vroomba Posted April 8, 2016 Report Share Posted April 8, 2016 A bit of fun this one. Professional corner weights are about £800 so can you spend 1/10th of that and use bathroom scales? Here's my video. https://youtu.be/071xPmVgE0E This time we weigh our car. Cheaply. If you are like me and obsess about car stats such as power to weight ratios or if you’ve removed or replaced parts on your car then you’ll want to know how much your car actually weighs. The cheapest corner weigh system I could find was just under £800. Bathroom scales are about £10 each so I wondered if I could use theses instead? My car’s handbook says the car weighs on average 1375 kg. Bathroom scales can weigh up to 180 kg each so 1375 divided by 180 is roughly 8. Surely putting two under each wheel would give close to the correct weight? I went to my local supermarket and bought 10 scales to find out. Here’s a summary of what we’ll be doing · Lift one wheel · Place scales · Place wood · Lower wheel · Repeat · Tools and parts you will need · Jack · Wheel Chocks · Ten Bathroom Scales rated to 180 Kilos · Wood at least 50mm thick. 1. Take a note of how much fuel is in the car. Here you can see I’ve about a quarter tank. You’ll need this to work out the final weight of the car. 2. Remove anything you are not going to keep in the car. Here I’ve removed the spare wheel toolkit and cd player. 3. I picked up two 2.4 metre “2x5”s from a local hardware store. These measure 47mil x 125mil. I made one cut at 900 mil on each piece of wood to give me four pieces: two of 900 mil and two of 1500 mil. 4. Next you’ll need to lift one corner of your car. Please click the screen now refer to my lifting guide if you’ve not sure about this. 5. Make sure the handbrake is on and lift the passenger side front wheel first. 6. Place two scales under the wheel then place a piece of wood on top. 7. Slowly lower the wheel onto the wood. 8. Place a chock in front of the wheel to stop the car rolling forward when you lift the rear. 9. Repeat for the remaining wheels. 10. If your car is light enough in theory that should be it. In reality the rear of my Boxster is much heavier than the front (due to the engine being there) and would error the scales. 11. To fix this I used 3 scales each on the rear wheels. You have to experiment with the scale’s position as you need to spread the load evenly over them. 12. Once you have all 4 wheels on scales and each scale giving you a reading remove the chocks and simply write down the reading on each. You will have to give each scale a nudge to get them to display the reading. 13. So here are the results for my Boxster. The front driver’s corner is 143.1+153.4=296.5 The front passenger is 139.5+130.7=270.2 The rear driver is 179.3+62.8+130.7=372.8 The rear passenger is 32.4+182.4+171.5=386.3 14. This gives a subtotal of 1385.8 kg The wood weighed 11.8 kg so removing that we have 1374kg 15. Let’s talk about the weight of the fuel. From my research petrol weighs 0.74 kilos a litre. My car has a 64 litre tank so a quarter of that is 16 so the fuel in the car weighs roughly 8 kilos. So without fuel my car weighs 1374-8= 1366 kg 16. So at 1366 kg that almost in the middle of the weight range for this car given by the handbook so whilst the bathroom scales may not be absolutely accurate they are in the ballpark. I’ll try to get the car on professional scales and see how accurate this in in the future. 17. For those who are curious, the weight of the spare tyre is 12.1 kg, the tool kit and warning triangle is about 3.2 kg (730+884+1640 = 3254g) and the cd player weighs just under 1.9 kg (1.894g) making a total of 17 kg 18. Final power to weight stats for all those interested. Boxster S: 252 bhp Car empty: 184 bhp/t (252/1.366) Car with half tank fuel and me: 172 bhp/t 252/(1366+24+75) As above but without 17kg removed: 170bhp/t 252/(1366+24+75+17) You’ll notice that removing the 17 kilos of weight from the car is the equivalent of an extra 2 bhp per tonne. Link to comment Share on other sites More sharing options...
