when you say that the base seat weighs 42lbs, is that per seat or for both

per seat

Is that 21 pounds for each CAT ... ?

Also why is this thread buried in the Brakes & Suspension Section ?

Pretty sure that's for both from when I was handling mine.

21 pounds is for both cats, because Stillen HFC are 11 pounds for 2, a savings of 10 pounds. Read that in either this thread or in another thread.

Question: Has anyone weighed either the front or rear bumpers? With all of the bumper swapping I would hope somebody has weighed them. I checked through this thread (again) and couldn't find bumper weights.

Correction: Berk HFCs are 11 pounds/pair. Stillen might be also, but it was Berk that advertised that weight. Sorry.

Does anyone know if there is a tire weight website like the wheel weight site?

Tire manufacturers usually provide weights on their own sites.

Just curious, but anyone know what the factory side mirrors weigh?

After reading the first pages again I saw mention of lighter lug nuts.

It reminded me that on my Porsche 951 the wheel lugs are made of magnesium and are extremely light. So light that when I first took them off I was pretty impressed.

I googled and found a few links:
BLOX Lightweight Lug Nuts - Lug Nuts
Lug Nuts

Well I'm not gonna knock anyone for hyper-optimizing on weight, seeing as I do it a lot myself :), but the lightweight lugnuts really aren't a big deal. Sure they're rotating unsprung mass, but since they're way to the center they don't count as much as tires or the outer rim of the wheel itself. That and even "normal" short straight-through lugs aren't much heavier than lightweight alloy ones.

I'm not sure if this was mentioned already in this thread, but anybody have the weights for the stock, stillen, whiteline, etc. sway bars (front & Back)?

Have any of the buyers of the new MotorDyne Shockwave E370 exhaust weighed it before installing it? Or were you all too excited to get it on? Please post weight here if you did. Thanks!

^ I think I read somewhere on here its about 10lbs lighter than the OEM exhaust.

Has anybody heard of or used Tomioka lightweight batteries? They come in 6, 12, 15, 17 and 21lbs. I may buy one of these if I hear some good reviews on them. Pretty good weight savings..

Lightweight batteries - Products

^ I'll have to research them. I can get the Odyessy batteries right down the street and always in stock. The Braille batteries, I've been hearing lots of bad crap with them.