Yeah, and this is kinda what I assumed given the amount of moog inner tie rods: the difference is model year based and not sport vs nonsport. This would explain what people have had issues reusing their inner tie rods as the threading (or w.e. else) was changed while the outers just don't seem to matter.

I really, really reeaaalllyyyy think the rack has different tooth pitch but that isn't being clarified by any store (would also explain why there are multiple full systems being produced concurrently).

This would also explain why the pinion is exactly the same for every model under the sun.

 

Here is the sedan 14.7 rack for 2011+ model years:
49200-JK62D

Using the 6MT option gets you there and shows you the correct racks.

This rack is specifically labeled for sport/sport premium g37's sedan 7AT and 6MT.

 

Yes and no. if you look at the interchanges and compare it to others it lists all rwd trims if you compare.

The when you look at the diagram 49200 is the part number for the rack alone. 49200 is ALL RWD racks.

One thought that crossed my mind is that this improved steering ratio might not be an improved STEERING RATIO but and improved steering angle by force of tie-rods

The ratio would be related to internal components vs angle which is dictated by externals.

I'll get some more info on this, hopefully dig up the more pics from the rack change i might have a pic of the rack. I compared the pinion of the since it was the easiest and it was exact.
Would it then be possible for the rack to be the difference with less teeth? I was under the impression like differentials that pinion would have to match the ring/rack for it to work however in a solid bar I take it wouldnt bind like a ring and pinion.

Would a rod with more or less teeth on the shaft improve this ratio or would it give the rack more steering angle?

Unless we can find visual proof of this from a Manual Sport rack I just can't see the change being in the pinion since ALL RWD pinions are the same part # and sold as unit so unless the shaft having less/more teeth is the actual change something tells me this ratio is more angle than ratio.

 

One of my previous posts shows diagrams of changing the steering ratios with different rack tooth pitch using the same worm/pinion gear teeth/pitch.

As for the steering angle, considering the knuckle used for all models is the same, so they have same distance from outer tie rod connection on the knuckle to center of steering axis (being the center point for tire rotation laterally, aka turning), the only way to change the steering angle would be to have different rack lengths (which could In theory provide more lateral force from the rack, but more on that in a min) , which would put us back to there being a difference in the rack itself, teeth or otherwise.

Lets assume the rack is identical across every model: we then have a constant distance between the knuckle outer tie rod connection and the racks inner tie rod connection. The only way we would be able to change the steering ratio is changing the force direction from the rack to the knuckle.

​​​​​​Imagine a circle on an x/y axis with a line down the center, parallel to the y axis. Next, place a point somewhere on that line. Next, connect a line to that point that is perpendicular to the y axis (parallel to the x axis). Now imagine the original line rotating about the center of the circle, with the second lines outer point (the one not connected to the original line) is fixed relative to the y axis but can move freely along the x axis, and the point connecting both lines together is free to move anywhere within the x/y axis so long as it stays connected to the first line at its original point. What you will see is that the the restriction on that second lines outer point to stay fixed to the y axis makes changing the rate the first line impossible. The only way you could theoretically do that is if those two points had varying rotations themselves, which a ball joint (inner rod, outer lines point) and pivot point (outer rod, point where both lines meet) do not have. They have fixed frictions and can not vary along their rotations.

Here is an example:


if we imagine the wheels in this are actually the top of the tires, and that rack in the middle is our steering rack, then as you can see, with a fixed length between the rack and it's connection to the tires, there is no way to change the ratio or steering angle given a fixed rack movement (aka, same rack for all models). If the point connected to those wheels was moved closer to the center, then you would absolutely change the steering ratio, but would consequently change the fixed length of the combined tie rod length.

Sorry for the long winded explanation, but basically, if we assume the rack lengths is identical across all models and the knuckle is the same across all models, then the combined inner/outer tie rod length is the same. Thus, the only way to change the steering ratio is with a different rate of movement from the rack, which can only be achieved through a difference in teeth and/or their pitch.

​​​​​​​I wholeheartedly believe there is a difference in racks if the pinion is exactly the same across all models. I think Infiniti are a**holes in their if differentiation of the rack and pinions they sell, and I feel bad for everyone who had their steering racks replaced by any shop as the chance they got the correct ratio is hilariously small.

