65LikesTune With Camber Links
05-04-2022 | 01:53 PM
#2221
Tech Fanatic
Joined: Aug 2008
Posts: 903
From: San Antonio, Texas
I'm feeling a bit nostalgic today. This thread is now over 11 years old and I remember a period of time in the early/mid 2010's when this thread was always on the front page of the Electric Off Road forum.
The information I gained in this thread from fredswain is still massively useful to me. I'll use my recent purchase of a 22 5.0 DCE as an example to illustrate. I bought the car second hand a few weeks back. I checked it over and the suspension setup was box stock. Before doing anything to the car I threw my electronics in it, mounted some tires, and drove it around on my tiny basement track. The surface is mostly smooth concrete and the grip level is a relatively good approximation of driving on a dry outdoor clay track. The car was a handful to drive to say the least. It felt super sensitive to throttle inputs in a really frustrating way, usually resulting in snap oversteer when trying to slow down before entering a corner. It was just undrivable to me.
The car came with a boat load of springs - I counted 17 pairs. I set the car on the bench and went to work using the spring balancing procedure outlined near the start of this monster thread. I use a phone to record the car in slo-mo as it rebounds from being pressed flat against the bench. As I suspected, and as is usual for all cars I've done this to, the front end snapped up way faster than the rear. Since I'll be running this car on an outdoor dirt track that tends to not be the smoothest of surfaces I decided to soften up the front instead of stiffen the rear. I wound up using what seems to be the softest front spring of the bunch, and even with that I still had to move the lower shock mounting position in one hole to get the front and rear end balanced (note: I also moved the battery fully back and added 2oz into the rear since I'll be on a loose outdoor track. I'd rather have a standup transmission but haven't bought one yet so this will suffice for now). But it was worth it.
The difference it made on my basement track was night and day. The car was so much easier to control. The driving characteristics of the car are way less affected by throttle input which for me makes the car feel so much more stable, consistent, forgiving, and predictable. Looking back at this thread I should probably do a bit more with oils and pistons but for the most part they line up with what I think they should be based on what I learned in this thread - namely the kit pistons use bigger holes in the rear shocks. That's actually rather interesting as there was a time I can remember tuning doctrine being "always use bigger holes in the front and smaller holes in the rear." The last two TLR kits I've had (the 3.0 and now this 5.0 DCE) have bucked that trend, so maybe there's hope they'll start equipping kits with more closely matched spring rates.
Sometimes I wonder why the information in this thread never took off. Every car I've ever used this method on has driven better for me as a result. Based on my experience, and the reported experience of others in this thread, it just seems like so many could benefit from it, but now that fredswain is no longer active the knowledge is at risk of being lost to time. At the end of the day it doesn't matter to me how anybody chooses to tune and run their car, but I just think it's a net loss for this information to fade away into the shadows of the past.
The information I gained in this thread from fredswain is still massively useful to me. I'll use my recent purchase of a 22 5.0 DCE as an example to illustrate. I bought the car second hand a few weeks back. I checked it over and the suspension setup was box stock. Before doing anything to the car I threw my electronics in it, mounted some tires, and drove it around on my tiny basement track. The surface is mostly smooth concrete and the grip level is a relatively good approximation of driving on a dry outdoor clay track. The car was a handful to drive to say the least. It felt super sensitive to throttle inputs in a really frustrating way, usually resulting in snap oversteer when trying to slow down before entering a corner. It was just undrivable to me.
The car came with a boat load of springs - I counted 17 pairs. I set the car on the bench and went to work using the spring balancing procedure outlined near the start of this monster thread. I use a phone to record the car in slo-mo as it rebounds from being pressed flat against the bench. As I suspected, and as is usual for all cars I've done this to, the front end snapped up way faster than the rear. Since I'll be running this car on an outdoor dirt track that tends to not be the smoothest of surfaces I decided to soften up the front instead of stiffen the rear. I wound up using what seems to be the softest front spring of the bunch, and even with that I still had to move the lower shock mounting position in one hole to get the front and rear end balanced (note: I also moved the battery fully back and added 2oz into the rear since I'll be on a loose outdoor track. I'd rather have a standup transmission but haven't bought one yet so this will suffice for now). But it was worth it.
