Bish_Z33

Hello I have a 2008 350z AT with these mods,
Injen Intake
Ported Upper Intake Manifold
Ported Lower Intake Manifold
Megan Headers
High Flow Cats
Invidia N1 Cat Back
I have not yet got it tuned but I want to know where I can go from here mod wise before or after the tune
preferably not FI because it is expensive

mr. sparco

iTrader: (13)

Rear lsd diff with 3.5 or 3.69 final drive. Will make your AT accelerate faster than all of the parts combined, better yet complement the mods further.

Bish_Z33

Thank you for the suggestion ive actually wanted to do this with the only thing holding me back is my lack of knowledge on the subject.
1.How does this effect gas milage because this is my daily until im able to get a another car?
2.what difs do you recommend?
3.how hard is the job?

bealljk

iTrader: (13)

I think it’s time to tune …

You can swap out your differentials if you like (it’s not a bad suggestion) but for the money (especially if youre watching where you spend money) it’s not worth it (if you ask me). I believe the 5mt has a 3.36:1 final drive? Going to a 3.5:1 or 3.7:1 isnt going to make a massive difference … especially with an AT where you’ll be shifting between gears that much more.

It wouldnt effect fuel economy too much - you might see a small drop in MPGs but that’s most likely you getting into the acelleration more than the mechanical disadvantage.

What diameter-size are your intakes?

What else is there to do on the HR manifold?

Who are you going to tune with?

jhc

This. The difference between the OEM 3.3 final drive and a higher gear will be profound for acceleration.

1. You may go down 2-3 mpg bc slightly higher rpm for given speed.
2. A good economical option is the 6 speed OEM LSD. They pop up on FB Marketplace for $120ish.
3. The skill level would be advanced as you have to lift 80lbs above your face, also the bushings need to be pressed out and replaced. A shop will charge around $500 to
R/R but you will smile every time you sit down. Then spend $500 and get tuned with UpRev. You won’t be disappointed!

Bish_Z33

Thank yall for all the help, after looking into it, it does not seem like a hard job and that I would be able to do it myself along with installing new poly bushings.
But Im pretty sure I have to use a AT dif because I have a AT and lengths change based on trans.
And were should I get it tuned,E tuned, dynoed(DFW)
The topic of tuning confuses me because I don't know what I need so I cant say how much itll be.

jhc

Ah, good catch. IIRC you'll need to remove and insert your AT axle stubs into your LSD pumpkin so they match your axle bolt pattern. As far as UpRev tuning in TX ima hand this off

@travlee

Bish_Z33

Yeah, so Im going to get a 3.692 LSD for a AT and it should just be plug and play.

But is uprev really the only option when it comes to tuning?

travlee

iTrader: (8)

Uprev is pretty much the go to. If I were you, and you can, I would road trip to Austin to have uprev do it.

Local choices are PRT performance in Lewisville. Steve khan (big in rx7 world) tuned my car there

Or Brice at Alamo Autosports in Arlington

Bish_Z33

How much was the tune at PRT

travlee

iTrader: (8)

Back in the day it was $700.....but that was 10 years ago

travlee

iTrader: (8)

And they use a mustang dyno....prepare to have feeling hurt some, they read lower than dynojet

Bish_Z33

Im not able to find a 3.692 lsd dif with the flange"yoke" that I need,

Is the differential yoke easy to change from the triangle to the circle


The dif from a manual g has the same companion flange as my AT 350z, are they compatible or would other parts need to be changed.
The g AT difs have the triangle flange so would I need to get that then change the flange

mr. sparco

iTrader: (13)

6MT manual, regardless of Z or G, rear diffs have a 4 bolt flange while all 5AT diffs have 3. You will need to swap out your flange so that you can run the 370z/G37 3.69 diff with your 5AT.

You can find vids on youtube and there are some old threads on here. You'll have to do some digging.

Going from 3.3 to a 3.69 is a significant improvement with the 5AT.

Bish_Z33

The issue is that I have a 5AT but a 4 bolt flange, I can swap the flange but ive heard that there are clearance issues with lengths so im confused on which dif to get.

Syner

"Where do I go now?"

Craigslist.

Bish_Z33

ah yes , still dont know what to look for

Syner

Whoosh...

mr. sparco

iTrader: (13)

Maybe you might already have a non-original diff from the previous owner?

Bish_Z33

is there a way for me to tell a difference between difs so i can tell if its different or not