E99 build and test thread

[RhoXi]

I recently picked up a decent E99 as my first Spyder ever. A lot of my friends had Spyders back in the day but I was a Tippmann kid. I cleaned this one up and put some paint through it. It shoots just like how I remember Spyders. That is to say, a little on the harsh side. I like everything else about it so I figure let's tune it up and see what happens.

I want to make a high pressure low-force build. Why? For one, I like the simplicity of not have a secondary regulator to futz with and two, I did this to my 98 custom and have been extremely pleased with the results. The idea is to promote flow and reduce the spring weights and striker weight. To that end, I've got a Warrior spring kit, an EKO valve, and an Azodin Feather hammer on the way. In this thread I will be chronicling my test results and see what makes a difference or not. Stay tuned!

[RhoXi]

Finally went out and bought some paint yesterday and took some shots over the crono this morning. I am using a handheld X-radar chronograph, Valken Graffiti Platinum, stock barrel, and a 48/3k standard output aluminum tank. Also stock striker, springs, and valve.

First, I want to see what difference the bolt venturi makes. I have seen many people advocate for removing it and I personally don't see a good reason for it's existence. I shot two ten shot groups and recorded the velocity of each shot. All velocities are in feet per second.

With Venturi: 250, 256, 247, 246, 261, 253, 257, 249, 265, 258
Average: 254.2
Standard Devation: 5.95
Spread: 18

Without Venturi: 255, 255, 247, 252, 243, 259, 243, 246, 255, 249
Average: 250.4
Standard Deviation: 5.31
Spread: 16

Notes: Velocity adjuster was all of the way in. The paint is running really small (it was rolling through my .680 Stella back ~50% of the time).

Thoughts: This thing is shooting more consistently than I thought it would but I was also surprised the results. I expected about a 10fps increase from removing the venturi but if anything I got about a 4fps decrease. This could just be due to normal variation in paint size and might require more testing but if anything removing the venturi made no significant difference in this case. Also, the paint might just be too small for the stock barrel to reach a decent velocity. That or the main spring is a little tired. Both seem likely. I have a one piece CP .689 I can throw on it but even that is probably too big. I will still probably leave out the venturi from now on but I think I'll keep it around for when the spring kit comes in and do testing with and without again. Now if USPS can finally get the parts to me that'd be great.

[scottieb]

The Eko valves are pretty consistent in their own right.

I'd get those new springs in pronto, especially the striker spring. You'll be able to have the RVA backed off a bunch more and be hitting better velocity.

Keep the venturi portion of the bolt out of the equation as doing so provides the best air flow.

I'd also suggest a Freak barrel or similar. As the paint size changes throughout a day of play due to temperature and humidity you'll be able to bore match.

[RhoXi]

All the parts were supposed to be here this past Thursday but it seems they lost track of it after it got to Chicago. Hopefully everything will be here in the next couple days.

Freak is definitely a possibility. I've been using AA's for years I'd just need a Spyder back and inserts.

[Sneak Miester]

This is a post I made on Pbnation years ago

https://www.pbnation.com/showthread.php?t=4096777

[RhoXi]

Good info here, thanks!

[Kit352]

You should get a better matching barrel and then make sure its a constant with the test along with the balls. i would do that before changing springs because its likely to have a large impact on your readings.
make sure your running fresh orings in the bolt and hammer at least. old spyder + old oring most likely.
The main spring might be smashed down from the etrigger holding the hammer back until someone powers it up to release it which could be days or in my case years.
lighten the hammer in stages. If you get to greddy it wont open the valve well enough for good performance.
Use something like hater lube or dye grease instead of oil on the bolt and hammer. Last longer and more consistent results.
You can back half it and get a more compact bolt
I would experiment with porting the stock valve and shaving the pin. The problem with too much flow in a HPA gun is waste and shooting hot. You may very well end up restricting something to get it to shoot under 300fps reliably. Springs can only take you so far.

I look forward to your results.

[RhoXi]

I should've mentioned this before but I did re-oring the whole thing before testing.

Bolt mass is one thing I am interested in reducing. The long cocking rod is not doing me any favors that's for sure but I don't know if I want to cut up the body because it's in pretty dang good shape. The Azodin striker I've got on the way is about 2/3 the mass of stock. I'm going to re-weigh them and record it once it arrives.

I think either getting a freak kit or like a CP or LAPCO .682 or .685 is going to be the next step before springs. The initial test made me realize just how overbored the stock barrel is. It's up there with Tippmann stock barrels.

