What are good general aero settings to use with the FOX? I've read that to make the fox fast you need low aero settings but how low is low? I don't think it would be possible to go 0/0 right? But what about 3/6 (front / back?) Obviously the track matters so I'm just looking for general guidance here.
One way to get a general idea is to calculate the efficiency of the wings (lift over drag) for the range of usable aero balance. 25-50% is a good place to start, althogh 50% will probably be too much.
He means the simple drag/lift ratio. Taking the FOX' front wing as an example, if you set it to 0° at 40m/s test speed, it has a ratio of 38/115 = 33%, whereas if you put the angle to full 20°, it has a ratio of 200/885 = 22.6%.
This basically means that in this example the front wing becomes more efficient as you increase its angle. So while reducing the front wing will reduce drag and make you faster on the straights, you lose proportionally more downforce than you reduce drag.
To understand why this happens, just imagine the extremes. If you put the wing angle in a position that doesn't create downforce (slightly upwards), then the whole wing assembly will still be there and produce drag. Or the opposite, if you put the wing to a full 90°, there will be no downforce but only heavily increased drag.
Seeing that there is no "general" track, there is also no universally correct wing setting.
The main thing to consider is the aero balance, meaning the ratio of front downforce to rear downforce, which is also shown in the setup screen. Once you have that set up in a way you like, you can relatively easy adjust the downforce per track by simply keeping the ratio the same, which means in general the car will also behave for the most part the same, just with more or less grip in the corners.
As to which values to choose, that depends on the track. The longer the straights and the faster the corners, the less downforce you take. In general you'll try to use as little downforce as possible, trying to find a balance between being fast on the straights and not losing too much time in the corners.
I guess I phrased the question wrong. I'm looking for a good place to start when setting up the FOX for a track. I've started with the default setup which seems to be overly tight on everything so to try and get a decent setup to start tweaking from I'm more looking for suggestions on what aero setup is a good place to start so I can then start dialing in the rest of the car.
The lift/drag ratios peak at 7° in LFS, for any wing. Note that, because the body creates a huge amount of drag but no downforce, the lift/drag ratio for the vehicle as a whole keeps increasing with wing angles.
It's not a figure I'd get particularly worried about in LFS though, least not until we can design our own wings.
For picking wing angles, I always use something that gives me about the same top speed at the end of the longest straight as what the WR lap manages. Let somebody else do the testing as to what the optimum settings are.
This is probably the best advice you can get, I tend to treat the wings like a mix between the gears and the dampers... you need to ensure that the amount of DF doesn't hinder your top speed doesn't allow you to overcook the back ( Single seaters can (and will) burn out clutches and tyres in just one spin) and keeps the from end tight enough to belt through the corners without getting understeer.
Understeer, your front/rear DF ratio is too low, ie raise the front/lower the back..
Oversteer, your front/rear DF ratio is too high, reverse the above
Being overtaken on a flat-out straight, both are too high
Becoming unable at high speeds, both are too low.
I'm sure you realised all of this but I will mention it again as this rather simplistic view of it all is fairly accurate, take for example, the FBM on westhill, because Westhill is a VERY fast circuit and in the FBM there are only two points where you won't be in at least 5th gear, thr DF on the front can be quite low, but you want a fairly decent rear DF figure to keep the grip up through the long fast corners...
Aston Cadet, however, is much different affair, the slower top speed of the track allows you to lower the back end DF, but the (quite tight) mid-speed corners require a bit more front end DF, and as the top speed is fairly low you can also sacrafice a bit more top end to gain grip through the corners.
Stop this false myth, they will NOT unless you do something wrong... Like, staying on the throttle while rolling backwards with autoclutch on...
If you disable the autoclutch (which will help shifting times btw), you'll have no problems whatsoever, as the car stalls before there is any noticeable heat...
I'd argue that instability (did you typo unstable?) at high speeds would be due to a front bias in the aero distribution. So more rear wing/less front would be needed. If you wings are set too low at both ends, this would cause corner speeds to drop, and you'd find, with all the extra straight line speed, you would be braking a lot more compared to someone with wing angles optimised for the particular combo.
I guess it depends whether we're talking oversteer instability or just at high speeds. Obviously the higher the speed the more you should notice the DF (ie the ride a little lower, the pressure on the tyres a little higher) but if you have both ends lose grip (ie a 4 wheel drift) thats instability due to not enough DF on both front and rear??
And due to a drop in tyre grip over momentum this is more likely at higher speeds, this what I was trying to get at with that post...
I find with the FOX that any more than a 46% front aero balance and it becomes very hard to set up the suspension to give good balance.
Most of my FOX sets are between about 3 degrees front/4 degrees back for low downforce circuits like Aston Historic and about 9 degrees front/13 degrees rear is about as much downforce as I ever need for somewhere like Fern Bay Black.
To understand what downforce I need I tend to watch the WR lap and output the lap data. I then output my own lap data and compare the acceleration, split times and top speeds using F1 Perf View. From this you can see very easily if you have more or less downforce than the WR holder.
So do you typically setup your aero first, then tune the rest of the car to it or vice versa? The spreadsheet I'm using that walks me through the steps goes something like this:
1 - set up the springs
2 - set camber and tire preasure
3 - set caster, then redo step 2
4 - set toe, the redo step 2
5 - gearing
6 - brakes
7 - dampers
8 - is aero.
