- 7,829
- U S A
- Tetsumura
- Nigel Fox
I hope you like essays. 
I may be captain obvious here, but with so much clamoring for tunes, I thought I'd post my technique I stumbled into a few days ago when trying to get some race tuned cars to perform better. And Lord knows, quite a few of these beasties are a handful, especially older cars and PORSCHES. Gah, those old 911s...
First, you need performance parts because only race cars come ready to tune as far as I know. At the very least sports suspensions, and race suspensions to go all out. The limited slip differential is practically a requirement to tame most cantankerous cars. Here is a TL;DR brief overview of the various tuning settings.
On the Adjustment page, you might make a duplicate of the current tuning sheet. Next to the name, click on the three dots button to make a copy and name it whatever you want, like Test Tune, and make sure you're in it. The system remembers all your changes in a history, but it might only remember the last five changes.
The system seems to have a pretty good idea of what each adjustment is going to do to your ride. I'll try to be brief here. Chortle.
Suspensions: lower is better. Negative camber is better for turning. Toe in is better for stability, with the front of the tires closer together, but also increases wear a bit. Toe out is better for turning, and almost always used on the front.
Be aware that very few cars can be lowered all the way, because the wheel will rub against the well and chassis. To check, go to any track and just as race or time trial begins, go into cockpit view and run the car up a bit to where you can get a good view of the tires in replay. Stop and turn the wheel. If it won't turn all the way from lock to lock, you have your suspension too low, and in the replay, you should see your tires stop turning. For almost all of my cars, ten clicks above lowest seems to be safe.
Back to tuning. Lower the suspension front and back to about ten clicks above bottom to start, then click the big red Measure button at the top of your spec display. Your PP value should increase a decent amount, because a low squat car handles and turns better. The stats should change too, with blue values indicating how your car now handles differently, hopefully for the better. The system seems to think a slightly higher rear end is better. The difference is usually small, though every little improvement adds up. You'll have to check your tire rub if you want to much lower, even if the PP meter says to keep going.
Anti-roll Bars: tighten the chassis making it flex less. Too much can make it snappy, so this has to be driven to see if you like the changes. Some cars like it looser, some tighter. They also seem to work better with a tighter rear, sometimes all the way to 10. Too tight in the front will make it harder to turn, while tight in the back causes more oversteer. Adjust both a few clicks and see if the PP meter goes up.
Damping Compression /Expansion: For racing, you want a stiffer suspension. Damping compression and expansion makes the suspension slightly more sluggish, and these are usually better with small changes, as you want the springs to do most of the work. A more sluggish expansion does keep the car from bouncing, but again usually slight is better. "Natural Frequency" is spring stiffness. For race cars, as the tutorial says, stiffness is usually around 3.0 - 3.5 front and rear. The PP meter often likes a looser suspension, so this is up to testing and judgment.
Camber and Toe: control the tilt and angle of the tires to aid in handling. With suspensions which allow it, play with the negative camber and check each three clicks or so by measuring them. I believe these are in degrees. Many race cars are set between 2 and 3, but so far the PP gremlin hasn't let me down. For me, I tend to keep rear camber below 2.0, usually 1.0 - 1.7. If your PP value goes up, trust it for now. Use higher values for the front since these tires contribute most of the turning, and a tilted tire gives more tire surface in a turn. I'm still usually below 2.0, but do what suits you and the PP meter. With rear toe-in, I usually ease that down a bit to 0.15 in the rear. Toe out in front helps with turning, but very much may make it overturn so be judicious, like 0.05 - 10 or so. Breaking news: I forgot to add something important about this when I came across it a couple of weeks ago. I also forget who to give credit to for this: Harmonic, Voss, Doughtinator or one of the others, but they have the best method for tuning camber. This setting depends on whether you're going to be racing your car on fast high speed turns or slower ones, but you'll notice that to the left on your master page of the tuning screen, you have three Rotational G listings with three speed ranges. This is how hard you can turn your car at those speeds before it loses grip. As you adjust camber and hit the Measure button, look to see if these numbers increase, meaning you can take these turns faster. Generally you won't be hitting turns much harder than 100mph / 130kph, but those kinds of tracks exist. Again, I tend to have more camber in the front than rear because these tires take the brunt of the turning friction, but both count towards a fast turn. I stop increasing camber when the Gs don't increase, because you'll be wasting traction on slower turns. I should have added this a couple of weeks ago, but I'm kind of slow.
Differential: this is some kind of black box to me. Why it contributes so much to handling in beyond me, but what do I know? Praiano has provided a helpful bit taken from a YouTube tuning tutorial.
