I am wondering if there any of you that have had the evo3.9 final drive installed. I know there are a few posts regarding this, but I would like personal opinions and feedback with the driveability, gains, installation/fitment issues if any, just an in depth overview. I have been leaning towards this mod and would want some final feedback before I order them. Thanks guys!

 

Its a great mod. No downside. Drives about the same, just pulls harder. The key to being happy with this mod is finding a good installer. Other than that I say go for it. I've had mine for about 8 months and wouldn't go back.

 

A fantastic mod! Here's an in-depth thread I posted after install a couple months ago......hope it helps...........

http://www.350zmotoring.com/forums/s...ht=final+drive

 

+1 on Zillinois' comment... the key to the whole thing is in the installer... i tried to have it done locally, it was screwed up, and i'm out a bunch of $ for labor and the parts were destroyed...

2nd time around, i had 350evo do it themselves... that is def. the way to go!

 

Thank you to everyone, this is exactly what I needed, I am sure there are others in the same boat as I.

 

a little bite off topic, but whats the top speed with this 3.9 final drive?

 

anybody have any good recommendations for an installer out here in the los angeles county area?

 

In theory, I had read before that the 3.9 loses about 10-15 MPH top end at redline vs. the OEM final drive. The exact MPH will vary depending on stock ECU w/6600rpm redline or re-flashed ECU w/ 7100rpm redline. I've only had my Z to 150, so can't speak for more than that............with the 3.9 gear & TS re-flash (7100 redline), if my memory is correct, I was at 150, 6th gear, approx. 5700 rpm - was still pulling at 150, but let off...........

 

I think I recall that Performance Nissan does them - I know they sell the 3.9, so I'm sure they do installs as well. Regardless, make sure the installer has experience in rear end modifications/installs & have ALL the Nissan shims in stock - never know which ones are needed until the re-assembly takes place. Just check with Jason @ Performance - I'm sure they do it.

 

did you mean you hit 150, and still got some rpm left from redline with your final drive?

 

For those with this mod, I'm curious how badly it has affected your fuel mileage. Anyone notice lower mileage?

 

Yes - still had about 1100 rpm's left before redline @ 7100. If you look back at the thread I posted above on the install, I posted a chart that someone had done on the mph with the OEM vs. 3.9 vs. 6600 redline vs. re-flash redline. It's pretty close to exact from my playing around up to 150. If you remove the topend governor (which the re-flash does) it is calculated that the Z with a 7100 RPM redline w/ 3.9 gear could hit somewhere around 170 or so - yikes! Need to try that one of these days - hahaha...........

 

As I posted on the above link, I lost around 2 miles per gallon on my trip up to Cincy for the install vs. the trip back after the install. I drove the same speed there & back. The main loss in MPG, however, will occur driving around town - the 3.9 makes you want to get on it everywhere - ha! Fun, fun, fun!! At 80 mph in 6th, the 3.9 gear will raise your rpm's approx. 300 rpm. Previously around town & highway, I used to ave. around 18.9 mpg on a full tank - it's down to around 16.9 mpg on a full tank now - city & highway combined. But worth every penny

 

i'm not gonna worry anything beyong 155, since the fastest i can go is around 150 on the front straight of the track.
guess i really need to try these.
thanks for the info btw.

 

lol, my MPG-display read 7.8mpg the other day after a quick reset and WOT run to speed limiter... -- wonder what else i can do to get the lowest economy possible

I still average 25mpg on trips (6th gear crusing at ~80mph)... with the 3.53 it was about 29mpg...

but as stated above, the new gears make you want to get on it everywhere, and that is really why your gas mileage goes down, because you're WOT everywhere (small, grid-like cities are like tracks )

 

Exactly!! Hahaha...... I did a reset one day and hit it hard thru first 3 gears and hit a 7.9mpg - what a gas-hog!!!!

 

How do yall think this gearing would fair the Z up against the M3 in stock form or basic bolt-on's ?

 

if i can find an M3 that wants to go at it when i get back from kentucky next week, i'll let you know

 

Thanks man! My prediction is if yall go from the hole he will hook up faster than you and you should be able to walk him down. But on the roll I think you will walk away from like a 60-130.

 

yeah, launching with the tilton can be a b*tch, but i'm getting better (Zillinois has it DOWN! -- see the vid )