topradio Posted April 8, 2016 Report Share Posted April 8, 2016 I think that you may have too much time on your hands Seriously though, interesting test. I would like to know how the result compares to a measurement on a dedicated setup. Also - I think you could corner the market in bathroom scales on eBay. Link to comment Share on other sites More sharing options...
vroomba Posted April 8, 2016 Author Report Share Posted April 8, 2016 Yes, you could be right Will look out for somewhere to go to get her weighed. I thought I go get it done at the local council weigh-station but they basically ignored me then told me it was was trucks only. If anyone owns corner weights and is happy for me to travel over to try them for comparison let me know! Link to comment Share on other sites More sharing options...
Boxob Posted April 8, 2016 Report Share Posted April 8, 2016 My idea is to drive the car to the weigh bridge at our local community tip and give the operator a fiver! I admire your ingenuity though If you haven't, read Marseille's thread about taking weight out his car. He removed nearly 100 kilos! Link to comment Share on other sites More sharing options...
Stuart21UK Posted April 8, 2016 Report Share Posted April 8, 2016 so not so evenly balanced as the drivers side weighed 669.3 kg and the passengers 656.5 kg... with a driver and no passenger then that makes drivers side even heavier... Link to comment Share on other sites More sharing options...
r1flyguy Posted April 8, 2016 Report Share Posted April 8, 2016 12 minutes ago, boxsternoob56 said: so not so evenly balanced as the drivers side weighed 669.3 kg and the passengers 656.5 kg... with a driver and no passenger then that makes drivers side even heavier... What sides the fuel tank???? Genuine question by the way. Is the fuel evenly distributed? Link to comment Share on other sites More sharing options...
Andy Mac Posted April 9, 2016 Report Share Posted April 9, 2016 I "think" (from swapping the fuel sender out on a 986) the fuel tank sits central - under the battery - evenly distributed. Link to comment Share on other sites More sharing options...
PaulQ Posted April 9, 2016 Report Share Posted April 9, 2016 Having replaced my pump a while ago, I would say yes, pretty central. Link to comment Share on other sites More sharing options...
paulchamby Posted April 9, 2016 Report Share Posted April 9, 2016 Interesting, I'm surprised it even worked but well done for giving it a go! The weight difference could be that the car was not perfectly level as it will then exert more force on the one side. Link to comment Share on other sites More sharing options...
vroomba Posted April 9, 2016 Author Report Share Posted April 9, 2016 Fuel tank is under the battery at the front of the car. Not taken it apart myself but looks pretty central from the repair manual. Link to comment Share on other sites More sharing options...
RobScott Posted April 12, 2016 Report Share Posted April 12, 2016 There's an even cheaper and easier way to do it with bathroom scales its all about levers Link to comment Share on other sites More sharing options...
vroomba Posted April 13, 2016 Author Report Share Posted April 13, 2016 I'm intrigued. Please divulge Link to comment Share on other sites More sharing options...
Stuart21UK Posted April 14, 2016 Report Share Posted April 14, 2016 ....indeed, go on... Link to comment Share on other sites More sharing options...
RobScott Posted April 15, 2016 Report Share Posted April 15, 2016 Its a pretty old trick of making up a metal or wooden lever system, you just hook it under the top rim of the wheel, push down on the lever till the wheel just lifts off the floor, and the scales are pushed down, you then multiply the result by the about of leverage you have used. Its not totally accurate as you also have the weight of the person pushing down, but you can subtract that too if you are being an*l. Link to comment Share on other sites More sharing options...
RobScott Posted April 15, 2016 Report Share Posted April 15, 2016 A similar idea to one of these: http://www.advantage-motorsport.co.uk/ada-corner-weight-gauge.html?gclid=Cj0KEQjwosK4BRCYhsngx4_SybcBEiQAowaCJeWS92gj1LROtMWzwoUwcsWaAwEcpYsx2m2E8oDdtWMaAoGF8P8HAQ Link to comment Share on other sites More sharing options...
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