home made corner weight gauge mk2

[lotusesprit1]

Finally found a way of easily setting my corner weights quite a lot of messing about but the car drives much better I wonder how much better if I had more experience and a track to test it on.

Must check the tracking again as I raised the front quite a bit.

I was really struggling to get repeatable results using platform scales which I no longer have access to so last week i made this out of a bottle jack.

I stripped and greased the platform threads as they had corroded fast in only 1000 miles and then set the platforms to the same height either side.

I almost don't believe the results I got but have checked it more than twice now. 

initial empty car results: 

FL 290kg  FR290kg RL338 RR 338!! 1256kg total

Add 2x 20kg batteries and a £25 bag of sand to the drives seat and i get

FL298 FR 338 RL330 RR 354 1320 kg total

Absolute accuracy is probably not that good but looking at the total weights not that far out. gauge scaling allows resolution to about 5kg

I found having the hand brake changed the results quite a bit if left on while measuring.

now do I leave well alone and make sure I have a passenger on track days? or fiddle so I know the settings for a track day....

with just me (-25 kg did not have another 25kgs around)the cross weight comes out to be 50.6% using the online cargister calculator

what I started with was so bad it was unmeasurable. would an average driver notice 1 % cross weight? What to people who track there cars regularly target?

 

 

 

[CarBuff]

Congrats, that is really clever.

 

More details and close-up pics, please... Are you lifting the wheel via that bottle jack and wood block?

 

Is that a dial indicator or something else?  What does it measure?  How is it hooked up?

 

+++++++

I'd set the car up for a driver only...with a passenger you are not planning to go 10/10ths, are you?

 

 

 

 

[lotusesprit1]

Its just an old bottle jack, pump still raises the piston I added a pressure gauge that measures the pressure in the big lift piston. the wood gives me a bit of height. I calculated it to give 50 kg per 100psi but extended the arm so now it read 31kg on the arm end to 100psi on the gauge scale, I used a piece of nylon on the parallel lift bar so as not to damage the wheel I am going to refinish these soon anyway but it does not leave a mark. calibrated with a set of bathroom scales and me.

Apparently you can get commercially made units.

The hardest part is finding a piece of truly flat ground to set it up on, I rest the wheel on a piece of paper and take a reading just as it can be pulled out while leaning on the leaver arm.

 

I think I will try setting the car up for just me as the main people who I take as passengers don't weight very much