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Thread: Ground Control AD Coilovers - Nitrogen

  1. #1
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    Ground Control AD Coilovers - Nitrogen

    BFC,

    Summoning the conventional wisdom of the collective genius:

    My race car came with a full ground control suspension, with freshly rebuilt Advanced Design coilovers (from 5 years prior - never used). Problem is that I am a 3-4 weekend per year HPDE kinda guy, and dont really want to invest in a 300 dollar nitrogen tank setup to set/maintain the pressures until one of them gives up the ghost and they need to go into the trash (GC no longer supports rebuilds). Any input on something simple (re: cheap) like a bicycle hand pump for around $30 dollars on amazon versus dealing with nitrogen? Not sure how big of a concern corrosion inside the shock itself is if they cant be rebuilt once one of them is blown anyhow.

    Keeps spinning my mind for loops so thought I would post about it! If I knew I could get them rebuilt, I wouldn't hesitate to spend the money on a nitrogen setup. Thanks in advance for any feedback,

    OM540

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    Quote Originally Posted by olemiss540 View Post
    BFC,

    Summoning the conventional wisdom of the collective genius:

    My race car came with a full ground control suspension, with freshly rebuilt Advanced Design coilovers (from 5 years prior - never used). Problem is that I am a 3-4 weekend per year HPDE kinda guy, and dont really want to invest in a 300 dollar nitrogen tank setup to set/maintain the pressures until one of them gives up the ghost and they need to go into the trash (GC no longer supports rebuilds). Any input on something simple (re: cheap) like a bicycle hand pump for around $30 dollars on amazon versus dealing with nitrogen? Not sure how big of a concern corrosion inside the shock itself is if they cant be rebuilt once one of them is blown anyhow.

    Keeps spinning my mind for loops so thought I would post about it! If I knew I could get them rebuilt, I wouldn't hesitate to spend the money on a nitrogen setup. Thanks in advance for any feedback,

    OM540
    Any tire place will have a nitrogen tank ... and most track support tire guys will have one as well. Just be nice, I'm sure they'll let you top up if needed. But you do need the valve tool, otherwise you have no idea of pressure. I would just borrow/beg/steal one, fill it to 200 psi, and forget about it. If you have a leak, then you can't rebuild anyway, right? Our motons and JRZ can go a full year without pressure drop.
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  3. #3
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    Based on the garbage quality I've seen of ADs, you probably won't get through a year of DE usage before you're tossing them all in the trash, so I'm not sure I'd invest too much on keeping them going for any length of time.

  4. #4
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    I used to have issues keeping the nitrogen charge topped up in my AD shocks. There was a local motorcycle shop that did shock rebuilds for bikes, and they had the equipment to recharge my shocks for me (just a nitrogen tank and a regulator). I did it a buch of times, and then I just started using a mountain bike shock pump (regular tire pump is not precise enough and can't do high enough pressures).

    A lot of the time the nitrogen leaks out around the shrader valve core. You can replace the core, but it has to be for high pressure (not a regular tire valve stem core).

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    That mountain bike pump was the option I was considering! Any input how long the shocks lasted for you before rebuilds?

    Thanks everyone for the input. I am definately going to try local bike shops to see if they have a nitrogen supply I could use. I have never really lived in a heavily populated area that has had any sort of racing shops.
    Quote Originally Posted by jakermac View Post
    I used to have issues keeping the nitrogen charge topped up in my AD shocks. There was a local motorcycle shop that did shock rebuilds for bikes, and they had the equipment to recharge my shocks for me (just a nitrogen tank and a regulator). I did it a buch of times, and then I just started using a mountain bike shock pump (regular tire pump is not precise enough and can't do high enough pressures).

    A lot of the time the nitrogen leaks out around the shrader valve core. You can replace the core, but it has to be for high pressure (not a regular tire valve stem core).
    Sent from my SM-N950U using Tapatalk

  6. #6
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    Quote Originally Posted by olemiss540 View Post
    That mountain bike pump was the option I was considering! Any input how long the shocks lasted for you before rebuilds?

    Thanks everyone for the input. I am definately going to try local bike shops to see if they have a nitrogen supply I could use. I have never really lived in a heavily populated area that has had any sort of racing shops.

    Sent from my SM-N950U using Tapatalk
    Here is a gauge you can use - https://www.amazon.com/Topeak-Shuttl.../dp/B000FICCP8
    These are getting re branded and sold all the time for automotive/racing use.

    Airgas can set you up with a tank, regulator and high pressure hose for not too much money. I got my tank and subsequent fill ups from them. I think I bought a hose, regulator, and shrader attachment from Amazon and pieced it all together for use with Motons. Or, sell the AD's, pick up a simple SA Koni setup and enjoy their simplicity.

  7. #7
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    The Topeak in that Amazon link is just a gauge. You need a regulator. You need to have the ability to set what pressure you're after and then connect the feed line from the nitrogen to the shock. The nitrogen tank is several magnitudes of psi above what you want to fill the tiny nitrogen chambers on the shocks to and you'd have no way of limiting that pressure.

    With the MTB shock pump you're only pushing small volumes of pressure at a time so it's easy to control how much pressure is going in.

    I cannot recall how often I was rebuilding the shocks (about 10 years ago), but I was daily driving the car.

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