Aero Base data

[uber_understeer]

Hi, I found out that aero is based off the cars weight % (front) so I did some testing and maths and I got a good base aero setup. It’s only used as a guide and for a solid starting base for good balance at high speed. (can be used for all tracks but better for tracks like the ring and spa and Silverstone GP.) This is not set in stone as my results are differ from each car and person and tune/build.

1st column is the cars front weight %( after upgraded)
2nd column is the % of rear wing downforce compared to front
3rd and 4th column is an example of is front wing is 100 rear should be starting at X (4th column)

60 -33 100 67.0
59 -28.15 100 71.9
58 -23.3 100 76.7
57 -18.45 100 81.6
56 -13.6 100 86.4
55 -8.75 100 91.3
54 -3.9 100 96.1
53 0.95 100 101.0
52 5.8 100 105.8
51 10.65 100 110.7
50 15.5 100 115.5
49 20.35 100 120.4
48 25.2 100 125.2
47 30.05 100 130.1
46 34.9 100 134.9
45 39.75 100 139.8
44 44.6 100 144.6
43 49.45 100 149.5
42 54.3 100 154.3
41 59.15 100 159.2
40 64 100 164.0
39 68.85 100 168.9
38 73.7 100 173.7
37 78.55 100 178.6
36 83.4 100 183.4
35 88.25 100 188.3

[HLR_PRKid]

Thanks for sharing your test results uber, it’s appreciated! Will certainly try these out on my next build.

[reaper_mech]

hmm this seems promising… will post back after some testing TY uber

[HLR_PRKid]

uber – some quick feedback…I went back to a couple of the tunes I like, and, guess what! I am within a couple of pounds of what you came up with, lol. I do a lot of trial & error, thus, have a baseline and tweaking from there would be great. Will check out other tunes that I thought did well for me and keep comparing. Again, thanks!

[SatNiteEduardo]

Am I reading this right?

A 1970 Camaro has 57% front weight stock.

So if front aero is 100 the recommended base rear aero is 81.6?

I look forward to testing this as these ratios for rear aero look like about half of what I am used to seeing from open source tunes.

[uber_understeer]

yes, but its not the stock valve, its the upgraded valve and (most) stock cars dont have wings.

[SatNiteEduardo]

@uber_understeer

yes, but its not the stock valve, its the upgraded valve and (most) stock cars dont have wings.

I know both of those points. I am not in front of my console so could only find a stock weight ratio.

I know that if I build the car including adding aero and the new weight ratio is 56% then that is used. In that scenario if I wanted 100 front aero then the rear aero (base value) would be 86.4.

My comments were that any open source tune that I have seen pretty much for any car does not have a rear to front aero ratio that low, therefore I want to test this to see how it changes things.

I know that I would need to change something else in my tune to compensate because my tunes currently turn reasonably well at speed with rear aero at something closer to 160 or more if the front is on 100 (assuming rwd). I do have some awd and fwd cars with aero ratios like the table above but not rwd.

[HLR_PRKid]

@SatNiteEduardo

@uber_understeer

yes, but its not the stock valve, its the upgraded valve and (most) stock cars dont have wings.

I know both of those points. I am not in front of my console so could only find a stock weight ratio.

I know that if I build the car including adding aero and the new weight ratio is 56% then that is used. In that scenario if I wanted 100 front aero then the rear aero (base value) would be 86.4.

My comments were that any open source tune that I have seen pretty much for any car does not have a rear to front aero ratio that low, therefore I want to test this to see how it changes things.

I know that I would need to change something else in my tune to compensate because my tunes currently turn reasonably well at speed with rear aero at something closer to 160 or more if the front is on 100 (assuming rwd). I do have some awd and fwd cars with aero ratios like the table above but not rwd.

Great point EduardoI The examples I mentioned above were AWD, thus, I’ll also check on RWD later on.

[HLR_Mick]

Wouldn’t a light nose need more rather than less aero to keep the car balanced, and conversely, a heavy nose need less? The table looks reasonable for the middle values, but kind of wrong at its extremes. Or am I just reading this all wrong? o_0

[SatNiteEduardo]

@WearyMick

Wouldn’t a light nose need more rather than less aero to keep the car balanced, and conversely, a heavy nose need less? The table looks reasonable for the middle values, but kind of wrong at its extremes. Or am I just reading this all wrong? o_0

I think you are reading it wrong.

