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Rank: Racing Permit
 3 users liked this post.
#1 Posted : Tuesday, January 8, 2019 1:55:01 PM(UTC)
Like most of you, l fell for the accepted method of using the max plus min times weight distribution formula to set a 'base', then saving the base and adjusting from there. I felt like the guy on 'A beautiful mind' with all the numbers l had scrawled down, punching away at a calculator. I realized there was a better way. Easier, and imo better. Before l explain my process, l'll put out a disclaimer. I wasn't good at math in school, so my terminology might be off a bit, but the math is on point. I'm going to use a 60/40 as an example throughout this post, and will be referring to this number that l get by dividing, in this case 60÷40 as my fw number. This number is 1.5 for a 60/40, 1.38 for a 58/42, and so on. Back to the 60/40. You set your springs at 300/200, 600/400, or 1200/800. You'll notice that if you set your front at 600, you divide 600 by 1.5, you get 400. Multiply 400 by 1.5 you get 600. This works with any combination of spring stiffness. I stick to multiples of my weight distribution, but you can pick any random stiffness that feels right, divide or multiply by your fw number (1.5 in this case) to get your other number. This works for any weight distribution as long as you get your fw number by dividing your front or highest percentage by your lowest. On rear engine, you'll divide your back by your front. Highest number, divided by your lowest. A 60/40 is still 1.5 regardless of where your weight is. So your springs are set. Hypothetically at 600/400 although l like a 300/200 for dirt circuit racing. I like running even damp, so my rebound damp sets at 6 and 4. Not gonna get into bump, as it's a personal preference. Mine is 66pct, but that's irrelevant to this discussion. On some GRC's or legendary cars, mostly bajas, the springs don't go to 600, and the damp doesn't go below 3, so you do end up with springs at 300/200 and double the damp, but there's flexibility. That's the beauty of this method, there's no setting a base, then adjusting a few percent. You set it where you want. Where it feels right, divide or multiply by your fw number, and it's set. As l said, in my experience evening rebound damp with your springs 'feels right', but doubling it in some cases is the next best. For example, a dirt trail car that l want at 300/200 spring stiffness, a 3/2 damp just doesn't grip on pavement. So l do run a 6/4 damp on a 300/200 spring, but l try to avoid that. If you're with me so far, and buying in, l've also experimented with going 10 pct of your total weight. The springs felt amazing, but l didn't like rounding up or down, on my damp. 5.454 almost sent me over the edge. Oh, AR bars. I made a post explaining my reasoning. All things even, your front is 'softer" bc of the extra weight, so when you soften the rear, you're essentially neutral. I run an even 10 on dirt, and 20 on pavement. But if you do want oversteer, set your first number, again divide or multiply by your fw number, and there you go. Btw, refer to my other post if you get those odd decimal numbers on your AR and spring scales. There's a simple way to get rid of them, and get them to match up again. Thanks for reading. I hope at least a few of ya'll try it. You'll never set a base tune or add a max plus min times weight distribution plus min, again. Just typing that blasted formula made me cringe a bit.

Edited by user Sunday, March 10, 2019 8:03:39 PM(UTC)  | Reason: Not specified

Rank: Racing Permit
#2 Posted : Friday, January 11, 2019 8:04:23 AM(UTC)
Good stuff, in this post and elsewhere. Thanks for sharing. I've added your calcs to my spreadsheet, and run a few comparisons.

I'm testing on tarmac right now, but I'll include some dirt as I progress. I adjusted your alignment formula to halve the rear camber (I've never run >1.5 negative rear, but I'll test that as well), and am not using the differential numbers. I also halved rear toe out.

Sometimes I modified spring /rebound by 1.5 rather than 2, but always keeping the ratio between front/rear and rebound/damp.

This yields cars that have similar lap times to my existing tunes, but in a couple of cases significant improvements - I trimmed a half second off my bone shaker tune on a 50-second track with a little tweaking. The rear toe out really helps turn-in and power-on oversteer.

And this is certainly an easier method, although I'd like to factor the power or power:weight ratio into both suspension stiffness and gear ratios. I'm also setting diff balance manually per-car. Mostly 65-70 rear, but some outliers.

Anyway, appreciate you posting more detail as you progress, and I'll do the same. I'm starting to have a decent dataset, so perhaps I'll figure out how to correlate power:weight and such back to settings that work and derive a formula.

