Just checking to see if l’m banned
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Looking forward to it! Please don’t forget to address some of the new features, especially the wheel offset option. I can’t find a lot of candid info out there about when or when not to use it.
Message me on Xbox, and l’ll get you going. I’m not great at getting my point across in text. I’ll get you set up on your suspension, and teach you a repeatable method. Working out gears and diff right now. Driving me nuts. Download my offroad tunes in the meantime. Anything with the file name Grp.1 or Grp.a.
Ok…here we go. This first section will be an intro into my tuning theories, my simple math, and finishing with suspension calculations that will have you ready to tune your own by the end of the post.
Tuning will forever be a learning process. You try new combinations, spring rates, damp…you always think it could be just a little better. For that reason, l’m going to avoid absolutes. l’ll be giving you the math, and my process of accounting for weight distribution. The math, and physics, l feel are perfect, but what you base your starting numbers on are left completely up to you. This suspension section will be based on off road builds. I’ll be using total weight percentage for my spring rate. I’ll make suggestions on how to apply this method to stiffer springs, but again, the range that you like will be left to your own preference.
The math:
I was a terrible math student. I am terrible at explaining math, but l’ll be making it easy to digest for this thread. But please, keep the remarks about my way of explaining it to yourselves. It works. First, you probably already know that weight distribution is crucial in tuning. This simple division will help get you the correct balance every time. You divide your highest number by your lowest.
Example:
On a 60 front, 40 rear you get: 60÷40=1.5.
58 front, 42 rear you get: 58÷42=1.38
This simple math will always give you the proper spread for you weight distribution. Simply start with the higher of your two settings, divide by this number. We’ll call it your weight ratio for this post. Once your first number is set, divide by your weight ratio, and there you go.
Example:
A 60/40 split with front springs that l’ve determined a front spring rate of 600.
600÷1.5=400.
Front spring: 600
Rear spring: 400
Determining spring rate:
This is essentially up to you. It should be based on something, though. It can be as simple as 560/440 for a 56/44 split, or as complicated as researching ‘Hooke’s Law’ and diving into spring rates, wheel rates, frequency, and so on. The method l use because it gives me a consistent feel across all my cars, and it’s easier for later calculations such as ride height, AR bars, and aero. I simply go a given % of my total weight. For rally cars, l go 15%. For road going cars you will need to experiment, but l’d start around 25% if it were me. When l say 15%, that’s my center, so there’s an extra bit of math to use this as center instead of your top or bottom numbers. Btw, l’m using nice round numbers for my examples…why? because l’m lazy, doing it in my head, and because l’m terrible at math.
Example: total weight 3000 lbs on a 60/40 split
3000 x .15=450
To get 15 pct as center:
450 x 2=900
900 x .60=540
You’ll always multiply by your FW number. Here it’s .60, for a 58/42 it’s .58.
Once your top number is set do the math using your weight ratio.
540 ÷ 1.5= 360
Spring rate: 540/360
Again, this is just my technique. Where you start is up to you. Whether you use a pct technique for spring rate at all is totally up to you. I’m just making sure you’re the right distance apart.
Ar bars:
This is a lot of feel, theory, and tbh maybes, but l carry my body weight percentage theory to my AR bar settings. Again, on my rally cars, l’ll be using 15 as my center. Imo, the 1 to 65 numbers of the scale represents spring/weight ratio. So on a 60/40 split, my ar settings are 18 rear, 12 front. Notice they add up to 30. If l do 10% like my raptor tunes they add up to 20…every time. You’re about to see why. The math on that 60/40 split, with 15 pct s/w ratio. It’s the same as figuring springs.
Example: for 15 pct, double that to 30.
for 10 pct, double to 20
15x2=30
30x.60=18
18 rear Ar
You can get the front a couple of different ways. Since you know it adds back to 30.
30-18=12
Or:
18÷1.5=12
Again, however you decide your rate, this is only a suggestion, and me telling you how l set my rates. I will highly suggest that your ar settings be based on spring/weight ratio, though. I’ve done a lot of testing at the dunes, and on the lake, and l’m very confident that your AR bars should represent the percentage of your body weight that your springs support. If your springs are supporting 25 pct of your total weight. The sway bars should represent that. This is of course, lmo.
