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cfg11
05-22-2010, 09:50 AM
When you scale a 4 bar car. Do you have to unhook the front shock? (on the LR) If so, do you also set your wedge and ride hight without the shock hooked up?


Thanks

WarsawSuspTec
05-22-2010, 11:01 AM
Yes,And unload your 5th coil to

JTSjet
05-22-2010, 11:02 AM
it's a really good idea to, especially if you're running a gas shock there. same with ride heights and wedge. it's just another point of friction that can inhibit the car from resting completely on the springs. when scaling, consistency should be the main focus, so whatever it takes. i also unload my 5th coil and disengage the lr axle as well.

scrub_fan
05-22-2010, 06:06 PM
when we unhooked our lrf shock the car lost i think almost 25 lbs of bite now when we hook it up it will gain it back so why even scale if when you put the shock in if it changes the numbers

jedclampit
05-22-2010, 07:29 PM
High pressure gas, unhook it, else...don't waste your time.

JTSjet
05-22-2010, 09:32 PM
when scaling, i wouldn't get too hung up on certain numbers necessarily. it's consistency and repeatability that really matters when setting up the car in the shop. you certainly wouldn't disconnect the shock to decrease the bite at the track, but if you wanted to decrease the bite next week you would do so based on the previous week's method of setting the bite. whether you keep it hooked up or not doesn't matter as long as you can scale it the same, with confidence that it will be the same from week to week (or how ever often you scale).

i think of it this way: every time i set the car up my objective is to kick everyone's a$$ by a long shot. so if that happens (ha!) i want to be able to do it again the next week. my gut tells me that jedclampit is probably right, but habit and OCD has driven me to disconnect it.


when we unhooked our lrf shock the car lost i think almost 25 lbs of bite now when we hook it up it will gain it back so why even scale if when you put the shock in if it changes the numbers

Luvgoinfast
05-26-2010, 07:59 AM
I was wondering why do you unload the 5th coil? I've been running Super lates for 6 years and never done that when I scaled. I'm not saying it's wrong or anything I was just wondering. I do take the traction shock loose though and I'm really particular on how it's scaled also just never tried unloading the 5th coil.

jedclampit
05-26-2010, 03:43 PM
It has a lifting effect with preload, usually decreases the cross, with normal preload, maybe 0-25#, myself I check it, but leave it loaded when scaling.

JTSjet
05-26-2010, 03:57 PM
i couldn't remember if it decreased or increased the cross years ago when i noticed there was a difference with it loaded and not. i started asking around and everyone said to unload it so that's what i've done. i can't say either way if one way is right or wrong. again, consistency is key.

clm15
05-26-2010, 10:21 PM
The 5th coil is hooked to the arm thats hooked to the rearend.The birdcages are not hooked to the rearend. This is where the springs support the car. The 5th arm only excepts the load from the engine. It don't load the springs in the car.It isnt a 5thcoil anymore.
Now if you have a 2 link with a 5th arm. you need to unload the spring.

Good idea to take the traction shock off to scale.
It has a lifting effect with preload, usually decreases the cross, with normal preload, maybe 0-25#, myself I check it, but leave it loaded when scaling.

JTSjet
05-27-2010, 08:33 AM
are you trying to say that pre-loading the 5th coil on a 4 link has no affect on scale numbers?


The 5th coil is hooked to the arm thats hooked to the rearend.The birdcages are not hooked to the rearend. This is where the springs support the car. The 5th arm only excepts the load from the engine. It don't load the springs in the car.It isnt a 5thcoil anymore.
Now if you have a 2 link with a 5th arm. you need to unload the spring.

Good idea to take the traction shock off to scale.

jedclampit
05-27-2010, 10:49 AM
Put an inch of preload in next time you scale...... and see what you got!;)
The force is fed thru the panhard and lifting of the front end.

clm15
06-05-2010, 07:25 PM
Put an inch of preload in next time you scale...... and see what you got!;)
The force is fed thru the panhard and lifting of the front end.

Why unhook the 5th arm when you scale? You dont race it unhooked. I would pull the RR axle.The panhard bar will change the weights real quick.why would you scale with it not where you run it.

JTSjet
06-05-2010, 08:48 PM
when you add preload to the 5th coil, your scale numbers WILL change. the significance of the change depends on a number of conditions. i preload my 5th coil .25". if i were to preload it 1.0" i would see a significant difference in my scale numbers. i generally run a 300# spring on my 5th coil (preloaded at .25"). if i change to a 450# spring at .25" preload i will see a significant change in my scale numbers. your car setup is one big complex equation. my opinion is to not make it any more complex than what it has to be. when you don't preload the 5th coil it takes those 2 variables out of the equation. if those "variables" remain constant (you always preload an exact amount and your spring rate doesn't change) then they are no longer variable thus simplifying the equation. whatever, potato tomato.