I've found a number of threads interesting as they relate to lightweight fx rx7's:
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-light-can-you-get-fc-what-more-can-i-remove-856588/
https://www.rx7club.com/race-car-tech-103/adding-lightness-lll-438477/
https://www.rx7club.com/race-car-tech-103/adding-lightness-ll-418976/
https://www.rx7club.com/race-car-tech-103/adding-lightness-407951/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/continuing-what-does-stuff-weigh-196297/

Here's my contribution (all from an 87 TII)...

speaker box over rear strut tower, with insulation, with cover, no fasteners
RH 4.0 lbs
LH 4.0 lbs

driver's door panel w/o fasteners, w/o power window switch
8.0 lbs

passenger door panel w/o fasteners, w/o power window switch
8.6 lbs

driver side quarter panel molded carpeting, has some small brackets attached
1.8 lbs

rear bin w/ fasteners
RH 3.6 lbs
LH 3.6 lbs

drivers side fiberglass support for rear bin
3.0 lbs

rear carpet with mat underneath
13.2 lbs

rear jack, cover, fastener, jack handle
3.8 lbs

aftermarket manual retractable antenna w/ wire and nut
0.2 lbs

passenger side fiberglass support for rear bin w/ fasteners
3.4 lbs

passenger side quarter panel molded carpeting
2.2 lbs

carpet padding under bins (both sides)
3.0 lbs

misc pads under bins
1.4 lbs

glove box lid and screws
1.8 lbs

passenger side sun visor, clips, screws
1.2 lbs

ashtray, cigarette lighter
0.2 lbs

AC compressor (this is off a 2000 LS1 v8 engine)
14.2 lbs

AC compressor bracket (ls1)
2.2 lbs

condenser (unknown make/model)
5.8 lbs

accumulator, hoses, fasteners, pulley, belt
2.0 lbs

front strut tower covers (both sides)
0.2 lbs

arm rest console w/o lid, security light, mirror switch
1.2 lbs

aftermarket alpine cd player
4.2 lbs

passenger side lower dash w/ speaker
3.8 lbs

security box/brain from passenger side lower dash, misc fasteners
1.0 lbs

speaker, cover, misc fasteners from driver's side lower dash
1.2 lbs

 

I put the car on Longacre scales today. Should be pretty accurate.

Without driver, 1/2 tank of gas:

Total 2589
LF 724
RF 705
LR 574
RR 585
Front 55%, Rear 45%

With driver and gear:
Total 2806
LF 787
RF 729
LR 672
RR 616
Front 54%, Rear 46%

 

good info

 

I spent some time pulling the front end off to remove the front bumper support. Here are the *real* weights...

bumper support 10.8 lbs

2 support brackets with fasteners 4.6 lbs

2 support tubes with fasteners 0.4 lbs

total weight savings from pulling out front bumper support 15.8 lbs

I removed my sunroof, and I'm working with a guy to have a fiberglass plug made. I can confirm the sunroof, with the brackets, motor, seals, etc was 27.8 lbs.

 

Dam. I like the sunroof, but I already will not fit with a helmet in the car, and it doesn't really work. Almost 30 pounds at the uppermost point on the car? Bye bye.

What do the S5 seatbelt tracks weight? Or the stock NA steel hood?

 

Logicon ventilation controller 1.4 lbs
Blower motor 6.3 lbs
Heater core + box 6.0 lbs
Blower motor relays and wiring jumper 0.4 lbs
Radio surrond, upper vents, idiot light bar, trim 1.8 lbs
2 (of 3) horns 0.6 lbs
Inner door seals 1.4 lbs

Total 17.9 lbs

 

Said goodbye to another 43 lbs:


6.4 driver's side door inner structure (cut out with angle grinder)
6.4 passenger's side door inner structure (cut out with angle grinder)
8.2 passenger's side door glass
8.2 driver's side door glass
6.2 driver and passenger window motors
4 passenger side window seal, window trim and tracks, door handle
4 driver side window seal, window traim and tracks, door handle
43.4

 

Passenger seat, oem T2, manual 33.4 lbs

 

instrument cluster 2.4 lbs
instrument cluster hood w/ switches 3.0 lbs
defrost dash cover 3.3 lbs
dash wiring harness 1.6 lbs
dash 20.4 lbs
ventilation mixer box behind dash (w/o heater core or AC evap) 9.4 lbs

 

Does this prove That the lsx does throw off the balance of the car?

 

It proves that taking 40 lbs off the rear with a lexan/fiberglass hatch, plus removing the spare tire and 100% of the interior back there affects weight distribution. It's not a daily driver, so it's inappropriate to compare some of the changes I've made to what would be more "normal" results.

Since I weighed it, I've added an accusump (in rear), removed headlights, bumper cover, sunroof, and dash, changed to a larger radiator and oil cooler. I would expect the distribution has changed. Later this year, I plan to add a 6-point cage. When I re-weigh it after that, I will corner weight it until I'm satisfied.

Also note the car started off with 183 hp at 2,849 lbs (15.56 lbs per hp). It currently sits at 2400 lbs with 398 hp (6.03 lbs per hp). Safe to say the performance and dynamics of the car have changed drastically.

 

New weight = 2407 lbs

This is without driver, roughly 4/5 tank of gas, no corner weighting. Some of the funny x-weights showing up are probably related to less than perfect weighting conditions - sloped garage floor, dropping the car onto the pads rather than driving it, etc.

 

NIce! I wonder how much my car weighs. Ill find out soon