Driving an LS400

[a.Lpha]

I've been working on my LS for a little over a year now... but I'm having a problem with the automatic transmission. It's not that it doesn't work exactly as I imagine it's supposed to, but it shifts so slowly, I can't get any power to the wheels when I want to take-off. I didn't expect it to be able to touch my M3, but even the Acura can eat it off the line. Now I know it's an older car, I'm just unsure as to what little tricks people have found while driving this car, as it's not my only one, though now my favorite and I would like to get more enjoyment out of driving it.

 

[spf_lexus]

here's a few issues an aging LS has going against it:

-Stock trans has a 2000RPM stall speed which pretty much takes out all the fun off the line and lower gears.
-Stock trans has the "lag" because the car was engineered to be smooth and whisper quiet.
-Stock suspension is so buttery a lot of your low end tq gets absorbed by the shocks as they react to the twists.
-LS400 has very mellow gear ratios for great fuel economy and top speed. It will do 150mph if you push it.


Easy way to chop off some 0-60 time:

-Buy a lextreme torque convertor with a 2800rpm stall speed. The TC really makes a large difference for $150. Tighten your transmission's kickdown cable. This is the cable/nut assembly on your TB... tighten the nut until the trans becomes as harsh as you like. It's this cable that dictates how soft/hard the trans shifts and at what RPM. The gear changes will feel harsh but the increased shift speed keeps friction to a minimum, preserving your clutch plates and shortening shift times. If you have heard of a shift kit, it does the exact same job but costs cash!
-Stiffer coils/shocks or preferrably a coilover kit where you can dial in the height/stiffness. Stiffer coils do not neccessary mean the ride will be harsh but it will basically help send more hp/tq to the wheels instead of the suspension play.

 

[spf_lexus]

There's a nice swap that Lextreme himself found by accident. my second LS400 (daily driver) has an SC400 version of the A341e trans found in both cars. Cool part is the SC has more aggressive gears and it's well suited for a heavy car... easily sheds a solid second off 0-60. Only issue so far is the speed sensor is messed up or is not recognized. Every plug fits exactly like stock but due to the gearing it's not communicating correctly w/ the ECU. I get a flashing "OD Off" light that blinks constantly... but really doesnt affect anything. Also if I press ECT on I get a check engine light until i turn it off again. It all points at the speed sensor and I have been too lazy to check it out. i have the original SC400 sensor and need to swap it in to check if it works. if so I found a really cheap mod that really helps acceleration in all situations. Lower MPG may result because of the 200rpm higher cruising speed at top gear.. but not by much.

 

[a.Lpha]

Awesome man, thanks so much this is great!