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Well ARC have come to the party with a neat little tunning aid (or toy :D )called a Down Force meter, it is capable of measuring downforce in Newtons and can compare cornering g's (+ or -3g's)

Test case S13 Silvia with a 3 step adjustable URAS wing (budget 3d style) 1550mm wide and 290mm high

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Above results are in newtons (example 120kmh step 3 (full deflection) saw 40n of downforce at 120km/h)

I always wondered exactly much force one of these things actually makes at what i will call normal road speeds. We had some real word testing results at race pace but it is never easy to gauge results at a street level. So this information comes in kinda handy.

During wet testing last year Cats gut feeling was that with the wing on full deflection she was experiencing more rear grip whilst entering (3rd and 4th gear corners) was indeed correct.... now we just need to measure it real time at a track and find the relationship between yaw angle and down force.

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Thats interesting but WTF are Newtons??? Convert to pounds per square inch, kgs, or something real?

The newton (symbol: N) is the SI unit of force

A newton is the amount of force required to accelerate a body with a mass of one kilogram at a rate of one meter per second squared.

Thats interesting but WTF are Newtons??? Convert to pounds per square inch, kgs, or something real?

As said, Newtons are the proper units for force. But if you do want to convert to something "real", 1kg = 9.81Newtons or 1Newton = 0.102kg

any sort of angle'd component on the car will provide downforce, nothing really special there.

the main question is - is it an improvement for street?

- will you require that extra downforce (which converts to traction) on the street?

- increase/decrease in fuel economy?

i suppose in your case, you can now fine tune to suit your track settings (where fuel is negligible), and see some solid performance results. isnt that the purpose of a wing? performance - or have ricer's just lost the plot?

i guess i'm just speaking out of my arse (and setting some context for discussion) and stating what people already know.

interesting results none the less; good to see some mythbusting type work going on.

EDIT: here's an after thought - are you able to log or graph the results?

maybe try a drag style launch from 0km/h to xxxkm/h and see if there are improvements in 1/4 mile. (although from the data you currently have it looks like it'll be minimal, since by the time you are going 80km/hr traction isnt much of an issue).`

also would be nice to see power/torque/whatever vs. downforce to find some optimality

any sort of angle'd component on the car will provide downforce, nothing really special there.

the main question is - is it an improvement for street?

- will you require that extra downforce (which converts to traction) on the street?

- increase/decrease in fuel economy?

i suppose in your case, you can now fine tune to suit your track settings (where fuel is negligible), and see some solid performance results. isnt that the purpose of a wing? performance - or have ricer's just lost the plot?

i guess i'm just speaking out of my arse (and setting some context for discussion) and stating what people already know.

interesting results none the less; good to see some mythbusting type work going on.

EDIT: here's an after thought - are you able to log or graph the results?

maybe try a drag style launch from 0km/h to xxxkm/h and see if there are improvements in 1/4 mile. (although from the data you currently have it looks like it'll be minimal, since by the time you are going 80km/hr traction isnt much of an issue).`

also would be nice to see power/torque/whatever vs. downforce to find some optimality

for the street forget it... unless you do top speed runs, i removed the rear lip off my soarer and it got squirrely at any thing over 170... put it back all good.

I am still playing but yes you can actually log laps ie downforce versus g" etc but i have to play a bit more with it.... all in japanese... fumbling through it.

yeah it's a pretty cool toy. I played with one a little bit earlier this year in japan. ARC had one set-up on display with a mini GT wing. you could push on it etc and see the readings. good for a bit of a laugh, but I reckon the results will be pretty predictible for you guys anyway. more angle=more downforce. deciding whether or not it's a good thing is up to the driver, the meter can just tell you how much you have.

yeah it's a pretty cool toy. I played with one a little bit earlier this year in japan. ARC had one set-up on display with a mini GT wing. you could push on it etc and see the readings. good for a bit of a laugh, but I reckon the results will be pretty predictible for you guys anyway. more angle=more downforce. deciding whether or not it's a good thing is up to the driver, the meter can just tell you how much you have.

yeah this one is on loan... just wanted to play with a new toy :thumbsup: but i want one :)

I'd also love to "borrow" that meter Trent :)

I've just invested in a set of Wing Upright Extensions for my car as I feel it should significantly increase the rear downforce but I'd like to know for sure if it has worked the way I think.

