "secondary reduction ratio".

 

dude you are way off on your numbers... i have a website that has a calculator that'll give you all the numbers.....

i'll post it up when i get home..

if i remember correctly.. ap2 top speed is like 153mph... and ap1 top speed is 168mph.... (obviously tail/head wind, down/up hill also play a factor) but both are limited by drag to around 155mph...

 

** just read the rest of the thread **

xviper already posted the site that has the calculator...

 

According to that calculator, AP1 is geared for 165 mph @9000 rpm.
I agree with you totally about the conditions at the time to determine "how fast" a car can go. It's easy to say "my car went xxx mph" when you don't state the wind velocity, wind direction, degree of slope on the run, air temp, road surface construction, etc. The only way to standardize such statements is to do this sort of run at about the same time, on the same road, in BOTH directions and correcting for STP (standard temperature and pressure) AND speedo error.
Additionally, "drag" limitations must assume level ground and "STP". It has been shown that this car can go over 170 mph on the speedo, but that was done on a long sweeping downhill run. Who knows what kind of tailwind there was or how much bouncing off the rev limiter there was?

 

So...how can I factor in the 4.56 FD into the gear calculator?

 

Yes, you can plug any number you like into that calculator. Just select the type of car (AP1 or 2 by MY) and hit "GO".

 

also keep in mind if you have aftermarket wheels and differnt tire sizes you need to plug that in too...