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In the end it all depends on the use of the car, if it needs a bunch of engine or suspension mods. Is it for some form of competition? Then yeah maybe. But then some mods can also add unnecessary weight as well. If its to be used as a towing vehicle then yeah the suspension may need some big time mods as well as the whole drive train.
But for a car to drive here and there, its all such a waste of everything.
So am not performing these modifications for competition.
Increasing (torsional) rigidity of the structure improves ride quality (reduced NVH) and improves handling. The suspension is performing the work instead of body flex.
It was reported LS430 torsional rigidity increased 30% over the 2000 LS400.
Does anyone care to understand how that was accomplished...
A clue... I learned something...
There seems to be little creativity on the LS400 forum and when you elude to this effort as a waste...I agree.
It is indeed a waste of my time to post information if the concept does not register with the recipient.
All automobiles have their deficiencies...
Toyota does many things well, but not all.
They did enough only to be better, but did not perfect the design from this author's perspective.
In the end it all depends on the use of the car, if it needs a bunch of engine or suspension mods. Is it for some form of competition? Then yeah maybe. But then some mods can also add unnecessary weight as well. If its to be used as a towing vehicle then yeah the suspension may need some big time mods as well as the whole drive train.
But for a car to drive here and there, its all such a waste of everything.
I think for the vaunted ride tech it has it sure could corner a lot better.Im leery to blast the LS400 hard into corners,yet I would take my 1975 Jaguar XJ6L into corners at 50% higher than posted and she just bit in and did it,no drama at all.Lets hear applause for big fat soft Michelin tires.
Originally Posted by YODAONE
All automobiles have their deficiencies...
Toyota does many things well, but not all.
They did enough only to be better, but did not perfect the design from this author's perspective.
I agree with YODAONE on this point,FWIW.While the LS400 is a FINE car,they made their fair share of mistakes.We all can list several and all will agree thats true. They also made compromises,fuel economy vrs weight vrs gov mandated safety features,even Toyota had to answer to that reality.
I would bet,all else equal,Yodas car out handles any pure stockers out there.Is it YOUR cup of tea,clearly not for many,but I just flat out love it.
Its just the old statement no one likes "what ever". I guess I don't like to hunt for projects since I have plenty of them. I just know for normal driving on "speed limited" everyday roads we all drive on that a stock un modified LS works just fine. Its not a waste of time posting good ideas that others can use for the correct applications. Its just a waste of time for some of us to even dream of changing the torsional strength of the unibody of the average LS400, and besides its debatable if making a stronger torsional strength body will improve a ride quality, usually its the less strong "spring" (<--- descriptive) that is going to give the smoother ride.
And YODAONE, your not wasting time posting here even us ones that think its a waste of time doing some of the mod stuff, we still appreciate your inventiveness and ideas you have posted here. And many of your ideas are also great for non LS applications as well. Keep up the good work.
yea i definitely appreciate you taking the time to lay this all out, and like i said if bracing the crossmember really improves handling and nvh out it's certainly something i'm interested in
The arrow stamped onto bracket suggests that it should point towards the front of the vehicle...
Here one was installed backwards.
Upside of bracket has arrow stamped nearest oblong through hole.
A closer view of bracket..the oblong hole allows for rapid fitment in a production line environment. The oblong hole suggests the bracket does not serve in a push-pull mode (no evidence of fretting or shifting), but in torsion.. I am able to twist bracket a few degrees with my bare hands...
Just get er done man. It's all about what you want out of it... No one has to agree, it only matters that you get what you want from it. I'd be interested because although i'm not trying to make my car a cone carver, i'd like the idea of enhancing it's ability to take a curve with less roll. Especially for pleasure driving on curvy roads.
I'd be interested because although i'm not trying to make my car a cone carver, i'd like the idea of enhancing it's ability to take a curve with less roll. Especially for pleasure driving on curvy roads.
I agree.While a highway cruiser par excellence,Im remarkably underwhelmed with its manners on the twisty's,nothing special at all.
"Advantages of Increased Torsional Rigidity. In the simplest terms, vehicles that have high torsional rigidity deliver a superior ride, superior handling and better response to driver input. Improving the torsional rigidityof a vehicle allows the suspension to work more efficiently and predictably."