Some say to start with all 5s, though that's essentially no effect, and you usually end up with something above 10, so your call on that. A few small changes can have almost no effect, so this requires some fussing. Some cars require little LSD, some a lot, and most effect is with acceleration. Again, the PP meter seems to steer me in the right direction. Ba-dum-tsh.
Torque-vectoring Differential: handles power transfer to front and rear tires. For 4WD / AWD cars, it's a good idea to buy this differential, which controls how much power goes to the two axles. More power to the rear makes the car handle a bit better, more naturally. Usually 40:60 or 35:65 works well, and this can only be judged with test driving. 4WD Lamborghinis can benefit nicely with one of these.
These two sections will have the most to do with how your car drives, but the next bit figures in too.
Downforce: should be self-explanatory. When you buy body kits, the downforce helps your car hug the road. Front downforce can help a lot with even moderate speed turns if you have a slippery car. The PP meter likes a lot of downforce, though if it goes down, you're excessively slowing your car from drag. Some of my cars require front downforce up all the way.
ECU: limits engine power. The racing ECU does more than improve engine performance, it lets you control the output to tame excessive PP values for restricted races. Usually it shaves off the performance peak, and if you click on the Full Control Computer pulldown, it shows you your performance curve. A steeper curve is better for acceleration, and the low power turbo gives a boost to lower RPMs. This usually doesn't provide a tremendous improvement, though it can give you an edge in passing. Also make it easier to spin out, so be aware of the traction control in your right foot. The PP values can be a little buggy at times. Just opening the detailed editor before a race can increase the PP value slightly, so you may find that your 699.89PP build is suddenly 700.18 and disqualifies you from a 700PP limit race, so be aware.
Ballast: uses weights to balance the car and reduce PP. The Performance section can have a big impact on handling too, particularly ballast. With mid- and rear-engined cars, balance can be a headache in turns, as you must brake early and give the car some gas to maintain balance. Braking with one of these cars through a turn, even a race car, can suddenly have much of the weight transfer to the rear causing an instant spinout. Ballast can alleviate some of that issue by putting a weight in all the way to the front. Shifting the balance just a bit can give you a car with much better manners. A balance of 50:50 might be ideal, but I'm hardly an expert.
Power Restrictor: as the name implies, it reduces engine power. I think it does it by choking down on fuel flow, though I could be wrong on that. Your power band is reduced overall rather than shaving off the peak. Breaking news: I discovered on all the cars I fiddled with this, that it also seems to boost low end power while restricting overall performance. My low end performance appears better on my Silvia versus the same power output using the ECU. With roughly the same horsepower, the power restrictor shaves off about a second in quarter-mile time versus using the ECU. This may well give you an acceleration advantage in initial stages of your gears, but be aware that if your car tended to spin out or lose traction before, you might not want all that low end torque.
Transmission: tune gearing for performance. I see a lot of requests about setting up the adjustable transmissions. It's really not that hard to figure out the basics. If your gearing graphic is towards the left, your car will accelerate faster but run out of gear faster, and opposite if it's to the right. That's basically it. Some set the first gear all the way to the right and adjust from there, but that makes a very slow acceleration from a dead stop. You can simply adjust the Final Gear to nudge all gearing left and right if you're happy with it to adjust to different tracks. You can change values in the Top Speed setting box, which adjusts the gearing as the system sees fit, which can get you into a ballpark setting to play with. Ideally you want to get through most of the last gear on the longest straight of a track, but have a decent amount left over for drafting so you can blow past a car in front of you. To set gears for turns, you have to do a test run of a track. See which gear you're in at certain turns, and if you run out of that gear and have to shift, then lengthen that gear and try again.
It's not a bad idea to go back and tinker with the suspension and differential settings when you get to the end if you want to squeeze a bit more performance out of your steed, but by the end I'm usually good, unless a test drive shows up some weakness. So far this has worked great for me.
This is my setting sheet I modified using my method for the Gr4 NSX. Note that Gr4s don't have adjustable transmissions. I have my own method for adjusting gear ratios, which has lower gears stretched out for steady acceleration. I'm funny that way, but it has served me well.
I've actually managed to turn unruly beasts into well mannered stallions using this method, so I feel much less need to pester anyone for help now. So, there you go. Be a happy tuner and only bug the pros when you need more help.
I may be captain obvious here, but with so much clamoring for tunes, I thought I'd post my technique I stumbled into a few days ago when trying to get some race tuned cars to perform better. And Lord knows, quite a few of these beasties are a handful, especially older cars and PORSCHES. Gah, those old 911s...
First, you need performance parts because only race cars come ready to tune as far as I know. At the very least sports suspensions, and race suspensions to go all out. The limited slip differential is practically a requirement to tame most cantankerous cars. Here is a TL;DR brief overview of the various tuning settings.