Random side note: best power to weight ratio of actually useful A-class cars is not the boneshaker. It's the Ford raptor.
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 1 user liked this post.
#3 Posted : Wednesday, January 23, 2019 12:48:15 AM(UTC)
Cool. Glad you tried it. The one thing l go back and forth on is throttle oversteer or dead center. Btw, divide your 1st gear by final drive, subtract by 100, this is your differential number. I work towards 25 pct, but l do gears from scratch, but 1st gear into final drive should work for you. I can give you my experiment data on pw ratios, but l decided it wasn't worth the trouble. Handled well, good top speed, but accell wasn't great. Raptor is my favorite truck. Especially A class. hmu on live and l'll show you how to get that diff down around 25 or 30. Download my tunes. Thanks for the feedback.
Rank: B-Class Racing License
#4 Posted : Wednesday, January 23, 2019 3:13:22 AM(UTC)
Do you have a specific example at hand (or a tune shared)? I’d like to compare it with my approach.

Edited by user Wednesday, January 23, 2019 3:14:07 AM(UTC)  | Reason: Not specified

Rank: Racing Permit
#5 Posted : Monday, January 28, 2019 2:51:07 AM(UTC)
Originally Posted by: slid3show Go to Quoted Post
Cool. Glad you tried it. The one thing l go back and forth on is throttle oversteer or dead center. Btw, divide your 1st gear by final drive, subtract by 100, this is your differential number. I work towards 25 pct, but l do gears from scratch, but 1st gear into final drive should work for you. I can give you my experiment data on pw ratios, but l decided it wasn't worth the trouble. Handled well, good top speed, but accell wasn't great. Raptor is my favorite truck. Especially A class. hmu on live and l'll show you how to get that diff down around 25 or 30. Download my tunes. Thanks for the feedback.


On AWD, do you apply that differential number to the axel supporting the most weight and then use your fw number to get the other setting? Any tips on decel?

What is your initial testing process like for springs, sway bars etc... ?

I'm having a hard time testing in FH4. I usually just use a one of the tuning calculators for springs, arb's, castor and dampers. After that, I adjust camber by driving in circles and adjusting until the telemetry shows my tires heating evenly when red or slightly more on the inside when yellow. Then I adjust the diff from the calculator's suggested setting if one of the inside tires is heating too fast during the camber testing process. Finally, I drive around on the surface it is intended to race on or use telemetry during a race to check tire pressure.

I've been pretty happy with results, but the process is still very time consuming; even with the tuning calculator, and I don't like having to rely so heavily on a tuning calc. I'd like a surefire method for testing the springs, sway bars, dampers etc... If possible, I'd like to know what exactly I'm looking for on telemetry for those so that I have a visual aid.


Thanks
Rank: B-Class Racing License
#6 Posted : Monday, January 28, 2019 12:51:36 PM(UTC)
.

Edited by user Monday, January 28, 2019 5:17:03 PM(UTC)  | Reason: Not specified

Rank: Racing Permit
#7 Posted : Friday, February 1, 2019 3:55:08 AM(UTC)
Originally Posted by: jdiab01 Go to Quoted Post
Originally Posted by: slid3show Go to Quoted Post
Cool. Glad you tried it. The one thing l go back and forth on is throttle oversteer or dead center. Btw, divide your 1st gear by final drive, subtract by 100, this is your differential number. I work towards 25 pct, but l do gears from scratch, but 1st gear into final drive should work for you. I can give you my experiment data on pw ratios, but l decided it wasn't worth the trouble. Handled well, good top speed, but accell wasn't great. Raptor is my favorite truck. Especially A class. hmu on live and l'll show you how to get that diff down around 25 or 30. Download my tunes. Thanks for the feedback.


On AWD, do you apply that differential number to the axel supporting the most weight and then use your fw number to get the other setting? Any tips on decel?

What is your initial testing process like for springs, sway bars etc... ?

I'm having a hard time testing in FH4. I usually just use a one of the tuning calculators for springs, arb's, castor and dampers. After that, I adjust camber by driving in circles and adjusting until the telemetry shows my tires heating evenly when red or slightly more on the inside when yellow. Then I adjust the diff from the calculator's suggested setting if one of the inside tires is heating too fast during the camber testing process. Finally, I drive around on the surface it is intended to race on or use telemetry during a race to check tire pressure.

