I've been working on this for a while and want to let people help me work some bugs out of it. The tranny sheet allows you to enter in all of your gearing info and tire diameter and then it creates dynamic output of the rpm at a certain speed in a gear and visa versa. It then performs a graph of rpm vs speed to see how the gear spacing looks. I made a web page that does the same via javascript but I want to work out the math bugs here if there are any left.

I'm pretty sure my formulas are correct but the numbers resulting are kinda skewed IMO. They seem a bit high. After I get it fully fixed, i'll repost the spreadsheet w/out locking it.

Thanks guys!!

Take a look here

 

They are a bit high. One thing missing is the secondary reduction gear. There is a 1.16 ratio gearset at the back of the transmission.

 

[QUOTE]Originally posted by dhayner
[B]

 

It's like an additional "final" drive reduction. In your formula, use ( ( RPM / ( Final Drive * Secondary Reduction * Gear ) * ( Pi * Tire Diameter ) ) / 1056
I agree with the rest of your formula, by the way.


It's in the S2000 service manual (Helm)

 

Now look at it.. wonder how i'm gonna find all the info for the other trannies..

 

Hey Ozy, this is great. If you're numbers are accurate, it will help me with the heel-toeing and rev matching.

 

Well now that I know about the secondary reduction gear, they do now seem correct for the S2000. On the second sheet "Honda Trannies" the S2000 section shows what RPM u'll be at when u do a 9000 redline shift at the lower gear

1st->2nd = 5874 @ 44.6mph
2nd->3rd = 6518 @ 68.4mph
3rd->4th = 7055 @ 94.4mph
4th->5th = 7527 @ 120.5mph
5th->6th = 7516 @ 144.1mph

Top gear speed 172.559mph

49.9mph in reverse!!!

Of course this assumes stock tire diameters. I could try generate a reverse direction on what speed it is safe to downshift @ to not over rev the gear under it.. mmmm that sounds fun!!

NOTE: Never hit vtec in reverse, a friend did in his SI and messed his car up somehow.

 

That still seems a bit high.... I recall 65mph & 91/92mph & 115mph being the highest you could possibly go in 2nd, 3rd, and 4th gears respectively (dunno if that's redline or rev-limiter, though).

 

Yes, do a downshift calculation. Heel-toe is a technique used when braking and downshifiting. I'm still practicing it and the rev matching is one of the hardest parts when you downshift.

By the way, some of the guys down in Houston have already VTECed in reverse. It didn't seem to mess up their cars.

[QUOTE]Originally posted by Ozy
[B]

Well now that I know about the secondary reduction gear, they do now seem correct for the S2000.

 

already did this work: http://hackforfood.com/s2000.xls

yours is prettier looking though