Weight Reduction...

[apoc]

Hey peoples,

Just a thing that popped into my head, as i was sitting here trying to think of how to make my car go faster without spending heaps of cash and thought,
Weight Reduction.

Now I had a quick look around and it doesnt seem that anyone has said much about this... (quick look....)

So I gonna throw some ideas i have out there and people can shoot them full off holes so i can forget about it

So here i go, I have an AUII Forte Auto, now supposedly having about 157kw of power, and a mass of 1505kg. Firstly what i want to know is seing how the cars performance is determined by the strict power/mass ratio (simplified i believe this to be a fact, can also be shot down for this too...) if i were to reduce the cars weight by 10% (got no idea how or what to do to get this just a theoretical) giving a new car weight of 1354.5kg.

Original car power to weight ratio = 157/1505 = 0.104
10% reduced mass p / w ratio = 157/1354.5 = 0.116

Where a higher p/w ratio is better...

So by the same token if i were looking to increase my cars performance to the same as that of the 10% reduced weight version of my car by engine mods i would have to obtain;

p/w ratio = 0.116 (that of the 10% reduced weight car)
weight = 1505kg (that of the stock car)
so power can then be worked out to = 0.116 x 1505 = 174.58kw (which is around that of XR6 VCT)

So there it is, as it stands on a very simple level i beleive that if I could remove the theoretical 10% weight in my car, it should be able to get up and boogie similar to that of an XR6 VCT.

I understand that there is probably didly squat that can be removed from the car aside from spare wheel and towbar that are of significant mass but hey what do people think anyways?

Whooo, its a book,
Simo.

[apoc]

Just another dumb number based of my inital calculations...

For each 8.6kg you can loose from the mass of your car will bring it 1kw closer to the XR6 VCT if you can ditch 151kg your sorted

Simo.

[Hibbz]

well every bit of weight reduction does count.

So yeh some simple options that wont effect its apperance to much ie. Interior

Remove Spare Wheel 20Kg
Remove Jack ???
Remove Tow bar Setup ???
Replace Bonnet with a fibreglass version 20KG

Also remember that 1kg of rolling mass count for 4kg in static weight so if you run stock 16" wheels and tyres that come in at a total of 80Kg compared to say your average 19" wheel and tyre which come in at 100Kg total thats a difference of 20kg rolling mass or 80kg static.

As a general rule every 50Kg lighter equates to about .1 second reduction to your quater mile time.

Thanks Jake

[Hibbz]

Originally Posted by apoc

Just another dumb number based of my inital calculations...

For each 8.6kg you can loose from the mass of your car will bring it 1kw closer to the XR6 VCT if you can ditch 151kg your sorted

Simo.

Lol going by your formula i have gained 1kw in the last 2 week cause i have lost about 9kg. :

[jimt3te50]

weight reduction can cost more than mechanical performance modifications- not necessarily a matter of pulling stuff out as having to replace some of those items with lighter and more expensive components.

Stripping weight from rotating mass is the most beneficial- ie. wheels, tyres, brake rotors, flywheel, driveshaft etc. as this has the effect of removing 8 times their equivalent in static weight......... eg. 10kg off the wheels is about the same as stripping 80kg off the car.

as far as taking stuff out, there isn't a lot you'd take out that would still make the car easy to line with day to day. For example, take the carpets, door trims, electric windows, water from the washer bottle etc and it'll be lighter but it'll look crap and won't go that much better for what you have done.

Tough one- not a lot of cheap solutions here I'm afraid- not without making your car look like you left it unlocked in the backstreets only to return to find it stripped.......

[TwistedEL]

I struggled to keep up with a Suzuki 4cyl shitter the other day - turned out the only interior it had was the drivers seat. My brothers VP commie couldn't keep up.

