Low Pressure – F.A.Q.

I have been getting dozens of emails from many that have questions on Low Pressure. So, as I have done in the past, thought I would type up a F.A.Q. about this. I am not an expert. I am writing this by my own experience as I have done this modification to my Original Spyder, Spyder Compact Special Edition (SE), Spyder 2-in-1, and many others that have come through my shop. This article deals with converting your Spyder to operate at a lower pressure. Any of the Kingman Spyders can be converted to LP. It is not for one type of Spyder. Whether you have an Original Spyder like me, or the latest Kingman marker, the Electra DX, you can convert them to LP.

Remove all air and paint prior to doing this modification. Read the instructions through. Make sure you have an understanding on what is involved in doing and what is needed for a trigger modification. If you attempt to do any of the home modifications listed on this site, I am not responsible for any damage done to, or from, modifying your marker. Also, by doing any of these modifications, you will void warranty of the marker. Kingman does not support the home modifications that I share.

In this article, I will discuss low pressure in four parts…

The Basics

LP is very debatable subject with many different viewpoints. Getting an LP setup is expensive. It will not be cheap. Especially if you choose the best quality items for this modification. Many will say that the money you put into an LP setup on a Spyder, you could have gotten a stock Mag or AutoCocker. Or at least a good down payment on a Shocker or an Intimidator. That is very true! When I was in search for the first time for LP parts, I have been told many times over that I am wasting my time doing this modification to a $100 Spyder. So don’t be suprised to get negative responses when looking for parts. I did. But look what I have now. Even Kingman has said that LP is a gimmick and not worth the money. Yet, they insist on adding an LPC on most all of there markers.

But you got guys like me that like the Spyder a lot and see no point in “upgrading” to a new paintball marker that I will eventually add upgrades to anyway. Guys like me want to squeeze every ounce of performance out of the Spyder. The Spyder is very comfortable to me. I even sold my Minimag and kept my LP Spyder. And I like gimmicks! As I have said in my Upgrades – F.A.Q. article, the Spyder is very upgradeable with the dozens of aftermarket parts available.

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The Concept

Now, onto LP!! Basically, what an LP system offers is provide more shots per tank, quiets your marker, provide less ball breaks, and a smoother operation which is easier on your internals. This is a lot better compared to the stock booming, gas guzzling, ball slapping operation that some complain about in a stock Spyder. It will not increase your rate of fire or make you a better player. Those that use CO2 will see much better performance with this gas. Especially in cold weather seasonal play.

There are no facts about LP written in stone. Not all paintball markers operate the same. Adding the LP modifications will be different from marker to marker. So I am going to comment on the Spyder and my personal experience about LP since I am a firm believer in it and hope to answer most questions. As I mentioned before, all of my Spyders have been converted to operate at lower pressures. And, I have also converted many Spyders that have been sent to my shop for the conversion

I have found that Spyders run about at about 50% gas efficiency because it is dependent on the pressure from the tank to maintain proper function at the regular operating pressure of 850psi. With an LP setup, the marker is dependent on more volume instead of a pressure. An increased efficiency to around 80-85% if not more can be expected. The larger the volume of air available, the lower the pressure is needed for proper functioning. But, there is a maximum of volume to pressure needed. An unbalanced ratio will not provide proper operation or best efficiency of the marker. Having an operating pressure of 250psi may not be as gas efficient as an operating pressure of 350psi. Each marker will have its peak efficiency pressure. Too much volume and it is not gas efficient. Too less of a pressure, re-cocking problems.

If not able to fire the ball at the desired velocity and re-cocking is a problem, then you will need to increase the pressure or increase the air flow area. That may mean modifying that valve pin, changing the type of valve, etc. I will go over ideal parts needed to add and consider for an LP setup later.

I have been asked what is considered the best operating pressure of an LP setup for a Spyder. Like I said before, nothing written in stone. But I would have to say that it should be at least half of your operating pressure of your non-LP Spyder. In this case, the psi goes from 800 down to 400. On average, an LP Spyder operating pressure is around 350psi. Well under half. I have seen some LP setups run as low as 200psi to as high as 450psi. My Spyders range from 225psi to 350psi without burping and being peak performance. And I have done minimal upgrades and modifications. I still need to do more. As well as other theories I like to test out. I have presented test results of various items, comparing the pieces side by side in Project – LP. The operating pressure that I have now will decrease even more when my LP conversion is complete.

