PDA

View Full Version : making your car lighter, any ideas?



vekara
6th September 2014, 07:10 AM
We all know a lighter car use less fuel, goes better and is often better handling. most 10 year old cars are very heavy, take Astra H for instance, the sri coupe weighs 1401kg according to specs. An earlier model Calibra weigh 1280kg. Manufacturers increased the safety by making the cars heavier and now the trend is to start sheading that weight, a new Mazda Mx5 weighs 100kg less than its predecessor.
Have you any good ideas that are economically viable to make your car lighter, legally without compromising safety or comfort?
I was looking at the brake components, they are all solid iron and weigh a lot, then comes wheels and tyres, they weigh 20kg each, seats, exhaust system, battery and so on.

dutchy
6th September 2014, 07:16 AM
Put only 5 litres of fuel in instead of 50.
Loose weight yourself.
Ditch passenger and rear seats.

But then again, I don't think it would make any sense on a road car to do all of that.

vekara
6th September 2014, 07:42 AM
Put only 5 litres of fuel in instead of 50.
Loose weight yourself.
Ditch passenger and rear seats.

But then again, I don't think it would make any sense on a road car to do all of that.

the fuel is a good point, I notice a small difference when the tank is almost empty compared to full. Also a factor is that old fuel becomes denser and gives more power per volume than fresh fuel, believe or not...
I would like to look at replacing the original 20kg lead acid battery with something high tech and much lighter. there are some racing Li-ion batteries that weigh 6kg giving same crank power. Anyone have one? there goes 16 kg without any adverse effect.

adam_92
6th September 2014, 06:20 PM
Strip all the seats out, all plastic trim panels, sound deadening and carpets, titanium exhaust, lightweight racing wheels, strip excess wiring, remove a/c system, plexiglass windows, carbon fibre panels...

The list is endless mate. Depends how far you wanna go, generally the more extreme you go, the more uncomfortable and unroadworthy the car will become

Sent from my GT-I9505 using Tapatalk

sskustomz
6th September 2014, 06:24 PM
Titanium bolts, carbon fibre everything, li-ion battery, strip everything


Sent from my iPhone using Tapatalk

gravy258
6th September 2014, 08:27 PM
buy a Calibra, it'll never run, thus saving fuel

gman
6th September 2014, 08:31 PM
I managed to get my TS Astra SRi-T down to 890kgs racing weight.

We had to get rid of everything non-essential, ripped out the standard electrical harness for a new light weigh racing harness.

Carbon panels, lexan windows etc etc...how far do you want to go? :)

Elliot_O
6th September 2014, 10:15 PM
the fuel is a good point, I notice a small difference when the tank is almost empty compared to full. Also a factor is that old fuel becomes denser and gives more power per volume than fresh fuel, believe or not...
I would like to look at replacing the original 20kg lead acid battery with something high tech and much lighter. there are some racing Li-ion batteries that weigh 6kg giving same crank power. Anyone have one? there goes 16 kg without any adverse effect.
If it's a daily, I wouldn't recommend one of those lighter batteries, they're not meant for continued use really, or any auxiliary components

vekara
8th September 2014, 05:11 PM
I took everything out of the booth including a blanket i use to protect the booth lining. The spare, tools and the booth floor panel weighs 28 kg, pretty good saving, although I believe it is illegal to remove the original spare from the booth and drive on public roads.

adam_92
8th September 2014, 06:31 PM
Not if you put a can of the tyre goo like most new cars have now

Sent from my GT-I9505 using Tapatalk

chris_r
8th September 2014, 06:52 PM
Not if you put a can of the tyre goo like most new cars have now

Sent from my GT-I9505 using Tapatalk
Well, there's a smart idea. Unless you get a blowout somewhere out in the sticks. Then I'd say you're royally screwed.

adam_92
8th September 2014, 06:56 PM
Yup. That would be an issue

Sent from my GT-I9505 using Tapatalk

dutchy
8th September 2014, 07:16 PM
Well, there's a smart idea. Unless you get a blowout somewhere out in the sticks. Then I'd say you're royally screwed.

Not really, you can always stuff the tire with grass, works really well :)

vekara
8th September 2014, 07:18 PM
From a practical point of view though, the foam can't fix a torn sidewall which i assume would be more likely in low profile tyres rather than a nail. Still, worth considering. I have carted a full size spare in the back of my Vectra for 15 years, never needed to replace it on the side of the road.
I wonder if the spare tyre is part of collision absorption system, it is between the crash bar and rear axle and seating.

adam_92
8th September 2014, 07:26 PM
I havent had a puncture in all the time iv been driving (6 years) and then had 4 in a month

Sent from my GT-I9505 using Tapatalk

sskustomz
8th September 2014, 07:28 PM
Can always use run flat tyres, but I think they weigh more.


