GodISmE

Guys, will this combo be optimal far my track car (08 HR)?
Is this 3.9 FD any good and will be ok on a track: https://conceptzperformance.com/niss...33_p_14604.php

Which flywheel would you recommend?

Anything I should take into account when installing all this at once?

vegasanthony

iTrader: (1)

Nice choice.. On gears
I would ask if you daily the car
That is too say does the car see street time if so how much
Any plans for FI??

GodISmE

It will be mainly a track car although I would probably be driving it to work occasionally so only short trips.

I already have the LSD but I haven't decided on the gears yet, for example 3,9 or 4,08 or maybe I should stay stock? The only problem I've noticed is too low rpms in a lot of 3rd gear corners on many tracks.

I don't know which flywheel to get yet, should I go for the lightest possible? Alluminum or steel?

Dblock55

iTrader: (4)

^^^ 4.08 or nothing at all!!!!
Ha im just playing, 3.9 is a very common choice. Most people will tell you 4.08 is too aggressive especially if youll be street driving it, drone will be annoying. I have the 4.08 and love them... Most people will say if you're ever planning on going FI dont do the 4.08 as you will be shifting more often and not taking full advantage of boost. If you're planning on staying NA id recommend the 4.08 but the 3.9 is a good choice too... it really depends on the tracks in your area really. Do you have massive straightaways? If so, top speed could become an issue with 4.08.

As far as flywheels ive been told that the z will actaully lose some power on the top end if too much rotating mass is taken out of the assembly. This is from a member who's gone thru several flywheel combos and has laptimes to back it up. I have a JWT aluminum flywheel but dont have much seat time behind it as my car is still torn apart. Your car will definitely build revs faster with a lighter flywheel but there is a break even point for the top end power somewhere... wish we knew what the sweet spot was.

Good luck!

GodISmE

I have decided to get 3.9 FD. Do they cost around $500 like this one?
https://conceptzperformance.com/niss...33_p_14604.php

Still not decided on the flywheel so looking for advise from someone that has one and tracks their car regularly.

terrasmak

iTrader: (8)

I will mention that the OS unit is set for stock flywheel. Talking to OS they say that flywheel weight directly effects the way the diff functions out of a corner.

It's cheap to have a custom setting for it when you order the diff, talk to them and take advantage of it

GodISmE

I already bought it some time ago. How can I tune it now to work with a 14lbs flywheel? What will actually be affected if I install it the way it's set up now but with a lightened flywheel?

EDIT: I've checked with OS Giken and they are saying that the original tune should be fine with <400hp car.

GodISmE

Will this flywheel by ok for NA track car?
https://www.z1motorsports.com/z1-pro...el-p-9154.html

I don't think I should go for the aluminum ones so I'm looking for the lightest steel flywheel.

Also, I probably need an upgraded CSC, right?