Just got my 3.9 final drive from Performance Nissan and they don't do installs. They referred me to Performance Gearing in Irwindale. Anyone have experience with them? Any other recommendations?

 

I had mine done at Street Image in Balwin Park.

 

How long didi the install take. This guy at Perfomance gearing said 2-3 days.

 

2-3 days? How much would that cost?

 

if u can take off ur diff i can do it for u in ONE morning.. iono if we can take off our diff tho.. never looked xP

 

what will the 3.9 final drive do?

 

Do a search...it's been discussed in depth.

 

Make you accelerate quicker and take away top speed. i figured id sum it up for you...

 

Your driveshaft will rotate 3.9 times to one rotation of the tire...eaiser to spin up the motor

 

Did u loose crusie control?
Did u loose that Comfy Luxury Feeling of the car?

Cuz i was planning on doing it too!

 

thanks...... much appreciated....

 

Dieselnuts pretty much nailed it, but i thought id emphasize a lil more.

1. Your car will accelerate or pull much faster, but also shift sooner because every gear is shorter. 1st gear will go by really quickly.
2. You will lose cruise control, due to the ECU not being able to adapt to the new gearing.
3. Your mpg will lower by about 2-3 mpg. This happens because you will be in a higher RPM in every gear, due to the shorter gearing. The higher the RPM, the harder your motor works, the more fuel you burn.
4.Your top speed will lower by about 10-15 mph. This occurs to the shorter gearing. You sacrifice top speed for faster acceleration. This doesn't really bother most people, because no one really tops out their car every single day. Top speed is about 165 for the coupe, your new top speed with the 3.9FD will be about 155.
5. Buck for buck, this mod is the best bang for your buck. You will lose about
.2-.4 seconds off your 1/4 mile time, and also shed about the same off your
0-60.

This 3.9FD isnt good for FI cars. For one reason, 1st gear would basically be useless, as you will not be able to get traction. If you have FI, taller gearing (3.2 out of a 5AT) would be better, as your able to stay in your powerband longer and also gain in top speed.

 

thanks chillibowl.... i was doing a search, not too much about the specifics... so thanks for that.... now what if i have a 6MT? is there a benefit as great as the 5AT? and would i still do myself a disfavor if i was planning on going FI?

 

No, all i posted was based on a 6MT. The gains on a 6MT are higher than a 5AT. If you were to go FI after the 3.9FD swap, im sure you could find someone with a 5AT to swap their gears with yours.

Also, 350evo is not the only one carrying these gears now.

http://www.z1auto.com/prodmore.asp?m...ne&prodid=1726

 

Unless your running slicks... Seems like it would be perfect for runnin the 1/4.. the lower gear would def make up for the TQ loss, and spool up the turbo or Supercharger a lot faster... ohh I had 4.56 in my Mustang hahaha. Ok im just bustin Chilibowls chops.. he is correct for street applications.

Good luck with the install.