I've been pretty happy with results, but the process is still very time consuming; even with the tuning calculator, and I don't like having to rely so heavily on a tuning calc. I'd like a surefire method for testing the springs, sway bars, dampers etc... If possible, I'd like to know what exactly I'm looking for on telemetry for those so that I have a visual aid.


Thanks

Yes. That number will be the rear accel. Divide your fw and bw to get your difference. Divide by that number. It's not linear. Meaning if you have 56 fw, you can't just go 6 less in front. Sometimes it works out to 6 on a 56 front, the closer you get to 30. You can try both and see what you think. I set my diff on 30 so l don't have to question it. At 30, you come up with the same figure dividing or by just dropping by your fw number. l set my accel and decel the same, and it works great for me. It makes up for engine weight. The telemetry is a different story. Too much to explain. I usually use the suspension screen and adjust to hover around center. The body accel for roll bars. After you exceed your lateral g rating, you'll start losing traction. You want to roll as close as possible to your limitations on average, and make sure your dots end up within the for open areas in general. When l go into a corner my dot hits the top edge of the open area, when l accel out, it hits the bottom edge, then arcs around to the middle of the white area. I have a formula for roll bar stiffness and balance, but hopefully you're good there. I have trouble explaining stuff in text. Especially math. I don't really mess with the other screens. Try this with your alignment, and you shouldn't have to mess with the heat or friction screens. Multiply 2.5 by your fw for your front. Multiply 2.5 by your bw. Toe out to match your front. Caster is your fw number. Example: 60% fw. 2.5x .60=1.5, 2.5x .40=1. Front: 1.5 Rear: 1.0 Toe rear out: .5. Caster 6.0 Probably not perfect, but definitely get a good contact patch and good turn in angle. If your diff or ar bars are off the toe out will be very squirrelly. I think l addressed everything. If you need ar help or more details or clarity let me know. I prefer a message on live, but l'll eventually respond on here. Try one of my tunes first to make sure you even like my stuff. I steady slay with my tunes. I won 4 races in a row online earlier, and am on the podium every race, but l realize they're probably not optimal, and aren't for everyone. Good luck.
Rank: Racing Permit
#8 Posted : Friday, February 1, 2019 4:01:43 AM(UTC)
Originally Posted by: jdiab01 Go to Quoted Post
Originally Posted by: slid3show Go to Quoted Post
Cool. Glad you tried it. The one thing l go back and forth on is throttle oversteer or dead center. Btw, divide your 1st gear by final drive, subtract by 100, this is your differential number. I work towards 25 pct, but l do gears from scratch, but 1st gear into final drive should work for you. I can give you my experiment data on pw ratios, but l decided it wasn't worth the trouble. Handled well, good top speed, but accell wasn't great. Raptor is my favorite truck. Especially A class. hmu on live and l'll show you how to get that diff down around 25 or 30. Download my tunes. Thanks for the feedback.


On AWD, do you apply that differential number to the axel supporting the most weight and then use your fw number to get the other setting? Any tips on decel?

What is your initial testing process like for springs, sway bars etc... ?

I'm having a hard time testing in FH4. I usually just use a one of the tuning calculators for springs, arb's, castor and dampers. After that, I adjust camber by driving in circles and adjusting until the telemetry shows my tires heating evenly when red or slightly more on the inside when yellow. Then I adjust the diff from the calculator's suggested setting if one of the inside tires is heating too fast during the camber testing process. Finally, I drive around on the surface it is intended to race on or use telemetry during a race to check tire pressure.

I've been pretty happy with results, but the process is still very time consuming; even with the tuning calculator, and I don't like having to rely so heavily on a tuning calc. I'd like a surefire method for testing the springs, sway bars, dampers etc... If possible, I'd like to know what exactly I'm looking for on telemetry for those so that I have a visual aid.


Thanks

Hmu on live. I just typed a long, detailed reply and apparently tapped the wrong box, and lost it. Yes, that's your rear diff. I'll answer any question you have in a party or by message on live. l can't even, right now. I have answers or at least opinions for everything you asked. I just don't feel like typing another paragraph..smh.
Rank: Racing Permit
#9 Posted : Friday, February 1, 2019 4:16:15 AM(UTC)
I don't have an initial process. I do the math, set my sliders, then check telemetry for ride height and ar bar balance. I'm usually within one move of the slider. Sometimes l don't adjust anything. Btw, if you try my tunes, make sure to only dl recent ones. File names grp.1 or grp.2.

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