Originally Posted by JaE35

I'm assuming it's going to be pretty hard to find a 3.7 for the right price...is there a big difference in the 3.5? Currently have the 3.3

Originally Posted by 4D05G35

I'm not sure how much the 3.7's run, but I ended up spending about $200 including new fluids. So that is something to also factor in.

Originally Posted by DaveB

Agree to disagree

I've got a set of 23.5" tall drag radials which give my car an effective gear ratio of around a 3.55 (car had the 3.34 gear set at the time). On same day at the strip, I did four runs with the 26.3" tall OEM 17s and 3 runs with the DRs, which were also 15lbs lighter each than the 17s. The car did consistent higher 14.4s and lower 14.5s@97-98mph with low 2.2 60 foots with the 17s. With the DRs, the car did consistent lower 14.5s at higher 96mph with mid 2.1 60 foots. It never could break into the 14.4s. The car was quicker off the line, in the 1/8 mile, just the same as the 17s at the 1000' mark, but the killer was the forced shift to 4th about 150 feet short of the finish. It crippled both ET and MPH.

Years ago, my friend had a 90 LX 5.0 nothback 5MT. It was basically stock except for a catback, pullies, and hacked airbox. It came stock with 3.27s. It did 14.0s@98mph with the stock gears. He then added 3.73s. The car totally woke up and felt awesome in 1st, 2nd, and 3rd. After that, acceleration tailed off. With the 3.73s it did 14.2s@97. 60 foots were better, it was quicker in the 1/8th, but since he had to run through a lot of 4th, the car slowed down. The 3.73s were just too much gear for that 5.0 that peaked at around 5000rpms. No problem though, he added a heavier breathing cam, intake manifold, valvetrain stuff which extended power to around 6500rpms and it was doing mid 13s. With extra breathing allowed the motor to fully use the deeper gears.

The only reason I went with the 3.54s in my G was because I wanted snappier daily driving, more gearing would help in the auto-x (sub 65mph racing), and I wanted the LSD (huge help in the auto-x). I haven't been to the strip in 2 years. I may try it again with my DRs which would effective gear the car to a 3.75.

Some cars come from the factory woefully undergeared. The 98-00 Cobras are prime examples. They come with 3.27s, but the motor makes good power in the mid to upper rpms and revs out 7000rpms. The long gear don't allow the motor to get into the meat of it's powerband quickly nor fully exploit the powerband. Adding a 4.X series gear will easily shed .3 seconds and add 1-2mph in the 1/4 mile. The G and Z aren't those cars, at least with stock cammed VQs. Nissan did a pretty good job gearing these cars for strong acceleration while trying to maintain some MPG sanity. There aren't many other V6 sport luxury sedan/coupes out there that perform as with just 260-280hp. Since these cars are already decently geared stock, they don't make significant gains when adding deeper gears. They definitely feel quicker since there's more torque multiplication therefore seat of the pants acceleration 'feels' more impressive. Put that feel under the clock and you'll see that the two don't necessarily agree. My friend's 5.0 felt downright brutal in every gear. It felt far quicker than 14.2s. All that torque multiplication mislead the mind.