I'am building up a n/a d16z6 in my ej1. My goal is ~150-160whp and with that little hp I know gearing can make or break you. I did a little messing around with the fatboy raceworks calculator and saw that going from a 4.25 final to 4.9 will do the following in comparison...

4.9
1/4 mile on 20" slicks
traps at 7500rpms if ~100mph

4.25
1/4 mile on 20" slicks
traps at 6500rpms if ~100mph

===========================

4.9
205/50-15 tires
cruise at 2550rpms at 50
cruise at 3500rpms at 70

4.25
205/50-15 tires
cruise at 2200rpms at 50
cruise at 3050rpms at 70

I guess my questions is...

Can a higher final drive give me a couple tenths more in the quarter? how much difference will this make in my mpgs?

 

also, is high 13's possible in a ej1 with 160whp+gearing+traction

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wfocrx &raquo;</TD></TR><TR><TD CLASS="quote">also, is high 13's possible in a ej1 with 160whp+gearing+traction</TD></TR></TABLE>

it is very possible.

on 20's, a 4.9 may or may not require 5th gear in the quarter mile, it will definatley make your car faster, but if it requires 5th, then I'd go lower on the f/d

 

with my 4.9 ats final drive with ats 1st gear 3.077, bseries build though, i'd end up top 4th and saving the shift to fifth saves a lil time, oh by the way my car is a daily driver, gas is gonna be a killer

 

Most people report getting better gas mileage with the higher FDs, myself included, due to having to use less throttle input when accelerating. Throttle position seems to have a greater effect on fuel consumption than RPM.