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Old 07-21-2015, 08:36 PM   #16381
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Well, I could take this to PM but this is a forum after all so let's share some wisdom.



I'm not Fred but I have enough knowledge about this subject. The original D8 had equal length shocks but the Motion Ratio was different front to rear AFAIK, that hurts more than the change in length could help. It was badly implemented. I'm not against unequal length shocks but would make it easier to "decode" our current shocks.



Yes only in RC. RC was modelled after the little understanding people had at the time about car dynamics. In the other classes they have teams dedicated solely to increase performance.

Bonus: What is so different fundamentally from the B5 and the RC10?
There is a lot of crossover between RC and full scale racing, of various types. From very prominent names to many lesser known ones, both drivers and technical types.

One example, the person in charge of product design since the ‘80s for a company that has won countless races has a significant background as a R&D technician for a major and very successful supercross team, where shock tuning is Kind of a Big Deal. The same company heavily involved in, if not leading, the suspension revolution of the ‘70s and on as scrambles morphed to moto and then supercross.

The basic suspension design most commonly used is fairly old and had been well analyzed long before off road RC existed. Simulation programs have been available for about as long to assist in understanding the many complex interactions, it is no doubt a complex challenge with many tradeoffs involved. Perhaps one of the most important being the balance of front to rear roll stiffness in various conditions, in which the location of the shocks are a major factor.

Testing isn’t on the same level as some full scale series, but there is a lot of testing going on at various levels. Not unusual for the driver to remain on the stand as different items are varied on the cars in order to avoid preconceived notions influencing the test results. Shock locations and setups are prime subjects of the testing and car development, nearly always have been.

But, one must always be open to finding a better way. Where are the gains to be made from a better understanding of shock setup? Where are the pros giving up performance because of their lack of understanding? Is it getting a clean launch off the huge jumps we have nowadays, limiting their ability to adjust in air for the next portion of the course? Braking and getting into the corners? Mid corner speed? Exiting?

If they are so far off, why hasn’t someone with more understanding came along and beaten them all badly?
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Old 07-22-2015, 03:05 PM   #16382
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There is a lot of crossover between RC and full scale racing, of various types. From very prominent names to many lesser known ones, both drivers and technical types.

One example, the person in charge of product design since the ‘80s for a company that has won countless races has a significant background as a R&D technician for a major and very successful supercross team, where shock tuning is Kind of a Big Deal. The same company heavily involved in, if not leading, the suspension revolution of the ‘70s and on as scrambles morphed to moto and then supercross.

The basic suspension design most commonly used is fairly old and had been well analyzed long before off road RC existed. Simulation programs have been available for about as long to assist in understanding the many complex interactions, it is no doubt a complex challenge with many tradeoffs involved. Perhaps one of the most important being the balance of front to rear roll stiffness in various conditions, in which the location of the shocks are a major factor.

Testing isn’t on the same level as some full scale series, but there is a lot of testing going on at various levels. Not unusual for the driver to remain on the stand as different items are varied on the cars in order to avoid preconceived notions influencing the test results. Shock locations and setups are prime subjects of the testing and car development, nearly always have been.

But, one must always be open to finding a better way. Where are the gains to be made from a better understanding of shock setup? Where are the pros giving up performance because of their lack of understanding? Is it getting a clean launch off the huge jumps we have nowadays, limiting their ability to adjust in air for the next portion of the course? Braking and getting into the corners? Mid corner speed? Exiting?

If they are so far off, why hasn’t someone with more understanding came along and beaten them all badly?
About the crossover, many faces are common with other motorsports but only few are known for their driving/setup abilities, and seems to be exclusive of Off Road Racing as I can't remember anyone in the On Road side that races 1:1 cars as their main hobby/job, DS Motorsports is the only one I remember now.

Does he works at a RC company? As I'm not into moto/supercross but aware of how their shocks work and tune.
Slight digression, CRP the shock company made a shock for 1/8th buggies based on real racing shocks but it didn't offered a palpable gain in performance AFAIK. I feel it's time we have tunable shim stacks in our pistons.