The difference it made on my basement track was night and day. The car was so much easier to control. The driving characteristics of the car are way less affected by throttle input which for me makes the car feel so much more stable, consistent, forgiving, and predictable. Looking back at this thread I should probably do a bit more with oils and pistons but for the most part they line up with what I think they should be based on what I learned in this thread - namely the kit pistons use bigger holes in the rear shocks. That's actually rather interesting as there was a time I can remember tuning doctrine being "always use bigger holes in the front and smaller holes in the rear." The last two TLR kits I've had (the 3.0 and now this 5.0 DCE) have bucked that trend, so maybe there's hope they'll start equipping kits with more closely matched spring rates.
Sometimes I wonder why the information in this thread never took off. Every car I've ever used this method on has driven better for me as a result. Based on my experience, and the reported experience of others in this thread, it just seems like so many could benefit from it, but now that fredswain is no longer active the knowledge is at risk of being lost to time. At the end of the day it doesn't matter to me how anybody chooses to tune and run their car, but I just think it's a net loss for this information to fade away into the shadows of the past.
05-04-2022 | 07:21 PM
#2222
. I too have my Tekno SCT410 cars setup using ideas from this thread. Only thing I’ve done since my off road setup was go one step harder in the front for oval. Also be sure to read the parts about the garden hose experiments - I tried it and it works to keep the rear end planted going over bumps
One thing I've been thinking about that Fred never really got into that I remember is ride height. Now that carpet and turf has taken off we have cars dedicated to running on them and one setup feature those cars are optimized around is really low ride heights - I've seen as low as 13mm on a 2wd buggy. Every technical article I've read about full size car tuning talks about the benefits of lowering ride height, so it makes sense to get your car as low as possible. But one thing I've noticed - people still seem to be running higher ride heights on dirt. I think the lowest ride height I've seen for a dirt setup was maybe 19mm? Why aren't people running the lower carpet ride heights on dirt? This is a genuine question.
On my basement track that's low grip smooth concrete my car got faster and easier to drive as I lowered the ride height. I'm at 15mm right now. Going that low did get the roll centers a bit out of whack - lowering ride height lowers static roll center. Fortunately these newer cars are designed to be able adjust the RC's back up even at lower ride heights so that's what I did. The car drives great and doesn't bottom out even when I overshoot the landing on my big jump and flat land. I'm excited to get it to a real track to see how it performs and what problems I might run into running the car that low.
What does anybody else think? Does running a 2wd buggy as low as 13mm on dirt sound crazy or a good idea?
05-05-2022 | 03:28 AM
#2223
................................................
Mick - if you go back to the first page of this thread and only focus on Fred's posts you'll get about everything you need in the first 10 or so pages. It will take a lot less time than you might think. But if you just want an abridged version of Fred's method it's this:......................................
Mick - if you go back to the first page of this thread and only focus on Fred's posts you'll get about everything you need in the first 10 or so pages. It will take a lot less time than you might think. But if you just want an abridged version of Fred's method it's this:......................................
Lots to read there.
MiCk B. :-)
05-05-2022 | 05:35 AM
#2224
Tech Fanatic
Joined: Apr 2017
Posts: 781
From: Vizcaya, Spain
I've been following this thread for a long time but I never put that much time on understanding suspension frequencies. I have been fighting for 2 years with my Yok CAL3 /3.1 trying to find a balanced setup. The car just looks very unbalanced. Found this, and thought it was time for a change.
The car is really twitchy up front with very low to zero chassis roll where it looks to wheel bounce all around, similar to having a super heavy front shock oil. The rear goes the same direction. Near to 0 roll to the eyes and losing grip pretty fast on corner exit.