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so let me get this right, at 120km/h on the steepest setting the difference was 4kg extra over the wheels? and you're sayin the driver could feel a 0.3% difference in a say 1200kg car?

Its a very interesting gauge and I'd love to give it a go myself....but % difference should be pretty disappointing. Or was the nm/kg conversion above incorrect?

as Duncan said - 120km/h on steepest setting is 4kg. That's nothing. Aero devices really have minimal effect until your speeds are higher (think 180+).

Removing a rear lip on your car is a slightly different story, as the lip tunes the airflow leaving the back of the car. I can certainly see how it would make a difference at freeway speeds, if the change is significant enough. For less significant changes you'd probably again feel it at 180+, as URAS found.

so for the streeet car this is purely for looks.

though for the race car that regularly sees 170+kph they are a benifit.

i had a similar wing though i never got arround to installing it.i do see the track a few times a year,though i sold the wing.still though if i owned a race car it would have aero mods.at least now we can see a real world result of the wing working and not just people tellin you that they can feel the rear end stick better to the road.

are you going to test out an adjustable twin blade wing.from word they are the best at providing downforce.

yeah well 80% of race track corners in Aus are 80-120km/h there are probably only 5 that you go through as quick as 150. All interesting food for thought.

Would also be interesting to see the figures URAS when there is yaw as well, the wing you have seems to be pretty big but the endplates extend down mostly not up which is where you would want the air to not spill?

BTW definately no impact at legal road speeds.....who is hitting a corner on a road at maximum traction limit on the rear tyres that needs an extra 4kg to stop a slide?

In a book i have called 21st century performance, they test the r32 gtr and find that at 100km hour it is generating 6kgs of downforce.

I think something is up when URAS' wing is only generating roughly 3 kgs at 100km hour.

Dunno whats right or wrong, just thought id throw it out there.

Edited by 2630GTS
yeah it's a pretty cool toy. I played with one a little bit earlier this year in japan. ARC had one set-up on display with a mini GT wing. you could push on it etc and see the readings. good for a bit of a laugh, but I reckon the results will be pretty predictible for you guys anyway. more angle=more downforce. deciding whether or not it's a good thing is up to the driver, the meter can just tell you how much you have.

Not quite more angle = more downforce.

You should find max downforce would be at around 45Degrees.

Going much further past this, and you will get less downforce, and more drag

The downforce should be something of a pure sine graph. Downforce = Sin(x)

Whilst the drag will become Drag = Sin(x/2)

This is why pure race cars are tuned, and a trade off is found with the minimal amount of downforce they will accept, and the max drag they will accept.

so let me get this right, at 120km/h on the steepest setting the difference was 4kg extra over the wheels? and you're sayin the driver could feel a 0.3% difference in a say 1200kg car?

Its a very interesting gauge and I'd love to give it a go myself....but % difference should be pretty disappointing. Or was the nm/kg conversion above incorrect?

Remmeber guys this is just an aid, it CANNOT read the TOTAL amount of downforce it is just giving you an idea as to what your changes (angle of attack and hieght etc) are doing, this newton reading along with your g dataloging allow the user to make an informed decision. Remmeber other forces like the boot latch, hinge mechanism and its affect on the leverage to the sensors all effect the readings.... it is a tool not a magician :(

One of the only ways i could find the total downforce would be to do two runs on a flat road, with pressure sensor's in between the rear strut tops and the body. Do one run as a control and log the results do another run with the wing at full deflection and minus the original results from the second.... this would give downforce as measured at the strut top... still not at the end user the wheels but for arguments sake fairly close.

Would also be interesting to see the figures URAS when there is yaw as well, the wing you have seems to be pretty big but the endplates extend down mostly not up which is where you would want the air to not spill?

It is based on a GT wing much like the sards and Voltex 3D wings, the 3d section allows the best comprimise between maximum downforce (more than std airfoil types) and minimum drag.

mate there is no way those 4kg over the rear wheels will make a noticable difference. Just put 4l more fuel in next time.

To increase rear traction, look at:

* the line you take through the corner (turn in later)

* increased throttle control

* better or wider rear tyres

* decreased camber at the rear

in that order

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