BlackZero6

iTrader: (2)

Correct me if im wrong, but this two can be used together

My question is why people dont use these with their turbo'd cars other than losing top speed?

Also I haven't found too much on this but would the same reason apply to a supercharger?

Vinny@VTR

iTrader: (2)

I have it...it makes first gear useless.....lotsa fun when your rolling though

BlackZero6

iTrader: (2)

Thanks noah, I assume youre running the NISMO lsd?

I guess the same rule would apply to a s/c car?

Rickdogg

iTrader: (234)

Yes, it can be used together. The reason why FI cars do not like super short gears is because they want their car to stay in high boost as long as possible, which is why you even see some FI guys going with the automatic 3.3 gears

Alberto

iTrader: (14)

With the power and early TQ you make Noah, have you considered swapping back to stock (3.5) or even the auto FD (3.3)??

OP-reason most dont do this with FI, especially turbo's is because 1st gear will be useless regarding of tire/size in the rear. And for drag racing, it may definetely require a shift to 5th where a stock geared car may finish in 4th (112mph redline at 6600rpm's)

Jason@Performance

iTrader: (11)

There is also a 3.7 gear set option...

BlackZero6

iTrader: (2)

Ok well I intend on going s/c in the very near future, would this be good or bad for me. Being as that a supercharger makes constant boost whereas a turbo makes boost later?

Also what is needed to install the LSD and FD seals or anything. I have 21k on my Z right now so im not sure what is needed. Also should I be concerned if the lSD is used?

Jason@Performance

iTrader: (11)

The NISMO LSD comes with all the side seals and side bearings you will need... you will need side adjust shims for installing the LSD...

For the Ring and Pinion Gear... you will need:

Front Pinion Nut
Front and Rear Pinoin Bearing
Spacer Housing
Adjust Shim
Front Pinion Seal...

all aprts can be found here...

http://mynismo.com/products/?id=5365

BlackZero6

iTrader: (2)

So all of those are needed if I buy the LSD used? also where do I find the shims?

rednezz

iTrader: (1)

Who makes it and do you sell it?

Jason@Performance

iTrader: (11)

NISSAN Makes it and yes we sell it...

BlackZero6

iTrader: (2)

Jason are you able to get the central 20 FD?

Brian@Performance

iTrader: (3)

We actually can get the Central 20 final drive but it takes about 90 days for them to get here from Japan.

dosu350

Can someone give me a link or tell me what a 3.9 compared to whats on a stock z and a 3.2?

Jason@Performance

iTrader: (11)

here is how to do the math...

i worked out the math in a thread...

I did this for the AT guys....


Ok here are my calculations on the gears:


1st - 3.540
2nd - 2.264
3rd - 1.471
4th - 1.000
5th - 0.834


Stock Tire Size 245/45/18 = Revs Per Mile = 756

FD = 3.3
FD = 3.538
FD = 3.700
FD = 3.917


Formula:

RPM / FD Gear Size / Tire RPM x 60 = Speed in MPH


RPM:

3000 RPM in 4th Gear:

3.3 @ 3000 RPM = 72.15 MPH
3.538 @ 3000 RPM = 67.29 MPH
3.700 @ 3000 RPM = 64.35 MPH
3.917 @ 3000 RPM = 60.78 MPH

3.3 @ 6000 RPM = 144.30 MPH
3.538 @ 6000 RPM = 134.59 MPH
3.700 @ 6000 RPM = 128.70 MPH
3.917 @ 6000 RPM = 121.57 MPH

Forumla for other gears:

RPM / (FD Gear Size x Tranny Gear Size) / Tire RPM x 60 = Speed in MPH


3000 RPM in 5th Gear:

3.3 @ 3000 RPM = 86.51 MPH
3.538 @ 3000 RPM = 80.71 MPH
3.700 @ 3000 RPM = 77.17 MPH
3.917 @ 3000 RPM = 72.90 MPH

3.3 @ 6000 RPM = 173.02 MPH
3.538 @ 6000 RPM = 161.42 MPH
3.700 @ 6000 RPM = 154.35 MPH
3.917 @ 6000 RPM = 144.21 MPH


6200 RPM in 1st Gear:

3.3 @ 6200 RPM = 42.12 MPH
3.538 @ 6200 RPM = 39.30 MPH
3.700 @ 6200 RPM = 37.56 MPH
3.917 @ 6200 RPM = 35.48 MPH




The 3.7 gear set works with any rear end that will work with the 3.5 or 3.9 gear set...

So, basicly all you need is a 3.5 6MT pumpkin w/ VLSD or can be used with any Aftermarket LSD that works with the 3.5 gear set...

THe 3.70 gear set is: $480 for the gear set alone... You will also need the same pinion nut, pinion seal, spacer housing, bearing, etc etc just like with the 3.5 gear set...

to date ive done half a dozen of the 3.7 gear sets into auto's...

dosu350

So the 3.9 has more lower end power then the 3.5? is what the z has stock a 3.5? and the lower the more top end power and higher max speed it has?

nareg

iTrader: (1)

manual transmission has 3.5 gears and the auto transmission has 3.3 gears from the factory. but im not so sure those calculations are correct because i always thought 4th gear at 7k was somewhere around 120 mph. ill have to try it for myself and see and what kind of top speed is it at 7k in 6th gear with the 3.9 final drive? just out of curiousity?

dosu350

So what drag racers use shorter gears?

Alberto

iTrader: (14)

If I was NA-Id use shorter gearing. 4th gear on standard Z's runs to 112mph, I trapped high NA and still had plenty left in 4th gear-where as most Z's finish barely into 4th (99-101mph). I would have opted for the 3.9FD and redlined 4th by the end of the 1/4 and picked up acceleration if I had stayed NA. Now that Im FI though, I like the stock gearing, its perfect, I was crossing the line at 7000rpm's in 4th to trap 115/116mph and avoid the shift to 5th. When I get my car back, there is no way Ill be able to avoid a 4-5 shift

BlackZero6

iTrader: (2)

Does the speedo need to be recalibrated on our cars? if so, who can do it?