JEEPWERX CJ7 Buggy Style

[Ryan]

I still have my accounts at blue coil and viper coil.

[M4wdFab]

he has toooos

you should start with what mike has in 571, basically same setup- you are probably within 300lbs car weight

[mr.mindless]

I would expect very close, probably 300-400# heavier with Jeep frame bits, heavier body work, and iron heads.

Do you have access to any race scales? If you do, you can just get it right from the beginning instead of guessing. I don't know my car well enough yet to rattle off spring rates. Some of many things I have left to learn

[JEEPWERX]

No scales between now and the weekend.
I can reinstall my air shocks for a test run this weekend.

Prob won't have True weight #s until I finish the build. Winch, front bumper, air tank,  rear storage, tools etc.
But i appreciate all the advice. I was doing carpenter math... 7+7= 14.

Getting anxious to move this pile out of the shop.

Trans and steering Coolers, fittings and hose will be here tomorrow.
She is 90% wired (we shall soon find out how good my memory is)
Fuel system is plumbed
Rear brake lines need to be reworked.
Wrap passenger exhaust (buy more wrap)

Thanks ryan.  I'll put an order together as soon as I get some weight info.

[mr.mindless]

Not sure what may be around for spare 2" coils between us, but you can do the math on sit-in to get rough weights too.

I'm pretty sure my coils still have readable numbers, but I'd have to look hard since I haven't washed the car yet. I won't be home tonight so I wouldn't have rough guesses for you until tomorrow night.

[JEEPWERX]

No worries. Thanks
Air shocks sound like a good plan for this weekend.
Then I can focus on testing mt or and cooling and electrical systems and not new suspension too

[M4wdFab]

i believe 571 rear is 16" 150 over 16" 150

front is 16" 150 over 14" 200



i would recommend buying all 16" springs so you can swap them around as long as the threads go al the way up to the upper eyes.

for that car i would get 3pairs of 150, 1 pair of 200, 1 pair of 250

[JEEPWERX]

I'll check the shocks and verify thread length.
Thanks smike

[JEEPWERX]

I wouldn't consider this all the way?

[M4wdFab]

hmmm, ya you cant run 16/16 like the profenders can then.

[M4wdFab]

one thing that would be easy to do is measure the pressure in your air shocks


with some look up and math this would give you your corner weights

[JEEPWERX]

Or I can just call in a favor from my neighbor... maybe she can get me in with DOT?

[M4wdFab]

well, race scales arent really what you want, you need your sprung weight corners (only what the shock holds up), not total corner weight.

axles / tires are sprung weight.  simplified (!), no effect on spring rates.

granted total weight and some assumptions you can get pretty close.  you just dont want to be running more than 2-3" of pre load if you guess way light especially without limit straps. 

[mr.mindless]

Race scale procedure: get corner weights with no springs or shock pressure, sitting on bump stops. Then put the chassis on jackstands off the stops to get the unsprung weight and subtract.

That's my thought, anyway...

[M4wdFab]

the air shock pressure method is actually the best and simplest- because it cancels out any math from the shocks being at angles assuming your C/Os are mounted the same. 


say 200psi  at right height- your shaft load is 863lbs with a 1 3/8" air shock shaft

so 50/50 droop you want that load about, so 1" preload plus 7" coil compression, that would be a total rate of 108lbs/in

a 200/200 would give you a little less than that, probably be right with a nitrogen charge on the shock. 

reasoning for ratio of upper to lower rate choice i dont know.  typ lower rate if different is larger number.  (only matters if your dual stops are set right)

i could show you the math in 2 min on a white board to get this.