Talion Talion V3 Ride Height Problem

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JMS RC

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Arrma RC's
  1. Infraction
  2. Kraton 8S
  3. Kraton 6s
  4. Kraton EXB
  5. Nero
  6. Outcast 6s
  7. Talion
  8. Typhon 6s
  9. Typhon 3s
I would like to get the front suspension sit so that the axles are horizontal. Even if I mount the shocks in the inner hole on the a-arm and in the lower hole on the tower and turn the collars all the way down on the shocks, it is still too low. Been reading about folks swapping out the springs for Tekno RC but the V3 is supposed to have springs that are very equal to those Tekno RC orange ones. I run the stock 2000cst shock fluid since it's summer and warm outside. These pictures are taken just after a run, pic 1 after the front been pushed down and pic 2 if i pump it up and down a dozen times. Nothing in the suspension is binding. Is it supposed to be like this or am i missing something ?? Change to a lower viscosity fluid ?
Rear is just fine, a little above horizontal although I had to turn down the collars quite a bit.
 

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Looks like your droop screws are turned in way too far, keeping the lower arm from traveling down any farther.

Thought about that too and since i recently switched to rpm arms i checked those, but they seem to be correct.

4.JPG



Let me know how you go? I heard the springs are too short and to change it to kraton ones.

Yes, i think the springs are short and longer ones would be nice, it seems though like they are stiffer than the Kraton/Outcast and Tekno RC ??

Talion V3 AR330500 Front 60mm Length 1.35N/mm (9.7lb/in)
Kraton/Outcast 2018 AR330507 Front 85mm Length 1.09N/mm (6.2lb/in)
Tekno RC Orange TKR6093 1.6×7.5T, 80mm, orange, 6.11 lb/in
 
Thought about that too and since i recently switched to rpm arms i checked those, but they seem to be correct.

View attachment 19260




Yes, i think the springs are short and longer ones would be nice, it seems though like they are stiffer than the Kraton/Outcast and Tekno RC ??

Talion V3 AR330500 Front 60mm Length 1.35N/mm (9.7lb/in)
Kraton/Outcast 2018 AR330507 Front 85mm Length 1.09N/mm (6.2lb/in)
Tekno RC Orange TKR6093 1.6×7.5T, 80mm, orange, 6.11 lb/in

Would the tekno tkr6093 good for track use?
 
Thought about that too and since i recently switched to rpm arms i checked those, but they seem to be correct.

View attachment 19260




Yes, i think the springs are short and longer ones would be nice, it seems though like they are stiffer than the Kraton/Outcast and Tekno RC ??

Talion V3 AR330500 Front 60mm Length 1.35N/mm (9.7lb/in)
Kraton/Outcast 2018 AR330507 Front 85mm Length 1.09N/mm (6.2lb/in)
Tekno RC Orange TKR6093 1.6×7.5T, 80mm, orange, 6.11 lb/in
Correct, the V3 Talion springs are "much stiffer" than the Kraton/Outcast or any of Arrma's optional shock springs that are available, so probably any of these other springs would be too soft. For stiffness, 9.7lb/in is a big difference between 6.2lb/in. However, compressing a Kraton spring a lot on a much shorter V3 Talion shock may help compensate for less stiffness in the spring? Hopefully Arrma or an aftermarket RC company will offer some optional longer front springs for the V3 Talion soon.

servalac: it looks like your front arms are close to level (horizontal) in your pics, and this is what you want for the V3 Talion. Are you running a bunch of heavy upgrade parts, heavy battery, etc maybe? If more ground clearance is needed offroad you could use the Kraton axles & try the Backflip tires.
 
O
Correct, the V3 Talion springs are "much stiffer" than the Kraton/Outcast or any of Arrma's optional shock springs that are available, so probably any of these other springs would be too soft. For stiffness, 9.7lb/in is a big difference between 6.2lb/in. However, compressing a Kraton spring a lot on a much shorter V3 Talion shock may help compensate for less stiffness in the spring? Hopefully Arrma or an aftermarket RC company will offer some optional longer front springs for the V3 Talion soon.

servalac: it looks like your front arms are close to level (horizontal) in your pics, and this is what you want for the V3 Talion. Are you running a bunch of heavy upgrade parts, heavy battery, etc maybe? If more ground clearance is needed offroad you could use the Kraton axles & try the Backflip tires.