I think I'm going back to factory setup and start setting up a correct spring fequency. I may upload some videos that could be helpful for everyone here.
Lots of info from here to there and many more setup adjusments makes it even more difficult. When axle heights and pills come into play make it even harder
The car is really twitchy up front with very low to zero chassis roll where it looks to wheel bounce all around, similar to having a super heavy front shock oil. The rear goes the same direction. Near to 0 roll to the eyes and losing grip pretty fast on corner exit.
I think I'm going back to factory setup and start setting up a correct spring fequency. I may upload some videos that could be helpful for everyone here.
Lots of info from here to there and many more setup adjusments makes it even more difficult. When axle heights and pills come into play make it even harder
05-05-2022 | 06:29 AM
#2225
Ok, since there seems to be some new visibility on this thread and the method I'll post some clips I uploaded about 4 years ago when I ran through this procedure with my 22 3.0. Hopefully these clips can really de-mystify the process. It's looks overwhelming when you type everything out, but to actually do and see the process you realize it's actually pretty simple.
You take the oil out of the shocks, put them back on the car, press the car down in the middle, and quickly release the car. Just like this:
In that clip the front end of the car is popping up faster than the rear. That means I've got a stiffer setup in the front than the rear. I don't remember exactly what I tweaked, it was 4 years ago apparently, but here's how the car looks when the front and rear rates are balanced:
The whole chassis stays more or less level as the front and rear suspensions pop back up. That's the balance you're looking for. I've found just doing this test alone makes a huge difference in how the car drives. But you can easily do this same test again to check your oil selections. it's the same test, only now you've got oil in the shocks.
I hope these clips illustrate just how simple this procedure actually is despite how wordy or intimidating the write up may look! Part of me thinks this information would really benefit from being presented in a video format so maybe I'll work on that when I get a chance.
You take the oil out of the shocks, put them back on the car, press the car down in the middle, and quickly release the car. Just like this:
In that clip the front end of the car is popping up faster than the rear. That means I've got a stiffer setup in the front than the rear. I don't remember exactly what I tweaked, it was 4 years ago apparently, but here's how the car looks when the front and rear rates are balanced:
The whole chassis stays more or less level as the front and rear suspensions pop back up. That's the balance you're looking for. I've found just doing this test alone makes a huge difference in how the car drives. But you can easily do this same test again to check your oil selections. it's the same test, only now you've got oil in the shocks.
I hope these clips illustrate just how simple this procedure actually is despite how wordy or intimidating the write up may look! Part of me thinks this information would really benefit from being presented in a video format so maybe I'll work on that when I get a chance.
07-18-2023 | 11:15 AM
#2226
Tech Initiate
iTrader: (3)
Joined: Mar 2023
Posts: 34
I've been following this thread for a long time but I never put that much time on understanding suspension frequencies. I have been fighting for 2 years with my Yok CAL3 /3.1 trying to find a balanced setup. The car just looks very unbalanced. Found this, and thought it was time for a change.
The car is really twitchy up front with very low to zero chassis roll where it looks to wheel bounce all around, similar to having a super heavy front shock oil. The rear goes the same direction. Near to 0 roll to the eyes and losing grip pretty fast on corner exit.
I think I'm going back to factory setup and start setting up a correct spring fequency. I may upload some videos that could be helpful for everyone here.
Lots of info from here to there and many more setup adjusments makes it even more difficult. When axle heights and pills come into play make it even harder
The car is really twitchy up front with very low to zero chassis roll where it looks to wheel bounce all around, similar to having a super heavy front shock oil. The rear goes the same direction. Near to 0 roll to the eyes and losing grip pretty fast on corner exit.
I think I'm going back to factory setup and start setting up a correct spring fequency. I may upload some videos that could be helpful for everyone here.