[jimt3te50]

Originally Posted by TwistedEL

I struggled to keep up with a Suzuki 4cyl shitter the other day - turned out the only interior it had was the drivers seat. My brothers VP commie couldn't keep up.

yeah it certainly has it's merits, but shitty old suzuki is a better thing to do it to then your AU...........

[Casper]

Originally Posted by apoc

Hey peoples,

Just a thing that popped into my head, as i was sitting here trying to think of how to make my car go faster without spending heaps of cash and thought,
Weight Reduction.

Now I had a quick look around and it doesnt seem that anyone has said much about this... (quick look....)

So I gonna throw some ideas i have out there and people can shoot them full off holes so i can forget about it

So here i go, I have an AUII Forte Auto, now supposedly having about 157kw of power, and a mass of 1505kg. Firstly what i want to know is seing how the cars performance is determined by the strict power/mass ratio (simplified i believe this to be a fact, can also be shot down for this too...) if i were to reduce the cars weight by 10% (got no idea how or what to do to get this just a theoretical) giving a new car weight of 1354.5kg.

Original car power to weight ratio = 157/1505 = 0.104
10% reduced mass p / w ratio = 157/1354.5 = 0.116

Where a higher p/w ratio is better...

So by the same token if i were looking to increase my cars performance to the same as that of the 10% reduced weight version of my car by engine mods i would have to obtain;

p/w ratio = 0.116 (that of the 10% reduced weight car)
weight = 1505kg (that of the stock car)
so power can then be worked out to = 0.116 x 1505 = 174.58kw (which is around that of XR6 VCT)

So there it is, as it stands on a very simple level i beleive that if I could remove the theoretical 10% weight in my car, it should be able to get up and boogie similar to that of an XR6 VCT.

I understand that there is probably didly squat that can be removed from the car aside from spare wheel and towbar that are of significant mass but hey what do people think anyways?

Whooo, its a book,
Simo.

Theres a flaw in your calculations to start with.. in your favour. You assume the XR6 VCT weighs the same as your Forte. Let me assure you its carrying a LOT more beef than that. Start by adding around 70-90kg's for all the extra electricals, IRS and even the extra weight of the VCT mechanism itself. Although it may have 172kw the excess weight made it slower than an XR6HP with 164kw. If you can get the Forte to 164kw equiv. then you will be doing well. Only problem then is the HP and VCT came with the 3.45 diff gears, the Forte didnt. The VCT also has significantly more torque and a different kw/rpm ratio just to confuse it more. As you can see the factors involved are more complex then weight.

Originally Posted by jimt3te50

weight reduction can cost more than mechanical performance modifications- not necessarily a matter of pulling stuff out as having to replace some of those items with lighter and more expensive components.

Stripping weight from rotating mass is the most beneficial- ie. wheels, tyres, brake rotors, flywheel, driveshaft etc. as this has the effect of removing 8 times their equivalent in static weight......... eg. 10kg off the wheels is about the same as stripping 80kg off the car.

as far as taking stuff out, there isn't a lot you'd take out that would still make the car easy to line with day to day. For example, take the carpets, door trims, electric windows, water from the washer bottle etc and it'll be lighter but it'll look crap and won't go that much better for what you have done.

Tough one- not a lot of cheap solutions here I'm afraid- not without making your car look like you left it unlocked in the backstreets only to return to find it stripped.......

I'll agree 100% with Jim here. Its possible but not practical.

I guess if you have 200kg's of subs and stereo in the boot then by all means dump that, it will make a difference. Apart from that though its not worth ripping out all the good stuff for the sake of a few 1000th's of a second. If you need to do something, strip the wheels and replace with super light alloys.. but thats not cheap either.

[HLC]

seats, door trims, centre console, spare, jack, towbar, fibreglass bonnet/boot

[347 mont]

This is proberly why the fellas in the US are getting low 11's, high 10's in their similar powered mustangs(380-450rwhp), those cars are much lighter than ours,less than 3500lbs where as a AU weighs 4000lbs. A XE Falcon is a little over 1200kg, more ideal for quicker 1/4's I reckon.