How do i find out more about this compression information?
 
This may or may not help, but gives some explination about springs and rates.

What is spring rate?
Spring rate refers to the amount of weight that is needed to compress a spring one inch. If the rate of the spring is linear, its rate is not affected by the load that is put on the spring. For example, say you have a 200 lb. per inch spring - it will compress 1” when a 200 lb. load is placed onto the spring. If another 200 lbs. is put onto the spring, the spring will compress another inch. At this point the load on the spring is 400 lbs. The rate of the spring, however, remains constant at 200 lbs. per inch.

Spring Rate Correction for Angle Mounting
If your spring is mounted at an angle you will need to consider that in your spring calculations. Measure the angle of your spring from vertical (A) in degrees. Use the examples provided on this page or the formula below to determine your Angle Correction Factor (ACF).

Theory_of_Billativity.png


Shock Angle Angle Correction Factor (ACF)
10° .98
15° .96
20° .94
25° .91
30° .87
35° .82
40° .77
45° .71
Angle_Mounting.png


The greater the installed angle, the stiffer the spring rate must be to support the same weight. First, determine the spring needed for the application if the spring is installed straight up. Then, to compensate for installations at different angles, find your ACF using the chart or formula above, and divide your straight mounted spring rate by your ACF.

Example:
Straight Mounted Spring = 200 lbs.
Spring Mounted at 30° = 200/.87 = 230 lbs.

The 230 lbs. represents the spring rate needed when mounted at a 30° angle to equal the desired spring rate of 200 lbs. when standing straight up.

How to select the spring rate for independent suspension

Select your spring rate by using the following calculations:

Independent_Suspension.png
D1 = The distance from the pivot point of the a-arm to the mounting point of the spring/shock.
D2 = The distance from the pivot point of the a-arm to the center of the ball joint.
Divide D1 by D2 to calculate the force ratio (Fr).
Force Ratio (Fr) = D1/D2
Weigh your car to determine the weight on the wheels (W).
Divide the weight on the wheel by Fr to determine the force required at the spring (Sf).
W/Fr=Sf

If your spring is mounted at an angle you will need to consider that in your spring calculations. Measure the angle (A) of your spring from vertical in degrees. Use the table above to determine your Angle Correction Factor (ACF). Now divide the Spring Force (Sf) from the earlier calculation by the Angle Correction Factor (ACF) to get the Adjusted Spring Force (ASf).
Sf/ACF=ASf

Note: This calculation determines spring FORCE not spring RATE.

The required Adjusted Spring Force (ASf) can now be used to select the proper spring rate for your application. The required spring force can be obtained several different ways. A lighter rate spring with more preload or a stiffer rate spring with less preload will generate the same spring force. The softer rate will generate a smoother ride while the stiffer spring will result in a firmer ride. You need to consider these options when you are selecting the proper spring rate for your application.

Springs should typically be compressed 25-30% of the free length when supporting the weight of the vehicle. Drag race cars will normally use a lighter rate spring (about 30%) to promote weight transfer while a street car will use a firmer rate spring (about 25%).

ASf/(spring free length x 0.25) = Firmer Spring Rate
Asf/(spring free length x 0.30) = Softer Spring Rate

Spring rate calculations for solid axle suspension are the same as above except the Force Ratio (Fr) = 1.
 
2fast4u,

Thank you for posting this from an in depth and technical POV

I've been looking for this info, especially the ACF multipliers in relation to degree.
 
This may or may not help, but gives some explination about springs and rates.

What is spring rate?
Spring rate refers to the amount of weight that is needed to compress a spring one inch. If the rate of the spring is linear, its rate is not affected by the load that is put on the spring. For example, say you have a 200 lb. per inch spring - it will compress 1” when a 200 lb. load is placed onto the spring. If another 200 lbs. is put onto the spring, the spring will compress another inch. At this point the load on the spring is 400 lbs. The rate of the spring, however, remains constant at 200 lbs. per inch.

