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Old 08-05-2019, 04:08 PM
  #16  
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Thinner diffs for tighter corners, especially if you want to drive smooth with the throttle. Imagine if you had a solid axle vs open diff and which one will allow you to make tighter corners. Thin as long as the car is still stable on power and has decent drive.

I remember seeing some lutz setup sheets from his early days when he was super punched, really high like 30k in buggy. Worked for him for a while, eventually his setups/driving became more normal in effort to be more competitive. This video looks like the old days, I think hes just having fun / showing off on this track, but, look how early he turns in and then powers through the corner like a sprint car! I will admit that his car looked good in the tight section on the left side of the track.
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Old 08-05-2019, 04:32 PM
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You will never get there with a pbs car. Try a Kyosho Mp10 or another car with a c hub front end.
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Old 08-05-2019, 05:51 PM
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That video paints a different picture to what I interpreted from your original post, a lot of that driving is very much on-power.
I'm not sure I'd call that babying the car (as above I don't think many people drive like that, though it's fun and I like it too), but either way it makes things much more clear.

Reading your post again now after watching, I think something you might be missing is that if you have to throttle to the point of snap-oversteer to get the rear "rotation" characteristics you like, often the problem / reason for it getting to that point is that the car is understeering and doesn't actually have enough turn-in under smaller amounts of power (initially). Basically, the car understeers too much, then you keep increasing throttle to get rotation, and at this point you're at a much higher level of throttle than optimal - thus are much more likely to spin out.

I have two suggestions:
1. Decrease rear toe-in. Dillon71 mentioned this already, in my experience lots of stock buggies run too much. What happens here is the rear wants to stay very locked in and requires a LOT of throttle to break it free, at which point it's excessive and not a smooth transition in and out of the slide. JQ touches on this if you read his setup guides also. I'd back it off all the way to zero or minimum and work your way up, just to see if there's somewhere in the "less toe" spectrum which works for your needs.
2. Check your PBS frontend's bump steer. I don't think you need to ditch your current car just yet, but PBS suspension does take a lot more tuning work to get a smooth bump steer curve without sacrificing droop. Set your droop, turn the wheels to full lock, and then cycle the suspension all the way to top out and bottom out. If the outside (cornering) wheel experiences much if any toe-out when fully compressed, it's likely reducing your useful steering as you load the buggy into a corner. This is caused by the steering turnbuckle not staying parallel with the suspension arms, and you can correct by adding spacers so that the link stays more parallel deeper in the travel. Better yet, using shorter knuckle-arms (then re-adjusting) can allow a longer turnbuckle which reduces the magnitude of the problem entirely. While doing all this, you want to maximise steering throw - which often happens at lower levels of ackermann. The inside wheel steering more doesn't help steer the buggy anywhere near as much as the outside wheel, so it's the outside that matters.
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Old 08-05-2019, 09:04 PM
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good point on getting max epa out of the outside tire
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Old 08-06-2019, 01:35 AM
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Thanks again for your insight!

@udi_mp7.5

I know the Lutz video is an extreme example, but you're right, I probably worded it a little wrong.. I don't drive entirely off-power, but I like applying tiny amounts of throttle and steering, which I would call babying when looking at 90% of other cars on the track (also much less than Lutz in the video) to set the car up to rotate naturally.

I think you pretty much hit the nail on the head with what you wrote here:

"Reading your post again now after watching, I think something you might be missing is that if you have to throttle to the point of snap-oversteer to get the rear "rotation" characteristics you like, often the problem / reason for it getting to that point is that the car is understeering and doesn't actually have enough turn-in under smaller amounts of power (initially). Basically, the car understeers too much, then you keep increasing throttle to get rotation, and at this point you're at a much higher level of throttle than optimal - thus are much more likely to spin out."

Perfect description of the problem. The thing is, this obviously works for most people, the setup I'm running is definitely not out of the ordinary, but like mentioned before, the car needs to be driven 'hard' to be great which is something I don't like doing and am also not good at.