[Kit352]

Yeah, stock barrels are huge, even by old standards. It wouldn't be uncommon to find .694 in some of them.
If you can swing the cost a freak kit would be the best for testing purposes.

[Tarsun2]

i used to glue a think(ish) o-ring to the bolt face to prevent roll back since back in the day paint was bigger... it helped allot with force-feed hoppers as well. Might be worth looking into.

[RhoXi]

EKO Valve testing 3/8/25

All of the parts finally arrived yesterday so I got busy swapping things around. The EKO was the first thing to go in but I discovered a compatibility problem with the E99. The front of the valve is much thicker than the sock valve. This causes the EKO valve to sit further back when pushed up against the pin in the body and misaligns the exhaust hole. Now, it's only a 1.5mm difference but that was more than enough to negatively effect velocity. I went ahead and jotted down the velocities anyway but something is going to have to be modified if I want to use this valve.

Misaligned EKO valve, no bolt venturi, stock barrel, stock striker, velocity adjuster all of the way in

Stock springs: 234, 222, 223, 235, 237, 236, 230, 223, 229, 231
Average: 230
Standard Deviation:5.39
Spread: 15

Black valve spring, stock drive spring: 259, 248, 248, 237, 243, 258, 253, 248, 253, 251
Average: 249.8
Standard Deviation: 6.27
Spread: 22

Black valve spring, Gold drive spring: 304, 312, 301, 312, 313, 303, 297, 308, 292, 316
Average: 305.8
Standard Deviation: 7.35
Spread: 24

Thoughts: My theory of the stock drive spring being worn out seems to be correct. The new drive springs in the Warrior kit are 0.16" longer and the couple of shots I took (but didn't record) with the lightest drive spring were higher than the stock. Compared to the velocities I was getting with the stock valve, the misaligned EKO valve is getting me about 20fps less. It took using the heaviest drive spring to get velocity up into a usable range. I think I am going to try milling down the front face of the EKO to get it back into alignment. I also noticed while dry firing the EKO valve seems to provide less blow back than the stock valve because it doesn't want to cycle reliably without paint or blocking the barrel. I want to pursue this as it makes the cycle a little bit gentler but the stock valve is going back in for now. I am also sticking with the stock barrel for now just to keep things consistent. A small bore barrel will probably be the last thing I add once I get the gun shooting the way I want it to.

Next up is the Azodin Feather striker.

[RhoXi]

3/9/25 Strikers

Today I wanted to see what difference the Azodin Feather striker has not only on velocity but on shot feel as well. Luckily I have a Kaos sitting around that already has one and was able to confirm that it works in the E99. The stock striker weighs in at 2.4oz/68g and the Feather comes in at 1.6oz/46g. Coincidently, the Feather striker weighs just about as much as the TechT Zero Kick hammer. At least, that's what the info I found online seems to indicate. The Feather striker is a no brainer at less than half the cost.

Stock valve, Black valve spring, stock barrel, no bolt venturi, velocity adjuster all of the way in

Black drive spring, stock striker: 275, 258, 272, 271, 278, 279, 277, 277, 258, 279
Average: 272.4
Standard Deviation: 7.64
Spread: 21

Black drive spring, Feather striker: 268, 254, 257, 270, 273, 251, 251, 262, 255, 262
Average: 260.3
Standard Deviation: 7.56
Spread: 22

Silver drive spring, stock striker: 292, 289, 294, 300, 296, 294, 296, 296, 292, 298
Average; 294.7
Standard Deviation: 3.03
Spread: 11

Silver drive spring, Feather striker: 290, 291, 280, 288, 274, 285, 292, 283, 281, 286
Average: 285
Standard Deviation: 5.35
Spread: 18

Thoughts: Now we're getting somewhere. The stock valve is performing much better than the misaligned EKO valve. I was almost hitting field velocity with the lightest drive spring and the ginormous stock barrel. The real story here is in the Feather striker. It only drops the velocity 10-12fps but it provides a much more pleasant shooting experience. I wish I have a way to measure this but it kicks less and vibrates less too. It still has a little more vibration than I want it to but I think I can get there once I get the EKO valve situation sorted out. I also want to look at reducing the bolt mass but it seems rear-cocking spyder bolts are harder to come by these days. I could take it out to local field right now as it sits and be good with the 285fps limit and that's the first time I've been able to say that. Yay for progress!