Spring Rate Correction for Angle Mounting
If your spring is mounted at an angle you will need to consider that in your spring calculations. Measure the angle of your spring from vertical (A) in degrees. Use the examples provided on this page or the formula below to determine your Angle Correction Factor (ACF).

Theory_of_Billativity.png


Shock Angle Angle Correction Factor (ACF)
10° .98
15° .96
20° .94
25° .91
30° .87
35° .82
40° .77
45° .71
Angle_Mounting.png


The greater the installed angle, the stiffer the spring rate must be to support the same weight. First, determine the spring needed for the application if the spring is installed straight up. Then, to compensate for installations at different angles, find your ACF using the chart or formula above, and divide your straight mounted spring rate by your ACF.

Example:
Straight Mounted Spring = 200 lbs.
Spring Mounted at 30° = 200/.87 = 230 lbs.

The 230 lbs. represents the spring rate needed when mounted at a 30° angle to equal the desired spring rate of 200 lbs. when standing straight up.

How to select the spring rate for independent suspension

Select your spring rate by using the following calculations:

Independent_Suspension.png
D1 = The distance from the pivot point of the a-arm to the mounting point of the spring/shock.
D2 = The distance from the pivot point of the a-arm to the center of the ball joint.
Divide D1 by D2 to calculate the force ratio (Fr).
Force Ratio (Fr) = D1/D2
Weigh your car to determine the weight on the wheels (W).
Divide the weight on the wheel by Fr to determine the force required at the spring (Sf).
W/Fr=Sf

If your spring is mounted at an angle you will need to consider that in your spring calculations. Measure the angle (A) of your spring from vertical in degrees. Use the table above to determine your Angle Correction Factor (ACF). Now divide the Spring Force (Sf) from the earlier calculation by the Angle Correction Factor (ACF) to get the Adjusted Spring Force (ASf).
Sf/ACF=ASf

Note: This calculation determines spring FORCE not spring RATE.

The required Adjusted Spring Force (ASf) can now be used to select the proper spring rate for your application. The required spring force can be obtained several different ways. A lighter rate spring with more preload or a stiffer rate spring with less preload will generate the same spring force. The softer rate will generate a smoother ride while the stiffer spring will result in a firmer ride. You need to consider these options when you are selecting the proper spring rate for your application.

Springs should typically be compressed 25-30% of the free length when supporting the weight of the vehicle. Drag race cars will normally use a lighter rate spring (about 30%) to promote weight transfer while a street car will use a firmer rate spring (about 25%).

ASf/(spring free length x 0.25) = Firmer Spring Rate
Asf/(spring free length x 0.30) = Softer Spring Rate

Spring rate calculations for solid axle suspension are the same as above except the Force Ratio (Fr) = 1.
Thanks man. This makes a lot of sense. Now just to fins out how much pressure i need for my springs for races etc.

Is it possible to use the talion springs? Or should i upgrade for a taller shock?
 
You're both welcome. I am in agreement with RCROD, the longer but softer Tekno orange springs may get you more ride height with the increased preload but it almost looks like the shocks are near or at full extension in your last pic. Which would leave you with little gain and no droop due to the shorter shock. I believe that V3 was designed for more speed and stability on smoother running surfaces. Hence, lower ride height, less droop and slightly (softer spring for that geometry). Standing the shocks as vertical as possible and moving the bottom of them closer to the wheel if you can will stiffen it a little.
 
Correct, the V3 Talion springs are "much stiffer" than the Kraton/Outcast or any of Arrma's optional shock springs that are available, so probably any of these other springs would be too soft. For stiffness, 9.7lb/in is a big difference between 6.2lb/in. However, compressing a Kraton spring a lot on a much shorter V3 Talion shock may help compensate for less stiffness in the spring? Hopefully Arrma or an aftermarket RC company will offer some optional longer front springs for the V3 Talion soon.

servalac: it looks like your front arms are close to level (horizontal) in your pics, and this is what you want for the V3 Talion. Are you running a bunch of heavy upgrade parts, heavy battery, etc maybe? If more ground clearance is needed offroad you could use the Kraton axles & try the Backflip tires.

