Universal Starting Setup - How to.
#16
In the TLR 8ight 4.0 the center-front CVD angle was reduced and in the TLR 8ight 3.0 the front CVDs were made parallel with the arms precisely to have less (or in the case of the arms negligible) axle bind to improve drivetrain efficiency and promote neutral driving characteristics.
I can't say I can measure it but my car rolls fairly free (not kyosho free though) but having less outdrive wear can't be bad!
The front has more axle bind, similarly to a TLR 8ight 2.0 and I can't tune it out completely without producing my own uprights, I'll post a photo later to compare both outdrives
#17
After wearing out a set of rear outdrives on my D815, I'm anxious to see what effect it'll have on my car with the new set along with new pins. I feel like axle bind is something very little of the non upper echelon racers understand is very real when it comes to feel of the car.
#18
After wearing out a set of rear outdrives on my D815, I'm anxious to see what effect it'll have on my car with the new set along with new pins. I feel like axle bind is something very little of the non upper echelon racers understand is very real when it comes to feel of the car.
And thank you for giving my method a try. You and My ST-RR Evo have one of the best car to make this alterations because the D815 has adjustable upright height, lower inner roll center bushings and various upright camber plates. While there are too many options on the lower bushings, two bushing positions and another two for hub height would suffice, the camber plates come in very handy.
#19
That's what made me post a photo of my outdrives, I read you wore out yours after what, a hour and a half? Please report back.
And thank you for giving my method a try. You and My ST-RR Evo have one of the best car to make this alterations because the D815 has adjustable upright height, lower inner roll center bushings and various upright camber plates. While there are too many options on the lower bushings, two bushing positions and another two for hub height would suffice, the camber plates come in very handy.
And thank you for giving my method a try. You and My ST-RR Evo have one of the best car to make this alterations because the D815 has adjustable upright height, lower inner roll center bushings and various upright camber plates. While there are too many options on the lower bushings, two bushing positions and another two for hub height would suffice, the camber plates come in very handy.
All pins were brand new to start the weekend, at the end, rear outdrives were hammered, and every single pin needs replacement.
#20
I wore the center driveline pins out after a weekend of racing at the US open. Friday I had 5, 6 minute practices. Saturday I had 3 7 minute qualifiers, and then sunday I had the 30 minute semi and 1 hour main.
All pins were brand new to start the weekend, at the end, rear outdrives were hammered, and every single pin needs replacement.
All pins were brand new to start the weekend, at the end, rear outdrives were hammered, and every single pin needs replacement.
#21
From my on-road experience, arm angle and bump steer have a lot of influence on handling. For example, if the arms point downward to the wheels, you get a car that is really responsive on that end. Basically resists rolling, and reach maximum grip on the tires earlier. Good on high bite, but handful on low.
For bump steer, it was a big deal on the Tamiya M03. Those cars had bump-in out of the box, and made it very twitchy. After making it neutral or slight bump-out, it was much easier to drive. I think the same applies to off-road cars too.
I'll setup my D815 race ready and see where my arms/axles line up.
For bump steer, it was a big deal on the Tamiya M03. Those cars had bump-in out of the box, and made it very twitchy. After making it neutral or slight bump-out, it was much easier to drive. I think the same applies to off-road cars too.
I'll setup my D815 race ready and see where my arms/axles line up.
#22
I wore the center driveline pins out after a weekend of racing at the US open. Friday I had 5, 6 minute practices. Saturday I had 3 7 minute qualifiers, and then sunday I had the 30 minute semi and 1 hour main.
All pins were brand new to start the weekend, at the end, rear outdrives were hammered, and every single pin needs replacement.
All pins were brand new to start the weekend, at the end, rear outdrives were hammered, and every single pin needs replacement.
#23
From my on-road experience, arm angle and bump steer have a lot of influence on handling. For example, if the arms point downward to the wheels, you get a car that is really responsive on that end. Basically resists rolling, and reach maximum grip on the tires earlier. Good on high bite, but handful on low.
For bump steer, it was a big deal on the Tamiya M03. Those cars had bump-in out of the box, and made it very twitchy. After making it neutral or slight bump-out, it was much easier to drive. I think the same applies to off-road cars too.
I'll setup my D815 race ready and see where my arms/axles line up.
For bump steer, it was a big deal on the Tamiya M03. Those cars had bump-in out of the box, and made it very twitchy. After making it neutral or slight bump-out, it was much easier to drive. I think the same applies to off-road cars too.
I'll setup my D815 race ready and see where my arms/axles line up.
Here's photos of my front outdrives, sorry haven't cleaned the front since last weekend mud fest.
#24
Less wear is a by-product of less axle bind, remember I use the parallel arms and axles. Less axle bind means less wasted energy and more efficient drivetrain.
In the TLR 8ight 4.0 the center-front CVD angle was reduced and in the TLR 8ight 3.0 the front CVDs were made parallel with the arms precisely to have less (or in the case of the arms negligible) axle bind to improve drivetrain efficiency and promote neutral driving characteristics.
