Outer Limits 4x4 Board

I'm looking to get a few opinions on this as I got no idea, weights are 750 front and 600 rear, total 1350kg, will have to add a little more for driver/ fuel /oil etc. Coilovers are duel rate 16" fox.

90mm up travel
Total front unsprung weight - 265kg
Total rear unsprung weight - 269kg

Dan, Talk to Buddy. He is good at this stuff. He will also need to know the unsprung weight, eg diffs and tyres etc.

Are the diffs and wheels included in your weight? If they are, how much does each axle/wheels weigh? What do your links weigh as a percentage of them should be factored in. Are you planning on running the coilover vertically and if not, what angle? Where in the shocks stroke do you want them to sit while it's parked on flat ground?

Once you've got all the info everyone needs to give you an educated guess, you could just type it all into the FOA calculator on their site.

That is total weight, I will weigh the axles and tyres very soon, the coilovers run fairly vertical with about 90mm up travel.

how did you work out your front and rear weights?

Weighbridge or more accurately a set of race car scales.

sloshy wrote:That is total weight, I will weigh the axles and tyres very soon, the coilovers run fairly vertical with about 90mm up travel.

90mm up travel gives you 77% droop. Is it a dedicated rock crawler?

georgey wrote:how did you work out your front and rear weights?

A set of race car scales as Buddy said. It actually gives you individual wheel weights, front and back weights and a total weight. The buggy is now stripped so I will take the front axle back with wheels and weigh it early next week.

91Mav wrote:Is it a dedicated rock crawler?

Pretty much.

Any of the big shock companies have online calculators that will give you the correct rate, its easy to work it out once you have a look at the calculators.
Mick

Total front unsprung weight - 265kg
Total rear unsprung weight - 269kg

Using the FOA calc I've added 50kg a corner allowing for driver, passenger, wiring, plumbing and accessories.

Front link length to axle centre is 39"
Rear link length to axle centre is 38"
Both front and rear shock mounts are on the centre of the axle
Shock mounting is 10 deg
77% droop

Its come up with
front- 88 over 133
rear- 65 over 98

Do you round up to the nearest spring rate?
What length should the springs be?

your main coil 2" longer than the length of travel the tender coil 2" shorter

wow

sloshy wrote:Using the FOA calc I've added 50kg a corner allowing for driver, passenger, wiring, plumbing and accessories.

Front link length to axle centre is 39"
Rear link length to axle centre is 38"
Both front and rear shock mounts are on the centre of the axle
Shock mounting is 10 deg
77% droop

Its come up with
front- 88 over 133
rear- 65 over 98

Do you round up to the nearest spring rate?
What length should the springs be?

both F/R is a bit light. Don't aim for so much droop 60-65% front is heaps and 50-60 in the rear max.

1MadEngineer wrote: both F/R is a bit light. Don't aim for so much droop 60-65% front is heaps and 50-60 in the rear max.

I agree, if someone is wanting to build a truck with a lot of drop and little up travel in my opinion an air shock is a better candidate.

Front 100 over 150
rear 100 over 125


Or should I go 100 over 150 in the rear to get the front to work a little more?

OH now i get it .... hang on .. nope i dont . i think it has already been said, but, WOW