Because of the lower operating pressure, your marker will be quieter. Instead of the loud popping sound, it will be a ‘puff’ sound. Also, your not slapping the paintball with 800 + psi when you fire. It is a much easier push. With that in mind, there should be less ball breaks. Since my last addition (better regulator) on my Spyder SE, I have yet to get a broken ball. Also, velocity is more consistent. This consistency helps you out with being more accurate with your shots. You will experience lower recoil.

As mentioned earlier, CO2 users will find a low-pressure setup a benefit in cold weather. In cold weather, CO2 is not a constant pressure. When warm, your PSI from the tank can be as much as 1,000 or higher. As you shoot the marker, the tank tends to get cold. This reduces the psi to around 700psi or lower. In cold weather, the PSI can be as lower as 450psi. Sometimes lower. With that in mind, an LP setup on a marker that is running at 350psi is less likely to malfunction in cold weather versus a marker running at regular pressure of 800psi.

And sorry, I have seen manufacturers advertise by adding just an LP chamber or a Turbo valve will make your marker into one. No it will not!! A good LP setup is a combination of parts, all working together. So, I will give you a list of what you need to get a successful LP setup. Some items are purchased items. But there are a few cheap modifications that you can do with regular tools found at home. I also suggest going slow. No need to drop all that money in one shot and get an LP setup immediately. Go slow and see what each component does when added. This will increase your knowledge of how your marker works and can minimize the time fixing something. Wondering how much that you may spend? By getting the bare minimum of parts that are listed below and doing the free home modifications when you can, you can expect to pay around $150 on average for an LP setup. Not only that, but the time you will spend adding, modifying, and changing parts is very time consuming. Getting the best parts will add on another $150. It depends on the deals that you can get on parts and what your marker already has installed.

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The parts to go LP

If you are not scared away by the average low price, then I guess you are still interested in a low-pressure setup. Below is a list, no particular order, of things that you need to have a healthy low-pressure setup. I have also mentioned some good brand named items. I again encourage you to read Project – LP for comparison test of parts next to each other.

a) Barrel. Yes, you may need a new barrel. As brought out in my Barrels – F.A.Q., a paint to bore match is very important. More important in an LP setup. Also, you need one that has no porting for at least 7″-8″. A paintball needs that much to get up to the desired velocity. In an LP setup, the paintball gets up to the proper speed slower as compared to a regular pressure setup. Having a lot of porting will cause you to use more gas than is needed to keep the ball moving. Not efficient and the opposite of what you want the LP setup to do. I have a barrel for each of the size paints available. Good barrels for LP are Custom Products, Lapco, and J&J. Also, the barrels with control bores or inserts to match the paint will help in an LP setup. Even if it is only for 5″. Lapco will be selling a 2-piece barrel that will have control bores that are 7″ long. Something to look into.

b) High flowing bolt. There are 2 ways of tackling this. Spend the money and get an AKA Lightening bolt that was designed for LP. Or, simply take out the Venturi (that star looking thing inside the bolt) from your stock bolt. This will increase the airflow. I also suggest that you sand the inside lip of the stock bolt so that it will cup the ball better. I have been asked about the delrin bolts. It is a nice concept. However, adding oil or playing in high humidity will cause bolts made of this material to swell and cause friction or even get stuck.

c) High flowing valve. Diamond Labs used to sell an LP valve. But since they have disappeared, AKA and Maddmann are the only two that makes an LP specific valve. You can get away with using any of the Turbo valves like the 32degrees, Omega, and Taso. They will work. The AKA and Maddmann are much better due to their design. Beware, the AKA may not work in your marker if it is a slim striker Spyder. To find out if the Spyder is a slim striker, measure the length of the striker. If it is longer than 2″, it is a slim. This you will hear from many stores that sell this valve. Even AKA claims this. I have not had that trouble. The AKA will fit inside the body. But you may have a re-cocking issue that can be tedious to work out. With the help of polishing internals and working with spring kits, I have had no trouble with getting AKA valves to work in any Spyder. The AKA Tornado valve is most expensive. The Maddmann Rocket is close to equal in performance, and is cheaper than the AKA. *Warning: Using the AKA Valve over 450psi for an extended period of time may cause the valve to malfunction and cease to work. It was not desigend to work at that pressure or higher.

