Alternative differential gearing

[cheapscheisst]

hey i'm wondering if there are oem or aftermarket diffs that will fit an s chassis that have 3.7 gearing or below. or, as an alternative, does any aftermarket company produce ring and pinion sets?

[Somnambulist]

What would you need an aftermarket diff for?

Infiniti Q45 also comes with 3.69 gears and should bolt right in. Are we talking S14 or S13?

[SoguRacing]

stock gears on the s13 diff are 4.083 right? so dropping the gearing to 3.69 would give better highway mileage.

[yunk_s14]

stock gears on the s13 diff are 4.083 right? so dropping the gearing to 3.69 would give better highway mileage.



i am wondering the same thing

[slidingsky]

S13 Manual Trans has a 4.08 IIRC the Automatic has a 3.96
S14 Manual Trans had 4.08 as well.

There are plenty of US Nissan Differentials that have lower gearsets. This Mainly includes the 300ZX Q45 & J30 with the 300ZX having the biggest variety.

[g6civcx]

As far as OEM goes, Nismo carries 3.7, 4.111, and 4.364. These items are really just OEM parts rebadged as Nismo products with a higher price tags.

If you know what to look for in the parts catalogue, you can find the exact same parts new for cheaper.

The problem I found was that you're really on your own when you start mixing and matching. You either have to spend money at the dealer or at the junkyard, and fitment isn't guaranteed.

Most junkyards wouldn't even let me open the diff to see what I'm getting. There are rumours that a bunch of cars fit, but I want to see for myself.

So if you don't mind digging through the junkyard to find the right ring and pinion with the right bolt size, then go for it. Report back what you find.

I'm personally thinking of doing a Ford 9" swap to get better ratio.

[g6civcx]

stock gears on the s13 diff are 4.083 right? so dropping the gearing to 3.69 would give better highway mileage.

Not necessarily true. Usually lowering cruising RPM helps with fuel economy, but it's better to cruise exactly at torque peak because this is the point where your engine is the most efficient, i.e. the engine can use less fuel to make more torque for cruising.

[cheapscheisst]

What would you need an aftermarket diff for?

Infiniti Q45 also comes with 3.69 gears and should bolt right in. Are we talking S14 or S13?

it's an s14, and yeah i've heard about the q45, but wanted to make sure it would fit correctly. also, could i transfer my kaaz 2way from my stock diff to the q45? as people mentioned above, i'm doing this for better gas mileage and better top end once i get a larger turbo.

[xkamikazestormx]

btw the j30s are 3.9 not 3.6

[yunk_s14]

thanks for the help

[Ali 556]

HoW To Swap Q45 Into S13/S14 :

http://forums2.freshalloy.com/showthread.php?t=172393

Hope This Help,

Regardas,

Ali

[Somnambulist]

it's an s14, and yeah i've heard about the q45, but wanted to make sure it would fit correctly. also, could i transfer my kaaz 2way from my stock diff to the q45? as people mentioned above, i'm doing this for better gas mileage and better top end once i get a larger turbo.

Not sure about that.. I guess you might be able to since they're both R200 diffs..

Someone else might know for sure.

[952jz240sxr]

i picked up a q45 diff and put s15 internals in there. the gearing was 3.54.
you also dont have to worry about that 12mm and 13mm bolt thing. the q45 uses 13mm bolts just like the s15

[xkamikazestormx]

i picked up a q45 diff and put s15 internals in there. the gearing was 3.54.
you also dont have to worry about that 12mm and 13mm bolt thing. the q45 uses 13mm bolts just like the s15

thats weird. if you used the s15s ring and pinion the gearing should be 4.1

[952jz240sxr]

i have the s15 torsen in a q45 diff. so i have 3.54 gearing

[cheapscheisst]

i have the s15 torsen in a q45 diff. so i have 3.54 gearing

so you're saying that i should be able to transfer my kaaz directly from my s14 drive gear onto the q45 one?