2014 IS350 F sport rear gearing swap
12-23-21, 06:42 PM
#1
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2014 IS350 F sport rear gearing swap
Hey guys,
Tried to find something on this subject, but nothing came up. I'm interested in swapping the rear diff out for something with more aggressive gearing to give my car better low end response. I had a 2007 IS350 before my 2014 and the 6 speed auto had a 3.52 first gear vs the 2014 8 speed autos 4.59 first gear. However, the 2007 definitely felt faster through first and second than my 2014 does. This also being proven by the 2IS350s having better 0 to 60 times than the 3IS350 does, despite having a more aggressive geared and faster shifting transmission and being roughly 40 to 50 lbs lighter. Of course, the 2IS had a 3.76 rear differential ratio, whereas, the 3IS has a 3.13 rear differential ratio.
Is it possible to direct swap a better rear differential from, say, a GSF or something? I dont remember where I saw it, but I thought one of the nicer Torsen rear diffs in one of the F cars had a 3.73 rear gear ratio and could swap right into an IS350 F Sport? I think having a 3.73 or close to the 3.76 rear diff ratio that my 2IS had would really wake the car up down low.
Thoughts? And yes, I came from mustang's where this was a common mod and it makes a huge difference.
Tried to find something on this subject, but nothing came up. I'm interested in swapping the rear diff out for something with more aggressive gearing to give my car better low end response. I had a 2007 IS350 before my 2014 and the 6 speed auto had a 3.52 first gear vs the 2014 8 speed autos 4.59 first gear. However, the 2007 definitely felt faster through first and second than my 2014 does. This also being proven by the 2IS350s having better 0 to 60 times than the 3IS350 does, despite having a more aggressive geared and faster shifting transmission and being roughly 40 to 50 lbs lighter. Of course, the 2IS had a 3.76 rear differential ratio, whereas, the 3IS has a 3.13 rear differential ratio.
Is it possible to direct swap a better rear differential from, say, a GSF or something? I dont remember where I saw it, but I thought one of the nicer Torsen rear diffs in one of the F cars had a 3.73 rear gear ratio and could swap right into an IS350 F Sport? I think having a 3.73 or close to the 3.76 rear diff ratio that my 2IS had would really wake the car up down low.
Thoughts? And yes, I came from mustang's where this was a common mod and it makes a huge difference.
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FSporting (01-07-22)
01-07-22, 05:27 AM
#3
Good question. Wonder if the 3.76 ring and pinion from the 2IS would be a direct swap?
01-07-22, 04:15 PM
#4
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I may have to just try it myself. I'm surprised that noone does this. Having a more aggressive rear gear ratio can improve low end acceleration alot. It's almost like adding another 40 hp and it's not an expensive mod to do.
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01-10-22, 05:46 AM
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03-12-22, 05:29 AM
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03-16-22, 03:49 PM
#12
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2is final drive is 4.08 , and the F cars are 2.9 . But if you're curious , the rear diffs should be interchangeable. I have a friend of mine upgrading his 2020 diff (3.13) with a gs350 diff (3.76) final drive . If all goes well i will update you guys!
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kaleo211 (03-16-22)
05-23-22, 01:49 PM
#13
Adding to the above, it sure looks like the 3IS AWD also has 3.77 gears as they kept the A760H 6spd trans from the 2IS. The three digit code is "225".
FWIW: there currently one on fleabay if someone is interested.
Swap time should be less than a 4 hours if you pop one axle free and lower the diff. No need to disconnect rear suspension. It's just extra work.
2IS 350 RWD is 4.083:1
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Polo2is350 (05-23-22)
11-15-22, 06:23 PM
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any update on this? Or even the OP? I have an 2020 RC350 RWD interested in doing the same to fix the 0-60 woes as well. Since the IS350 and RC350 powertrain wise are pretty much the same, would mean I have the 3.13 as well. Was thinking of fitting either the 3.76 or the 4.08 final drive. I think i’ve read somewhere that the whole housing just interchanges, though this *might* just be hearsay.
