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View Full Version : Weight - putting things into perspective!


darrenwm
06-07-2007, 05:14 PM
Today I was carrying some boxes and I noted the weight of them.

A 34kg box was a heavy for me, and 20kg boxes were weighty too.

Now I didn't think 20kg or so was much, but if I had one of these boxes in my boot it would be enough to slow the car down noticeably.

This inspired me to do some research...

A washing machine weighs 75kg, and a 50" Plasma weighs 45kg...

So the difference between a Rallye and a GTi is a washing machine in the boot!

How much does petrol weigh - 1kg per litre??

semtex
06-07-2007, 05:16 PM
:pare you bored Mr Mayne ?

Bean0
06-07-2007, 05:19 PM
Density of Petrol - 737.22 kg/cu.m

1 cubic metre = 1000 litres

737.22 / 1000 = 0.73722 kg/l = 737 g/l (3sf)

:)

Nazor
06-07-2007, 05:22 PM
A guy who competes over here in Ireland at Autocross/sprint events (his yellow 106 is pictured in my Gallery) only carries the bare minimum of fuel in his car to save weight.

They have it done to a T - they know exactly what the car needs at certain events - he won the last time out - just sunday past.

makes a difference id say - a big one.

However, another guy i know likes to have a fair bit of fuel in as the 106 can be quite jumpy with no weight in the back. So i guess there is a compromise to be had.

dynofiend
06-07-2007, 05:22 PM
my xsi went from 920kg to around 780kg, im sure you can imagine the difference that would make!

Bean0
06-07-2007, 05:27 PM
my xsi went from 920kg to around 780kg, im sure you can imagine the difference that would make!

Assuming the engine put out 135bhp, you've gone from 146 bhp/tonne to 173 bhp/tonne.
To get the same ratio with the heavier car, you would have needed approx 160bhp.

I bet it cost a lot less as well :)

darrenwm
06-07-2007, 05:29 PM
Density of Petrol - 737.22 kg/cu.m

1 cubic metre = 1000 litres

737.22 / 1000 = 0.73722 kg/l = 737 g/l (3sf)

:)

Interesting! So my tank of fuel weighs 33kg :(

I like a tank for MPG calculating purposes, but it's akin to losing 4bhp! lol

Fuzzy Orange
06-07-2007, 05:39 PM
My entire car with half a tank of fuel weighs 820kg :D

vossy
06-07-2007, 05:48 PM
my caged s1 weighed 785kg with half a tank.
weighed on proper accurate scales (not weighbridge with 20kg tolerance!)

semtex
06-07-2007, 05:58 PM
anyone know how dave p is getting on with his weight reduction scheme ?

darrenwm
06-07-2007, 06:21 PM
anyone know how dave p is getting on with his weight reduction scheme ?


He's down the gym a lot.

Brycey
06-07-2007, 06:21 PM
anyone know how dave p is getting on with his weight reduction scheme ?

He was last seen at Slimmers World (Cheaper than Weight Watchers ;)) About to gain his first Gold Star.

:lol:

Bean0
06-07-2007, 06:26 PM
anyone know how dave p is getting on with his weight reduction scheme ?

Last seen heading to the moon after he was informed everthing weighs less there :p

Gus
06-07-2007, 07:07 PM
I certainly notice a difference with a full tank, or even one passenger :o

G-Dub
06-07-2007, 08:32 PM
I drove my mum and two friends home last night from the Rod Stewart concert with about 60 empty beer bottles in the boot and a full tank of fuel and I honestly thought the poor little Rallye was going to throw in the towel. The weight reduction of the likes of Dyno's car must make a massive difference to fuel economy and performance. My rallye drinks fuel so maybe it's trying to tell me i'm a fat bastard :(

Matt_H
06-07-2007, 09:02 PM
My Rallye went from about 820kgs to about 950kgs when I got into it.

Dave P
06-07-2007, 09:22 PM
anyone know how dave p is getting on with his weight reduction scheme ?
My car was last seen at Castlepark Autobody in Ellon gathering dust :yikes: (thats extra weight) :yikes:

My hopes are for 700kg & hopefully 200bhp.

You wont see me at a gym BTW... but possibly inside Pizza hut or the like. ;)

darrenwm
08-07-2007, 11:08 AM
What do back seats weigh?

darrenwm
08-07-2007, 01:55 PM
Ok...

I've taken the easy bits out and weighed them: rear seats 15kg, space saver wheel 10kg.

How much more is there to lose with the rear belts and plastics?

My car is now completely impractical and only risen from 121 bhp/ton to 124 bhp/ton - lol!

Tom J
08-07-2007, 02:21 PM
I've stripped the back seat, boot mat, door bins, spare wheel etc out of the Diesel. If I can just get rid of the passenger now, I ought to get 70mph out of it, as well as 70mpg.

