YODAONE

LS400's have excellent body integrity but the rear quarter panels would respond well.to additional vibration dampening..

Design improvements were incorporated over the evolution of the LS400, but options remain....

The 1999 LS400 employs a token patch for NVH (noise, vibration and harmonics) control as applied to the rear trunkside skin of the quarter panels.

Simply knocking on the quarter panel suggests this accomplishes little.

Acquired three sections of 12.5" X 24"" Boom Mat 4mm thick to remedy the problem

Material is Butyl with Aluminum scrim.

Applied one full.sheet to each quarter panel vertical plane and half sheet immediately above wheel well arch.

After application, no hollow beer can sound... solid like a 1/4" steel.

A test drive supports NVH reduction.

Rear tire noise less discernible and NVH transmitting from rear quarter panel to roof panels is reduced.




Factory dampening on right..not very substantive.

Losiracer2

How much weight does that add?

YODAONE

5 sheets weigh about 15 pounds.

Sligtly over 2 square feet/panel.

Used 1-1/2 sheets per quarter panel = 9 pounds for both.

About 60% coverage of rear quarter panels.

93LS500

after i radiused my rear fenders and cut up the inner wells i added the window seal spray can foam stuff from home depot and now no rattles or smoke in the cabin and when my door shuts it sounds like a freakin vault door....THUD i dont think it added any weight either maybe a pound or 2

YODAONE

Auto structural engineers are using automotive grade foam to improve torsional rigidity of the chassis with the added benefit of NVH reduction.

Used correctly foam offers benefits...however two part foam (catalyst ) is preferred in automotive production to promote curing in enclosed areas.

Closed cell foam is appropriate to prevent water absorbsion

Carefull using Home Depot stuff

RA40

iTrader: (6)

Good job YODAONE. Way back when the car had the noisy BFG tires I went in to see what could be done about some of the road noise that would reverberate up through the wheel well arch. They don't have much to absorb there so this will remedy that. A local installer had some thin stuff that I applied around the arches and top deck which helped to some degree. I wasn't willing to pull the C pillar to place some in that area.

I've not felt the LS400's were all that quiet to some cars. I must hear or have different expectations of "quiet".

93LS500

I have used the 2 part foam in the past for other car modifications and there is no way i could have filled the cut up inner fenders and it would have made a huge mess. not to mention it cost way more, i did both my rear fenders for $8.00 and was super easy to use.

I could be wrong but a/b foam also weighs considerably more than the expanding foam i used and i wasnt trying to strengthen anything or increase rigidity... may not matter to some people but i have a fully stripped LS with lexan windows and stuff.

its been in there for a few years now and no problems yet