 

I did some research this weekend and it wouldn't surprise me if this whole endeavor is specific to my car. You see my vehicle is a 2010 4WAS and as I was looking at the specs it doesnt talk much about the 4WAS specs. This tech was released in 08 for the V36 so I had to go back to those years and I found in the specs the 4WAS has a variable steering ratio. This ratio variates from 12-20:1



This is 12-20 ratio is being operated by a "16.4" ratio rack and I've never thrown a 4WAS lights for errors. I have thrown lights in the system before.

I know in the 4WAS there is an actuator in the Steering Column that gives dances with the rear but I wonder if this whole ordeal is specific only to my case.

In reality I have a 16.4 rack being controlled by the 4WAS to be whatever ratio is commanded. I was under the impression anything sport should have had the 14.7 however it seems like this is mainly closer to 6MT sports only.

There's a lot of info here to check.

Im checking Service data sheets between the 09 sedan (only ones FSM has 4WAS info) compared to other coupes Sports as well and theres just no clear info of the "sports ratio" everything seems to be:

2wd with or without 4was
2wd sport and or 4WAS
AWD

 

Here's what I've found so far:

2013 Coupe

 

2009 Sedan

 

Both models share:
Steering gear model
Fluid capacity
Steering wheel end play
Wheel turning force

Steering angles:
Seems like it's broken into 2WD/AWD only and it being the same from coupe to sedan as long as they share drivetrains

Column length

Rack stroke is different
2WD 69.0 (2.717)
AWD 17 inch tire 65.6 (2.583)
AWD 18 inch tire 64.9 (2.555)


Rack sliding force is different

Rack stroke is divided into 2WD and AWD no mention of sport or 4was

Inner socket (inner tie rod)
length is different
Coupe 2wd - 63.2mm
Sedan 2wd 50.8 mm
Coupe AWD 54.2 mm
Sedan AWD 51.8 mm

 

You could actually test the lock-to-lock yourself when just barely moving (to make it easier you your arms and pump). Given that they report the turning radius is the same, it would makes sense for the lock-to-lock on the low end(2.20) being less rotations on the steering wheel with 4was (rear wheels will be pointing the opposite direction, giving you the smaller ratio). How accurate of a way of testing this is, not sure, but it would give you some idea of the rack.

The rack sliding force is noted for 4was and sport models as being the same, same goes for the pinion torque. I imagine this is because they both use the same pump (as you had noted earlier I believe).

the 'inner socket length' is not the length of the tie rod itself (I suppose the short lengths make that obvious), but from the edge of the boot placement ridge to the edge of he lock nut when installed into the outer tie rod. Just used as a guide to make sure the rack is as centered as possible before toe is adjusted. (You probably saw this in the fam as well)


​​​​​​Another nail in the coffin for tie rod length having any meaning as a differentiator. As another user did and I had suggested, just screwing in the inner to outer gets you the same result.
And just to add on top of this. In your own photos of the tie rods, you can clearly see that the ridges for the boot are in the exact same location. Hence, this measurement applies to either style and has no bearing on inner socket length. What we have seen are issues of people not being able to find tie rods that fit into their racks (there is a thread on here about someone asking and the same place where that guy just just screwed his inner in further) because of different threading and size.
To those people, moog's website does actually specify between between sport and non-sport to a degree in the actual part listing. As an example, the 370z inner tie rod fits these racks:



2008 G35 inner rods:

G37 sedan 2011-2013:


Etc...etc...

Found here:

https://www.moog-suspension-parts.com/category/infiniti_g37/front-inner-tie-rod-end
So clearly there is some different and it seems to be the threading size on the rack side, no necessarily for sport and non-sport, but it can be.
​​​​​
also, this thread of someone saying they swapped in a 370z rack into the m35 and saying "you will need the z inner tie rods which are 18X1.0mm vs 16X1.0mm in the M" (https://forums.nicoclub.com/370z-steering-rack-install-rules-t591532.html).

Whether 4was uses the sport or non-sport rack, I'm not really sure. But I think there needs to be an update to your posts concerning the difference between the two as people have already taken your advice in ordering base model racks to replace their sport racks, thinking they will still have their same steering ratio. There is enough evidence at this point that the tie rods have no bearing on the steering ratio and that he rack itself, whether from the teeth or otherwise, is at the center of the difference.

​​​​​