Yes, the rear of the pod is lower than the front of the pod (chassis), that's what gives droop.

Pod droop is controlled by the length of the shock, not the tightening of the collar. The collar on the spring is for ride height adjustments.

I'll have to let protc3, odpurple or adrian answer the tech. aspects of what droop does. As I don't think I can fully explain what it does.

E

I think there is some misunderstanding about checking droop, ride height and what we call sag. Droop is checked with the chassis un-weighted (in the air), it is how much below level the back of the motor pod is when it is hanging. Ride height is of course checked on the tech block with the chassis fully loaded (batteries, etc), you check it at the front, rear, and middle. Sag is when the front of the motor pod sits lower than the rear, or the middle ride height is less than the front and rear of the chassis. Sometimes a little sag makes the car more forgiving, and you should never run it above level.

Clear as mud? :lol:

Sag :confused: I don't think I knew about that one. I've always set the front of the pod level with the chassis. So if I have sag in the pod it takes away steering all the around, high/ low speed steering or does it do something else?

E

droop in a 1/12th does exactly the same thing as in a touring car and i measure it the same way.what it does is controls the amount of weight transfer to the front of the car during deceleration or off power.front droop does the same but during acceleration or on throttle it controls the weight transfer to the rear of the car.both adjustments also help control the car over bumps so it kind of a trade off.i check my rear pod droop by placing the car on a flat piece of glass and adjust my ride height with all the race gear in the car.i set my shock spring preload so that the collar preloads the spring by 1 full turn on the collar when fully extended.now what i do is compress my suspension to the ground,let it fully rebound and then check my ride height.now that i know my ride height after a full rebound i lift the car slowly by the front of the upper pod plate until my shock bottoms out at its full extension.i measure the distance over my ride height untill the rear wheels lift.usually i run 1.5-2mm over ride height for asphalt and .5-1mm for carpet.to change this i will adjust the length of my ball cups on the shock,i never adjust the collar once it is set unless i lose alot of ride height.for front droop i do the same deal but i shim it so there is about .010-.015 of preload on the front springs at rest.when the car is at ride height it will have about .5mm of up travel over ride height.this is with .020 front springs.rear pod sag i never use.i always run the rear pod dead level.at ride height i check all 4 corners of the pod and make sure that it is level.

another side note on the diffs,i always run my diff as tight as possible with it being as free as possible.what i do is sand the diff rings with a fine grit sand paper to create a smoothe but slightly abrasive surface to the rings.this gives the diff balls something to grip so the diff doesnt slip easily.you will find that if you sand the diff rings and get them really flat,you will not need to tighten the diff nearly as much and it will be locked when you try to slip it.i cant slip my diffs with a 4.5 brushless motor but when you spin one wheel it feels like a stock motor would smoke it out.a diff is one of the most important parts of a 1/12th car.tires and diff make up at least 75% of the decision if your car is gonna be good or bad.get em both right and you can win with any car on the market. ;)

so i do do this right. :lol:
after all these years.

What grit sandpaper do you use on the rings?

odpurpuple - I think I actually understand your message - there is hope for me yet :D

To what extent do you mean by "un-weighted"? Motor out? I imagine motor in or motor out would be a big difference in droop measurement.

I had a little sag in the car yesterday. I did it with the shock collar. It looks like I need to make these adjustments with the ball cup threaded on more or less of the shock shaft... Or, run it level like Jason says.

OdP, Do you run level or a little sag?

Thanks!

to be honest,i cheat and i use my surface grinder :lol: i grind it to about a 32 finish

Jason, I want to clarify rthe shock spring preload. I understand you run the chassis and rear pod level by measuring eight locations to ensure this (four corners of the chassis and four corners of the rear pod) you use the ball cup to obtain this level of levelness ;)

Now, do you then keep the car perfectly level and add one turn of preload with the shock at this position, OR, do you extend the shock fully by pulling the rear pod back/down - or simply removing one end from the car... - and then add one turn of preload? I am guessing the latter.

Do you have the spring on the shock, or the collar backed off, when setting ride height? Or, is it all in the shock oil/rebound to keep the center of the chassis and front of rear pod level? Because if the shock spring is on and has any tension created by the collar when setting ride height, won't your ride height measurments change when you fully extend the shock and turn in one round of preload?

Can a guy just set the spring preload before you even begin messing with ride height? Fully extended is fully extended, right? Oh, wait; I answered my own question. If we have to turn the ball cup end on the shock shaft to adjust ride height, that will change our "fully extended" shock length. How did I do? :D

Boy, this keyboard racing is fun.!!! :D It really bites to think through this stuff, spend the hours to attempt to properly prepare your vehicles, and then stink up the joint when you place the car on the track. Trust me - I am always faster on the way to the track then on the way home... :ha:

Thanks for sharing your wisdom!
Jeremy

:lol: what i do is start by removing the shock all together and fully extending it untill the piston bottoms out on the cap.then i run the collar down until it just kisses the spring.then i go 1 full revolution on the collar for preload.now i put the shock back on the car.i will set my ride height by adjusting the length of the shock with the ball cups until my pod is level in all 4 corners of the rear pod and then use the ride height adjusters on the axle to set my ride height.if need be i will cut the ball cups a little shorter depending on how short i run the shock.now i will check the pod droop by lifting the center of the car by the top area where the top of the shock mounts.i will then slide a ride height gauge under the rear of the chassis right as the shock bottoms out.this measurement over ride height is your droop.the more uptravel you have the more weight transfers to the front under deceleration.in otherwords,more off power steering.after i do all those things,i fine tune with shock collar and length to maintain a level rear pod.you dont want to preload the spring too much due to the the fact that springs are progressive.

:blush: I'm not sure what 32 finish translates too but will 400 grit sandpaper work?

i would go with 400 and wet sand with 1000 afterwards

actually,if you have a worn piece of 400 you can finish with that.you just want to make sure its flat and smoothe enough that the diff isnt gritty.when they are flat,all the diff balls have even pressure applied to them so you have more holding force with less tension on the balls along with an unpolished surface so the balls can bite in real good

will do, thx