I got the spreadsheet from a link someone posted in one of my other threads. Are these the same steps you guys follow?
I completely disagree with that spreadsheet. Gearing and aero are definitely one of the first things to set up roughly, otherwise any tampering with springs and dampers is futile. You need to actually drive the car a good amount of laps to be able to make suspension adjustments that aren't complete guesses, and as long as gearing and aero are completely off the info you get from driving the car is inherently flawed.
In reality it looks more like this:
1) Set up gearing/aero roughly
2) Do a quick sanity check on tyres/suspension
3) Drive
4) Tweak tyres/suspension
5) Drive some more, get good experience
6a) Finetune tyres/suspension
6b) Adjust gearing and aero to your higher driving skill (mostly means longer gearing and less aero)
6c) Adjust tyres and suspension to your higher driving skill (mostly means more oversteer)
6d) Repeat at #5
I don't set things up in any particular order. I just change settings that 'feel' incorrect as I am driving. I am only able to do this because making setups has been my passion in LFS for over 3 years now.
It takes a long time to learn how setup adjustments change the feel of the car. Best thing to do is just to start lapping. When you can lap consistenly (to within 1 or 2 tenths at each split time) then you can start making small adjustments and feeling the effect of those changes. Over time you build up experience as to what has what effect. There are no shortcuts.
And no matter how good you are at understanding the dynamics of setup, you will still have to do say 100 laps of a circuit if you want to make a set of any quality.
A lot of the time I think people mistakenly believe that you can learn setup skills by reading simple rules and guidance. It doesn't work like that. Experience is the only thing that counts.
When I test drive, I ask myself these things:
Does the car react slowly or quickly?
If the car is too 'squirrely' you may need to run a generally softer set.
Is the car generally oversteery or understeery?
Oversteery? u need softer rear/harder front or less power diff lock/more coast lock.
Is the car oversteery or understeery over bumps?
Oversteery? u need more front damping or less rear damping
Is the car oversteery or understeery at corner entry?
Oversteery? u need more front bump damping (or more rear rebound but to a lesser extent) or less rear brake or more coast lock.
Is the car oversteery or understeery at corner exit?
Oversteery? u need less rear bump damping or less rear rollbar or more front rollbar or less power diff lock.
When the suspension is fully loaded i.e. mid corner, is the car oversteery or understeery?
Oversteery? u need more front ARB and less rear ARB
Ofcourse if the answer to any of these questions is 'understeery' then just make the opposite change.
Tyres? Simple, make sure the temps are as well balanced as they can be from front to back if you intend to do long runs with the set (less important on quali sets)
Also, The inside edge of the tyre should be 10-15 degrees above the optimum temp, middle should be 5-10 degrees above optimum and outside edge I find works best when about 5 degrees below optimum. If you want more inside edge temperature increase the amount of negative camber. I always leave tyre setup until the end when I am happy with the suspension and aero balance. Ofcourse that doesn't mean I won't change some suspension settings and then need to go back and amend the tyre pressures and cambers.
If you are completely lost and don't know what you are aiming for then why not 'Test Drive' the WR hotlap setup and simply try and make your car feel the same. This has been very successful for me in the past.
These are some general guidelines but as I said before, you need to be able to have driven enough and to have made enough setup changes to know all this stuff for yourself.
Oh, and as far as aero is concerned I generally try and use as little rear downforce as I can get away with. Rear downforce promotes understeer which always equals slower times.
As I mentioned before 46% front aero is about as aggressive as you can go and to achieve that the downside is that you need a lot of front suspension stiffness which can then result in understeer in slow corners where the wings are not having an effect.
That brings me on nicely to another important point. Aero settings have a greater affect in high speed corners and almost no affect at all below about 50mph. Suspension settings will affect all speeds of corner however a high aero setup can mask problems with the suspension settings which will become more apparent in low speed corners.
Hope this helps. If you need more advice then come visit gentlefoot.com#1 one weekend. There are always a few of the GFC boys about to help you.
Thanks for the advice Gentlefoot and I did check out your site. Looks nice. Please don't get the impression I'm trying to shortcut the learning process but by asking questions I've gotten a lot of information, especially things to look for like if you did this then you should be feeling this type of stuff. In fact a few times I didn't know what I was feeling until someone told me.
I put in over 160 off line laps just working on camber / tire pressure not to long ago, that was on top of the laps to learn the track ect so I'm willing to put the time in, please don't think I'm one of those people unwilling to work hard. Infact, that's one of the reasons I don't want to use other peoples setups, so that I have to learn how to be fast.
You will do well with that approach. I used to just steal people's sets and use them but although I was pretty quick it it wasn't enough. Only you can set the car up to the way you like it. When I started doing that I found the extra 5% I needed to turn podiums into wins.
Come along to the gentlefoot server on Saturday. We can give you sets so you can get a feel for how the FOX should respond. Also we can give you some tips on lines and stuff. It will be very useful for you to watch some of the GFC guys lapping.
I can make some changes to the set too for you, tell you what I did and you can feel the differences.