[apoc]

Hey all cheers for the input,

Hibbz - "As a general rule every 50Kg lighter equates to about .1 second reduction to your quater mile time."

Can you put this into perspective a little bit... i must confess i have never had a run or been to the drags : so is this kind of reduction very noticeable in terms of feel? Say the 150kg was lost how much crankier do you think the car would feel?

jimt3te50 - "Tough one- not a lot of cheap solutions here I'm afraid- not without making your car look like you left it unlocked in the backstreets only to return to find it stripped......."

hehe yeah i kinda figured that out as i was writing the post as i made it all up and crunched the figures as i went.

Casper - "Theres a flaw in your calculations to start with.. in your favour. You assume the XR6 VCT weighs the same as your Forte. Let me assure you its carrying a LOT more beef than that. Start by adding around 70-90kg's for all the extra electricals, IRS and even the extra weight of the VCT mechanism itself. Although it may have 172kw the excess weight made it slower than an XR6HP with 164kw."

Well i dont know if you can trust redbook but the VCT has a weight of 1490kg for Apr 2000 and 1505kg for Forte but I know i didnt take this into account but at 11pm i wasnt up for it...

Casper - "If you can get the Forte to 164kw equiv. then you will be doing well. Only problem then is the HP and VCT came with the 3.45 diff gears, the Forte didnt. The VCT also has significantly more torque and a different kw/rpm ratio just to confuse it more. As you can see the factors involved are more complex then weight." I understand there are more factors involved...

Apoc - "So there it is, as it stands on a very simple level i beleive that if I could remove the theoretical 10% weight in my car, it should be able to get up and boogie similar to that of an XR6 VCT."

Bottom line is it was just some very simple workings so that i could roughly picture what loosing some weight from the car would do for it. Basically i discovered that loosing 150kg odd would help the car a bit but it is generally unfeasable without resorting to replacing things with carbon fibre. I had to get some sort of perspective as i was thinking of pulling some of the less essetial things from inside doors etc, speakers etc, i know that the collective weight of these things does not come close to 150kg nor probably 50kg and as such renders it pretty much a waste of time.

I'll still be taking off my towbar , the tongue and ball weigh 6kg on their own i can at least pretend it makes a noticable difference hehe.

Cheers again,
Simo.

[S3SR]

just replace all steel with aircraft grade aluminium/carbon fibre...that should drop a few 100kgs...and few $100k

[Hibbz]

Next month at the AFF Drags if i can i will do some testing to see how much difference it makes if i drag with my 19's compared to my 16" stockies and how much difference it make if i remove some static weight so i wont know till then.

Thanks Jake

[jonbays]

Originally Posted by apoc

."

Well i dont know if you can trust redbook but the VCT has a weight of 1490kg for Apr 2000 and 1505kg for Forte but I know i didnt take this into account but at 11pm i wasnt up for it...

Cheers again,
Simo.

Dont trust redbook its wrong.

Have a look here for some "more" accurate Ford figures http://www.fordforums.com.au/photos/...cat=500&page=1

[Casper]

I WISH my car weighed 1490kg's!!!. :

I think 1620kg's is much closer to the mark.

Based on that the figures are:
Forte 157/1505 = 0.104
VCT 172/1620 = 0.106

Based on that all the Forte needs is to drop 25kgs to meet the same power to weight ratio as the VCT. You also may want to get a 3.45 diff gear setup and reconfigure where all the power and torque arrive though.

[S3SR]

Originally Posted by Casper

I WISHBased on that all the Forte needs is to drop 25kgs to meet the same power to weight ratio as the VCT. You also may want to get a 3.45 diff gear setup and reconfigure where all the power and torque arrive though.

or be 25kgs lighter than the driver of the VCT

[JefXR8]

Just cut all the fat and sugar out of its fuel and feed it some low carb engine oil that should do the trick