350z Final Drive.....

[rmezz13]

Has anyone changed their final drive to 3.9? Seems to be a pretty popular mod in the 350z world. Not necessarily increasing any power but increasing the power already made, transferred to the ground/wheels.... Seems to increase 1/4 times by nearly .5 seconds.... I figure it would be a good mod for people no worried about warranty (me) and is worth the money... Thoughts/Info? I'm looking into this as a mod for me.

[spitalul2bad]

I will be doing this mod the next chance I get (money-wise). It's been said that you should do it together with a new LSD. It's been said that it increases acceleration drastically and is worth the money.

However, you will be losing about 15 mph on the top end.

[rmezz13]

never hit top speed, never needed to.... no one else has any input on this at all?????

[R350Zz33]

were were just discussing this at my friends house today they make a bunch of different gear sets for us

[rmezz13]

i remembered this thread a minute ago and read most of it then emailed the OP to see if he ever tried it. Will post what he says if he doesn't post it himself....

zerothread/345542

Good info which is why i stickied it awhile ago....

[evildky]

intended use of the car plays a huge role in gear selection, keep in mind a higher ratio means that you will loose mpg at the same speed on the highway as you'll have to run a higher rpm to maintain the same speed, I am an autocrosser and find that most courses just don't allow me to use as mcuch of first gear as I'd like, so a lower gear ratio (numerically) will give me additional speed in forst allowing me to use more top end of first where I'd normally be in the low end of second out of the power band

[rmezz13]

i'm not worried about MPG its not my daily and is really just for a hard on which is getting softer by the minute. I just figured:I am looking for faster acceleration on straights and coming out of turns and at higher speeds. I was racking my brain thinking of mods to increase power when i thought "what about final drive"... googled 350Z final drive and checked out a few things for sale and some comments on things, completely forgetting about the other 350z Final drive thread - which is more informative than what i found on anywhere else (NICO FTW), then thought i could increase the thing i want most now for less money and without actually increasing power which actaully is so much more BA than adding power to make it faster.... I want to go for the frontier final (4.3) for the most possible acceleration... Someone have some insight on that besides the thread i previously posted? I kind of want to know if it has been done and how much success it was. Will it bolt right up? Do i have to change the VLSD out for a better dif?

[rmezz13]

Found this, this morning...http://toyboxauto.net/inc/sdetail/12904.08 gears made for our cars.... Anyone in AZ familiar with them? Has anyone on here dealt with them....Looked on Injected Performance and was surprised they had nothing for the 350z/G35 final drive

Anyway looks like $499.99 + $29.95 install kit + $7.50 shipping = $537.44 .... Maybe doing a group buy we could knock them down to $500 shipped? Save $37.44, worth a try.

[spitalul2bad]

Sure. I'll buy this.

[R350Zz33]

i would after i buy tires. i was thinking bout saving up for the stillen headers too.

[evildky]

Do i have to change the VLSD out for a better dif?

how else you gonna put a better diff in wthout removing the old one?

most aftermarket carriers intended for the Z33 are intended to be used with cars that were equipped with factory vlsd (unequal output shaft length)(these interchange with Z32 n/a and 88SS Z31, S14SE) there are some specifically built for the base model cars (they have equal length output shafts) t(hese interchange with the 77-89 Z cars and S13's and non SE S14's as well as S12's)

back to the gear ratio, it all depends, thats why race teams will run different ratios at ifferent track, if you are leaving a given corner int he powerband right now you'll have to upshift to take the same corner whihc means you won't nbe int he power band anymore, if however you are exiting a given corner below the power band a taller rear gear will put you inthe power band for that given turn

most people misunderstand grearing and thing it's gives you mroe power everyewhere, ti just moves what part of the power band you are in at a given speed

[phyzicxz]

awhh man fastest i did with mines is 155 mph.. befor i p**** out.. hahaha changing gear ratio pretty much suck your top end.. especially suck when your trying to outrun cops.. HA

[rmezz13]

how else you gonna put a better diff in wthout removing the old one?

I meant do you have to change it out when you change the final drive....

most aftermarket carriers intended for the Z33 are intended to be used with cars that were equipped with factory vlsd (unequal output shaft length)(these interchange with Z32 n/a and 88SS Z31, S14SE) there are some specifically built for the base model cars (they have equal length output shafts) t(hese interchange with the 77-89 Z cars and S13's and non SE S14's as well as S12's)

back to the gear ratio, it all depends, thats why race teams will run different ratios at ifferent track, if you are leaving a given corner int he powerband right now you'll have to upshift to take the same corner whihc means you won't nbe int he power band anymore, if however you are exiting a given corner below the power band a taller rear gear will put you inthe power band for that given turn

most people misunderstand grearing and thing it's gives you mroe power everyewhere, ti just moves what part of the power band you are in at a given speed

I am looking for faster acceleration in general. If it changes the actions of the car as far as performance in and out of turns then i will reverse it or it just means its time for suspension to go a little faster thru the turn

I appreciate the help evil. I really want to talk to someone that has done this to there 350Z and looks like we have 0 replies as far as that goes....

