Colorado B.S. Thread

You'll have to take a picture or I'll have to look at your setup.
It sounds weird to me that you would mess with the pressure regulator at all in relation to the sprinklers.
Usually, the tee for the irrigation system comes off the main line prior to the regulator as you want full pressure to the sprinklers.

 

I had to put one of those behind my front loading washer when I first bought it. Like you said prior, the valves open and close much quicker so it sends that pressure (?) through the pipes. When I first heard it I had no idea wtf it was and thought my house was about to collapse.

Side note: I put pressure regulators on my irrigation system zone that is strictly for the drip system in the raised beds. Needed to tone down the pressure to those lines.

 

More teeth = lower speed reading on your spedometer.

 

Both. you kind of have me wondering if we're talking about the same thing now.

Pressure regulator valve


Backflow preventer

 

My pressure regulator effects my sprinklers as well. As the outside line t's off in my basement after the pressure regulator.

 

Lol!! Sean that's the funniest looking back flow job. But it works lol. You know Chris's brother could have sweat those pipe joint in a few seconds lol.

 

@BDN

Stock speedo gear is a 30 tooth. I run a 28 with my larger tires and 4.10s. Think you need a 33 to compensate for the gears.

Think about it as percentages.

19% change in gears: 30 tooth x 19% = 35.7 gear

6.5% change in tires: 35.7 x 1-.065 = 33.38

 

You hooked your back flow preventer up to a wall hydrant?
I honestly can't say I've ever seen that done before.
Did you have water hammer (a single bang when a valve closed) or was the back flow preventer continously chattering while the sprinklers were running?
If it was the latter, I'm wondering if the anti siphon on the hydrant affects the back flow preventer somehow (it's kind of redundant to have both)

 

My moms is set up with 2 pressure reg. her sprinklers ts off water main her shut off is in ground by meter..1 reg in house 1 @ sprinklers near back flow. as soon as valves turn on she gets the hammer then it quits..

 

.

Math
I'm looking at a 13% change if I did my math right...but mine is a little rougher.
Does the dealer carry those little gears?
Also, mine is a cable driven speedo, not a speed sensor drive...not sure if it's the same gear. I was going to pull it out later today and take a look.

 

A side pic for our resident plumber
Re-last night's side discussion.
TH350 speedo gears, same diameter, varying tooth count. These gears all fit the same GM transmission and give you different speedo readings. And they are very close to being the same diameter, if not actually the same. The pitch and cut of the gears I think is how they get away with it.

 

Bet Sean can solve your problem *Cough*Ban*

 

Just based on what you're describing Sean, I think I know what your problem is/was.

Here's a cutaway view of your backflow preventer


You need to have enough water pressure to overcome the springs on the diaphragm so that when it's turned on, there will be a good seal on top of the poppet.
Two things can mess this up. Too low water pressure or a bad seal. Either one will cause that "chattering" you experienced as the seal bounces off the top.

Your pressure regulator lowers your water pressure. Turning on another fixture (like the shower) temporarily lowers the water pressure.
Your backflow is connected to a commercial wall hydrant (hose bib, sill cock, spigot, pick your term) How the hell that thing ended up in your house and why the sprinklers are connected to it is beyond me, but it has an anti-siphon valve in it and it is further reducing your pressure.

 

ROFL at posting a labeled diagram and then using completely different words to explain the components as you explain what was happening.

 

I will soon start going gray much more quickly than I would have. https://instagram.com/p/6NXg3bIZE_/

 

So I had 19% larger gear for the 4.88s, and a 6.5% smaller gear for the tires, seems like we've come to the same conclusion.

IIRC, the gears themselves are not any different from the cable vs electric spedos, and yes they're available at the dealership. Super easy to take a look at. With switching back and forth from winter tires, I've gotten pretty good at it. Takes 5 minutes or less. Pull the 12mm bolt from the top of the sensor unit, not the phillips head screws. Be prepared to loose an ounce or two of gear oil. Gear is held in by a c clip.

 

More like a cup, lol
You were correct, 30 tooth. Dealer can order a 32 tooth and that's the largest they carry. So I should be closer than what I am now. I'll find out in a few days.