whats the diff from these two 3.9 FD gears? its bout 400 diff thats alot hehe.. anyone thnks.... btw anyone heard of Kaaz they are a LSD and Diff specialist... thnks again.

 

no difference except the price. central 20 makes good products despite being cheaper. as 4 the diff. wutever u do, dont get a full open, ul regret it if its ur dd.

 

whats ull open? and DD? thnks again.

 

full open is a 2way diff. its strictly 4 the track, and itll cause u hell on ur daily driver (dd)

 

thank ya i will keep that in mind!

 

why would a full open lsd 2.way would suck as a dd???

 

I'm not sure myself, but I've heard the best option to go with is the 1.5. It has to do with how the LSD works.

 

How much if any can the 3.9 gears decrease the 0-60 or quarter mile time? In other words what are the benefits in this to counter higher gas cost with gears?

 

The 3.9 gears give you about a 10% boost in acceleration in each gear. As such, your will lose a little bit of time off your 1/4 mile and 0-60. However, you lose some MPG when cruising because your revving higher in each gear now and you will lose some top speed (maybe 2-3 mph).

 

the 2 way will lock on acceleration and deceleration, if i understand correctly.

 

so u lose 1/4 time,0-60 and gas as well???

 

yup. you can get around .3-.4ish off your et. i started hitting fuel cut in 4th though.. technosquare ecu is coming tomorrow.

 

there is no fuel cut on a Z...you hit the rev limiter

my car lost 0 gas mileage

 

so does the z rev limiter cut the ignition? how does it stop the motor from revving higher?

it felt pretty nasty when i hit the hard limiter

 

it's encoded into the ecu

a reflash, or a utec, can be used to raise the rev limiter

fuel cut happens when you've max'd out the mass air sensor

 

You're mixed up, a 2-way is a diff that locks under decel and accel. An open diff only sends power through the path of least resistance, i.e. the wheel that has the least amount of traction. A 2 way would actually be considered almost fully locked, which is impractical for daily driving. An open diff however is fine for dd but not for performance driving where power needs to be transfered to the tire/tires with the most grip.

 

exactly.

 

1.5 way under 60% lock is bearable for DD but still has great performance gains. 2 way is a PITA apparently for DD or a 1.5 way under like 80-100% lock sucks DD too. Get the Nismo 1.5 way and the central 20 3.9 fd, 350evo is dying, you might never get your stuff.

 

So doesn't the ECU have to cut something (either ignition or fuel) to stop the motor from revving higher?

I'm trying to understand how the stock 350z ecu can stop the motor from revving past a certain point without cutting fuel. Felt like fuel cut to me.