Hopefully sometime this week I'll get brave enough to take a file to my shiny new valve and get some numbers down.

[RhoXi]

3/15/25 EKO valve modification

Yesterday evening after work and an adult beverage, I went ahead and took a file to the front of the EKO valve in order for it to able to clear the valve cross pin in the body. Honestly it was easier than I thought it would be. I just took my time and measured frequently. The finish on it isn't perfect though. I might pretty it up later but it'll work for now. Did some shooting this morning and these are the numbers I put down.

Modified EKO valve, Black valve spring, Silver drive spring, Feather hammer, Stock barrel, no bolt venturi, velocity adjuster all of the way in

295, 293, 307, 305, 291, 286, 296, 306, 303, 308
Average: 299
Standard Deviation: 7.35
Spread: 22

Thoughts: It's shooting nicely indeed now. Very little kick and muzzle dive and vibration has been reduced significantly. Still not quite as smooth as my 98c but that probably is just due to the tippy being heavier. The EKO valve does indeed seem to provide better flow seeing as how the average over the stock valve with the same springs went up about 14fps. Less blowback gasses also helped smooth out the shot too. The drive spring tension is higher than I'd like it to be though. I might experiment with the stock striker again but I am happy with it for now.

Throughout all of this testing, some additional issues have popped up. It seems I am getting some stack clipping because every once in a while I am getting barrel breaks. It's definitely not the paint being brittle because this Valken Graffiti Platinum is designed for mag fed and is hard af. I took a few and dropped it from ceiling height (8ft) into my bathtub and all of them bounced... To remedy the barrel breaks, I am going to see about adding a cure style ramp to the bolt and adding a second ball detent. Another problem is that I am occasionally getting double fires with or without air. It could be the trigger switch is going bad or that it doesn't like how much overtravel is built into the system naturally. It's a funky looking microswitch though so if anyone has a lead on a new one please let me know. I also want to see about adding some sort of adjustable post travel to the trigger. More to come!

[Tarsun2]

i stand by my original suggestion of gluing an o-ring to the bolt face. this will keep the ball inline with the feed neck stack. iirc, its when the ball rolls back that it becomes an issue. a second detent would have to be behind the ball. not sure if youll have the room...

[RhoXi]

I was considering that too. What kind of adhesive would you suggest? I also assume something like a 015 duro 90 would work just fine.

[Tarsun2]

i used regular super glue. seemed to hold up fine and never popped off.

[MrKittyCatMeowFace]

Looking forward to more. Sometimes STBB's can be a real pain to get shooting right.

[flyweightnate]

I'll be contrarian and ask about adding the venturi back in.

If you're running high pressure, it might help break it up/ smooth it out, where you shouldn't be as concerned about losses as a low pressure system.

I have no evidence to back it up, just curious. Since you're already testing.

And then you could add a "foamie" to the venturi face to reduce roll back, if you don't have room to glue on an oring.

[RhoXi]

Hmm, I like your thinking here and you've given me an idea.

[RhoXi]

3/19/25 Venturi redux

Per flyweightnate, I decided to throw the venturi back in and see what happens.

Black valve spring, Silver drive spring, Feather hammer, stock barrel, velocity adjuster all of the way in

Without Venturi: 303, 293, 287, 301, 301, 294, 303, 314, 309, 296
Average: 300.1
Standard Deviation: 7.52
Spread: 27

With Venturi: 315, 288, 315, 306, 301, 310, 302, 311, 299, 306
Average: 305.3
Standard Deviation: 7.82
Spread: 27

Thoughts: Very interesting results. Firstly, the results I got with no Venturi are very similar to the numbers I put down on the 3/15. Secondly, the results I got with the Venturi installed showed a similar increase in average over not having the Venturi installed as I had back in the beginning on 3/2. I think I was wrong about venturi not doing anything. I am going to leave it in.

Still having stack clipping/roll back problems. I'm having to single load for now. I tired gluing an o-ring to the front of the bolt but the detent kept ripping it off on the return stroke. I probably just need a more suitable glue but all of this venturi talk has given me an idea. Stay tuned!

[flyweightnate]

Very interesting. Supports a hunch.

I think the venturi helps when the gun gets air too fast, and both evens out the flow turning the corner into the bolt and reduces early expansion so it carries the energy farther. But, it's obviously not the most optimized design, and creates tons of drag on a less- dense jet (e.g LP high flow).

I want to see your anti-rollback venturi!