Okay, so I’ve been talking to Nova about teaching some tuning. Not digging up bones, I want this to be something positive for everyone. I’ll have to do this in bits and pieces to avoid double posting and taking up to much of the page. There are steps to my philosophy on how you tune one of these cars. I’ll do step one now.
Step #1: engine/ballast combo
You most likely can’t run the same engine/ballast combo all season. The PP goes up and down forcing you to make changes. Then different tracks prefer different combos as well. The engine package that makes the most PP isn’t always the fastest. Same for the chassis. You can max PP and be slower in other words. So it’s a trial and process of elimination that gets you the right combo. Your car has a set balance 55:45, 50:50, 46:54, whatever it is. So the biggest adjustment you have to offset this is your ballast. Engine performance cannot supersede ballast in most cases and ballast cannot supersede engine performance in most cases. So once again it’s trial and testing to see what the particular track/PP fits best. So you move the ballast to its lowest PP setting. Put together an engine package, use the computer to tune it. Then dial the ballast back to see if it fits within spec. So it takes like 4-6 cars to do this. Then the aero comes into play. 50:50 isn’t really 50:50 because you have to use some math to figure the true balance out. So my car is 3131lbs. I take and divide that in half which gives me 1565.5. Then you take and add your max downforce numbers to that. So mine is front 100/rear 350. So it’s 1665.5 front/1915.5 rear. That’s just a 50:50 example. So you have to offset this with ride height/spring/sway bar adjustments which I’ll get into more in step2. Keep In mind that the aero doesn’t make these changes but at high speed. But the point is you know you have to wedge the rear up a little because it will have more weight pushing it down into the track than the front. So slow tracks not so much, high speed you better be looking into it. Then you can determine what ride height/spring or(NF) combo to go with. Lol
Step#2
Ride height ,Natural Frequency and sway bars.
Ride height:
The ride height is a important part of the setup. This is because everting that follows it will have to be manipulated if it is moved. More times than not, it cannot be moved without sacrificing downforce, or mechanical grip. The idea is to get the car as low as possible to lower the center of gravity. Too low and the car can bottom out, too high the downforce doesn’t work correctly. I usually start around 1/4 of the total height. You lower the car the natural frequency must be raised to limit the travel of the suspension. Although ride height is the beginning of the process, it can also be the end of the process. Raise the front and it is called negative rake. Raising the rear is positive rake. It’s good practice to keep both ends of the car around the same height and use other methods of adjustment to manipulate handling characteristics.
So now that we have established our ride height and total weight. We have done our calculations to find out where it actually is at speed. We have to determine what Natural Frequency is needed to properly support the (sprung weight). There is no exact calculation I can give you to establish what these are. All I can give you is ball park estimates that have been established from years and years of race teams using these figures. Both natural frequency and sway bars effect the center of the corner. It can effect the transitions both in out of the corner. But the main thing here is to establish a good overall balance of the race car. And then you can use other methods such as dampening and differential setting to further adjust both overall feel and the transitions of the corner. The Natural Frequency examples are found at the bottom of the page.
Part 2 of step#2
Sway bars
As I stated previously sway bars effect mostly the center of the corner. But they can be altered to effect the transitions both on and off the corner. But they are most importantly used to find the best overall feel and grip of the car.
Start in the middle 5/5 paired with the best natural frequency that suited your car. Then take them both up a click 6/6, then down 4/4. If 6/6 feels better than 4/4 then go to 7/7. Test and repeat this process until you feel the most comfortable with what you have. Then begin to split the two. 7/6, 6/7, 7/5, 5/7. Until you find the best combo. Remember this is not the final setup for the traditional stages of the corner. We can use other methods to achieve this. You may decide to use natural frequency or other methods to make overall handling changes to the car example 2.5 / 2.7 paired with 7/6. The NF settings must be moved up and down, then split in the same process as I showed you with the sway bars. Think of the 4 corners of the car. It’s better practice to have the nose roll less because if a corner is raised, downforce is lost. So the idea is to have the nose as low as possible and as level as possible without effecting mechanical grip.
Dampening:
Effects all 4 corners of the car.
Extension (rebound):
The dampers are the most confusing part of the process. Try to think of the car as a rocking chair. You have rubber bands on both sides that cause resistance as you rock. This would be an example of (extension). The more rubber bands you add the number goes up. Then when you take them away you can rock in that direction more quickly. Extension is what you typically want to use to adjust handling characteristics. You want to work on the opposite side of the car you want to adjust. So corner exit (oversteer) you would want to take extension away from the front of the car. So the cars weight sets back onto the rear tires faster. If you are having (under steer) on corner entry, you’ll want to take away extension from the rear. (Number goes down). You are taking the rubber bands away to let you rock forward faster. Too high overall rebound (extension) can cause the car to dig in and snap. Too low and the car will feel as if it is wondering around. It is typical and ideal to have higher extension numbers than compression numbers. This is the proper way to set the dampening.(in most cases) lol
Compression (bump):
The other setting you will have with dampening is compression or as I call it (bump).