I will definitely give your tips a try. I have played a little bit with rear toe but I will try again. It's a shame the AE car doesn't allow toe-in to be set in smaller increments, only full degrees. The problem I experienced when I first played with it, is when going to less toe, the freshness of my tires started to play a huge role. With less than 3 of toe I felt like the drop off in traction was way more significant when tires started to go away. Anyway, i will definitely try again.

The bump steer thing, wow. Never even crossed my mind, haven't looked into this at all. I've never seen any different setting than stock on any setup sheet, so I'm very much intrigued. I am already using the B3 steering plates which allow for a longer turnbuckle but ackermann is set to stock and I'm not sure if I've already tried running less ackermann since I've started running these plates.
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Old 08-06-2019, 03:22 AM
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Originally Posted by Fearo View Post
Thanks again for your insight!

@udi_mp7.5

I know the Lutz video is an extreme example, but you're right, I probably worded it a little wrong.. I don't drive entirely off-power, but I like applying tiny amounts of throttle and steering, which I would call babying when looking at 90% of other cars on the track (also much less than Lutz in the video) to set the car up to rotate naturally.

I think you pretty much hit the nail on the head with what you wrote here:

"Reading your post again now after watching, I think something you might be missing is that if you have to throttle to the point of snap-oversteer to get the rear "rotation" characteristics you like, often the problem / reason for it getting to that point is that the car is understeering and doesn't actually have enough turn-in under smaller amounts of power (initially). Basically, the car understeers too much, then you keep increasing throttle to get rotation, and at this point you're at a much higher level of throttle than optimal - thus are much more likely to spin out."

Perfect description of the problem. The thing is, this obviously works for most people, the setup I'm running is definitely not out of the ordinary, but like mentioned before, the car needs to be driven 'hard' to be great which is something I don't like doing and am also not good at.

I will definitely give your tips a try. I have played a little bit with rear toe but I will try again. It's a shame the AE car doesn't allow toe-in to be set in smaller increments, only full degrees. The problem I experienced when I first played with it, is when going to less toe, the freshness of my tires started to play a huge role. With less than 3 of toe I felt like the drop off in traction was way more significant when tires started to go away. Anyway, i will definitely try again.

The bump steer thing, wow. Never even crossed my mind, haven't looked into this at all. I've never seen any different setting than stock on any setup sheet, so I'm very much intrigued. I am already using the B3 steering plates which allow for a longer turnbuckle but ackermann is set to stock and I'm not sure if I've already tried running less ackermann since I've started running these plates.

I believe Ty Tessmann used to and developed, together with HPI,the HB car to be driven like that. I tested it myself and found the car to be quite diffcult to drive with so much rotation into corners.
his setup stood out in the way the diffs were thin (5 3 2) how stood up the shocks were and how little camber gain /much roll he had.
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Old 08-06-2019, 04:14 AM
  #22  
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Originally Posted by Fearo View Post
You make a good point. Funny you should mention the diff oil setup, as 10-7-5 is what I have felt most comfortable with on med to high grip. But what would you suggest for low grip with tight and slow 180s?
You can go as low as 5-7-3 on low grip tracks with a lot of 180's. If the rear breaks out mid turn, up the diff fluid a little. I drove 5-7-5 on our nats race this weekend and it worked pretty good. I started with 5-7-3, but rear end came around really fast midcorner and it was still sliding when going on the power again so it was hard to drive. 5k in the rear really tamed it down.
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Old 08-06-2019, 08:19 AM
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What is your actual setup now? It sounds like you want to get the thing to rotate more off power. The b3.1 car can have a TON of off power steering. I actually was taking some out.

A 1/8 buggy that is pushed by the rear end is going to understeer. It also can't be driven like a 1/10 buggy, as I'm sure you are aware. It sounds like you may have been trying to get your desired result the wrong way.

