torsion bars

[lelef]

Hi,
I've used the stock torsion bars (front and rear) for my buggy, the suspension arms are longher than stock 3x3 rear arms modified plates for more travel and fox shocks unfortunately the torsion arms seems to have lost some strength
What torsion bars I should buy? or converting to coilover how can I find the right spring ratio?
Thank You

[cbeck]

I think you can find a torsion bar chart on sway-a-way's website

[lelef]

this ?
https://swayaway.com/tech-room/volkswagen-torsion-bars-maximum-angle-twist/
but what about the stock rate?
and for the front?

[joescoolcustoms]

You would be much better to search the Off Road Forum than the FG forum.

I searched this very topic last night. For my buggy that will get updated to run the NORRA 1000 next year, I came up with 28 mm torsion bars in the 21 3/4 length. I was set on 27 mm, but with the added weight of spare tires, the 28 on the rear best suited my direction with running 2 X 3 rear arms. For the front of mine, I will switch to the 30% greater rate leaf packs offered by places like Mores parts.

But my buggy is heavy at 2020 pounds empty. Yours may be different depending on your set up and weight.
_________________
Bad News Racing 2018 NORRA 1000 3rd in Class
Best Day Ever Racing 2022 NORRA 1000 2nd in Class and first All Female team to complete the race

Everyone is gifted. Some just do not open the package.

Looks like it was painted with a live chicken,polished with a brick and buffed with a pine cone

[lelef]

thank you,
my buggy is around 600kg +/- 1322 pounds
the original vw torsion bars and leaf springs was good when I,ve built it, or better, at the beginning a little too hard with time they becamed softer and softer and today aren't good, the vw torsion bars probably aren't able to support long suspension travel
I think that the 24 mm (But I don't know how to calculate it) ,the smaller from sway a way are good for my buggy
for the front, looking at the Moore online shop the coilover springs for the Fox are not too expensive and I would like to change to coiover
but I've no idea how to calculate the springs load needed !

[joescoolcustoms]

4 corner weigh your buggy so you know what each wheel has to support.

Jack the buggy up to where the tires are just touching the ground. Measure the length of the shock at this position. Lower the buggy until you get the desired ride height. Measure the shock length again. This difference in the shock length is the weight the shock spring will need to support.

So, if your buggy weighs $ 250 pounds at each front wheel, and the shock difference is 1.5 inches, then the springs need to be rated at 166.66 pounds per inch. (pounds divided by inch of shock travel). Usually springs are rated at either 150 pounds/inch or 175 pounds/inch. So you will get close.

This is assuming you are going to eliminate the front torsion leaves and use through rods and use the coil over to totally support the front suspension. BTW, stock VW shock towers are not made stiff enough to use by themselves to support the entire suspension.

For the rear, just index the torsions until you get the desired ride height.

(BTW, I have run 21 mm '66 rear short torsions with 1.5 inch longer arms for 46,000 miles and have also suffered some settling, but I have just re-indexed the torsions to get the ride height back to where I want.)
_________________
Bad News Racing 2018 NORRA 1000 3rd in Class
Best Day Ever Racing 2022 NORRA 1000 2nd in Class and first All Female team to complete the race

Everyone is gifted. Some just do not open the package.

Looks like it was painted with a live chicken,polished with a brick and buffed with a pine cone

[lelef]

now I understand, thank you !
As you suggested first I will try to re-indexed the torsions