Now think of the same rocking chair. Under the rockers you have squish balls. The more squish balls you put under the rockers the more resistance (high number). So it slows you down rocking back and forth. You take them away, the faster and more freely you rock back and forth (low number).
Bump is to fine tune what you have done with natural frequency. It is typical to run a low bump in most cases. Bump effects grip, rebound (extension) isn’t as effective at achieving mechanical grip. So you need to get the natural frequency and sway bars close then use bump to further enhance that. The lower the bump the more of the track you feel. The higher the bump the car feels like it’s not digging into the track. High bump can cause the car to hop when curbing is used. You need to have good bump so you can utilize the curbing to your advantage. Curbing if used correctly can actually pull the car around the corner giving you extra rotation. So it’s really important you get proper bump settings to shave off time and give your car a good stable platform to race hard. This is what keeps you on track and gives the driver some forgiveness in side by side situations when the proper line cannot be utilized. Bump can induce under steer or over steer (over steer 25/27) ( under steer 27/25). Just remember that it is more common to use Extension to adjust the attitude of the car. You don’t want to sacrifice bump to get the car to handle the way you want it to. Then the car can’t handle the curbing.
So the proper order is as follows. From left to right.
#1 Engine/Ballast/Aero
#2 Ride Height/Natural Frequency/Sway bars
#3 Compression/Extension
#4 Camber/Toe
#5 Transmission
#6 Differential
Camber/Toe
Okay, so the final step in the suspension is Camber and Toe.
This is where things get tricky. Everything we have done so far is going to be manipulated by these settings and there’s a million ways to go with this. The only thing with Camber that I can tell you for sure, is that we don’t want to use positive Camber.
Negative Camber:
Negative Camber is when you lean the top of the tire (at the top of the fender well) in towards the engine.
When the suspension compresses the A-arm or strut, whatever the car used squishes the bottom of the tire out. This is because it is really a lever. So when you lower the car, it kicks the bottom out. When you run a soft natural frequency, it kicks the bottom out under load when cornering.
So if you run softer settings you don’t have to use as much Negative Camber. The suspension takes care of that for you to a degree.
Negative Camber effects the entire corner, but can influence transitions both on and off. It can be manipulated to induce certain characteristics in these transitions. So just know this. The more you crank Negative Camber into the setup the more your stopping distance is likely to increase. Especially with a stiff setup because you have the tire kicked out even when the car doesn’t have a load on the suspension. Negative Camber also will most likely cause the driver to have to turn the wheel more on entry because the part of the tire touching the ground actually has to turn further. It is further away from the car. So this is where a blend of Toe comes in to correct this and get some of that trade off back. So they have to be tuned together.
Not enough Negative Camber:
Car will feel edgy, loss of grip under cornering load (center).
Too much Negative Camber:
The car will suffer from increased stopping distance and increased tire wear. Sudden unexpected loss in grip when cornering.
Start at 0.0 for both front and rear. Then add in .5 increments until you go too far then dial back to optimal handling.
Oversteer: 1.5/.5
Understeer: .5/1.5
Optimal Camber especially on the driven wheels can give the driver a sense of security.
Also on high speed tracks optimal Camber in a straight line can improve top speed.
Toe:
Both the front and rear of the car can have toe adjusted independently from one another to assist Camber and create either speed or security. And can even induce certain handling characteristics.
Front Toe:
Front Toe in most cases effects corner entry and straight line stability.
Front Toe In/Toe out:
If you spread the front portion of the front tires apart, that’s Toe out. If the car feels sluggish on entry you can Toe the tires out to give some rotation or response to the car on entry. The car will dart to the apex quickly. The down side to Toe out is a loss of straight line speed due to tire scrub, as well as additional wear to the tire.
If you Toe the tires IN you’re going to get the opposite effect. The car will feel more secure while cornering. Start at 0.00 then go out .05 , then in .05
See what the car likes, then increase in that direction until you go to far. Then bring it back to the optimal setting.
So just remember you’re sacrificing some speed and tire wear when you start to manipulate handling characteristics with Toe.
Rear Toe:
Rear Toe can be independently adjusted from the front. This setting is typically moved a lot more than the front to create stability.
Effects: Rear Toe can take the nervousness out of the race car on both entry and exit.
It can cause a loss of strait line speed.
It can increase tire wear.
Rear Toe Out:
This is when the front portion of the tires towards the front or the race car point out away from each other.
