Traction isn't really the issue here, though, with the shorter gears. The problem is that you'll be shifting to 5th gear, effectively slowing you down at the end of your runs. I shift to 5th anyway with the stock gearing and on 27"(?) ET Streets already, though.

 

i noticed that the 305/30/19 was just slightly shorter than the stock 19" g35 sport tire (which is what i have) so that would also slightly numerically raise the effective gear ratio. i calculated that it would have the same effect as the stock tire with 4.156 gears. i dont see what the problem with being in fifth in general is, as it is just the 1:1 gear... i guess the time is lost in the shift itself. in my 5 speed mustang, id finish in 4th (1:1, 5th was OD)... same in my honda and the same as third in my automatic equipped 5.0 mustang. all of those cars had nitrous and finished well into the 1:1 gear. i can definately see how it would slow you down if you were just making the shift at the end of the run and staying in it for half a second. is this what you are referring to? how far do you get through 5th 3three5ive0ero?

 

Yes, that's what I'm referring to. I believe it's literally about a second or so in 5th, but it's been a while since I visited the drag strip.

 

good to know... i might get most of the way through 5th if i upped the gearing.