4.08 or 3.90 gear questions...

bleunetizen

I personally think the FD swap needs to be done depending on what your requirement is, on which track/road course or whatever..

while the shorter FD increases 1st gear launching and give you out of the hole G force, you need to remember that you will have to shift earlier, and depending on what kind of power band you will be sitting in which gear, the FD might actually make your car run slower because you will be out of your power band earlier, just as you would be in the band earlier. Depending on which gear you will be in most of the time, this may help or hurt your results. But shorter FD generally makes the driver a bit more busy/alert which is always fun and I think that helps with lap time.

Back in my 350Z days started almost 10 years ago, people were craving about 3.9 FD set (stock is 3.5 in 350Z) and I got that swapped out when I was doing the LSD. The track I went to quite regularly was pretty much spot on for the 3.9 because I could run in 3rd gear all the way in the areas where I had to use 2nd and 3rd gear. But in some other cases, I had to shift a lot more and it seemed to eat up my time. With shorter FD It seemed more frequent to fall in to the band where it was awkward to either stay in gear or shift up.

You need to remember, while a car with shorter FD will accel faster when compared to a stock geared car gear to gear, 3rd gear to 3rd gear for example, shorter car's 3rd gear will be accelerating slower than stock cars 2nd gear and if you happen to shift into 3rd where stock cars can stay in 2nd - you are losing.

Not sure how 4.1 would feel.. probably a bit too short? I found 3.9 somewhat short already, but that's compared to 350Z's stock 3.5 FD. However the extra HP of 370Z probably will make it feel a lot shorter.

Funny how we cant really settle with the stock settings and always try to make it slightly different in the hopes of improvement. Even if the cars came with 3.9FD people would still try the shorter gear

I gotta try the same track with my 370Z, only recently got the car and haven't had a chance to visit a track yet.