Lighten up this beast!

[The Flea]

I've gone through 5 frame off restos and 2 full guttings. In that time I've reached a few conclusions about weight.

1) You can't make a big car light and lots of weight will render all of your hard work and money spent on an engine program useless. I used to bracket race with a guy who had seriously 1/2 the torque I had, but his car weighed 1000lbs less and was still faster by 3-4 tenths. When you're doing 8's, this is like an eternity...

2) A few lightweight items can add up to a lot saved, but not usually. The reality is that the weight is built into the car. The 62 Tempset I used to race literally has thicker steel then the Toyota I'm building. Massive efforts were made on my Toyota to save weight from the factory, whereas Pontiac was concerned no one would buy their car unless it looked heavy.

3) It's still better to spend money on shaving weight because it only happens once, whereas an engine program requires money everytime you step up. But, at first only shave weight if it's huge gains. This is really impractical for a Lexus owner.

I hope this doesn't come across arrogantly. If you're new to this particular area of the industry, I hope it saves you some time and trouble.

One more thing. Your Lexus has an auto, you won't save any weight with a lighter flexplate (flywheel for automatics) they're very thin and light to begin with.
Carbon driveshafts are stronger than steel or aluminum. Filimant wound carbon has been used in missile tubes for years. It is incredibly strong. All of the big dollar operations use them.
Light bolts and nuts are a waste.
Glass is thinner and lighter nowadays, so use polycarbonate in extreme cases.

If you want to go fast, start with al light car or have a mold made from your entire LS and have it vacuum bagged using carbon fiber. This should only be about $30K

 

[turboandrew]

Good points by "the flea". Remember, this is a luxury car. What compromises do you really want to make here? Getting rid of things like A/C, PS, stereo don't seem like a good idea -might as well start with another car. IMO, I would do the easy stuff first, no spare or tools (fix-a-flat), lighter but comfortable seats (like cloth ones from a Supra non-turbo or RX7), and anything lighter on unsprung weight, like light wheels (but not larger ones), light tires, lighter coil overs like tien CS, brake conversion with lighter aluminum calipers and rotor centers.

 

[LEXUSV8NZ]

Well actually there are carbon driveshafts(most people know about them through Gran Turismo on Playstation)
They are used widely in JGTC (***anese Grand Touring Cars) behind 5.0L Lexus based V8s putting out around 500hp(restricted to 500 in the GT500 class) these engines run twin throttle bodies with restrictor plates, in Supras

Logan

 

[retrodrive]

I am currently working with this one company that may have a 1st gen LS CF hood on the market.

Things to do to make the car lighter: Replace front seats with lighter ones, replace 22gallon gas tank with a 10 gallon fuel cell, lighter suspension, lighter brakes (4piston Rotora), cut out the floors in cabin and trunk and replace them with honeycomb aluminum.

These are the things to do for starters.

 

[Zuffen]

The Flea is right about weight.

Top race teams used to use Boron for brake rotors before cabon fibre ones. They only cost US$3,000.00 each and lasted for a race.

I wouldn't replace the tank with a smaller fuel cell but I would suggest not filling the tank. If you keep 5 gallons in there and not 20 gallons you have saved 150lb. And its free.

Of interest how much do you weigh? If you weigh 300lb I would suggest a diet. Again its cheap and will lighten the car. Remember you are part of the car when it is being driven.

To save the last few onces go to the gents before going for a drive.

Heavy cars require heavy suspension, brakes etc to control/carry the weight.

The lighter you can make the all up package (sensibly) the faster it will be around any track or down a strip.

 

[retrodrive]

I wouldn't replace the tank with a smaller fuel cell but I would suggest not filling the tank. If you keep 5 gallons in there and not 20 gallons you have saved 150lb. And its free.

What you are forgetting is the weight of the gas tank itself as well as the fact that larger tank with less fuel will allow gas to come to one side of the gas tank at turns; thus, putting a lot of weight on one side.

Heavy cars require heavy suspension, brakes etc to control/carry the weight.

Wrong. Good aftermarket suspension is lighter then stock. Same goes for brakes. How do I know? Because I have both on my car and I had a chance to compare the weight personally.

 

[persian451]

just sell the LS and buy a SC or a GS and do a 2GZE swap that will make it lighter

 

[Lextreme II]

My philosophy is this. Lets not spend the money on the weight reduction modifications, if in doubt increase horse power to make the hp to weight ratio. It would too much money to reduce weight, but rather increase HP. Lets face it, Lexus LS400 WAS NOT meant to handle well. Its a cruiser... If you want better handling, get a NSX.

