Reducing Nitrogen Pressure in shocks

[rhyary]

Hello Everyone,
I have a very specific question and looking for the exact sequence to accomplish the task.

I want to reduce my Nitrogen pressure from 225 PSI to 200 PSI.

I know how to charge the shocks and I get it how to increase the pressure.

I also have all the equipment I need to accomplish the task.

If I connect the tank, Schroder valve and set the regulator to 200 psi, will the gas from the shock flow into the tank to equalize at 200?

or

Do i need to release the pressure at the shock below 200 and charge it to 200?

If have to release the pressure first, into the atmosphere, what would be a safe procedure to release the pressure?

[XCUSE_M3]

Originally Posted by rhyary

Hello Everyone,
I have a very specific question and looking for the exact sequence to accomplish the task.

I want to reduce my Nitrogen pressure from 225 PSI to 200 PSI.

I know how to charge the shocks and I get it how to increase the pressure.

I also have all the equipment I need to accomplish the task.

If I connect the tank, Schroder valve and set the regulator to 200 psi, will the gas from the shock flow into the tank to equalize at 200?

or

Do i need to release the pressure at the shock below 200 and charge it to 200?

If have to release the pressure first, into the atmosphere, what would be a safe procedure to release the pressure?

You will need to release the pressure. Pressure in the tank will be A LOT higher then the pressure in your shock so it won't rerun to the tank will just hold the same pressure. Just relieve the pressure from the shock then fill it again as if it was at zero. Hope this helps.

[rhyary]

Originally Posted by XCUSE_M3

You will need to release the pressure. Pressure in the tank will be A LOT higher then the pressure in your shock so it won't rerun to the tank will just hold the same pressure. Just relieve the pressure from the shock then fill it again as if it was at zero. Hope this helps.

It does.
yes the tank is 2000psi.
come to think about, how would a 225 psi will push back into 2000 psi. Dah.

Any suggestions on how to release the pressure safely?

[XCUSE_M3]

Originally Posted by rhyary

It does.
yes the tank is 2000psi.
come to think about, how would a 225 psi will push back into 2000 psi. Dah.

Lol yup good luck!

[rhyary]

Originally Posted by XCUSE_M3

Lol yup good luck!

Thanks,
I am picking up the tank tomorrow filled up from a local welding shop. So will know soon enough.

[rhyary]

This ended up an easy job.
My fronts were on 130 psi and rears were on 150.

JRZ says minimum 150

I set all four corners to 200 psi and will see how it works on June 30th track day.

[rhyary]

I would love to understand what I should feel or expect from changing the N2 PSI from 130 to 200.

If you have the knowledge, and don't mind spare few sentences, please educate us.

[M3SQRD]

Originally Posted by rhyary

I would love to understand what I should feel or expect from changing the N2 PSI from 130 to 200.

If you have the knowledge, and don't mind spare few sentences, please educate us.

The nitrogen pressure in the reservoir results in an effective spring rate in compression. It's not a huge effective spring rate and the damper manufacture should be able to tell you the effective stiffness per psi. The pressure is acting on the damper piston area which results in a lifting force - did you notice an increase in ride height when going from 130 psi to 200 psi? It's typically used to help fine tune brake dive and/or roll. Another use is to to drop the pressure in wet conditions to improve grip. Also, nitrogen pressure is used to prevent cavitation in mono-tube dampers. Damping force is proportional to the pressure difference across the valve and cavitation results in air bubbles in the fluid which hurts damper performance.

[rhyary]

Originally Posted by M3SQRD

The nitrogen pressure in the reservoir results in an effective spring rate in compression. It's not a huge effective spring rate and the damper manufacture should be able to tell you the effective stiffness per psi. The pressure is acting on the damper piston area which results in a lifting force - did you notice an increase in ride height when going from 130 psi to 200 psi? It's typically used to help fine tune brake dive and/or roll. Another use is to to drop the pressure in wet conditions to improve grip. Also, nitrogen pressure is used to prevent cavitation in mono-tube dampers. Damping force is proportional to the pressure difference across the valve and cavitation results in air bubbles in the fluid which hurts damper performance.

Thank you.
What started my research into the topic was that I felt perhaps my car springs are to stiff. The JRZs were suppose to be charged at 225psi. JRZ advised to go to 200.

Once I got the N2 equipment I found out the charge was not 225 psi. So this is why I decided to go for 200psi to create a base line.

Around town it is hard for me to tell a difference. But on the track I have specific spots that test my suspension high speed and low speed dumping ability.

I will know more once I do a track day with the new setting.