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Discussion Starter · #1 ·
Hey people I love useless gadgets that serve no purpose in my car other than looking pretty. But I hate it when they have no English instructions.

Can anyone hook me up with some or have a translation of some sort. Obviously iv checked the web but couldn't find anything related.

:)
 

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Hey people I love useless gadgets that serve no purpose in my car other than looking pretty.
:chuckle:
I as well

Have one of these too, but can't calibrate the pressure sensors. I thought it wouldn't be that hard to figure it out, but it is.

EDIT: freakazoid3: It has pressure sensors, which should be mounted under the trunk lid
Besides of that, it has a build in G-force sensor, which messures the lateral and longitudinal G-force
 

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Discussion Starter · #4 ·
Hey David I'm not the only one with one of these then :)

So if I wire it in to the power without the pressure sensors all plugged in will it still measure the lateral and longi..? The reason I ask is I can be arsed to run all the wired for the sensors if I can't set them up (yet)
 

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I don't know if it's working without the sensors.
I have them in the right position. It just measures less than it actually should.
For example, my body weight of 75kg on the rear wing show only 36 kg on the downforce meter. I think it can be calibrated, but don't know how.
The shown g-forces sound plausible to me. You can set a warning too. Mine beeps at 1g or more, don't know how to change the value.


There is something in the manual, that the downforce meter can use the speed signal from the ECU too, but I don't know whats that for.

Lot's of open questions with this thing.
 

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Discussion Starter · #7 ·
Just found this.

Taken from:
http://www.tune2win.com/index.php/ad...wnforce_meter/

With the use of load cells, also known as strain gauges, the ARC downforce meter is able to measure the force generated by your rear wing. This makes it possible to evaluate multiple wing settings as well as multiple wing shapes without having to spend mega bucks to rent a windtunnel. Installation requires positioning the pair of load cells beneath your trunk�s bump rubbers. These are typically threaded to set the height that the trunk lid will rest at when closed. These bump rubbers transfer the majority of the vertical load from the trunk to the chassis and consequently are the ideal place to locate the ARC load cells. Simply remove the adhesive backing and place one load cell on each side of the chassis, where the trunk bump rubber will contact the load cell. Next, locate the ARC Downforce Meter display unit in the passenger compartment where you can easily read the display. Finally, connect the supplied harness to switched 12-volt power and ground and you are ready to power up the unit.

Calibration can be performed as follows. With the trunk open, power up the meter. The unit automatically calibrates to 0 Newtons every time it is started. Now adjust the trunk bump rubbers full short and close the trunk, the meter should still be showing 0. Open the trunk and start lengthening the bump rubbers equally until the meter reads 100 Newton with the trunk closed. Now simply reset power and you should see zero on the unit. This way there is no delay in response from the unit as force is built from your wing. Next apply a known weight to the wing and record the value on the display. We simply used our body weight fully supported by the rear wing to achieve our scaling value. With our application we found that 145 lb force was equal to 110 Newtons or 11 on the Downforce Meter (Newtons*10). For reference, 100 lb force equals 444.8 Newtons, so it is clear that the trunk mounts, striker, and weatherstripping are all distributing load and skewing the value seen at the bump rubbers. The correction for this is to apply a scaling factor. Knowing that 145lb force = 11 on the display, 145/10 = 14.5.

Now, simply multiply the ARC downforce Meter output by 14.5 to get your actual downforce in lb force. In our case our setup registered 17 on the Meter at 118 mph. 17x14.5 = 246.5 lbs.

Here we are only using one known weight to perform our scaling. To account for non linearity in the deflection of the trunk supports/surrounds you can use multiple known weights close to your target downforce. With this information you can plot a curve in a program such as Microsoft Excel, and then following a run, overlay your display output on the curve to get an even more accurate reading.
 

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Thanks
I have found this before, it will help by the installation, but not by setting it up. Don't wan't to calculate the forces by myself or whit an excel document. I want accurate readings from the device on it's own display. I think there must be something to re-calibrate it, think that's on the last site of the japanese manual.
 
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