 

[xirforever]

I half agree with you and half don't.... I agree with putting more money on HP gain instead of weight loss. But when you talk about the LS not being ment to handle well, your right, doesnt mean we cant do things to make them handle better. I know my shock tower support beam helps the car handle a ton better. And lightening the car up will let you go faster while handling better and reducing stress on various parts of the car. There is always the obvious, take out that spare tire! lol But maybe your right, maybes its not worth the trouble. All i have to say is i have to work with what i got.

 

[The Flea]

I like what's been said by everyone and agree with a lot of the points. Here's a couple other things to throw in the mix.

Engines have their own duty cycles. My old Pontiacs made peak torque at only 3800 rpm. (Most modern engines can't run with the A/C on until 3800rpm). All things being equal aside from the displacement, you'll have to lean on that 244ci 4L Lexus motor a lot harder to make the hp. Granted it has state of the art engineering, but you get the picture: Smaller engine + heavy car + the desires to go fast = you to push the little 4L pretty hard. No big deal right? Well, after a while you'll notice that you're going through parts maybe a little faster than normal. Or maybe you just can't rely on it holding together for as long when pushed over and over.

I guess another thing is go to some drag races and look at what other cars are doing when they pull out the stops. This is the dream stage.

Then look for similar cars (heavy stock sedans with limited displacement) and then see how fast they're going. This will give you a reality check.

Set a course and go for it. You'll feel better about the idea of massacring a LS400 when you're on track to some low 10's vs low 14's.

 

[Pro]

hehehe.

why lighten the car and lose the luxuries when you can make 1000hp on AVGAS / twin turbos / stroker bottom end and make a mockery of 4000lbs....!

co$t is a factor...but hey, who's counting?

 

[jibbby]

I am currently into weight reduction so I will attempt to list other weight reducing or transfering mods..

-Stock battery to light weight performance battery and placed in the truck (maybe save 5-10lbs plus the weight is transfered to the rear)

- Deleting the hydro fan, pump, motor, shroud, oil cooler, lines, hoses, fluids, etc..Swap in Electrics 25-35lbs off the front end...

- Of course Carbon Fiber hood and trunk...What maybe 70lbs or so...

- Stiff coilovers in place of stock 10-15lbs... Also can remove the sway bars with stiff coilovers another 5-10lbs probably...

- After market seats, supra's or S2000 drop 70lbs or so....

- Gas and water weighs 6.5 pounds per gallon...
Full tank of gas - 17 gallons times 6.5 = 110lbs
VS. Empty tank - 3 gallons = 20lbs

- window washer tank 1.5 gallons = 11 lbs

 

[jtucci]

if you are going to be rebuilding your motor, it may be worth looking into titanium bolts. i'll look into having camshaft/crankshaft/accessory pulley bolts replaced with Ti. basically anything that moves. i feel this would be the most beneficial. and for cost may actually prove to be worth it, but i dont know anyone who has tried it.

http://www.unitedtitanium.com

 

[Autobahn_stormer]

Shedding weight isn't just goin to help you go around corners faster. Weight reduction will improve almost every facet of the car. Straight-line performance, cornering, braking, fuel comsumption and even wear and tear, and it's not like you have to drop 500 lbs and live without AC to acheive a somewhat noticeable gain.
Don't just attack your car with a sawzall, chisel, and case of beer. CHoose your areas of improvement wisely. Start at the four corners of the car and work on the un-sprung weight. Then move onto getting the center of gravity lower in the car.
Even better weight distribution will provide an improvement. Try moving your batter to the trunk, or rethinking the placement of your big heavy stereo.
If you make some educated decisions and think about the car and your actions as a whole you'll end up with a well rounded package. It'll still be heavy as ****, but it'll be a vast improvement.
But having said that, an LS400 with a carbon roof and driveshaft and supra TT seats would be pretty sick!

 

[jibbby]

You also forgot to mention the less your car weighs the power it can hold without failure.. Less ground weight to push means less strain on all moving parts..Transmission, drivetrain, motor, etc... Unless of course your traction is improved along with your cars weight reduction..

Many advantages to consider......

 

[Autobahn_stormer]

that's what i meant by wear and tear. and the traction thing is the purpose of moving weight around, maximizing what you have. unless i misunderstood what you meant there (which is possible, i JUST woke up)...neway...i forget who said it, but they were exactly right. The LS400/Celsior; no matter what you do, will always be a big heavy luxury car. You can lighten the load and do wonders for most every aspect of the vehicle. But it'll never be a sportscar.
But WHO CARES! when ur blowing the doors off unsuspecting drviers at stop lights and ESPECIALLY on the highway.
god i love the 1UZ

 

[jibbby]

You can go on diet yourself and lose alot of weight if your a slob...No one mentioned the driver losing weight in this thread...

