2013FSport

iTrader: (2)

Read at your own risk and IF I build a circuit that disables VDIM with a button push at start up, clearly you are on your own and I am not responsible for anything you do!!!

Anyway, because the E-brake and foot brake are on off switches it seems it would be pretty easy to build a circuit to mimic the pedal dance needed to disable VDIM for one drive interval. I've made other timing circuits one of which is DRL switchback for the street bike. If I do this, I'll toss a schematic and part list up. It should be relatively non invasive. Power on with ignition, a ground, and two taps for the brake systems.

I'll keep you posted as I dig into the solution.

LXMEUP

Sorry, are you referring to the Pedal dance that disables all traction control?

I did the dance and gave the car a caning, with the open diff it was still kinda boring.

I wish they put a tighter LSD in it that would let me throw the car around a lot more on the track.

2013FSport

iTrader: (2)

Stupid system is annoyingly aggressive. Cross braking over a simple turn in the road. But ya, I need more facts but I'm looking for a donner 3rd member w 4.08 gears and I'll toss an LSD in there to minimize down time.

Just curious if there is a desire for a push button solution.

andper10

FYI on all 2IS years except for 2006 you can fully disable traction control and VDIM by holding the TRAC OFF button (next to the ECT PWR switch) for about 5 seconds when the car is not moving and it will stay off until you turn the car off. There will be two separate orange lights on the dash once you have held it long enough. You can also swap a used part pulled from a 2007+ car to a 2006 car for around $150 to gain this functionality if desired.

Also something similar has been discussed here but never implemented as far as I know: https://www.clublexus.com/forums/is-2nd-gen-2006-2013/784817-traction-control-off-by-default-is-this-possible.html#post9040743

andper10

I track my IS350 with the stock diff and it is definitely not boring but it would be more fun with an LSD. The 2010+ ISF LSD fits in the IS350 but you need to change the final drive gears to 4.08 from an IS350 diff. There is also an available LSD made by OS Giken but it is expensive and requires shaving down the differential case (pumpkin) for installation clearance. IS250 owners can get a used Subaru BRZ / Scion FRS LSD for a lot less money.

Agreed, the stock system will cut all throttle for at least 2 seconds if you slip the inside wheel slightly when turning onto a feeder road with 50mph traffic from a stop which is a recipe for getting rear-ended. You can install a 2011+ ISF power steering ECU (part number 89650-53041) to gain access to the less intrusive traction control (and to get better steering feel) when running in ECT PWR mode but the part costs around $500 new.

https://www.clublexus.com/forums/is-2nd-gen-2006-2013/844400-isf-steering-ecu-upgrade-on-is250-350-a.html

2013FSport

iTrader: (2)

Thanks guys... I've done a bit cross compatible checks. The bearings, spacers, input/output yokes and stuff all seem to be the same. The LSD: 41301-53051 is used in:
IS-F, RC-F, RC350, 300, 200T, LS460... If it does fit, perhaps there are other options out there for less cash??

But I haven't found for 100% certain it drops into our 350 housing.... More reading to do.

andper10

It does according to this thread:
https://www.clublexus.com/forums/is-2nd-gen-2006-2013/747848-is350-limited-slip-diff-options.html, but I would leave it in the ISF housing if possible since it has more cooling fins according to this post: https://www.clublexus.com/forums/is-f-2008-2014/835457-rc-f-differential-into-is-f-3.html#post9650588

P.S. Welcome to the limited slip differential rabbit hole

2013FSport

iTrader: (2)

The LSD: 41301-53051 is used in:
IS-F, RC-F, RC350, 300, 200T, LS460....

Looks like this is an option too: 41301-53050
But stay away from this: 41301-53040, open diff from early IS-F...

LXMEUP

for tracking the car, is there not a way of shimming up the current LSD to lock it down a little more?

bazzle01

No lsd fitted.