d16y7 gears

[jahasiel]

whats the top speed that a stock d16y7 with a stock m/t tranny can go in each gear?

[klungemonger]

That depends...there are different final drives for Y7 trannies depending on body style. Hatchbacks have a longer f/d gear than the coupe/sedans.

[98civcEK]

for the coupe,

1st = 30
2nd = 60
3rd = 100
4th and 5th, it doesn't have enough power to run to the end of either of these gears, unless going down hill

[klungemonger]

I believe the 1-5 gearing is the same for all of them but the hatch has a 3.76 f/d and the coupe/sedan has 4.06 or some such thing. Here's a simple formula for you to figure out the speeds yourself:

RPM @ redline / final drive ratio / gear ratio = RPM at wheels
(Tire diameter / 12) X 3.14 = Tire circumference, in linear ft.
1 Mile / Tire circumference = Wheel revolutions per mile
(60 / wheel revolutions) X RPM @ wheels = top speed

Here's an illustration to break it down. Say you have a GSR that redlines at 8000rpm. You have tires that are 24" diameter. The tranny is a 4.4 f/d and first gear is 3.23...

8000 engine rpm / 4.4 fd / 3.23 = 563 wheel rpm
(24" dia / 12) X 3.14 = 6.28 ft
5280 ft (1 mile) / 6.28 = 840.76
(60 / 840.76) X 563 = 40.17mph

Once you have some of that data all figured out all you need to do is just change the gear ratio (third number in the first formula) and recalculate. OR...go to this link and just add in your numbers and it will spit stuff out. I wrote this because while a web calculator is the easy way, you should still understand the principles of how/why you get the numbers. Just put your 1-5 ratios one at a time into the "overdrive gear" box after filling the other stuff in.

http://www.mysportscar.com/tools/topspeed.htm

[jahasiel]

thanks a lot, now i can figure more what the top speeds for each gear are, also thanks for the formula , its a little confusing but easy at last