Okay guys, here is my final statement about the 4.10 to 4.33 rear end swap. one word: TORQUE! One thing our cars don't have much of down low. a taller rear end would give you a constant ammount of torque multiplication, giving you more power down low, giving you better gas mileage because it takes less effort to take off from a standing start, and cutting your top speed from about 140 to 130mph. Big Friggin Deal. Some people here are talking about power going to the road being greater and something like that. THERE IS NO WAY TO MULTIPLY POWER EXCEPT FOR MODIFYING THE ENGINE!!! With a 5% difference on a N/A S5 engine, you have about 140ft.lbs of torque. that is about an extra 7 FT.LBS OF TORQUE.

This is why when I get the money, guess whats going in my rear end.

 

3.9 to 4.1 you get a 1.2 second faster 0-60mph time, this is what makes s4 verts so freakin slow.

 

torque multiplication comes from gearing
it works like levers, pullies and the such.
all those things multiply torque input though as someone else said the hp stays the same.

why do you think you can take off in first gear but not 5th gear?

you start out using the rpms trying to start in each gear it is just that with 1st gear there is more torque beign applied to the wheels


some downsides of more gear though is shifting can cause loss of speed being it takes tiem to do so

also since you have to shift at an ealier point you can also come into some problems of actually having less torque applied at some points being 2nd gear puts out less torque then 1st gear does
and so with the 4.3 gears you are already in second when the 3.9 you can still be in first gear putting down a little torque