Sorry Laura. ;)

dynofiend
08-07-2007, 04:59 PM
dont forget, that reducing weight tends to have just as much, if not more effect, on braking and cornering performance than on bhp/ton ;)

busta
08-07-2007, 08:13 PM
My stripped 16v S1 weighs 784 with 25 litres of fuel. Interestingly over 500kg of that is on the front wheels!

Loosing more weight wouldn't be too tricky though. A race battery, losing one of the buckets and stripping the dash would help. With perspex windows and fibreglass boot and bonnet it'd probably be an afternoon with a holesaw away from 700kg. Then it would be over 200bhp/tonne!

Even with a standard S1 (100hp, 825kg) -10kg = +1.5hp/tonne. Getting a slimmer girlfriend will work wonders for your performance!

What have you done so far Dave P?

My 1.5D has 70kg of stereo. Thats -8hp/tonne, then consider the 2hp (1500 watts=2.01hp) it takes from the alternator to run it at full blast! That leaves me with 58hp/tonne! Add me at 81kg and, with just 54hp/tonne I'm surprised it even moves!

Don't you just love maths?

Hatton
09-07-2007, 07:08 PM
Ok...

I've taken the easy bits out and weighed them: rear seats 15kg, space saver wheel 10kg.

How much more is there to lose with the rear belts and plastics?

My car is now completely impractical and only risen from 121 bhp/ton to 124 bhp/ton - lol!

In my opinion, the most weight is in:

Seat belts, spare wheel and cage.

I've removed: Rear seats, all seat belts, replaced seats with OMP Records and harnesses, removed Boot plastics, rear interior lighing, brake light cover, rear door cards, sound deadening from the rear arches and rear "door" (or where the door would be) sound deadening, spare wheel and spare wheel cage.

Also removed: Ash tray, standard exhaust for Pugsport, standard manifold for Raceland, standard.

Car is most definately lighter and a lot louder, the road noise overpowers any attempt at conversation.

danlilley2000
09-07-2007, 08:09 PM
Correcto. one litre of water weighs 1kg, no piont in mentioning difference in weight for water/petrol. so, yes a full rallye tank can weigh 35kg, thats a lot! it may seem annoying dropping into the station every 75 miles but i always put just a tenner in and i can feel the difference in weight if i fill up.(plus youll be using up more fuel carrying it around!):)

Miles D
09-07-2007, 09:34 PM
i definetly notice a difference with a full tank, hardly ever fill it up just put 20's in lol

1st time i drove it completly stripped with 1 bucket i was impressed, felt alot quicker, but as said, theres no point in tying to have a conversation above 30mph, and u need the stereo on flat out just to hear it!

didnt feel any quicker with just the back seats out thou, have to go all the way;)

darrenwm
09-07-2007, 10:38 PM
I really love mine at the mo. It feels a touch quicker, and as Dyno says braking is better too.

Stripped all the way, baby!

Dave P
09-07-2007, 10:48 PM
What have you done so far Dave P?

Check out the link in my sig. ;)

danthedon
09-07-2007, 10:58 PM
weight is the enemy lol. mines pretty stripped, two buckets, no carpet, no roof lining or plastics at all, no door bins, half a dash, cut up front and rear bumpers, completley cut inside of tailgate (untill grp one is sorted) fibreglass bonnet lol. but then i added a 16v with a raceland manifold as i couldnt add the standard one its too heavy lol

i also have fibreglass buckets with no steel frames inside and poly carb windows in the rear and soon to be front aswell :)

thiscocks
10-07-2007, 08:19 AM
i definetly notice a difference with a full tank, hardly ever fill it up just put 20's in lol

1st time i drove it completly stripped with 1 bucket i was impressed, felt alot quicker, but as said, theres no point in tying to have a conversation above 30mph, and u need the stereo on flat out just to hear it!

didnt feel any quicker with just the back seats out thou, have to go all the way;)

-If you didnt notice a difference with the seats out how do you notice a difference with less than half a tank?:confused:

Miles D
10-07-2007, 05:53 PM
-If you didnt notice a difference with the seats out how do you notice a difference with less than half a tank?:confused:

i mean comparing a full tank, to having it on the red, u notice a difference

thiscocks
11-07-2007, 09:00 AM
Agree. My weight reduction scheme: Staying single (no passanger, and no distractions). Requires the special type of repellent fragrence of wd40, used engine oil, and exhaust fumes. I may start bottling it and sell it as 'pugoff' women repelent.

I need help

busta
11-07-2007, 07:27 PM
Thai Brides are a smaller, lighter alternative to their English Counterparts.

Worth considering when people want to take things to the next level!