d) Regulator. I have preached getting a regulator over an expansion chamber for high-pressure setups. A regulator will give you measured amounts of air that will give you better accuracy because it feeds your marker a consistent amount of air. With an LP setup, your are now able to reduce that 800psi from the tank to 400psi or less that the marker needs to fire paintballs. Bob Long regulators work well with CO2 along with a Palmer Stabilizer and the AKA Sidewinder. For those that have invested in HPA/Nitro tanks, I suggest a Vigilante. Vigilantes are built just for HPA/Nitro and you can get an LP spring for it. For those that do not have a limit on funds, the Smart Parts MaxFlo is the best. Another important thing is the placement of the regulator on your marker. For the LP system to be effective, or for that matter the regulator to be effective, the regulator must be mounted in a vertical position. The air should pass through the regulator before hitting the valve. Most all the Spyders with the compact body style already has this. I get into more detail down further at g) Vertical Adapter. A regulator mount under the grip frame (like the Kingman regulator) will not measure properly because it has a lot more space to “re-charge” after each shot. The result of this is burping or simply an air restriction. Or, if the regulated air from a grip-mounted regulator has to travel through an x-chamber, it has to squeeze through all the chambers.

e) Spring kit. A must have for any Spyder owner, LP or not. This simply will help you fine-tune your internal operations. For LP use, you may need to adjust the valve spring to a stronger one and the main spring to a weaker one to get the lowest psi/desired fps. However, the mentioned spring combinations may vary. At the time of this writing, my SE is setup as such, but my Original Spyder is a stock main and a strong valve. See the last few paragraphs of Project – LP for more info on spring combos. The Maddman kit comes with 3 different main springs, and 1 useable valve spring. Not exactly the best kit for fine tuning. It does have a trigger and sear spring that will enhance the trigger pull. Also, if you choose to use the Maddmann Rocket, that valve has a built in adjustable valve spring. The other recommended spring kit is the 32degree spring kit. Comes with 3 main springs and 3 useable valve springs. When I say “useable”, I mean that there are other valve springs. Remember that the Spyder comes in a full size and compact body style. The full size bodies will use the longer valve spring while the compact uses the shorter springs. Maddmann comes with a total of 7 springs (this includes the trigger and sear spring) in the kit. The 32degrees comes with 9 springs total.

f) Low pressure chamber (LPC). Many of the Spyders now come with a LPC (or low-pressure chamber). Another name for it is ‘volumizer’. Some people will change them to a “better” one. Sorry, they’re all the same. It is just a tube that stores extra volume of air before being fired. The only time you should change it is for the looks. There may be one that will match your Spyders look better. Some Spyders do not have an LPC. I had to get one for my original and SE Spyders.

g) Vertical adapter. I mentioned this back in d) Regulators. There are two types. One type is for the Spyders with the full size bodies. This is a simple adapter that replaces the braided hose coming from the bottom of the body (like the Spyder 2000 and Spyder Classic). This allows you to mount a regulator close to the valve area. The remaining Spyders are of the compact body style (Xtra, E-99, TL+, etc…). They already come with the vertical adapter. It is suggested that you re-drill the hole in the stock vertical adapter. The existing holes are a little restrictive for LP. Or, purchase either a Bob Long vertical adapter or the Check It 15* Assault Block. Both are excellent for LP. If you have a Spyder Compact SE, you will need to invest into a vertical adapter or similar so that you can house a LPC. The two VA’s that I have mentioned have the most area for the air to travel through. Sometimes, if you have re-cocking issues, upgrading the VA is enough to help. AMG Users: As mentioned earlier in d) Regulators, I mention that the best position for a regulator is mounted vertically. However, the AMG has a different setup in the fore grip. There are 2 screws that hold it in place with an air chamber in the center. This is extra space for the regulated air to travel through. Plus, you are limited on only a few grip-mounted regulators. I have designed one that will work, but do not have a metal shop that will make one at a reasonable price. There is a commercially available VA that can be made in either a straight or 15* configuration. To inquire about this, contact SpyderVenom for details.

h) Lines and air fittings. Count this in also. Microlines are too air restrictive. Go with macrolines. Or, better yet, go with the stainless steel braided line. These will last longer and will withstand punishment. Use Teflon tape on the threads of the fittings to attain a good seal.