Sent from my iPhone using Tapatalk

SilentShout
8th September 2014, 11:40 PM
would it be worth looking into a space saver prehaps?? smaller wheel hopefully means less weight?

also how much does the AC system typically weigh?? Mines currently not running and im tossing up whether to fix the pully or take the whole thing out to reduce weight?

havnt used it in the year its been broken :lol:

also on the topic of fuel in the tank, I used to know someone with a 350Z who never filled up more than $20 at a time and was managing an extra 100kms over what the car typically averages due to the lack of weight. The issue with that though was his fuel was technically more expensive as he would pay for it on cheap days and expensive days too. so i guess it didnt really work finanically.

vekara
9th September 2014, 05:58 AM
Ac compressor weighs about 8kg, if you pull all the other parts that will be a bit more, there is the heat exchanger and plumbing.
Z350 is a heavy car, a 20kg weight saving is not as noticeable as in a Barina. But a tank tank is about same as a small person... you would notice that.

SilentShout
9th September 2014, 06:22 AM
I ment the full works. Compressor, piping, core etc. It means a different sized belt but bonus is the belt is only driving the altinator, even though the compressor pully is clutched I think it would still have some sort of mass to it, even if its a gram. Doesnt mean you would notice though.

dutchy
9th September 2014, 07:03 AM
http://i880.photobucket.com/albums/ac8/dutchy_02/weightreduction_zps88ebec1e.jpg

adam_92
9th September 2014, 11:41 AM
Aircon system would be close to 14-15kg inc compressor, pipe work, extra radiator and fan etc

Sent from my GT-I9505 using Tapatalk

Elliot_O
9th September 2014, 12:14 PM
Could take out the power steering as well if that's not considered a drop in comfort

chris_r
9th September 2014, 01:57 PM
Could take out the power steering as well if that's not considered a drop in comfort
Power steering in Corsa C, Astra G-on models is electric driven and pretty much a part of the steering column, so I'd leave it there for the very small amount of weight you'd take out of the car.

Elliot_O
9th September 2014, 02:17 PM
Ahh gotcha, thanks Chris.

guy 27
9th September 2014, 03:08 PM
fill tyres with helium
replace coolant with liquid hydrogen
remove doors that don't get used.
join jenny craig.
cut 1 leg off.

SilentShout
9th September 2014, 04:36 PM
Or add a turbo =) then you can keep your leg.

vekara
9th September 2014, 05:21 PM
that must be the lightest astra around.

sskustomz
9th September 2014, 07:01 PM
You win dutchy! I weighed all the aircon bits after I pulled them out of the corsa, 23kg


Sent from my iPhone using Tapatalk

SilentShout
10th September 2014, 02:26 AM
23kgs probably wont make much of a difference compared to the comfort it provides,

What about fiberglass panels?? anyone know if its legal?

my old s15 had a fiberglass bonnet (one of the few ADR approved ones in Australia)

but it also had fiberglass kit, and side wheel arches.

i Imagine it would shave a bit of weight, but now your sacrificing safety.

vekara
10th September 2014, 06:08 AM
Bodypanels are part of safety, doubt you could replace them with fibreglass. heavy stuff that aircon system, i an surprised.
Now guy 27, you are going into extremes, helium in tyres... why not just shave the tyres to its minimum tread. talking about tyres, the old nylon (not steel belted) tyres of the bygone era were much lighter than the modern ones.
make the exhaust out of thin steel or even aluminium, that whole system is quite heavy.

Doing some research about the subject, the greatest effect on acceleration comes from reducing the weight of the wheels and brake disk rather than the non rotating weight of the body. The magic is that the tyres need energy to be accelerated to rotate as well as move forward. Porsche recons it is 1:7 but some general estimates are 1:4. That means that if you fit lighter tyres and rims and lose total of 20 kg, it has the same effect as losing 140kg according to the Porsche rule. that is quite serious effect and achievable. That's like removing one big bastard sitting in the back seat.
Another is the tyre rolling resistance. I have 205 Michelin Pilots under my vectra and it is hard to get moving by pushing on flat surface. My astra has Kumho ecsta 225 wide is considerably easier to push, and the weight of the car is not that much different. All tyre alignments are good as the tyre wear is even. I am tempted to swap the wheels over to see what the difference is.
All those boy racers whom fitted wider tyres than the specified actually made their cars slower!

