I think the lack of power, high weight and fact that an already front heavy car will have weight taken from the backend off will induce even more understeer it’s a pointless mod.
I’ve seen a few threads on replacing the rear sway bar to the stock RC350 bar. Problem is rear subframe has to be dropped, but I saw a guy on here say there’s a way to make it fit by removing a few rear suspension components, he claimed he could do it in 2 hours. I Wouldn’t reduce and rear end weight but I’d def install a stiffer rear sway IF I could find out exactly what suspension components had to be moved I’d get my mechanic to try it. A few hundred for the labour and a few hundred for the bar would be a better mod than taking off 50 pounds from the rear, IMO.

 

I agree. And that would be an interesting replacement on the rear away. Probably sharing the general idea with your mechanic would be sufficient.

When I said that would make the greatest difference I was referring to his comment in lighter wheels I believe. But I think the most efficient would be lighter batter. For an extra $100, if someone was interested in shedding some lbs.

 

Buddy removed the 3IS rear seats (~200 lbs) and also replaced the OEM driver seat (~100 lbs) with brides. Not functional for every day, but it does show where weight can be aggressively removed.

 

200 lbs on the rear seats? I'm skeptical I'd think 50-60lbs. Thsts how much most weigh.

 

For sure he’s gonna feel it acceleration wise but he’s making a front end heavy car even more front heavy. Things gonna start understeering like a FWD car.

 

I haven't seen any other posts talking about this, but yes. I think removing unsprung mass (i.e., lighter wheels) would make the biggest different per pound.

 

I don't remember exactly how much, its been a few years, but I was very surprised at how much it weighed.
He also had a huge swan neck Voltex wing, so that probably offset some of that weight

The rear deletion: https://scontent-lax3-1.cdninstagram...32&oe=5E9B177E

Front seat deletes (sorry, Cusco seats, not Brides as I originally recalled): https://scontent-lax3-2.cdninstagram...a0&oe=5E951301

 

I'm not looking to reduce the weight of my 3is, I bought it to enjoy it as a daily and occasionally auto-x it in stock form until my track toy is "done", so below is more or less related to my current & former more track oriented cars.

Weight reduction depends on several factors:
driver/passenger comfort (aka level of NVH you're willing to accept)
budget
intended use (primarily track, primarily daily, 50:50 track/daily)
There is also weight distribution to consider; eg. if you take everything out of the trunk you make the car even more nose heavy which can actually negate the lost weight due to negatively affecting handling characteristics.

First off, if you are trying to lose wight, don't carry anything in the trunk you don't need; you've already got a gallon of washer fluid in the bottle behind the bumper, why keep an extra 8.5-ish pounds in the trunk?

low hanging fruit with minimal impact on NVH:
trunk stuff (carpet, insulation, spare, jack, first aid kit etc.) remove/reduce all of this
engine cover
rear floor mats
lightweight battery

low hanging fruit with a big impact on NVH:
carpet underlay/ gummy seam sealer

low hanging (although expensive) fruit:
wheels and tires - go lightweight; a set of Enkei RPF1's can be had for reasonable money, there are lighter but you pay more
Titanium exhaust with high-flow cats
look at your suspension, anything that is stamped steel look for an aluminum piece to replace it in the aftermarket
larger hollow swaybars

not-so-low hanging pricey fruit:
carbon framed fixed back seats
carbon one-piece driveshaft (not even sure if one exists in the aftermarket currently)

balance:
Have the car corner weighted with you in the drivers seat in "track day trim" (wearing track day gear, and anything removed from the car that wouldn't be there during the track day), work your balance & reduction from there.
move the battery to the trunk, won't save any weight but takes weight off the front end (unless you buy a lightweight battery)
focus on reducing weight at the front of the car before the rear
"speed holes" wherever possible under the skin - need a dimple die press though

track only moves - what can you live without:
rear seat
carpets & floor mats (put deck tape on the drivers side floor)
headliner and all interior trim
dash pad/dash cover
center console
glove box
under-body/wheel well insulation panels (you will want make new panels for aero though, out of plastic or aluminum.)
replace all glass besides the windshield with lexan or other thin synthetic
remove the moonroof and put a reinforced sheet metal panel over the hole
dimple die as mentioned above
excessive wiring (don't need power/heated seat wires in a track car)

You could go real crazy, but if daily driver is your goal, everyone's NVH increase and luxury reduction tolerance is different.
I knew guys that raced vintage stuff; they went as far as to sand/grind down the body panels to reduce weight.