Lots of info from here to there and many more setup adjusments makes it even more difficult. When axle heights and pills come into play make it even harder
Tuned in for your progress on this. Bought a cal3 second hand and going through setting it up. Was considering taking this path as well.
subscribed
07-19-2023 | 09:12 AM
#2227
Welp I got a wild hair this week and did the spring and dampening balancing. The pistons and shock oil I was already running worked out well but the springs ended up a head scratcher. Seemed that every conventional rear buggy spring was way to soft and it wasn’t til I used a SCT front spring in the rear did the frequencies match up. The closest track (sealed clay) is a 6hr round trip and I’m heading there this weekend to see show it goes. I know there’s a lot more involved but I’m running low roll centers and Avid 13mm bodies on my 22 5.0
1x1.0 + 1x1.7 + 1x1.8 2.5mm pistons 32.5w AE V2 white (3.4 lb/in) fr
1x1.0 + 2x1.8 2.5mm pistons 30wt Serpent orange (SCT front 3.0 lb/in) rr
1x1.0 + 1x1.7 + 1x1.8 2.5mm pistons 32.5w AE V2 white (3.4 lb/in) fr
1x1.0 + 2x1.8 2.5mm pistons 30wt Serpent orange (SCT front 3.0 lb/in) rr
07-20-2023 | 06:43 AM
#2228
Every single car I've done the spring balancing test on has had a significantly higher suspension frequency in the front compared to the rear with the kit setup, and I've had to resort to some unusual setups to get things balanced.
Back when I had my AE SC10 4x4 I ended up using a front spring on the rear of the car to get it balanced. Also around that time when spec SCT was still a big class and you could only run parts that came in the box, I had a Losi XXX-SCT and I had to swap the front springs to the rear and the rear springs to the front to get it balanced (it wasn't technically against the rules to use parts in the box for other-than-intended purposes). The spring balance test can certainly result in some very unconventional setups but as I've said multiple times, I always like the result.
Good luck this weekend! I hope the setup changes work out for you.
Back when I had my AE SC10 4x4 I ended up using a front spring on the rear of the car to get it balanced. Also around that time when spec SCT was still a big class and you could only run parts that came in the box, I had a Losi XXX-SCT and I had to swap the front springs to the rear and the rear springs to the front to get it balanced (it wasn't technically against the rules to use parts in the box for other-than-intended purposes). The spring balance test can certainly result in some very unconventional setups but as I've said multiple times, I always like the result.
Good luck this weekend! I hope the setup changes work out for you.
07-22-2023 | 07:51 AM
#2229
Tech Rookie
Joined: Jun 2023
Posts: 5
Last year I asked Ray Munday about spring and damping frequency. Seems that its not fully applicable on our scaled cars. His answer below.
"Regarding spring/damping frequency - our vehicles are extremely overdamped so it's not super critical to match spring frequency. Typically our cars run a higher front spring frequency than rear which helps with the rear kicking more off jumps to help with a nose down attitude. But the damping balance is more important as the damper has much bigger forces than the springs. Small changes in hub positions etc are not important, but for major changes (eg going from a standup to laydown transmission) I will change front and rear springs to match the weight bias change (eg for standup I will use softer front spring / firmer rear springs)."
"Regarding spring/damping frequency - our vehicles are extremely overdamped so it's not super critical to match spring frequency. Typically our cars run a higher front spring frequency than rear which helps with the rear kicking more off jumps to help with a nose down attitude. But the damping balance is more important as the damper has much bigger forces than the springs. Small changes in hub positions etc are not important, but for major changes (eg going from a standup to laydown transmission) I will change front and rear springs to match the weight bias change (eg for standup I will use softer front spring / firmer rear springs)."