Well, the camera lies a little, it is close to horizontal but the shocks are mounted in the inner position on the arm and on the lower position on the tower and the collar all the way down to achieve this. It would be nice to get the front horizontal without maxing everything out. I do run some pro-line shockwaves 3.8 so the ground clearance is OK if I could get the front horizontal. Since the front suspension is below horizontal whenever I hit a jump the front skidplate hits first, and even the arms gets scraped. I don't have any heavy upgrades mounted. There are 2 lightweight 2S mounted. I have always been taught that the arms and the axles are supposed to be as horizontal as possible, this might not be true with the Talion ? The Talion V3's I own have out of the box been really low in the front, and the angles of the arms and axles do not seem right ? I will try the Tekno TKR6093 in the front. Also gonna change the shockfluid to 1000cst and see if that makes any difference.

You're both welcome. I am in agreement with RCROD, the longer but softer Tekno orange springs may get you more ride height with the increased preload but it almost looks like the shocks are near or at full extension in your last pic. Which would leave you with little gain and no droop due to the shorter shock. I believe that V3 was designed for more speed and stability on smoother running surfaces. Hence, lower ride height, less droop and slightly (softer spring for that geometry). Standing the shocks as vertical as possible and moving the bottom of them closer to the wheel if you can will stiffen it a little.

Yes the shocks are at their full extension in the last pic. I also do believe that the V3 was designed to ride lower, but riding low with the arms and the axles in such a steep angle does not seem right ? Since the front suspension is below horizontal whenever I hit a jump the front skidplate hits first, and even the arms gets scraped. My Talion V3's came with the shocks mounted on the inner hole in the arm and on the top position on the tower, I mounted the shocks on the lower position on the tower to gain height !? Will mount the shocks in a more vertical position and see if that makes a difference.
 
Camera angles are tricky. Yes the arms should run at or near horizontal. Maybe the springs are incorrect, even though they came on it. I am not familiar with all the different springs and rates arrma has or what may or may not fit but be incorrect. Heavier oil will help some with the bottoming out prematurely issue but it is not the silver bullet. The spring carries the weight. As far as rates for racing, it all depends on the track conditions and your driving style.
 
Well, the camera lies a little, it is close to horizontal but the shocks are mounted in the inner position on the arm and on the lower position on the tower and the collar all the way down to achieve this. It would be nice to get the front horizontal without maxing everything out. I do run some pro-line shockwaves 3.8 so the ground clearance is OK if I could get the front horizontal. Since the front suspension is below horizontal whenever I hit a jump the front skidplate hits first, and even the arms gets scraped. I don't have any heavy upgrades mounted. There are 2 lightweight 2S mounted. I have always been taught that the arms and the axles are supposed to be as horizontal as possible, this might not be true with the Talion ? The Talion V3's I own have out of the box been really low in the front, and the angles of the arms and axles do not seem right ? I will try the Tekno TKR6093 in the front. Also gonna change the shockfluid to 1000cst and see if that makes any difference.



Yes the shocks are at their full extension in the last pic. I also do believe that the V3 was designed to ride lower, but riding low with the arms and the axles in such a steep angle does not seem right ? Since the front suspension is below horizontal whenever I hit a jump the front skidplate hits first, and even the arms gets scraped. My Talion V3's came with the shocks mounted on the inner hole in the arm and on the top position on the tower, I mounted the shocks on the lower position on the tower to gain height !? Will mount the shocks in a more vertical position and see if that makes a difference.

Yes, sometimes hard to tell in pics. I agree, in your 1st pic, your Talion is way too low. I'm not sure exactly what you mean by 2nd pic you pumped up 12x? The best way to check your ride height (preload) is to drop RC from about 3ft. Where it now sits, is your ride height. Your last pic, to check you full downtravel (& adjust droops screws), it would have been better if you had Talion chassis on a truck stand or block, as hard to how much downtravel? Also, is your Talion bottoming on the "landings" from the jumps?

