ls400 boxed lateral arms

[spf_lexus]

I just took off my lat arms (big long ones in the very back of car) to re-grease a bush that never got enough grease and got to thinking about these puny stamped POS's and how much flex they gave. I have a lot of suspension mods on my LS, its pretty stiff and one weak link faces more stress than in any stock situation. These arms are stamped on the top/sides but has an open bottom. What i did was I went to a local metal shop and picked up 3' of 1/5'' thick by 3'' strip of mild steel. I just took some paper and traced the bottom shape and cut out a plate to be welded to the other sides, effectively making this flexy piece a fully boxed arm. The actual procedure is cake if you're a pretty decent mig welder. Just trace a plate thats 2'' short of each end (clearance reasons) and weld in place. I used the sides of plate/flange seam for the welding. What i did since the arms arn't perfectly flat (it has a slight curve to it) I took 2 vice grips and held the plate to that flange that protrudes out at the bottom of the arm... this place is the spot where I welded the whole piece together.

You can see in the pics how I used a vice/vice grips and welded the piece when its held tightly together, this creates a more solid arm, more solidity means less flex. This mod will make a noticeable difference in handling. i used to pull into my driveway at an angle and the car would creek/ flex a little and now you dont feel the arms flexing when all the vehicle weight hits the rear and less body roll.

 

[spf_lexus]

 

[spf_lexus]

here's a few sorry I didnt get a more complete group of pics from start/finish but i got into this one a bit... lost track of priorities :veryhappy:


I was thinking of beading only in one inch sections and use a real mig welder ( dont own one... must beg friend!!) but i just used my basic lincoln electric and it layed a thick enough bead that there is no way in hell these are moving at all. I guess the only downside is the added weight, this isnt a problem for me I will have SC'er soon and weight wont kill me so much but traction/handling will. I might end up adding a small plate around the sides where it bolts up to the subframe for even more rigidity. Tell me what ya think guys!

 

[spf_lexus]

Ok I live near the ortega highway and I just took my 91 LS thru it w/ no back seat w/ these boxed arms up and WOW! the easiest way to describe the improvement is the feeling you get when you swap out stock sway bars for larger ones..... flat cornering. I gave a 2000 Mercedes S500 a nice canyon run and he couldnt get me off his ass until he hit a rare ortega straightaway just for me to catch up in the turns (damn easy if you ask me!) and I have a real rubber issue now, this car is fairly driftable even in its N/A form. wider meat is the next step since I get no body roll when I lose traction, pretty unsafe and unpredictable. You wont have this problem like me if you already have average tire width (I have puny 235/35's). I did this mod for $7.50 and its just the same performance you would get out of a custom arm thats just as stiff for $250+. Overall you add around 2lb to the arms by adding the plate, obviously but its still a easy mod killer IMO.

 

[gmacrae]

Great mod! if i had a mk1 LS id do this for sure

 

[spf_lexus]

Thanks, very happy with the results and how laughably easy it was. I have an entire 1998 rear end and it's THE EXACT SAME as the early 1990-1994 models. I spun mine out and needed all the arms for the rear end and without swapping the 1998 subframe, (to my surprise) it was an exact swap.. I even got the beefier rear brakes yours comes with.

 

[gmacrae]

Thanks, very happy with the results and how laughably easy it was. I have an entire 1998 rear end and it's THE EXACT SAME as the early 1990-1994 models. I spun mine out and needed all the arms for the rear end and without swapping the 1998 subframe, (to my surprise) it was an exact swap.. I even got the beefier rear brakes yours comes with.

So the arms were all the same measurements? Thats sweet. That might give me more options for tweaking/modding the rear geometry (damn toe/camber). I know the subframes are totally different.