07-23-2023 | 09:51 AM
#2230
So I ended up bringing my LD2 to Coyote Hobbies as well after doing the spring/dampening balancing just for the hell of it. Now, typically this track is sealed but they had just redone it and had not glued the surface so it was run as a wet track. My 22 5.0 was a bit pushy, because of the lower roll centers and lower grip but was great on the jumps and felt very safe, I guess is a good word for it. Raising the roll centers a bit would help with rotation but the car felt very composed. There is a large triple on the near side of the track that I flat landed a couple of times and to my surprise the car was very composed and just absorbed force of the landing with no chassis slapping or weird snap rotations. Right after the triple is a 90 degree turn, you can downside the triple setting yourself up for the turn and you’re golden. If you overshoot and flatland you immediately have to kick the rear end of the car out to make the turn. Even though I tried to downside a few times I overshot and flat landed but it didn’t seem to upset the car at all it was still very composed. Now, if you got outside of the main groove the track was very slick and I’d end up in a 4 wheel drift sliding wide and bouncing off of the pipe, this would happen if you didn’t downside so you really wanted to downside lol I then ran my LD2 which I had setup with a slightly higher front roll center than my 22 since the last time I had it out (also the first time with it) I was lacking a bit of steering and wanted to give that a shot. Also, I put it on the corner scales after the run and noticed it was very tail heavy and light at the front (even with the lips full forward) compared to my 22, to the tune of 28 grams in the rear and 23 in the front. I added a bit of brass under the servo to help balance things out and did the rear chassis mod which cuts off the square corners which could hit the track during hard cornering (it’s a Schumacher thing lol) After all of that and the the suspension changes (upped front oil to 40wt and went up in rear spring rate (2.8lb/in from 2.0lb/in) it was money! It helped that my silver Ellipses sanded slick w/RM2 foams front and rear seemed to be the hot ticket but the car itself was great. Stable, rotated at will, was very predictable, it was a blast to drive. I never went back to my 22 lol Turned out that a lot of the local guys were at a JBRL race in Saugus so it ended up being a practice day. My LD2 was handling so well I was really looking forward to racing but it was not to be. I’m sure a few changes will need to be made after the track is sealed and traction goes through the roof. This is when not having a local track really sucks, I want to do the same suspension balancing to my wheelers and stadium truck and give them a try…now. Your results may vary but I’m sold!
07-30-2023 | 06:54 AM
#2232
Tech Elite
Joined: Dec 2001
Posts: 4,649
From: Bristol, UK
For what it's worth I think there is a lot to be gained by understanding how wheel frequencies actually work in practice, however a 2wd buggy front end kick up creates so much mechanical resistance against the purely vertical motion that the bench test described is going to give some misleading readings.
Buggy springs may seem "stiff" at the front in that test, but I think we would mostly agree that kit settings are not far off in practice.
I seem to remember reading that when Gene Husting et al were designing the RC10 40 years ago they built themselves a "suspension Dyno" that was a few strips of wood on a board. They got the rates pretty good for the day of release, this shocks and springs were still under world champion cars 20 years later.
Buggy springs may seem "stiff" at the front in that test, but I think we would mostly agree that kit settings are not far off in practice.
I seem to remember reading that when Gene Husting et al were designing the RC10 40 years ago they built themselves a "suspension Dyno" that was a few strips of wood on a board. They got the rates pretty good for the day of release, this shocks and springs were still under world champion cars 20 years later.
07-31-2023 | 07:22 AM
#2233
Whatever the front kickup's contribution is to the chassis' behavior when driving, it's hard to imagine a way in which that contribution is somehow not present when doing these suspension frequency balancing tests. Regardless, my cars drive better as a result so does it even matter if the test doesn't measure what I think it measures?
09-22-2023 | 07:34 AM
#2234
Tech Apprentice
iTrader: (3)
Joined: Aug 2023
Posts: 95
I seem to remember reading that when Gene Husting et al were designing the RC10 40 years ago they built themselves a "suspension Dyno" that was a few strips of wood on a board. They got the rates pretty good for the day of release, this shocks and springs were still under world champion cars 20 years later.
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