Off Road suspension design was taken from the VW Beetle like the Rough Rider and the Scorpion, they are more like scaled down buggies than RC cars with suitable suspension design like the RC10 that turned them obsolete. Suspension design is not the most important aspect in performance, you can make anything work provided it uses well the grip provided by the tire. There is not correct suspension geometry, just some happen to work good almost everywhere and others don't. Crucial to that is what you call balance of front and rear roll stiffness, known as roll axis and allow me to say that shocks shouldn't handle roll stiffness, that's roll center related. As you know, with the roll center at the CG height the car wouldn't roll and the more distance between RC and CG the more the car rolls. The shocks working because of that interaction is a symptom.

I don't understand that kind of testing, RC cars have little room to grow performance wise. Disregarding tire sauce here because I wholeheartedly believe it's not the answer nor changing to polished clay/synthetic track surfaces. Anyone can increase a fair amount of total grip with proper tuning procedure (instead of new go fast parts but parts sell and therefore money for the manufacturers) but it would be impossible to reach a way higher level of performance solely on tire design/construction and suspension geometry. That's why we are stuck with a generic suspension geometry since the 2.2" wheel came out.

Pro's tune the way they learned, often by trial and error and I don't blame them, current cars are complicated enough to have a clear tuning procedure. On that behalf, using shock tuning to control roll stiffness leads to another handicaps and then adding weight and so on and so forth. They have to know what is fast and what isn't, if it means driving a handful car but 0.09s faster than closest competition they will.

Yep, and that finding a better way presented us tire sauce. Instead of suspension geometry that loaded the tire a bit more and was compatible with the friction profile of that tire. That alone tells me suspension design is so specialized that it's better to change tire's grip and track surface material than change suspension geometry.

Someone to beat them can't rely solely in superior tuning knowledge to drive a car that isn't much faster (but it's easier to drive at the limit) with the same driving ability he ever had. Now if say a talented driver had access to proper tuning knowledge and was as fast as the pro's then nothing would hold him back, maybe money to race and to have enough parts to tune shocks and suspension geometry.

I have no problem saying that proper tuning would not make a big enough difference in pro tiers but we weekend warriors that depend on fast and easy to drive cars that adapt very well to any track condition it's a no brainer. Would having a car that was so consistently fast that allows you to fit a lap or two more on your main make a big difference?
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Old 08-02-2015, 09:06 AM   #16383
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Hey guys, I've shown off my custom dex210 here quite a few times. Well, if you're interested, you can buy it! Link to for sale thread.
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Old 08-03-2015, 09:03 PM   #16384
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Looks like TD are testing a non cab forward body at the Euros

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Old 08-03-2015, 09:25 PM   #16385
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Selling my friends DEX210 for a steal! Check out my for sale thread!
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Old 08-04-2015, 02:09 AM   #16386
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Looks like TD are testing a non cab forward body at the Euros

I do like the shape of the new body, looks like close to that one from the "spyshot"-car, i was never a big friend of those cap forward bodys, but thr durango ones, from the 210v2 and the 410v4 are not to bad.

Looks like, they test a shorty pack across the centre line, too!?
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Old 08-04-2015, 04:44 AM   #16387
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No front hexes? Even on the cutting edge of prototype design they still can't even provide 12mm front/rear hexes. That's just shooting themselves in the foot.
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Old 08-04-2015, 06:26 AM   #16388
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From the pictures so far, it looks like they are running standard v2 buggies at the Euros, apart from the bodies.
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Old 08-04-2015, 10:33 AM   #16389
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Chris Doughty has already said that the new 2wd will have the option of both front wheel bearings or front hexes.
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Old 08-04-2015, 11:47 AM   #16390
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Old 08-04-2015, 02:53 PM   #16391
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Originally Posted by 30Tooth View Post
Does he works at a RC company?
I'm going to respond with a simple question of my own. If your criteria of rc car intelligence is based on whether or not they work for an rc company, how are you able to judge whether or not they are right or wrong since you yourself don't work at an rc company? By your own standards, that would seem to invalidate your own opinions about how and why rc is the way it is.