Another rumor i was reading that GM US insisted putting thinner gearbox oil in its Cruze models to reduce losses and reduce fuel consumption. Europe did not because they knew that it will reduce the life of the gearbox. The rumour is that gearboxes in the US started to fail too early and some GM service places quietly replaced the thinner oil with thicker standard oil to risk manage the problem. The oil thickness was not that much different, 80 against 90W.

dieselhead
13th September 2014, 11:44 AM
Light wheels. Best thing I have ever done for my Clio was to replace the 10 kg each OEM 17" x 8 with Oz Racing Alleggerita 17" x 8.5. 3 kg per corner of unsprung weight gone! Steering feels even more agile now and the new rims look amazing, too.

Sent from my Nexus 10 using Tapatalk

SilentShout
14th September 2014, 07:42 PM
I had another thought on this one, depending on how much oil your car takes, prehaps a dry sump setup?? iirc it reduces the oil capacity of the engine, less fluid = less weight.

another thing which is very underestimated is cleaning out your car :lol:

shit you not i just shaved 10kgs of rubbish and unnessesary items :P

gman
15th September 2014, 11:16 PM
Actually a dry sump would increase weight overall as capacity usually goes up. Mine has a 3 gallon tank plus the weight of the tank, lines and pump as well.

Still you could buy one of these. :)

http://img.tapatalk.com/d/14/09/15/ve4ezegu.jpg

SilentShout
15th September 2014, 11:52 PM
ah didnt know a dry sump added a reservoir elsewhere, thanks for clarifying :)

if you want to go to extremes i guess you could start drilling out holes of metal wherever you can, e.g. non vital support beams etc,

again though i imagine this would compromise the car severely in a crash.

-=UPDATE=-

Reading online one thing people do is fit a full rollcage, which technically adds more weight, but increases the structure of the car to the point where they can start to remove side impact beams, internal metal paneling, inner wheel arches etc.
Aparrently drilling holes in the correct places has little impact on metal parts, i dont know about this one, as stated earlier im guessing thats an extreme measure.

http://forums.pelicanparts.com/porsche-911-technical-forum/523230-looking-ideas-pictures-drilled-out-parts.html

^Interesting forum thread where the car owner goes all Swiss cheese on his car. cant seem to find total weight saving though, only up to page 8 as i have to get back to work :(

http://www.torquecars.com/tuning/car-lightening.php

^Article for reading too if you want.

last on the list is diet :lol: its true though.

no use racing if your an unnessesarily larger person.

vekara
16th September 2014, 06:02 AM
Interesting points made here and gman's hood looks mean, great and of carbon fiber. just to add something that has not been discussed here is the windscreen washer tank, it takes about 3 litres, don't keep that full all the time, just enough to wash a couple of times, if you live in a dry area.
I think the reduction of rotating non sprung weight seems most efficient; tyres, wheels and brake disks.

sskustomz
16th September 2014, 01:41 PM
Unsprung weight is the key, suspension works better, acceleration and braking is better. Iirc 3kg of Unsprung weight = 8kg of sprung weight by virtue of the performance increase it gives


Sent from my iPhone using Tapatalk

vekara
16th September 2014, 01:55 PM
Unsprung weight is the key, suspension works better, acceleration and braking is better. Iirc 3kg of Unsprung weight = 8kg of sprung weight by virtue of the performance increase it gives


Sent from my iPhone using Tapatalk
'
We need to clarify unsprung non rotating and rotating parts, some estimates for rotating unsprung weight benefits such as the tyres, rims and brake disks is equivalent to 4 times dead weight, so 3 kg off wheels give same benefit as at least 12kg of dead weight.

SilentShout
17th September 2014, 04:10 AM
the only thing is i have never came across a lightweight set of rims that I like :(

sskustomz
17th September 2014, 05:45 PM
Compomotive, oz racing Both are nice


Sent from my iPhone using Tapatalk

gman
22nd September 2014, 09:54 AM
Team Dynamics are very nice. OZ Ultraleggera's are beautiful rims. Enkei also do some nice ones. Compomotive are proper race spec rims. There is a company from Melbourne that does carbon fibre rims, mainly for Porsches, but they are currently the lightest rims you can get and only about $10K a set!!!!! :lol:

kabel
22nd September 2014, 01:49 PM
Unless you are taking the approach gman has , really you are wasting your time on a street car.
What was your end goal. Quicker track times, faster 0-100 or 1/4 mile times ?

More power is probably a better solution than a compromised noisy car.
Just my opinion.

vekara
24th September 2014, 07:38 AM
Unless you are taking the approach gman has , really you are wasting your time on a street car.
What was your end goal. Quicker track times, faster 0-100 or 1/4 mile times ?