Toe Out can increase rotation into the corner. But it’s kind of a gimmicky way to do this. Toe Out isn’t used a lot for this type of race car. It’s more of an oval/F1 type of setting. NASCAR uses this, they’ll toe the drivers side rear In and the passenger side tire Out. This creates stagger(dog walking). It makes the rear track behind the front, kicked out. This creates side force and pokes the rear spoiler out from behind the green house. This allows for additional downforce on the rear of the car. I’m their world 1 pound of downforce equals about ten horsepower.
F1 uses this to create what they call flick. They go so fast through tight corners that they have to use this. They make a ton of downforce and have really big tires. So the negatives aren’t as noticeable. Like I said, this is a different style of diving where you yank the wheel into the corner and kind of have to know where you’ll end up on the other side. Carting, Indy, F1 type of stuff. Really tight street circuits, high speed kinks, all that. It can be used in our world, but you’ll most likely end up in a four wheel slide. We just don’t have the downforce, or the tire for it. I don’t prefer it, you may.
Effects:
Can add rotation.
Increases tire wear.
Costs straight line speed.
Creates nervousness in the race car.
Rear Toe In:
Rear Toe In is when the front portion of the rear tires towards the front of the car are pointed towards each other. This is somewhat the same as with the front, but not as noticeable. Start at 0.00 and add until you feel as you have went too far, then dial back to optimal setting.
If you feel you need to add more than half a degree of Toe (slider to the right all the way). You need to be looking elsewhere to fix the handling issue.
This can correct over steer on entry and help with over steer on exit. The more you crank it up, the car tightens up. You go down it loosens up. I use this quite a bit, blended with some front toe, and camber both front and rear.
Effects:
Rear Toe In can add stability to the car.
Increases tire wear.
Costs you straight line speed.
Transmission:
The transmission we will be using will be the Racing Transmission, not the Fully Customizable Transmission. Do not mistake one for the other. The Racing Transmission is superior in every way. It consists of 3 main adjustments.
Gear Ratios
Final Gear
The Quick Adjuster
Quick Adjustment:
The quick adjustment is just what it says it is. This is for guys who go track to track on a race night. It’s a fast way to get close overall with out having to adjust individual ratios. Upside is it’s a quick and easy way to establish an overall ratio for a track.
The downside is it doesn’t give you the ratios you need for particular corners, unless you go in and adjust them.
I’ll use this just to see where I’m at baseline and then go to manual adjustments to perfect each individual ratio. It’s useful but short lived.
Gear Ratios:
The Racing transmission allows you to adjust individual ratios. I’ll get the suspension feeling good overall, then if I need a little more, I’ll adjust ratios. You can do things like take a shift out on a short chute or adjust your launch gear for the start. Engine performance can have an effect on transmission ratios. The higher the engine can rev, the shorter the gears you can use. The main thing is to keep the engine in the power band as much as possible. The way the power band hits on corner exit can be effected by the transmission ratio as well.
So you dive off into the corner, get to the apex, and start to pick up the throttle. If the ratio is too long you’re going to have understeer, then when the power-band hits, you’re going to snap loose and go for a spin.
If it’s too short then you can get some wheel spin but it could be a little easier to deal with. You can easily just do a short shift to get things under control. But the right gear will have good rotation and pull hard out of the corner, giving you more acceleration to your next corner. This sim (GT7) does a poor job of representing engine braking. So you don’t have to worry about wheel hop too much. I still blip the throttle out of habit to rev match. So it’s just whatever your driving style is. I use heel and toe, don’t use the clutch at all, or a blend of the two. So it’s just how your rig is setup and your hardware. I’ll have some videos for ones that don’t know the difference between heel and toe , and sequential left foot braking.
Afterthought Notes:
No, I’m talking about engine mods. Balancing, boring, racing crank, cams. Then the bolt ons. Filters, superchargers, turbos, exhausts. Then using the ECU/restrictor to tune the engine. Just remember that dialing back the ECU vs the restrictor can be more costly. Because you’re cutting back on the amount of usable power and revs the engine can produce. But you can blend the two together to produce a flat broad power band. In other words you are better off most times to make say 390 hp from 4500-7500 RPM, than to make 395hp from 6000-7500 RPM. Because example A makes the peak hp power longer. It’s like a 2 stroke vs a 4 stroke type deal. Then you have HP vs. Torque. Which is better? I can’t give you the answer. It just depends on what track or track conditions you face. Example: You can make 999 lb.ft of torque. But if you can’t put it to the ground it does you no good. This is what defines lb.-ft of torque. Not to be confused with ft.lb of torque. That is a measurement of pressure you put on a fastener. Lb. Ftf of torque is a measurement of output or energy it takes to move a one pound object, over one foot of linear distance. Lb.FTF (pound foot or feet of force.) So whatever it is. Kind of confusing.