Damp:
Do what feels right. You should have the tools by now to make sure you have the distance between, correct. Personally, l set my rebound in the middle. If it’s a 60/40, my rebound is at 6 and 4. 58/42? 5.8/4.2. I set my bump at .66 pct. Boom. That’s it.
Ride Height:
Like Ar bars, once your spring to weight ratio is determined and set, you’ll need to set your ride height as such. Simply take the max height and multiply what’s not accounted for in your springs…ok, l didn’t explain that well. If you are at 10 pct spring/weight ratio, you multiply your max height by 90 pct. 15 pct s/w ratio, multiply by 85 pct.
Example: 10 inch max ride height. 10 pct s/w ratio
10x.90=9
Ride height is 9.
Even the slider and you’re done.
That was horrible. I’m sure l missed, or was unclear on things. I felt myself rushing. Sorry. I hope you guys get the idea. Stay tuned. Let me know if there are any questions. I’m covering alignment, brakes, and differential in the next post. The differential section will lead into the third and hopefully last, more advanced custom gearsets, and making sure your transmission and differential gears are working together, perfectly.
A lot of this looks pretty reasonable. Good job!
My take on ARB tuning is pretty close to yours (Stiffer springs in the front means softer ARBs in the front, vise versa for rear), but for the general stiffness of both ARBs I tend to feel it out. I’m not sure how to get the ARBs right for rally tuning, but for road tuning you generally want the ARBs as stiff as possible without the tires losing grip in the corners. When the car rolls then the tires as a pair lose their grip. When the ARBs/Springs are too stiff then the outside tire is overloaded and lose traction. It’s best to find a sweet spot in between the two and your ABRS are set.
I was “feeling it out” when l realized that your AR bars should represent percentage of total weight. Yeah, l used to do my testing at the beach. Those dunes aren’t very forgiving on improper ar bars. I used to run “ranges” for cars, trucks, whatever. But, l noticed it was all over the place…because my spring rates were all over the place, in relation to my body weight. Once l started running my spring rate based on weight pct, l started noticing my settings were more consistent, and that my AR numbers felt butter at the same as whatever my body weight was. Pretty sure it’ll work for road going cars. I have a couple tuned with this technique…l went with 20 or 25 pct (springs and ARB) with my road going cars, and it works pretty well, still. Like l said, when l give tuning advice l try and stay away from telling people what numbers they should plug in. The numbers are fluid. A lot of this is personal preference. My goal is to show how to make sure you’re the right distance between your numbers to allow for weight distribution. I know you hate pure math tuning, and that, l don’t do. I got these techniques from feel, l just started checking numbers and noticed patterns. I use quick division to get close on some things, but it usually takes small tweaks. Springs, ARB, and damp are usually spot on with no adjustments though.
Thanks for the positive feedback. Trying to get motivated to put up my custom gear and diff section and a small section on oddball stuff like ride height, brakes, aero, and alignment. It’s probably going to get some resistance. My differential theory, anyways. But, it’s in development. l do things a little different than what l’ve noticed others doing, but it works for me. Idk if my way’s better, or if l’m just weird
I am probably the biggest tuning noob out here. …and I love the depth of tuning available. So here is some advice for folks who don’t necessarily have the time/patience for in-depth tuning. One thing I noticed is that once you have your basic tune in place (lets say… parts upgrades & final drive ratio only) there is a very good benefit to simply driving the vehicle as much as possible without changing anything. The more you get to know your car and track the faster you will be. It is possible to compete at unbeatable difficulty without massive amounts of tuning. I like to exhaust all the parts-swapping combinations before going into the tuning section…especially if you can reduce your car’s PI (for class specific builds) by swapping in lower level tires or springs…which gives you more PI room to add horsepower.
the telemetry display can tell you a lot about what is going on with your car … for me especially tyre temperatures …
and what you say about driving is important … the car will behave differently cold/hot … weather cold /hot … and familiarity helps you feel the changes more
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