- Body height Adjustment: lower is better, but only so low
- Anti-roll Bar: tight in front=understeer, tight in rear=oversteer
- Damping Ratio Compression / Expansion: restricts suspension movement
- Natural Frequency: spring tension, tighter for racing
- Negative Camber Angle: tilt of the wheel, helps with turning
- Toe Angle: helps with stability and turning
- Differential: helps with handling and acceleration / decelleration
- Initial Torque: overall differential effect
- Acceleration Sensitivity: engages more with higher settings
- Braking Sensitivity: same
- Torque-vectoring Center Differential: balance of front / rear axles in 4WD cars, more rear is better
- Downforce: more increases handling and traction
- ECU: improves / limits engine power
- Ballast: useful for balancing mid- and rear-engined cars, and modifying PP
- Power Restrictor: shaves off engine power in all RPMs
- Transmission: alter gearing in adjustable trannys
On the Adjustment page, you might make a duplicate of the current tuning sheet. Next to the name, click on the three dots button to make a copy and name it whatever you want, like Test Tune, and make sure you're in it. The system remembers all your changes in a history, but it might only remember the last five changes.
The system seems to have a pretty good idea of what each adjustment is going to do to your ride. I'll try to be brief here. Chortle.
Suspensions: lower is better. Negative camber is better for turning. Toe in is better for stability, with the front of the tires closer together, but also increases wear a bit. Toe out is better for turning, and almost always used on the front.
Be aware that very few cars can be lowered all the way, because the wheel will rub against the well and chassis. To check, go to any track and just as race or time trial begins, go into cockpit view and run the car up a bit to where you can get a good view of the tires in replay. Stop and turn the wheel. If it won't turn all the way from lock to lock, you have your suspension too low, and in the replay, you should see your tires stop turning. For almost all of my cars, ten clicks above lowest seems to be safe.
Back to tuning. Lower the suspension front and back to about ten clicks above bottom to start, then click the big red Measure button at the top of your spec display. Your PP value should increase a decent amount, because a low squat car handles and turns better. The stats should change too, with blue values indicating how your car now handles differently, hopefully for the better. The system seems to think a slightly higher rear end is better. The difference is usually small, though every little improvement adds up. You'll have to check your tire rub if you want to much lower, even if the PP meter says to keep going.
Anti-roll Bars: tighten the chassis making it flex less. Too much can make it snappy, so this has to be driven to see if you like the changes. Some cars like it looser, some tighter. They also seem to work better with a tighter rear, sometimes all the way to 10. Too tight in the front will make it harder to turn, while tight in the back causes more oversteer. Adjust both a few clicks and see if the PP meter goes up.
Damping Compression /Expansion: For racing, you want a stiffer suspension. Damping compression and expansion makes the suspension slightly more sluggish, and these are usually better with small changes, as you want the springs to do most of the work. A more sluggish expansion does keep the car from bouncing, but again usually slight is better. "Natural Frequency" is spring stiffness. For race cars, as the tutorial says, stiffness is usually around 3.0 - 3.5 front and rear. The PP meter often likes a looser suspension, so this is up to testing and judgment.
Camber and Toe: control the tilt and angle of the tires to aid in handling. With suspensions which allow it, play with the negative camber and check each three clicks or so by measuring them. I believe these are in degrees. Many race cars are set between 2 and 3, but so far the PP gremlin hasn't let me down. For me, I tend to keep rear camber below 2.0, usually 1.0 - 1.7. If your PP value goes up, trust it for now. Use higher values for the front since these tires contribute most of the turning, and a tilted tire gives more tire surface in a turn. I'm still usually below 2.0, but do what suits you and the PP meter. With rear toe-in, I usually ease that down a bit to 0.15 in the rear. Toe out in front helps with turning, but very much may make it overturn so be judicious, like 0.05 - 10 or so. Breaking news: I forgot to add something important about this when I came across it a couple of weeks ago. I also forget who to give credit to for this: Harmonic, Voss, Doughtinator or one of the others, but they have the best method for tuning camber. This setting depends on whether you're going to be racing your car on fast high speed turns or slower ones, but you'll notice that to the left on your master page of the tuning screen, you have three Rotational G listings with three speed ranges. This is how hard you can turn your car at those speeds before it loses grip. As you adjust camber and hit the Measure button, look to see if these numbers increase, meaning you can take these turns faster. Generally you won't be hitting turns much harder than 100mph / 130kph, but those kinds of tracks exist. Again, I tend to have more camber in the front than rear because these tires take the brunt of the turning friction, but both count towards a fast turn. I stop increasing camber when the Gs don't increase, because you'll be wasting traction on slower turns. I should have added this a couple of weeks ago, but I'm kind of slow.