There is also the "gram" approach where you look at something (synthetic leather shift boot for example) and replace it with something lighter, then do that all over the car.

Honestly, you'd be better suited having a dedicated "street legal" track vehicle; a 200-ish WHP track focused NB Miata is going to be way more fun than a 300-ish CHP daily driven Lexus; not to mention the down time when you break stuff at the track, which will happen.

 

lol i've never broke 200 pounds but hitting the gym is never a bad thing

 

no worries, you guys took care of me and allowed me a Brand New 4x Bridgestone Blizzaks including mount/balancing

this made up for having to go to the Auto Parts store and come back becayse I didn't have a tire iron i usually keep in the car

 

Exhaust mods? can you clarify? do you mean adding Aftermarket Exhaust or Deleting mufflers? or something else




if this is 100% on point, i think it would also depend on RWD or AWD

i got AWD so it may be even more heavier upfront

50:50 ratio is too important to me because i want Performance. i rode around with an 18" Wheel Tire and that new Battery in the trunk + all the other OEM stuff and i could notice a difference when i removed the:

18" Wheel and Tire (bro-in-laws)
New Battery



​​​​​​​

Awesome thanks! got some catching up to do, will definitely check those 2 Threads


​​​​​​​

agreed, going from OEM 18 to Rays Engineering/Volk Racing Forged Wheels there was a noticible 0 to 60. Again, since i'm AWD, the staggered OEM wheels doesn't help me like it does for RWD guys




​​​​​​​

it really depends on the Wheel maker. Rays Engineering/Volk Racing make far superior Forged wheels then say another brand

here's a great Video about the extentsive quality control, time, and better materials used by Rays:



i remember my first time seeing a gutted Celica and it was quite impressive how intense he went with it. i like certain things like cup holders...my buddy went FULLY gutted


​​​​​​​

i wonder what Apex means by "Warranty." i wouldn't say you were road coursing with them, just doing day to day things and hopefully Apex will honor the Warranty if it ever comes up


Interested in your progress as well!

yeah man, i went super Detailed showing the differences from OEM Real to Fake/Replicas. I was grateful for the fellow Lexus owner who schooled me on it


not having to shipped helped, i got close to what i was asking and the guy was in-state too. he's got a Lexus going 2JZ or LS1 and he came in his Truck that was packing 400HP+! still gotta get some burnout videos from him




i definitely agree that better Sway bars can literally make it feel like a different car

my 7th Gen. Accord got TL-S sway bar upgrade on front and rear, made the car handle like night and day. RWD would probably benefit even more. being AWD, i've tried my best to make them tires squeal, still trying...lol


pic of my TLS Front/Rear sway bar upgrade plus DC Sport Front Strut Bar. I bet these bars look thin compared to ours or the RC



​​​​​​​

thats significant reduction! i want to keep my Rears for now and i like all the functions of OEM - lumbar, tilt, heat function

Brides are definitly one of the best out there for Seats. wonder if he upgraded his Seatbelt too and got 5 point or 3 point harness





for sure Wheels can make a huge difference. doesn't even necessarily have to be Forged. Import guys tend to like:

​​​​​​​Enkei RPF1's. These in 18" probably still wouldn't clear our Front Caliper and running 19 or higher is too big for me




eyeballing it, i think it would be closer to 50lbs than 200lbs unless he meant everything Rear like Spare Tire, Amplifier, etc.




had to look up what NVH is: Noise, vibration, and harshness (NVH), also known as noise and vibration (N&V), is the study and modification of the noise and vibration characteristics of vehicles, particularly cars and trucks


thanks for being so thorough...i'll try and post weights of different things as i go along

 

Have you already moved the battery to the trunk?

 

moving the Front Battery to the trunk area would help with more equal weight distribution. It definitely will require quite a few additional parts


what i did on my old ride was put a Rear Trunk Battery + Trunk Tray Cover + connected to most of my aftermarket modifications to the Rear Battery. my main reasoning was i did a lot of driving to UT, WY, SD, NE, etc. for work and the extra Battery was a good reassurance in case the Front one failed esp. during Winter

 

Nice! Have you tried to move the battery to the back on the IS?

 

i would perhaps try something new like the 2IS guys and motorcycle or half size Batteries. i would think the Battery would have to be swapped more frequently unless you could get a 5 years Warranty like i had at Pep Boys

i worked for them in the past due to a lot of aftermarket modifications and a couple different large audio systems, i think i used that Warranty about 3 times


one of my main concerns with going with a smaller/lighter Battery is would the frequency to need to swap it out be offset by the MPG even if a minut amount, still counts