I can't say I can measure it but my car rolls fairly free (not kyosho free though) but having less outdrive wear can't be bad!
The front has more axle bind, similarly to a TLR 8ight 2.0 and I can't tune it out completely without producing my own uprights, I'll post a photo later to compare both outdrives
In the TLR 8ight 4.0 the center-front CVD angle was reduced and in the TLR 8ight 3.0 the front CVDs were made parallel with the arms precisely to have less (or in the case of the arms negligible) axle bind to improve drivetrain efficiency and promote neutral driving characteristics.
I can't say I can measure it but my car rolls fairly free (not kyosho free though) but having less outdrive wear can't be bad!
The front has more axle bind, similarly to a TLR 8ight 2.0 and I can't tune it out completely without producing my own uprights, I'll post a photo later to compare both outdrives
#25
Wouldn't the pin hitting the one exact spot within the out drive over and over not cause more wear in that one spot in the form of a notch and the rest of the out drive "slot" would remain new? Then again I guess I could see how a pin moving in and out could act like a saw. Usually the rear out drives wear more sooner, then the center out drives and then the fronts. Yes on the D815, the front axles sweep back a little with the"standard" front wheelbase settings.
That's a pretty good question, let's think in hypothetical scenarios:
-example #1: zero dogbone plunge/axle bind -when the pin is facing the car longitudinally and we push and pull the suspension up and down the pin doesn't travel in or out of the slot and when the pin is facing the up-down axis the pin angle equals the arm angle- the average place where the pin sits becomes narrower, the pin is under rotational forces from the outdrive slot. When the arm moves the pin angles accordingly, the pin is no further pushed nor pulled.
-example #2: dogbone plunge/axle bind is present: the pin slides in and out with suspension movement. The average place of where the pin sits becomes larger, the pin is under rotational force from the outdrive slot and pull and push forces from the suspension arm. If the axle points downward to the center of the car the pin angle is arm angle plus X angle from the axle, meaning more average angle when the suspension is compressed. If the axle points upward to the center of the car the pin angle is arm angle minus arm angle, meaning less average angle when the suspension is compressed.
In the example with axle bind, the pin is under twisting force and stronger pull and push forces, a saw motion like you said. Therefore rotating the outdrive and applying a push/pull to the axle increases exponentially the axle bind.
Try with an outdrive and dogbone in your hands: dogbone parallel to the outdrive, twist the dogbone and feel the bind, with the outdrive in the same place move the other dogbone end up and down and feel the bind while twisting the dogbone and applying brake to the outdrive. Now lock the outdrive and while twisting the dogbone move it up and down, front and back and in and out the outdrive. Which did you felt the most axle bind?
Thank you for checking it out, can you say if you picked up the rear so the kickup angle becomes zero, the axle angle increases or decreases?
Last edited by 30Tooth; 12-18-2016 at 04:09 PM.
#26
Objective: Shorter springs to have less rebound.
Wouldn't shock rebound be affected by spring length?
Bare with me, you have for example a no rebound shock setup, but the spring length you are using causes the shock to always extend to maximum length, meaning you will always have rebound.
Wouldn't be better to run a spring that didn't further mess shock rebound?
Conclusion: I used that on my on road chassis, they aren't supposed to jump so you have the shocks as dead as they can be, short springs included. In my current race cars I can choose to have long shocks or shorter shocks, the longer shocks always provide more stability with everything but shock preload the same, I thought it was because the piston would be further from the bladder but apparently that's an added bonus.
I'm thinking about doing this to the front, I shouldn't do it because I'm using the outer arm hole for shock mounting but unscrewing the rod end would net me the same stroke at the wheel but less spring preload at extension.
Wouldn't shock rebound be affected by spring length?
Bare with me, you have for example a no rebound shock setup, but the spring length you are using causes the shock to always extend to maximum length, meaning you will always have rebound.
Wouldn't be better to run a spring that didn't further mess shock rebound?
Conclusion: I used that on my on road chassis, they aren't supposed to jump so you have the shocks as dead as they can be, short springs included. In my current race cars I can choose to have long shocks or shorter shocks, the longer shocks always provide more stability with everything but shock preload the same, I thought it was because the piston would be further from the bladder but apparently that's an added bonus.
I'm thinking about doing this to the front, I shouldn't do it because I'm using the outer arm hole for shock mounting but unscrewing the rod end would net me the same stroke at the wheel but less spring preload at extension.
Last edited by 30Tooth; 12-18-2016 at 04:11 PM.
#27
Great explanation about the out drive wear.
as far as lifting the rear of the car, I'll have to see what effect it has on the front axle angle when I get a chance. Just from visualizing in my head, the axle would always have to have an angle it just would change the direction depending on how you oriented the car.
as far as lifting the rear of the car, I'll have to see what effect it has on the front axle angle when I get a chance. Just from visualizing in my head, the axle would always have to have an angle it just would change the direction depending on how you oriented the car.
#29
D815 rear bone angle. Running short wheel base.