Differential: this is some kind of black box to me. Why it contributes so much to handling in beyond me, but what do I know? Praiano has provided a helpful bit taken from a YouTube tuning tutorial.
And a picture is worth a thousand words here, for a good basic understanding of how the differential works, again thanks to Praiano.
Some say to start with all 5s, though that's essentially no effect, and you usually end up with something above 10, so your call on that. A few small changes can have almost no effect, so this requires some fussing. Some cars require little LSD, some a lot, and most effect is with acceleration. Again, the PP meter seems to steer me in the right direction. Ba-dum-tsh.
Torque-vectoring Differential: handles power transfer to front and rear tires. For 4WD / AWD cars, it's a good idea to buy this differential, which controls how much power goes to the two axles. More power to the rear makes the car handle a bit better, more naturally. Usually 40:60 or 35:65 works well, and this can only be judged with test driving. 4WD Lamborghinis can benefit nicely with one of these.
These two sections will have the most to do with how your car drives, but the next bit figures in too.
Downforce: should be self-explanatory. When you buy body kits, the downforce helps your car hug the road. Front downforce can help a lot with even moderate speed turns if you have a slippery car. The PP meter likes a lot of downforce, though if it goes down, you're excessively slowing your car from drag. Some of my cars require front downforce up all the way.
ECU: limits engine power. The racing ECU does more than improve engine performance, it lets you control the output to tame excessive PP values for restricted races. Usually it shaves off the performance peak, and if you click on the Full Control Computer pulldown, it shows you your performance curve. A steeper curve is better for acceleration, and the low power turbo gives a boost to lower RPMs. This usually doesn't provide a tremendous improvement, though it can give you an edge in passing. Also make it easier to spin out, so be aware of the traction control in your right foot. The PP values can be a little buggy at times. Just opening the detailed editor before a race can increase the PP value slightly, so you may find that your 699.89PP build is suddenly 700.18 and disqualifies you from a 700PP limit race, so be aware.
Ballast: uses weights to balance the car and reduce PP. The Performance section can have a big impact on handling too, particularly ballast. With mid- and rear-engined cars, balance can be a headache in turns, as you must brake early and give the car some gas to maintain balance. Braking with one of these cars through a turn, even a race car, can suddenly have much of the weight transfer to the rear causing an instant spinout. Ballast can alleviate some of that issue by putting a weight in all the way to the front. Shifting the balance just a bit can give you a car with much better manners. A balance of 50:50 might be ideal, but I'm hardly an expert.
Power Restrictor: as the name implies, it reduces engine power. I think it does it by choking down on fuel flow, though I could be wrong on that. Your power band is reduced overall rather than shaving off the peak. Breaking news: I discovered on all the cars I fiddled with this, that it also seems to boost low end power while restricting overall performance. My low end performance appears better on my Silvia versus the same power output using the ECU. With roughly the same horsepower, the power restrictor shaves off about a second in quarter-mile time versus using the ECU. This may well give you an acceleration advantage in initial stages of your gears, but be aware that if your car tended to spin out or lose traction before, you might not want all that low end torque.
Transmission: tune gearing for performance. I see a lot of requests about setting up the adjustable transmissions. It's really not that hard to figure out the basics. If your gearing graphic is towards the left, your car will accelerate faster but run out of gear faster, and opposite if it's to the right. That's basically it. Some set the first gear all the way to the right and adjust from there, but that makes a very slow acceleration from a dead stop. You can simply adjust the Final Gear to nudge all gearing left and right if you're happy with it to adjust to different tracks. You can change values in the Top Speed setting box, which adjusts the gearing as the system sees fit, which can get you into a ballpark setting to play with. Ideally you want to get through most of the last gear on the longest straight of a track, but have a decent amount left over for drafting so you can blow past a car in front of you. To set gears for turns, you have to do a test run of a track. See which gear you're in at certain turns, and if you run out of that gear and have to shift, then lengthen that gear and try again.
It's not a bad idea to go back and tinker with the suspension and differential settings when you get to the end if you want to squeeze a bit more performance out of your steed, but by the end I'm usually good, unless a test drive shows up some weakness. So far this has worked great for me.
This is my setting sheet I modified using my method for the Gr4 NSX. Note that Gr4s don't have adjustable transmissions. I have my own method for adjusting gear ratios, which has lower gears stretched out for steady acceleration. I'm funny that way, but it has served me well.
I've actually managed to turn unruly beasts into well mannered stallions using this method, so I feel much less need to pester anyone for help now. So, there you go. Be a happy tuner and only bug the pros when you need more help.
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