The V3 Talion comes out of the box with suspension adjusted really low. This is great for those street speed runs, but any offroading, the shocks definitely need to be adjusted right away. I agree, for most RC's, RIDE HEIGHT should be when arms are level/horizontal, and this is also the best setup for the Talion. The Talion's LP design (shorter shocks/towers) will not allow the Talion to sit higher than level, and even if longer springs were used, there would be virtually no preload, which would greatly affect the ride quality, if you know what I mean. However, for MT's & the Kraton, the ride height is usually much higher, with the arms sloping downwards from the chassis, which gives them more ground clearance + the bigger tires of course. The new V3 Kraton springs rates and length are great and I did not need to adjust the suspension at all.


On my V3 Talion, I have adjusted my suspension so arms sit bone level (horizontal). The rear shock spring length is good, as I have adjusted my rear shock spring collars "only" about 30% down the threads (I have approx 17mm thread left). On the front, I did need to adjust my shock collars about 80% down the threads (approx 6mm thread left). I used digital calipers to match each side.

I am not sure why your Talion does not sit level, even with your front shock shock springs adjusted all the way? I see you also have used the inner hole on the arms and the lower hole on the shock tower, so not sure what else you can do? Your tires are heavy which would affect bottoming out more after jumps, but since they are unsprung weight, they should not affect your ride height level? Also your RPM bumper would not weigh much more than my TBR Typhon bumper, so weight for our V3 Talion's should be similar? The only thing I can think of for why my Talion sits higher, is maybe the RPM arm shock hole location is different than stock arms, or you have a lot more wear/use on your Talion/shocks, and they are sagging a bit now? Did your Talion sit higher before the RPM arm install?

If you use a longer but noticeably less stiff spring, it may help a bit with the preload, but may bottom out easier on big jumps. By adding thicker shock fluid impacts jumping, handling during cornering, acceleration and braking. It will not affect ride height, or preload though. Here is a link on tuning with shock fluid:
http://rctruckstop.com/2012/05/16/tuning-with-shock-fluid/

Since V3 Talion rear springs are ok, what we need is a longer front spring with the same high stiffness spring rate. This should fix your problem, and hopefully Arrma or an aftermarket RC company will step up...
 
RCROD:
Thank you for an excellent reply and answer.

If i pumped the suspension up and down several times, it did return to the set ride height easier, kinda like the shock fluid had to be warmed up. (even though we have about 25-30dgr C here right now) The inner shock position on the RPM 81482 is very similar to the Talion V3 stock.
12.jpg


I have been wrong about the axles sitting horizontal, this is not possible due to that the axles and lower a-arms are not parallell. It is like you say the lower a-arms that should be horizontal and this leaves the axles in an angle leaning towards the diff. I have been watching the official Talion V3 videos, and that seems to be the way Arrma runs theirs, at least in their basher videos. I have a brand new Talion, this is almost right out of the box. I have changed the position of the shock on the tower in this pic.

11.jpg

This pic is from Arrma site. https://www.arrma-rc.com/rc-cars/latest/talion/blx/story-board.
Check out the position of the spring collars and the horizontal lower arms. Check out the position of the shock
on the tower. It also looks like the shock rod end is longer !?
TalionFront1.jpg




Don't know if my shocks are worn out or damaged, they seem OK. Anyway I decided to change the shock fluid, my front shocks came equipped with the nr12 piston, reused that and added 1000cst 80w fluid. Mounted the shocks in the inner position on the arm and on the top position on the tower (stock). Adjusted the springs so that, like yours, has some threads left. Now it sits nice with the lower arms horizontal. What i gained with the shock fluid is that the front came alive somehow, more responsive and the rebound, so much nicer now. Perhaps the stock 2000cst shock fluid is to thick, especially with the nr12 piston ? Ran through a pack yesterday, and worked real nice. The Pro-Line Shockwaves are slightly larger in diameter than stock, now the rpm bumper hits the ground at the same time the shocks bottom out, if you would run a lot larger tires, the shocks would probably bottom out first.
10.jpg


Been searching a lot for longer springs and i thought the Tekno's were the solution until i read the stiffness numbers (which can be tricky, manufacturers/retailers use a lot of different weight factors ) I stumbled upon this thread
https://www.arrmaforum.com/threads/are-the-springs-on-the-new-kraton-2018-upgraded.6011/
I´'m not ordering the Tekno's since it probably not gonna be a difference.