If your already skinny please disregard this post....:1244:

 

[XT-1]

What kind of car do you have? You can lighten it but it will cost you some safety and luxury.

Carbon fiber hoods and trunk lids are available for the SC at www.importfan.com There may be fitment issues so be warned. After my accident 1.5 years ago, I'd never replace the hood or trunk. The factory hood works with the crumple zone in a front impact. The last thing I'd want is shards of carbon fiber flying at me or at other people. Also, when the hood folds, it can protect you from oncoming debris that your windsheild cannot. I don't seen to be able to post a pic of my old SC but it was not pretty.

You can begin pulling interior peices as well. Those monter 75lb electric seats can be replaced with light aftermarket ones. The Supra TT brackets and sliders will work. Pull the sound deadening material.........ect.

You can begin replacing the steel bolts and nuts with aluminum or titanium. In order for it to be effective you'll have to replace a lot but it'll lighten it. [/img]

carbon fiber doesnt "shard" it almost becomes harmless when it breaks (unwinds and become "fluffy" on a sense), your windsheile is safety glass, and it does afine job af keeing things out- use polycarbonate...BULLETPROOF glass is made from polycarb.
Total waste of time to replace all your nuts and bolts to save weight..compromise integrity for one, I can take a dump before I race and lose more weight than changing all your nuts and bolts...spend that time porting/polishing your intake for time better spent.

here is my two cents

You can probably save up to about 40 pounds from just replacing bolts.. it is worth it.
Replace glass windows with Lexan or plexiglass
Remove the radio, stereo and speakers
Remove the air conditioning, heater and defroster
Remove the windshield wipers, the washer system and mechanism
Remove the ashtray and glovebox
Remove Horn, Charcoal Canister
Aluminum wheels (the stockers are heavy!!!)
Remove spare tire and jack
Smaller battery
Lightwieght flywheel
Carbon Driveshaft
remove the carpeting, door panels, and headliners (track only)
When racing - remove ur headlight, taillights, and exhaust
Remove your passenger seat and backseasts when racing
Aluminum Radiator
Track only - remove the airbags
Remove the EGR
Remove the Antenna
Remove the car manual (mines weighs 2 pounds!)
Remove the parking brake
Remove the Sun Visors
Remove the windshielf wipers and resevoir and anything else in that system
REmove all the sound deadener in the car

That should keep ya busy :S

Is there such a thing as a lightwieght alternator?

TADA... Race car... you answered his question the best. do you want a race car or AC?

Yes, I know it was done to make fun of ricers, but it also proves a point. The less creature comforts you are willing to live without, the lighter you can make your car. It is definately not a "guide" on how to get performance from your car. I would never recommend 90% of the things in that article.

I am personally not willing to live without my creature comforts. I love my 75lb monster seats and would never consider not having AC here in Vegas. Hell, the reason I bought the Lexus in the first place is for those extras.

mybrainisimmense had some excellent ideas in his suggestions.

I think the "article" he was refering to was the one that said to change out the nuts and bolts

I am currently working with this one company that may have a 1st gen LS CF hood on the market.

Things to do to make the car lighter: Replace front seats with lighter ones, replace 22gallon gas tank with a 10 gallon fuel cell, lighter suspension, lighter brakes (4piston Rotora), cut out the floors in cabin and trunk and replace them with honeycomb aluminum.

These are the things to do for starters.

brakes (rotating mass unsprung weight) can help alot for each pound of unsprung weight you save (wheels/tires/shocks/springs) is like reducing your car by 10 lbs

What you are forgetting is the weight of the gas tank itself as well as the fact that larger tank with less fuel will allow gas to come to one side of the gas tank at turns; thus, putting a lot of weight on one side.

Wrong. Good aftermarket suspension is lighter then stock. Same goes for brakes. How do I know? Because I have both on my car and I had a chance to compare the weight personally.

no he is not wrong, you misunderstood....HEAVIER means a stiffer spring rate not heavier as in weight wise.

You can go on diet yourself and lose alot of weight if your a slob...No one mentioned the driver losing weight in this thread...
If your already skinny please disregard this post....:1244:

why do you think horse jockeys are so small...think about that horsepower to weight ratio!!!:shock: 1 hp to like 115 lbs!!! LOL

 

[Thermactor]

Start with a 2nd gen LS, they're lighter to begin with

 

[Autobahn_stormer]

well if we're gonna start with a different chassis....why not put a 1uz in a lotus exige?
totally impractical and probably not worth the ENORMOUS effort if it's even possible..but it'dbe light as heck.