hey adam, this is david...jp's friend. i remember talking to you about the gearing, whether or not to buy jp's 3.7. i just purchased my 3.9 but my concern when talking to you was if you using nitrous would affect your shifting and make your gears too short. if not, then go with 3.9 but if so, then reconsider. does anybody on here drag with notrous and uses a 3.9 gear? this would be good to know. also, talk to andy at performanced nissan, he has a 3.7.

 

I can't honestly answer as I don't drag race nor do I have any experience with Nitrous, sorry

 

acceleration change ~= to cube root of the torque [tire/road] increase.

Don't confuse with 1/2Gt^2 because we want instantaeous acceleration NOT AVERAGE ACCELERATION

http://www.stealth316.com/2-fwp.htm

 

Does anyone know the exact top speed of each gear with a 3.9 FD? I remember one of the guys from 350evo posted a chart a while ago, but I can't seem to find it through search.

 

What RPM? For the HR, 7500 rpm shifts:


Engine speeds in top gear:-
30 MPH = 1169 RPM 40 MPH = 1558 RPM 50 MPH = 1948 RPM 60 MPH = 2337 RPM
70 MPH = 2727 RPM 80 MPH = 3116 RPM 90 MPH = 3506 RPM 100 MPH = 3895 RPM

Top Speed in 1 gear = 40.134 MPH
And changes into 2 gear at 4591 RPM dropping 2909 RPM
Top Speed in 2 gear = 65.564 MPH
And changes into 3 gear at 5237 RPM dropping 2263 RPM
Top Speed in 3 gear = 93.894 MPH
And changes into 4 gear at 5880 RPM dropping 1620 RPM
Top Speed in 4 gear = 119.771 MPH
And changes into 5 gear at 5906 RPM dropping 1594 RPM
Top Speed in 5 gear = 152.109 MPH
And changes into 6 gear at 5925 RPM dropping 1575 RPM
Top Speed in 6 gear = 192.543 MPH


For the revup/non rev up(with raised limiter) @ 7000:
Engine speeds in top gear:-
30 MPH = 1169 RPM 40 MPH = 1558 RPM 50 MPH = 1948 RPM 60 MPH = 2337 RPM
70 MPH = 2727 RPM 80 MPH = 3116 RPM 90 MPH = 3506 RPM 100 MPH = 3895 RPM

Top Speed in 1 gear = 37.459 MPH
And changes into 2 gear at 4285 RPM dropping 2715 RPM
Top Speed in 2 gear = 61.193 MPH
And changes into 3 gear at 4888 RPM dropping 2112 RPM
Top Speed in 3 gear = 87.635 MPH
And changes into 4 gear at 5488 RPM dropping 1512 RPM
Top Speed in 4 gear = 111.786 MPH
And changes into 5 gear at 5512 RPM dropping 1488 RPM
Top Speed in 5 gear = 141.968 MPH
And changes into 6 gear at 5530 RPM dropping 1470 RPM
Top Speed in 6 gear = 179.707 MPH
************************************************************ ******************************

 

Just got the 4.08 gears installed... Drove it for a little back to work. Really can tell a big difference going from 1rst to 2nd.

I will give more driving impressions tomorrow.

Todd

 

3rd and 4th pull oh so much harder on my HR too

 

Just did a quick run to grab a bite to eat... Yep, 3rd to 4th are really improved.

Lets just say i use spin the tires from 1rst to 2nd shifting fast, Now.... I roast them

Going to do some quick shifting from 2nd to 3rd on the way home from work tonight. See how that works for me

I will write a nice little review tomorrow

Todd

 

First time I shifted to 2nd at the track on my one and only run (launched from ~1700 cause of my clutch issues) I hit 2nd and went sideways

I hook a lot better on the 275's in the back now, but still break them loose

Put up your review, I'll add my comments to it

BTW, still on the stock LSD? My nismo lsd is much much nicer than the stock viscous.

 

See this thread

https://my350z.com/forum/showthread....97#post4390297




Todd

 

Already seen

 

i wanted to add one more question... i know people say you should go with a 3.7 or 3.9 with a supercharger but when i get my vortech tuner kit and crank out around 400+ to the wheels and than add another 100 shot of nitrous... isnt that going to be a little much for the 3.7 or 3.9??? am i going to be better off just staying with the 3.5 or what do you guys think?

 

Superchargers put out very peaky powerbands, hence the shorter gears help more than the longer gears.

 

ok... as i have heard, but what about with the added kick of nitrous???

 

would very much depend where the nitrous is kicking in (ie is it rpm dependant, TPS dependant etc)