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Pro's tune the way they learned, often by trial and error and I don't blame them...
There's no denying that. Lots of people do. I'll throw this out there, if the person they learned from, and the person they learned from, etc. never learned what to do and made assumptions, potentially wrong ones, and then passed that information down the line, does that originally flawed logic suddenly become right at some point or is it still flawed but accepted for some unknown reason? I originally learned by trial and error too. Then one day I wanted to know how exactly things worked and it invalidated many of the things I thought I knew from unguided trial and error. Informed trial and error to validate or invalidate ideas and concepts changed what I originally thought and helped to explain how and why things work the way they do. It turns out that tuning is actually quite easy when you understand what things do.

At the end of the day, I don't really care if you believe me or even like me. I don't require you to listen to anything that I say nor do I really care about what you think. I would like to ask you a question though. Are you basing your skepticism on the fact that you actually tried the methods and found them to be wrong or are you just mentally uncomfortable with the idea that things may not be what many think they are? If the latter is the case and you don't have any experience with it, then you really don't have any case against it. You are either testing or you are guessing. You might accidentally arrive at the right answer by guessing but the odds are strongly against you, no matter who you are or where you work.
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Old 08-04-2015, 06:11 PM   #16392
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Originally Posted by 30Tooth View Post
About the crossover, many faces are common with other motorsports but only few are known for their driving/setup abilities, and seems to be exclusive of Off Road Racing as I can't remember anyone in the On Road side that races 1:1 cars as their main hobby/job, DS Motorsports is the only one I remember now.

Does he works at a RC company? As I'm not into moto/supercross but aware of how their shocks work and tune.
Slight digression, CRP the shock company made a shock for 1/8th buggies based on real racing shocks but it didn't offered a palpable gain in performance AFAIK. I feel it's time we have tunable shim stacks in our pistons.

Off Road suspension design was taken from the VW Beetle like the Rough Rider and the Scorpion, they are more like scaled down buggies than RC cars with suitable suspension design like the RC10 that turned them obsolete. Suspension design is not the most important aspect in performance, you can make anything work provided it uses well the grip provided by the tire. There is not correct suspension geometry, just some happen to work good almost everywhere and others don't. Crucial to that is what you call balance of front and rear roll stiffness, known as roll axis and allow me to say that shocks shouldn't handle roll stiffness, that's roll center related. As you know, with the roll center at the CG height the car wouldn't roll and the more distance between RC and CG the more the car rolls. The shocks working because of that interaction is a symptom.

I don't understand that kind of testing, RC cars have little room to grow performance wise. Disregarding tire sauce here because I wholeheartedly believe it's not the answer nor changing to polished clay/synthetic track surfaces. Anyone can increase a fair amount of total grip with proper tuning procedure (instead of new go fast parts but parts sell and therefore money for the manufacturers) but it would be impossible to reach a way higher level of performance solely on tire design/construction and suspension geometry. That's why we are stuck with a generic suspension geometry since the 2.2" wheel came out.

Pro's tune the way they learned, often by trial and error and I don't blame them, current cars are complicated enough to have a clear tuning procedure. On that behalf, using shock tuning to control roll stiffness leads to another handicaps and then adding weight and so on and so forth. They have to know what is fast and what isn't, if it means driving a handful car but 0.09s faster than closest competition they will.

Yep, and that finding a better way presented us tire sauce. Instead of suspension geometry that loaded the tire a bit more and was compatible with the friction profile of that tire. That alone tells me suspension design is so specialized that it's better to change tire's grip and track surface material than change suspension geometry.

Someone to beat them can't rely solely in superior tuning knowledge to drive a car that isn't much faster (but it's easier to drive at the limit) with the same driving ability he ever had. Now if say a talented driver had access to proper tuning knowledge and was as fast as the pro's then nothing would hold him back, maybe money to race and to have enough parts to tune shocks and suspension geometry.

I have no problem saying that proper tuning would not make a big enough difference in pro tiers but we weekend warriors that depend on fast and easy to drive cars that adapt very well to any track condition it's a no brainer. Would having a car that was so consistently fast that allows you to fit a lap or two more on your main make a big difference?
Quote:
Originally Posted by fredswain View Post
I'm going to respond with a simple question of my own. If your criteria of rc car intelligence is based on whether or not they work for an rc company, how are you able to judge whether or not they are right or wrong since you yourself don't work at an rc company? By your own standards, that would seem to invalidate your own opinions about how and why rc is the way it is.