Like you say, we need a longer front spring with the same stiffness/spring rate.
 
Yes, sometimes hard to tell in pics. I agree, in your 1st pic, your Talion is way too low. I'm not sure exactly what you mean by 2nd pic you pumped up 12x? The best way to check your ride height (preload) is to drop RC from about 3ft. Where it now sits, is your ride height. Your last pic, to check you full downtravel (& adjust droops screws), it would have been better if you had Talion chassis on a truck stand or block, as hard to how much downtravel? Also, is your Talion bottoming on the "landings" from the jumps?

The V3 Talion comes out of the box with suspension adjusted really low. This is great for those street speed runs, but any offroading, the shocks definitely need to be adjusted right away. I agree, for most RC's, RIDE HEIGHT should be when arms are level/horizontal, and this is also the best setup for the Talion. The Talion's LP design (shorter shocks/towers) will not allow the Talion to sit higher than level, and even if longer springs were used, there would be virtually no preload, which would greatly affect the ride quality, if you know what I mean. However, for MT's & the Kraton, the ride height is usually much higher, with the arms sloping downwards from the chassis, which gives them more ground clearance + the bigger tires of course. The new V3 Kraton springs rates and length are great and I did not need to adjust the suspension at all.


On my V3 Talion, I have adjusted my suspension so arms sit bone level (horizontal). The rear shock spring length is good, as I have adjusted my rear shock spring collars "only" about 30% down the threads (I have approx 17mm thread left). On the front, I did need to adjust my shock collars about 80% down the threads (approx 6mm thread left). I used digital calipers to match each side.

I am not sure why your Talion does not sit level, even with your front shock shock springs adjusted all the way? I see you also have used the inner hole on the arms and the lower hole on the shock tower, so not sure what else you can do? Your tires are heavy which would affect bottoming out more after jumps, but since they are unsprung weight, they should not affect your ride height level? Also your RPM bumper would not weigh much more than my TBR Typhon bumper, so weight for our V3 Talion's should be similar? The only thing I can think of for why my Talion sits higher, is maybe the RPM arm shock hole location is different than stock arms, or you have a lot more wear/use on your Talion/shocks, and they are sagging a bit now? Did your Talion sit higher before the RPM arm install?

If you use a longer but noticeably less stiff spring, it may help a bit with the preload, but may bottom out easier on big jumps. By adding thicker shock fluid impacts jumping, handling during cornering, acceleration and braking. It will not affect ride height, or preload though. Here is a link on tuning with shock fluid:
http://rctruckstop.com/2012/05/16/tuning-with-shock-fluid/

Since V3 Talion rear springs are ok, what we need is a longer front spring with the same high stiffness spring rate. This should fix your problem, and hopefully Arrma or an aftermarket RC company will step up...

Well, I have not yet been able to find some stiffer springs, I wanted to try some longer rod ends just like I believe is in the official Arrma pic above. I fitted RPM long rod ends for Traxxas and this is the result.

22.jpg

23.jpg

24.jpg

Check out the spring preload. I use the top pos. on the tower and the outer pos. on the RPM arm as you can see, the outer pos. on the RPM arm sits further out than on the original arm. I had to remove the plastic collar on the shock shaft otherwise the shock would bottom out too soon. Now the shocks bottoms out almost at the same time the chassi. This is with the Katar wheels, with the Shockwaves the shocks bottoms out first so the rod ends could be about 5mm shorter. Don't know if I have really accomplished anything !?, tried it a short bit yesterday and the car nosedives a little easier now and behaved somewhat strange. This might probably not solve the absence of stiffer springs, anyway it was worth a try :)
 
Last edited:
This may or may not help, but gives some explination about springs and rates.