Bottom image of LS400...Numerous points to fortify. Have acquired a supply of automotive grade two-part closed -cell structural foam to be used in front and rear bumpers...and am contemplating use in the hollows of unibody frame rails. Will significantly reduce NVH and appreciably improve handling.
Have you done any FEA on that part to see if there's an actual improvement to be made? Toyota spent 1 Billion producing and developing this car with some of the best engineers in the world. I doubt boxing it is going to do much but add weight and add NVH. Plus, how do you know that that part of the suspension is purposely made that way to "give" when the suspension cycles?
If everything was rigid, you'd get much more NVH into the cabin. Take the poly bushings that people like to swap in place of the rubber strut rod bushings on the front arms....horrible choice because people think they can get a part that lasts 3x as long but don't think how bad the vibrations are when the suspension cycles over small bumps that normally wouldn't have been felt with the factory part.
Also, on your photo, it looks like the mounting point is starting to get pretty rusty, I would address that before strengthening anything, as that could be another possible failure point. Need to cover all your bases first and make sure that suspension member is structurally sound first.
Located this information online relating to increased NVH by stiffening chassis.
So the author seems to suggest ride will not degrade but that a flexible frame offers a more cushy ride...
The 2001 LS430 incresed torsional rigidity 30%, with lower profile tires, yet the ride is more serene.
I suppose it matters how and where you increase rigidity...
Secondary treatment will fill the boxxed braces with automotive grade two-part closed cell polyurethane foam so braces absorb and transmit less NVH between structures...
Located this information online relating to increased NVH by stiffening chassis.
So the author seems to suggest ride will not degrade but that a flexible frame offers a more cushy ride...
The 2001 LS430 incresed torsional rigidity 30%, with lower profile tires, yet the ride is more serene.
I suppose it matters how and where you increase rigidity...
Secondary treatment will fill the boxxed braces with automotive grade two-part closed cell polyurethane foam so braces absorb and transmit less NVH between structures...
Yes, but the suspension on the LS430 is probably different. I can't install LS430 shocks/struts onto my LS400..so changes were made in the mounting, geometry and most likely materials choice to get that effect to happen.
1995- 2000 (1990-1994?) LS400's use stamped braces (labeled #52295 in Lexus exploded parts diagram) to increase rigidity and reduce flexation of the rear suspension cross member (labeled #51206A in Lexus parts diagram)
The project here is to box in the brace therby increasing it's torsional rigidity.
Some images depicting the brace on vehicle.
Lexus parts diagram depicting front and rear crossmember. and rear suspension member brace.
The rear suspension member brace is a stamped part that is prone to twisting. Boxxing in trough will significantly increase torsional rigidity without much expense. Will post after images. May elect to fill the modified brace with automotive grade closed cell foam for NVH reduction....in fact, the rear crossmember assembly appears comprised of large diameter formed hollow tubing that could be filled with automotive grade foam to reduce NVH ..
Braces after boxxing, but before painting
Excellent fabrication and welding by Vector Fabricating in Chicago The upper plate was machined parrallel with bottom plate at bolt through hole so flange bolt clamps uniformly.
Vector welded a spacing block between upper and lower plates at through hole to avoid compression bending where fastener clamps bracket..
Original bolt is M10-1.25 X 20 hex head bolt zinc-plated with captive washer. Adding upper plate necessitated increasing to 30mm length. Purchased JIS M10-1.25 X 30 flange head bolt, grade 10.9 from McMaster-Carr . Perfect fit.
The flange head bolt offers increased clamping area over OEM hex bolt/ washer
i could be reading this post wrong but my last ls400 ucf10 had these braces and some in the front modified when i bought it, mine look to be a manufactured piece from another car not a custom OE one like yours.
I didnt realize it untill i was parting the old car and i swapped the "modified" braces to my new LS
I go drifting all the time and noticed less wheel hop at a familiar track and a longer lasting alignment with these modified ones,however other things were modified at the same time i installed these so who knows
04-09-18, 07:10 PM