The table assumes front is always 100 and calculates a rear value and it reduces the rear value if the rear has a lower weight ratio.

[HLR_Mick]

@SatNiteEduardo

@WearyMick

Wouldn’t a light nose need more rather than less aero to keep the car balanced, and conversely, a heavy nose need less? The table looks reasonable for the middle values, but kind of wrong at its extremes. Or am I just reading this all wrong? o_0

I think you are reading it wrong.

The table assumes front is always 100 and calculates a rear value and it reduces the rear value if the rear has a lower weight ratio.

No, that’s what I thought I was reading. So if I set the front aero to 80 on a 50/50 car I should set the rear to 92.4. You’re also going to run into trouble being able to set the rear aero slider low enough in some cases. Doesn’t sound right, but hey, don’t knock it if you don’t try it. I’ll have a test and see what I think.

[SatNiteEduardo]

@WearyMick

No, that’s what I thought I was reading. So if I set the front aero to 80 on a 50/50 car I should set the rear to 92.4. You’re also going to run into trouble being able to set the rear aero slider low enough in some cases. Doesn’t sound right, but hey, don’t knock it if you don’t try it. I’ll have a test and see what I think.

oops I misread your post. My apologies.

uber is saying the aero goes where the weight is.

You are sort of saying you need aero to hold down the light end of the car.

I guess the comparison is what aero would people put on a Ruf? I will need to check my Ruf tunes in a few hours.

[Stringer54_x]

@SatNiteEduardo

@WearyMick

No, that’s what I thought I was reading. So if I set the front aero to 80 on a 50/50 car I should set the rear to 92.4. You’re also going to run into trouble being able to set the rear aero slider low enough in some cases. Doesn’t sound right, but hey, don’t knock it if you don’t try it. I’ll have a test and see what I think.

oops I misread your post. My apologies.

uber is saying the aero goes where the weight is.

You are sort of saying you need aero to hold down the light end of the car.

I guess the comparison is what aero would people put on a Ruf? I will need to check my Ruf tunes in a few hours.

My brain hurts :S

[freakinout1969]

@WearyMick

Wouldn’t a light nose need more rather than less aero to keep the car balanced, and conversely, a heavy nose need less? The table looks reasonable for the middle values, but kind of wrong at its extremes. Or am I just reading this all wrong? o_0

I’ve been thinking about this question, and this is what i’ve come up with. If you add aero you will notice no red weight gain it just adds weight in green to the entire car…because of the direct correlation with weighht distubution i assume its just adding weight straight over the wheel.

[Psycho_Sasuke]

@uber_understeer

Hi, I found out that aero is based off the cars weight % (front) so I did some testing and maths and I got a good base aero setup. It’s only used as a guide and for a solid starting base for good balance at high speed. (can be used for all tracks but better for tracks like the ring and spa and Silverstone GP.) This is not set in stone as my results are differ from each car and person and tune/build.

1st column is the cars front weight %
2nd column is the % of rear wing downforce compared to front
3rd and 4th column is an example of is front wing is 100 rear should be starting at X (4th column)

60 -33 100 67.0
59 -28.15 100 71.9
58 -23.3 100 76.7
57 -18.45 100 81.6
56 -13.6 100 86.4
55 -8.75 100 91.3
54 -3.9 100 96.1
53 0.95 100 101.0
52 5.8 100 105.8
51 10.65 100 110.7
50 15.5 100 115.5
49 20.35 100 120.4
48 25.2 100 125.2
47 30.05 100 130.1
46 34.9 100 134.9
45 39.75 100 139.8
44 44.6 100 144.6
43 49.45 100 149.5
42 54.3 100 154.3
41 59.15 100 159.2
40 64 100 164.0
39 68.85 100 168.9
38 73.7 100 173.7
37 78.55 100 178.6
36 83.4 100 183.4
35 88.25 100 188.3

This is very good and solid! I don’t know what’s the exact formula you are running but the math looks very solid. The formula i’m using gives me very similar results (10LBS difference). So I used your numbers and with some suspension tweaking The car felt better the lap time has not improved (YET) but the car felt better.So yeah! This is an excellent base aero setup! Thanks for sharing

[HLR_PRKid]

@Psycho_Sasuke

I don’t know what’s the exact formula you are running but the math looks very solid. The formula i’m using gives me very similar results (10LBS difference). So I used your numbers and with some suspension tweaking The car felt better the lap time has not improved (YET) but the car felt better.So yeah! This is an excellent base aero setup!