There's no denying that. Lots of people do. I'll throw this out there, if the person they learned from, and the person they learned from, etc. never learned what to do and made assumptions, potentially wrong ones, and then passed that information down the line, does that originally flawed logic suddenly become right at some point or is it still flawed but accepted for some unknown reason? I originally learned by trial and error too. Then one day I wanted to know how exactly things worked and it invalidated many of the things I thought I knew from unguided trial and error. Informed trial and error to validate or invalidate ideas and concepts changed what I originally thought and helped to explain how and why things work the way they do. It turns out that tuning is actually quite easy when you understand what things do.

At the end of the day, I don't really care if you believe me or even like me. I don't require you to listen to anything that I say nor do I really care about what you think. I would like to ask you a question though. Are you basing your skepticism on the fact that you actually tried the methods and found them to be wrong or are you just mentally uncomfortable with the idea that things may not be what many think they are? If the latter is the case and you don't have any experience with it, then you really don't have any case against it. You are either testing or you are guessing. You might accidentally arrive at the right answer by guessing but the odds are strongly against you, no matter who you are or where you work.


Yowsers, this thread has gotten deep what ever happened to racing these toy R/C cars for fun?
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Old 08-05-2015, 03:29 AM   #16393
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Originally Posted by fredswain View Post
I'm going to respond with a simple question of my own. If your criteria of rc car intelligence is based on whether or not they work for an rc company, how are you able to judge whether or not they are right or wrong since you yourself don't work at an rc company? By your own standards, that would seem to invalidate your own opinions about how and why rc is the way it is.
I'm sorry if that reply came out wrong. It was a sincere question, I had the impression that gentleman Dave spoke worked with RC shocks but didn't want to assume. I just wanted to see his work.
My reply was more directed to Mantis Tobbogan... Now that I have your attention - and hope I didn't triggered you - your work made me do a spreadsheet to show some basic suspension stuff. If you want to check it out the links are in my signature. It's two threads but first post is the same for all, the last version is lite spreadsheet.

Quote:
Originally Posted by fredswain View Post
There's no denying that. Lots of people do. I'll throw this out there, if the person they learned from, and the person they learned from, etc. never learned what to do and made assumptions, potentially wrong ones, and then passed that information down the line, does that originally flawed logic suddenly become right at some point or is it still flawed but accepted for some unknown reason? I originally learned by trial and error too. Then one day I wanted to know how exactly things worked and it invalidated many of the things I thought I knew from unguided trial and error. Informed trial and error to validate or invalidate ideas and concepts changed what I originally thought and helped to explain how and why things work the way they do. It turns out that tuning is actually quite easy when you understand what things do.

At the end of the day, I don't really care if you believe me or even like me. I don't require you to listen to anything that I say nor do I really care about what you think. I would like to ask you a question though. Are you basing your skepticism on the fact that you actually tried the methods and found them to be wrong or are you just mentally uncomfortable with the idea that things may not be what many think they are? If the latter is the case and you don't have any experience with it, then you really don't have any case against it. You are either testing or you are guessing. You might accidentally arrive at the right answer by guessing but the odds are strongly against you, no matter who you are or where you work.
From my observation, that flawed logic becomes accepted if for some reason it works, for example the rear shock piston being having equal piston hole size as the front one while having different MR front and rear. You know better than me how difficult it is to show how it's supposed to be.

Two things, I believe in you and no homo but yeah I kind off like you for sharing knowledge with us. Skepticism? Me? Oh man, I really didn't made me understandable in that reply, sorry for that. I believe in your method (always did), if I wouldn't believe it I wouldn't made a spreadsheet to help me tune suspension frequency and choose MRs. Fred, Im really sorry if I came out like I was dissing you and your methods, but I wasn't.

My scepticism is towards the supposed sources of information, like Pro drivers and manufacturers. If they can't give reliable and true advice for suspension tuning how can I believe they grasp suspension tuning knowledge?
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Last edited by 30Tooth; 08-05-2015 at 03:39 AM.
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Old 08-07-2015, 03:28 PM   #16394
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want to make my 210 into stock class buggy, is it the same final drive ratio as the B5m, and will associated spur gears work on this car
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Old 08-07-2015, 04:14 PM   #16395
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sorry for the repeat question, I found my answers a few pages back, thanks anyway
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