dogger15

This is some information for those that self support their Cup cars.

I recently went through the "fun" of setting up a portable Nitrogen supply for my car. There were several lessons leaned along the way and I thought I would post them to help the next lucky newbie that wanted to go this route.

1. The air jacks on a 997 cup will work OK at 400 psi, but will work a lot better at 35-38 bar (500-550 psi). 35-38 bar is the recommended working pressure range per Porsche.
2. 3/8" ID air hose minimum.
3. Air hose rated to 500 psi is a hose failure waiting to happen. I recommend 1000 psi hose at a minimum.
4. If you recycle a welding gas regulator, look at the Harris motorsports model. It's one of the few with 3/8" ports to allow a high flow rate to go with the high pressure.

All of the above is just getting some equipment compatible with air jacks. The fun part for us here in the U.S.A is coming to grips with metric and British fittings.

Here in the U.S., we are all familiar with NPT (national pipe thread tapered) fittings because 99.9% of everything we have uses them. Well your European manufactured wand uses BSPP (british standard pipe parallel) threads, also
known a "G" threads. The other possibility is BSPT (british standard pipe tapered), also known as "R" threads. This is important because these different thread designs are not even close to being compatible. Another useful nugget
for the un-initiated is a BSP fitting requires a copper crush washer to seal where a BSPT uses the same teflon tape as an NPT. This can all get a bit confusing when you start mixing Made in America and Made in Europe components.

My new system is a mix of Italian (Paoli), German (Staubli), Swiss (CEJN) and American (Catalina Cylinders and Goodyear), so I have a little bit of everything when it comes to thread standards.

Anyway, hope this help anyone trying to set up a system or trying to make heads or tales of the various connectors.

weekendbob

>3. Air hose rated to 500 psi is a hose failure waiting to happen. I recommend 1000 psi hose at a minimum.

Are you referring to working pressure or burst pressure? Thanks.

dogger15

Working pressure. It's easy to find 3/8" pressure washer hose with working pressure ratings of 1000 psi and much higher. Check out EBay if you can't find one at your local hardware or building supply store.

I got mine from a True Value. 35' 3/8" Goodyear rated at 3000 psi working and 9000 psi burst. It came with male NPT fittings at both ends. I think I paid around $30 on sale.

93 FireHawk 968

Very helpful thread..... I used a local welding shop to help get set up but wished this thread was available a few years ago, would have saved a bit of time. Certainly buy the highest quality components all around.

bimmer60

What size tank do you use?

ir_fuel

You are dealing with a lot of pressure here. You don't want anything to go wrong. Could be fatal.

Viperbob1

We just use a 125 cylinder. Then a 2 wheeler to roll it around.

911racer

The motorsports regulator makes a huge difference. The motorsports regulators flow much faster than the standard welding ones and therefore the car raises much faster. You pay the price, though.

We changed from a regular welding regulator to a Lincoln Motorsports and I was amazed at the change. I thought the low flow was the diameter of our hose. I was wrong.

Thanks

Ed

dogger15

I use a 60 cu ft Aluminum cylinder from Catalina Cylinder and a two wheel cart to roll it around. You can go steel or Aluminum for your cylinders, I chose Aluminum for less weight and less maintenance. This size tank is fairly compact while still holding enough N2 to run your jacks, power tools and even air up your tires. I use the same rig with a precision gauge/bleed fitting for my remote shock reservoirs. These kinds of carts will accept a pretty good selection of cylinder sizes if you want bigger or smaller.

I keep a mongo cylinder back home that is serviced by my local Airgas. I use the big cylinder and a trans fill adaptor (stainless steel braided line with two CGA 580 male fittings and a 5000 psi gauge), to fill my smaller bottles. The big cylinder last for months but when it starts to get low, I call Airgas and they send a truck around to swap it out.

So far, seems to be a pretty good arrangement.

Here's a picture (supplied by the manufacturer), showing the cart with regulator mounted and a similar size cylinder. The two horns on the back of the cart are for coiling your air hose and the ring on the right side is for holding the wand:

ir_fuel

The amount of money they charge for those carts is ridiculous though.

dogger15

True statement.

I was thinking about fabbing up my own, but the amount of work and time to do it brought me back to my senses. Here in the USA, the cost of the cart is not as bad as the shipping charges from Italy,
at least you would get a break in that respect.

ir_fuel

I bought a $50 alu cart and installed my bottle on it using some straps. Does the job perfectly.

ir_fuel

Cyril

What quick couplers do you use for 550 PSI?
Milton quick couplers supports 250 PSI other 300.

Very helpful thread btw, thank you.

dogger15

Good question and good catch on the max pressure. When I was doing my research, I noticed none of the QDs were rated as high as the working pressure the system would be operating at, yet all the air jack and wheel gun rigs I saw still sported them. I called my contact at Paoli and he told me they have been using Oetiker and CEJN QDs as part of their systems for years with no reported failure up to and including 69 BAR (1000 psi) at supply (prior to reduction), pressures. On my rig, the first QD is located on the reduced side of the regulator so it doesn't see anything higher than 600 psi. I'm using CEJN European high flow E-Safe QDs. They work great and are an easy one handed operation even at high pressure though I do recommend turning the pressure down a bit before you attempt to attach a gun or wand, just in case you don't get a good lock.

CEJN QDs can be purchased in the U.S. from MSC industrial supply. The only problem I ran into was finding a domestic source for a CEJN BSPT male QD fitting for my wand. I ended up getting that from Demon Tweaks in the UK.