What rear sway bar are you running? It sounds like you may need a bigger one, and perhaps more rear spring to start.
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Old 08-06-2019, 11:33 AM
  #24  
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Originally Posted by Spads11 View Post
This type of scenario is exactly why I chose to start running the new Xray XB8. It gives me the opportunity to run both c hub and pbs type. I have run the c hub in Kyosho cars and love it, but for me (emphasis here on me), is that it doesn't allow me that "switch" in a race where I need to pick my pace up. It did not seem to like being pushed hard at all and almost lulls you into this comfortable slow pace. However, what I find is that c hub is more direct/precise on the front versus pbs having some forgiveness built in. Generalities aside, I think either can be tuned for balance, but takes a lot of time you don't have some help.
of you want one car easy you can use xray it has a very stable rear
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Old 08-06-2019, 11:47 AM
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First let me say im not a expert haha but
Maybe a c hub car with less castor most cars are going to more castor 17 18 19 20.
But maybe Iike a c hub car wjth 12-15 degree castor blocks and thin oils. Of course every car is different so setup will always need to be tuned etc for your driving.
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Old 08-08-2019, 10:35 AM
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You have tried a lot of car setups to get the car to do what you want and you haven't found what you like yet. Maybe you can find the right feel with different tire combos. I know a lot of guys that run AKA like Lutz will run impact fronts and gridiron rears to get the car to do what they want.
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Old 08-08-2019, 01:25 PM
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Originally Posted by tom1974 View Post
of you want one car easy you can use xray it has a very stable rear

He is already running a long arm short pivot. Not the long pivot short arm.
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Old 08-11-2019, 10:20 AM
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Originally Posted by Fearo View Post
Thanks again for all the suggestions guys. Many things written here I have already tried but certainly not all of them.

The problem with some things that simply add steering like caster for instance is that they make the car more twitchy. I don't actually need more steering, I need the rear to be more free, so that it rotates in a controllable way yet still holds traction.

A good example of what I would call a rear steering car is this:
Ryan lutz Agama 319

I know he's a pro and makes it look easy but this is sort of what I'm looking for, even though Lutz actually drives really punched and I don't. You can see that the rear is doing most of the work and he just gives light steering inputs. In some of the corners his front wheels are already perfectly straight before he's halfway through the turn. That's what I like doing, only with less throttle and 10 times slower.
Ok, so in that video Ryan is pitching the car on a number of the turns, anticipating the turn, and once hes cleared apex he goes "on throttle early", its fairly deceiving. If you look closer, the front tires are ballooning, expanding quite a bit on exit, showing that hes actually driving more of a front wheel drive setup. Also, the front of that car is MUCH lower on spring pressure and ride height than the back, this allows the quick transfer of weight to the front when off power. Notice hes not off power much, or for very long? That is because hes driving an "on-power" diff setup, with a front weighted suspension setup. If you are trying to make the car steer from the back, you are chasing the wrong setup. Additionally, you might need a certain brake bias to get that quick brake tap, front end drop to pivot that hes doing. You dont want rear steer, you want a quick front pivot, front wheel drive, and on power driving style. That style takes years to master, and he has been driving like that his entire RC career. I've personally been destroyed when coming out of corners by Lutz himself, its amazing how soon he decides to pass, the setup happens early in the lead up to the corner. It sucks because you are making a nice smooth fast apex, and he makes an early V shape, then powers passed you, just as you roll on throttle. After the corner he gains another 10 feet because hes on power and you are just spooling up. lol.
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Old 08-11-2019, 07:49 PM
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Originally Posted by Dillon71 View Post
Thinner diffs for tighter corners, especially if you want to drive smooth with the throttle. Imagine if you had a solid axle vs open diff and which one will allow you to make tighter corners. Thin as long as the car is still stable on power and has decent drive.

I remember seeing some lutz setup sheets from his early days when he was super punched, really high like 30k in buggy. Worked for him for a while, eventually his setups/driving became more normal in effort to be more competitive. This video looks like the old days, I think hes just having fun / showing off on this track, but, look how early he turns in and then powers through the corner like a sprint car! I will admit that his car looked good in the tight section on the left side of the track.
Other than he's driving the prototype A319 that just came out a couple weeks ago.
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Old 08-11-2019, 09:00 PM
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2wd 10th scale cars push on power, I would start with 5-7-10 in my diffs. Going up only in the rear that should get your car pushing a little.
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