What is spring rate?
Spring rate refers to the amount of weight that is needed to compress a spring one inch. If the rate of the spring is linear, its rate is not affected by the load that is put on the spring. For example, say you have a 200 lb. per inch spring - it will compress 1” when a 200 lb. load is placed onto the spring. If another 200 lbs. is put onto the spring, the spring will compress another inch. At this point the load on the spring is 400 lbs. The rate of the spring, however, remains constant at 200 lbs. per inch.

Spring Rate Correction for Angle Mounting
If your spring is mounted at an angle you will need to consider that in your spring calculations. Measure the angle of your spring from vertical (A) in degrees. Use the examples provided on this page or the formula below to determine your Angle Correction Factor (ACF).

Theory_of_Billativity.png


Shock Angle Angle Correction Factor (ACF)
10° .98
15° .96
20° .94
25° .91
30° .87
35° .82
40° .77
45° .71
Angle_Mounting.png


The greater the installed angle, the stiffer the spring rate must be to support the same weight. First, determine the spring needed for the application if the spring is installed straight up. Then, to compensate for installations at different angles, find your ACF using the chart or formula above, and divide your straight mounted spring rate by your ACF.

Example:
Straight Mounted Spring = 200 lbs.
Spring Mounted at 30° = 200/.87 = 230 lbs.

The 230 lbs. represents the spring rate needed when mounted at a 30° angle to equal the desired spring rate of 200 lbs. when standing straight up.

How to select the spring rate for independent suspension

Select your spring rate by using the following calculations:

Independent_Suspension.png
D1 = The distance from the pivot point of the a-arm to the mounting point of the spring/shock.
D2 = The distance from the pivot point of the a-arm to the center of the ball joint.
Divide D1 by D2 to calculate the force ratio (Fr).
Force Ratio (Fr) = D1/D2
Weigh your car to determine the weight on the wheels (W).
Divide the weight on the wheel by Fr to determine the force required at the spring (Sf).
W/Fr=Sf

If your spring is mounted at an angle you will need to consider that in your spring calculations. Measure the angle (A) of your spring from vertical in degrees. Use the table above to determine your Angle Correction Factor (ACF). Now divide the Spring Force (Sf) from the earlier calculation by the Angle Correction Factor (ACF) to get the Adjusted Spring Force (ASf).
Sf/ACF=ASf

Note: This calculation determines spring FORCE not spring RATE.

The required Adjusted Spring Force (ASf) can now be used to select the proper spring rate for your application. The required spring force can be obtained several different ways. A lighter rate spring with more preload or a stiffer rate spring with less preload will generate the same spring force. The softer rate will generate a smoother ride while the stiffer spring will result in a firmer ride. You need to consider these options when you are selecting the proper spring rate for your application.

Springs should typically be compressed 25-30% of the free length when supporting the weight of the vehicle. Drag race cars will normally use a lighter rate spring (about 30%) to promote weight transfer while a street car will use a firmer rate spring (about 25%).

ASf/(spring free length x 0.25) = Firmer Spring Rate
Asf/(spring free length x 0.30) = Softer Spring Rate

Spring rate calculations for solid axle suspension are the same as above except the Force Ratio (Fr) = 1.
Wow holy taking me to suspension school ! Do u have a solution for the talion ? I’m trying ya add power but it barely handles the stock system with the suspension on the rig when u give it 6s power the wheels just want to chatter and your basically out of control id live to have a solution to this and I will try to apply this formula to the best of my ability to find the corrections needed aka stiffer longer springs ,axles,shock position,oil weight etc thank you for the info and again if u have a solution for especially on pavement or light off road as I am shooting for over 100mph with new setup Wich is light work for the system I’m installing but again I can’t get the power to the ground it’s a total rebuild all carbon fiber new motor and esc ,Servo ,wheels etc
 
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