More power is probably a better solution than a compromised noisy car.
Just my opinion.

True, it is all about "bang for buck", many people tune their cars at very high cost and get very little for the money. I have written about this before, the cheapest bang for buck is to mix octane booster into your fuel, few dollars gives better performance which you can feel. to get the same increase in performance you would have to spend a pretty penny on other upgrades.

kabel
24th September 2014, 01:28 PM
Not sure how much "performance feel" you would get by adding Octane Booster to a tank of fuel in a stock 1.8l N/A automatic Astra for example, possibly a placebo effect !

I do take your bang for buck comment though however would not be my preferred method as a first option. I would spend some money on handling upgrades if you want to increase the fun factor and keep it safe.

But do let us know how you go with your experiment. If memory serves me correctly Top Gear may have done an episode on this subject.

dutchy
24th September 2014, 01:51 PM
better put 98 in your tank then for the money as that is much cheaper thank a bottle of octane booster. now just putting 98 in your tank doesnt make you car a rocket all of a sudden.

SilentShout
24th September 2014, 03:19 PM
I had a thought, things like a lightened flywheel might help too, e.g. factory wheel is 10kgs, lightened makes it 5kgs, thats 5kgs of savings.

swapping other components out for lighter parts too, alluminium rad (if you car has a heavy one) etc etc.

vekara
24th September 2014, 05:28 PM
We have had few Opels in our family;
2003 1.8 astra auto where 98 or 102 octane made virtually no difference compared to 95 octane.
2001 V6 Vectra does benefit from 102 octane and becomes noticeable more responsive and reduces fuel consumption by about 10%.
2006 astra turbo, 102 octane does make it snappy with the traction light flickering through second gear. That car is so fast with 98 octane that really any difference needs more sophisticated measuring method than a bum on seat.
2003 2.2 litre Astra manual benefited most from 102 octane, the engine became alive and responsive.

increased octane does not necessarily increase the max power but what it does is make the engine run more efficiently with what it has. more efficient engine is more responsive because of advanced spark timing so the max power comes out faster. It all depends on how the ecu mapping has been done, what the parameters are. I used to fill with Shell racing 100 octane fuel and it made a big difference to the 98 octane. also the fuel consumption went down by 7% so the extra cost really was no extra cost.

Nulon sells octane boost Pro, add 40ml to every 20 litres of 98 octane and see what it does to your car.

Shortstuff
14th November 2014, 09:29 AM
I read an article about a new design of ringless piston, which meant they are almost friction free. It uses air pressure to do the job of the piston rings.

The article said the reduced friction meant massively lower operating temperatures which means components of the cooling system could be made smaller. They reckoned smaller radiator, fan, water pump could save around 10kg.

guy 27
14th November 2014, 10:04 AM
I think konigsegg's camless engines will be the next big thing to come in. Each valve is controlled by an actuator.
Timing section and cams are all therefore removed saving plenty of weight.
Their system can be put into any existing engine as well.

Shadow110
14th November 2014, 10:35 AM
I think konigsegg's camless engines will be the next big thing to come in. Each valve is controlled by an actuator.
Timing section and cams are all therefore removed saving plenty of weight.
Their system can be put into any existing engine as well.
Saw a video of this a few months ago. They can rev to infinity (almost).
They have the system on an old saab 9-3 aero and have done something like 100k miles in it and hasnt missed a beat...
Freaking amazing idea, konigsegg just bought the guy that invented it, well played victor... well played.

SilentShout
14th November 2014, 10:57 AM
Saw a video of this a few months ago. They can rev to infinity (almost).
They have the system on an old saab 9-3 aero and have done something like 100k miles in it and hasnt missed a beat...
Freaking amazing idea, konigsegg just bought the guy that invented it, well played victor... well played.
That makes sence, last i heard alpha romeo was the one behind the camless engine, but they struggled to get the engine past 5k rpm as the computer they were using at the time couldnt process fast enough. Another thing they noted was solenoids which is what they were using at the time were bloody noisy and somewhat unreliable.

I read this a fair few years ago now though (05-06)

Iirc they wanted to couple it to a variable compression engine and make a high powered 1.5l turbo engine or something.


Nissan went the other way with the Zeod. They looked into low friction tech and have come up with a 3cyl 1.5l engine making 400hp and weighing in at 40kgs.

dutchy
14th November 2014, 01:18 PM
I can't wait for the day that cars are obsolete and/or old school and everybody is flying UFO's. Sadly, I won't be here to see that.