Retrofitting Mechanical Limited Slip Differential (LSD) 08-09 ISF
08-22-09, 01:21 PM
#17
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Anything is possible with lots of labor and an unlimited budget. The skid control ECU is so incredibly simplified, you would need to replace the wiring harness and the skid control ECU/brake actuator (they are now a single unit with a single connector) in order to get the new goods. I just broke out both wiring diagrams and they've cut the number of wires by 2/3 when they integrated the ECU into the brake actuator. There's no easy way you're going to "upgrade" from the 2008 version to the 2010 version. At least if youi own an '06 350, if your skid control computer goes out, the replacement gives you all the functionality of the '07 - '09 IS350.
08-23-09, 08:16 AM
#20
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6. Differential
The rear differential has been changed from FD21A type to FD21AT (TORSEN* LSD) type.
*TORSEN is a JTEKT registered trade mark.
The rear differential has been changed from FD21A type to FD21AT (TORSEN* LSD) type.
*TORSEN is a JTEKT registered trade mark.
Lets keep our fingers crossed on this one..!!!!
Joe Z
08-23-09, 06:15 PM
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The other good news about this is the IS350 guys could order the spool and put it in their cars too. Lexus should get smart with this and make it an F-Sport part.
08-23-09, 06:23 PM
#23
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From what you see, is the LSD (spool) going to be something we (IS-F owners) can order as well??
or
Is it going to have to be a FULL Differential swap out???
LSD untis were any easy swap, back in my early Mustang days...
Joe Z
08-23-09, 07:07 PM
#24
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Can't say 100% with Lexus trying to reduce parts count, but they appear to be swappable from looking at the service manual. Unfortunately, there are no details about bearing ID/OD or possible small differences in the cases.
If you do plan to do this, you'll need to engage someone with a talent for aligning ring gears. There's a whole selection of snap rings for positioning the spool correctly and making the teeth mesh with the right pattern. Not something for the average home mechanic as tolerances are held to 0.02mm (0.0008"), and you'll need a small array of SSTs for the job.
If you do plan to do this, you'll need to engage someone with a talent for aligning ring gears. There's a whole selection of snap rings for positioning the spool correctly and making the teeth mesh with the right pattern. Not something for the average home mechanic as tolerances are held to 0.02mm (0.0008"), and you'll need a small array of SSTs for the job.
08-23-09, 10:50 PM
#26
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Me too! I always felt that this, lack of LSD is what made the F a little more difficult to handle than the m3 (i didnt say less fun though!) But having it instead of a faux LSD is much better. Besides, the v8 motor we have in the F craves this!
09-03-09, 07:44 PM
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Hi guys, I've just been discussing the LSD issue with some guys at TOMs in Malaysia, and everyone here seems to be right on the buzzer. Retrofitting a mechanical is the easy part, its the flashing of the ECU to get it to work is the difficult bit. However, and I think this is a big BUT it is entirely possible.
Im just not sure im willing to try it just yet. We'll wait for the 2010 ISF reviews + see if any aftermarket parts appear based on the Torusen model that is in the 2010.
Im just not sure im willing to try it just yet. We'll wait for the 2010 ISF reviews + see if any aftermarket parts appear based on the Torusen model that is in the 2010.
09-03-09, 10:58 PM
#29
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Hi guys, I've just been discussing the LSD issue with some guys at TOMs in Malaysia, and everyone here seems to be right on the buzzer. Retrofitting a mechanical is the easy part, its the flashing of the ECU to get it to work is the difficult bit. However, and I think this is a big BUT it is entirely possible.
Im just not sure im willing to try it just yet. We'll wait for the 2010 ISF reviews + see if any aftermarket parts appear based on the Torusen model that is in the 2010.
Im just not sure im willing to try it just yet. We'll wait for the 2010 ISF reviews + see if any aftermarket parts appear based on the Torusen model that is in the 2010.
but in Japan..
One is the Tom's LSD unit (1 way).. $2,040. USD
The other is an OS Giken LSD unit (1.5 way).. $2,700 USD
There is hope...
Joe Z
09-03-09, 11:09 PM
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Maybe, i should make more friends in Japan, owing that I Go there really often because i'm the vice chairman of the Kyokushin Karate Committee in Malaysia. Japan beckons... for more than JUST karate now lol. When i do go, ill give you guys the heads up and see if i can get stuff for you!
JoeZ, that looks awesome. There definitely is hope then!
JoeZ, that looks awesome. There definitely is hope then!