Sure. I'll buy this.

Please take pics and do a write up on the install. I would appreciate it - start a new thread about it tho and keep us posted about when you buy it and get it and when your installing it, please...

[R350Zz33]

the stick final drive is 3.5 and the auto final drive is 3.3 right? so if i did this my z would have lighting fast acceleration.

[evildky]

mezz, no you don't have to change your carrier to change your gear set, it just might be easier, when changing gears you have to set them precisely or they self destruct

the acceleration gain that comes fomr taller rear gear helps most out of the hole, in drag racing anything you gain in the 60 footer is reflected the long end, so if you take .1 off your 60 foot time you take .1 off your ET, the issue becomes traction, if you have the traction to handle greater holeshot acceleration you get the gain

it will help you through each gear a little quicker but the largest gain comes in first

[R350Zz33]

is that the right final drives for auto and stick ?

[rmezz13]

mezz, no you don't have to change your carrier to change your gear set, it just might be easier, when changing gears you have to set them precisely or they self destruct

the acceleration gain that comes fomr taller rear gear helps most out of the hole, in drag racing anything you gain in the 60 footer is reflected the long end, so if you take .1 off your 60 foot time you take .1 off your ET, the issue becomes traction, if you have the traction to handle greater holeshot acceleration you get the gain

it will help you through each gear a little quicker but the largest gain comes in first

You're the man Dave, what else do you got for me?I have a buddy that is a diesel mechanic and is always in and out of school for auto mechanical things, i'm pretty sure he could guide me through it/do it with me so i am confident in doing this in the driveway/garage.

Richie - i believe mine is 3.4XX and yours is 3.3XX i am not quite sure but i know mine is 3.4 something.... Could be different in 2008 but the gear set i posted is for standard shift cars from 2003-2007....

Oh and by the way, my rear tires are getting close to change time.... Will be needing some this summer for sure. Fronts are in great condition tho so no change there....

[ldstang50]

http://www.fatboyraceworks.com...are=1mezz if your curious what your speeds will be with a new rear end, hit this link up.

[matt_2036]

I would only suggest if you are into autox or track.

The good....It makes your car feel faster and if more fun to drive.It seems to always be in the perfect gear on the trackIt gives you a huge edge in autox that you have to only be in second gear for anyway.You get to shift more.

The bad....You have to shift more.In the quarter mile you actually need to shift an extra time. Atleast with the mods i have I have to. It makes you shift out of 4th into 5th at around 105 if I remember. Out of 2 into 3rd a tad under 60mph even.Gas milage is about 10% worse.It's not an easy job.

[matt_2036]

I have my car tuned which eliminates the governor. With 3.9 gears the new top end is 167. Theroetical top end with the 3.5 gears is like 180 but it would take you to long to get there anyway (assuming you dont have a governor). My car gets to 155 pretty fast....over 160 starts to lug with wing resistance.

[rmezz13]

what are all your mods besides the 3.9 rear end?

[raremotive]

what are all your mods besides the 3.9 rear end?

Hey Ryan... what are you afraid of?

did you know that the Mine's R34 went from a 3.6 to a 4.1 final... part of their secret of fast lap times.

You will achieve both better engine braking, and off line acceleration if you have good traction.

Lighter flywheel is also ideal for faster acceleration and smoother shifts. if you want to read what I wrote: zer...re-hp

[matt_2036]

the stick final drive is 3.5 and the auto final drive is 3.3 right? so if i did this my z would have lighting fast acceleration.

The final drive is 3.3 in the autos compaired to 3.5 (aprox) for the stick due to having diffrent ratio's in each gear, and due to ahving one less gear. The auto's don't work very well when you change the final drive on them from what I ahve heard. You would need to get an additional part, and maybe even a tune.....note total sure. Just like the saying goes, if you want to buy a sports car don't get an auto.

[DWilson]

That seems strange that you hit 5th in a 1/4 mile, I've got an 06 GT with the basics intake, HFC's, exhaust and I barely hit 4th crossing the line at 100mph? How could you be hitting 5th? Even with the 4.083 gears I would only hit 4th?

[raremotive]

[raremotive]

Damn Ryan, you are one missing moderator....