I) Polishing internals. This is probably the most over looked step in a good LP setup. Sure, adding the above parts may work and get your operating pressure down. There is still some friction between the bolt assembly and the rest of the internal parts. Polishing internals consists of simply sand the bolt and striker bodies, valve pin, and the top of the sear with very fine grit sandpaper. Be careful not to sand to much as you can ruin the parts, like having a not so round bolt. An oblong bolt may start to cause unusual wear in the inside. Just enough of sanding to get any rough ridges to disappear and get a nice shiny look. Nothing below 800 grit. But you can start off with lower grit like 400 at first. Better yet, use a 400 to get out the rough spots, and then use a 800 and 1,000 grit to finish. Wipe off the dust and polish these items. I like to polish with Mothers Mag found at an automotive store. Any metal polish will do. I also like to polish (not sand) the inside of the receiver where the bolt and striker assembly moves. Remember to remove oil and dirt before you polish. I will add polish, as needed, after every 3 – 4 cases of paint. Only light sanding if it is needed.

Well, that is about it. There is one more piece that I did not mention. That is a gauge. They’re not very accurate. And some regulators will not allow you to mount one on (like the Vigilante). If this is the case and you want a gauge, you can mount one on the body itself or the compact vertical adapter. Click on the link for directions on how to do this. It is easy.

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The Installation

After you get all of your parts, installing them can be a pain for those that have no patience. It does require time to get the marker shooting right. There are two ways to finding out your optimal operating pressure. They require your marker, a filled air tank, and a chronograph.

The way I set up an LP system is install the desired spring combo that you want. Doesn’t matter what springs, as you will be changing them anyway. Start with the stock springs. Also, turn up the regulator to around 500psi. The velocity adjuster should be 2/3rds of the way screwed in and locked in place. Gas up your marker and shoot about 3-5 paintballs. Reduce your pressure and shoot again, about 3-5. Keep doing this pressure reduction until your marker burps. When it does, you have found the approximate lowest pressure for that spring combination. Turn up the regulator between 15 and 25psi. What is your pressure? Make a note of that. Change one of the springs and retest for the lowest pressure. Or change both the main and valve spring. Retest and adjust as needed. For the LP setup, the valve usually needs to be open longer to increase velocity. So, a lighter valve and/or a heavier main spring may be used. This is the way I find the optimal spring combination and pressure.

Now that we found the lowest PSI with a certain spring combination, check the velocity. Is it low? Probably is. Remember that we locked the velocity adjuster? Don’t touch it!! Adjust the velocity using the regulator. This should always be done when major velocity changes are needed. Only change the velocity adjuster for minor changes in velocity. If the velocity is low, you need to increase the regulator pressure to increase the air volume. This will speed up the paintballs velocity. Once the desired velocity is reached, lock the regulator in place. You are done!

Remember, for peak efficiency, you may not need to have the lowest possible pressure. The average optimal velocity is around 350psi at 280 – 285fps. Having an LP setup is almost a science lab in progress when getting the best air efficiency. On my one Spyder, I have been able to get my marker to shoot at 225psi at 285 fps without problems. However, my air usage was the same as it was for non-low pressure setup. I am now at 325psi at 285fps and getting the best air efficiency… doubling my shots per fill.

Setting up your marker is a lot of trial and error. Other than the investment prices, getting the LP to work properly can be a strain. It is not a simple “plug and play” deal like most computer equipment. Some tweaking on your part along with patience is needed. This is where knowing your marker comes into play. On my site are Troubleshooting and a diagram for the Spyder (and other blowback markers).

I have gotten several questions about the type of gas used. Some have expressed that when they were using CO2, they got a very nice low pressure. However, when they changed to HPA (same day without changing any settings) the marker fails to re-cock. Actually, they needed to increase the regulator for it to re-cock the marker. Some changes were significantly higher. I do not know for sure why. But, I do have a theory.

CO2 is a heavy gas. Probably why it is close to being a liquid. When you fire the marker, the tank will cool and the gas will not evaporate from its liquid state. HPA is air that we breathe. It takes a severe temperature change to cause it to be a different substance. In short, CO2 has a heavier mass than HPA. I do not know if this phenomenon is true for N2.

For a more in depth look at setting up your LP marker with test results on various name brand items, see Project – LP.

This is a lot of information to take in. And is a bit overwhelming. Going LP is an investment. But if done correctly, you will have the best shooting Spyder on the field. You can get most all of your parts from G3 Paintball or from Polecat Paintball. They do not offer the cheapest prices. I would say they are about average. There are some pictures of what the parts look like on their sites so that you can make sure what you’re interested in is what you want. Or, give me a shout. Or look at my article Project – LP for pictures of the various components.


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