What equation are you using Psycho?

This linear equation, based on uber understeer’s aero tests, would be as follows:

RDF = FDF + [258 - 485*(%FW)], OR, FDF = RDF - [258 - 485*(%FW)]

where, RDF = Rear Downforce, FDF = Front Downforce, and, %FW would be the front weight % expressed as a decimal (ex. If 55, it would be 0.55).

Hope this helps!

@ uber - again, thanks for sharing your data. Hope this equation makes it a little simpler for the community.

PRKid

[Spot_The_Kitty]

@RelaxedPRKid

@Psycho_Sasuke

I don’t know what’s the exact formula you are running but the math looks very solid. The formula i’m using gives me very similar results (10LBS difference). So I used your numbers and with some suspension tweaking The car felt better the lap time has not improved (YET) but the car felt better.So yeah! This is an excellent base aero setup!

What equation are you using Psycho?

This linear equation, based on uber understeer’s aero tests, would be as follows:

RDF = FDF + [258 - 485*(%FW)], OR, FDF = RDF - [258 - 485*(%FW)]

where, RDF = Rear Downforce, FDF = Front Downforce, and, %FW would be the front weight % expressed as a decimal (ex. If 55, it would be 0.55).

Hope this helps!

@ uber - again, thanks for sharing your data. Hope this equation makes it a little simpler for the community.

PRKid

RelaxedPRKid,

How would I scale your formula if the min/max weren’t the regular 50/75 and 100/200.
In other words how did you derive 258 and 485?

Thanks a metric ton.
Meow.

[HLR_PRKid]

@Spot_The_Kitty

RelaxedPRKid,

How would I scale your formula if the min/max weren’t the regular 50/75 and 100/200.
In other words how did you derive 258 and 485?

Thanks a metric ton.
Meow.

@ Kitty – it should work the same. Of course this is assuming that the linearity that uber found during his test remains.

Getting to the 258 and 485 is basically analyzing the slope and intercept of a linear equation using to points in the x-y graph. Google it. y=mx + b, m=(y2-y1)/(x2-x1) after having m, then, plug in a pt (x,y) and you get b.

Hope this helps!

PRKid

[Spot_The_Kitty]

@RelaxedPRKid

@Spot_The_Kitty

RelaxedPRKid,

How would I scale your formula if the min/max weren’t the regular 50/75 and 100/200.
In other words how did you derive 258 and 485?

Thanks a metric ton.
Meow.

@ Kitty – it should work the same. Of course this is assuming that the linearity that uber found during his test remains.

Getting to the 258 and 485 is basically analyzing the slope and intercept of a linear equation using to points in the x-y graph. Google it. y=mx + b, m=(y2-y1)/(x2-x1) after having m, then, plug in a pt (x,y) and you get b.

Hope this helps!

PRKid

PRKid,
Thanks for the maffs, I love the nitty gritty of the numbers.
Thank you again.
Meow.

[HLR_PRKid]

@Spot_The_Kitty

@RelaxedPRKid

@Spot_The_Kitty

RelaxedPRKid,

How would I scale your formula if the min/max weren’t the regular 50/75 and 100/200.
In other words how did you derive 258 and 485?

Thanks a metric ton.
Meow.

@ Kitty – it should work the same. Of course this is assuming that the linearity that uber found during his test remains.

Getting to the 258 and 485 is basically analyzing the slope and intercept of a linear equation using to points in the x-y graph. Google it. y=mx + b, m=(y2-y1)/(x2-x1) after having m, then, plug in a pt (x,y) and you get b.

Hope this helps!

PRKid

PRKid,
Thanks for the maffs, I love the nitty gritty of the numbers.
Thank you again.
Meow.

Glad it help Kitty! And…saw the numbers you produced, right on!