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Does any one know what the max rail pressure is that you can run safely? Thanks
 

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With two shims in the relief valve mine runs to 27,500 psi. I have about 6000 trouble free miles running at this pressure for what it's worth. According to TS Performance it's safe to run with all three shims in the relief valve, which I'm sure many here do without any problems I've heard of. With the TS "Plug" I saw 28,500 psi max, which I suspect is probably the upper limit of the sending unit based on what I've read elsewhere, although I could be wrong on that. I wouldn't be surprised if a lot of the MP-8 equipped trucks aren't running in the 30K psi range. As a point of information, it seems the pressure is limited to 22,500 by the trucks computer with the MP-9 off and the TS Plug installed (which is equivalent to running with no rail pressure relief valve). Others will chime in soon I'm sure, but hope this helps.

Bill
 

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I think TS has it posted on their website. I dont remember for sure but i read that Bosch says its good to either 27k or 29k. Being that you saw 28.5K then i would think it was 29k.
 

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Bosch tests them at 29K i believe.
yeah but I would worried to see that on my rail pressure gauge. The relief valve opens at 27500 stock. Personally I would not want to be over 26k too much.
 

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Has anyone pop their valve with 3 shims while on the MP8?

Is a shimmed plug safer than the TS Plug?
 

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The shimmed relief valve can at least reduce pressure at some point. The TS Plug is just that - a machined PLUG that will not relieve at any pressure. I believe there is another relief valve somewhere in the CP3 pump, but never found anyone that convinced me if it's there, what it's setting is.
 

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Smells like Bananas
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Well the other problem that is happening is that with the Relief Valve shimmed you are adding to how much PSI that it will hold, We all know that. But here is the problem that i have encountered. With the MP8 and PMT turned up. It can not relieve the pressure fast enough. Which causes the truck to keep running. This is a point at which you can damage a Injector. Since the releif can not relieve the psi that is built up it has to go some where. Well if you are hard on the acclerator and then get off your injection pulse is now at a minuimun. Now that there is a ton of volume and fuel built up it has to go somewhere and it is going through the injectors by forcing its own way.
 

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So has anyone had their shimmed valve pop? I guess the question I am trying to get an answer to is... if I am not stacking, and if I use the TS plug instead, am I running a *real* risk of hurting the pump or injectors? Or does the CP3 not put out more than 29k PSI and there is no diff between the plug and the shimmed valve?
 

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the pressure statement I saw on the ts site was that bosch quoted 29K as being a safe limit for the injectors. a little off topic here, but how much hp is the cp3 going to be good for if you have a FASS 150/150 behind it? I am really close to stacking an mp8 and will be adding the FASS at the same time and am really curious if I will be stressing the cp3 at all.
 

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So has anyone had their shimmed valve pop? I guess the question I am trying to get an answer to is... if I am not stacking, and if I use the TS plug instead, am I running a *real* risk of hurting the pump or injectors? Or does the CP3 not put out more than 29k PSI and there is no diff between the plug and the shimmed valve?
If you are not stacking then you should be just fine with the plug. The MP-8 alone will not force the Rail Pressure high enough to exceed Specs alone.
 

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Where you might find a problem is if you are on the streets. You get on it real hard and then you have to stop really fast. Even worst on a manual then a auto. ITs when you get all of that fuel and no place for it to go. This wont happen at high way speeds or really It probably wont happen unless you are in 1st gear. So if the system has to relieve fast there is no place for it to go but through the injectors. If the throttle is at 0% the fuel has to force its way through the valve in the injectors.

I am sure some of yall have noticed this. Its like a echo. The truck keeps going not at a steady pace but at a jerking pace and its a little weaker with every jerk. The rpms keep spiking up as the volume of fuel is relieved.
 

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u can run it a 29k all day long with no problems thats from bosch
 
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