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Discussion Starter · #1 ·
I see PPE sells the shim kit for the 1093 fuel pressure and they also have a "race" version which is a complete replacement unit. The unit is a solid stock with no relief available. Since we are modifying the stock units to hold more pressure with the shim kit, what would be the down side to the race version? Is the race version a bad idea?

http://www.pacificp.com/pdf/manuals/racereleasevalve.pdf
 

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The down side is absolutely no pressure relief. When you shim you still have some pressure relief, just at a higher point.
Shimming is a better option IMO.
 

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I would be way too scared to run a race valve. If something went wrong at 23,000 PSI, I like knowing my fuel system has a safety releif valve...

Just does not seem like a good idea completely defeating the releif valve...
 

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I agree with Ben...I looked @ PPE's race valve, but with that kind of pressure and absolutly no possibility for any relief, I'd be a little worried about the fuel rail and attached hoses, etc...
 

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would you remove your oil filter bypass which is a relief no and just think of what would happen if something whent wrong at 24000 plus psi that just spells trouble to me
 

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24000 plus psi
max rail pressure on the 2001-2005's is 23,055 PSI or 160 mpa.;) :)

But whatever the pressure when its up in the tens of thousands, who cares!! It could still be dangerous if something were to burst! It'd go right thru you. Thats why when checking hydraulic systems on tractors at work, we always a piece of card board to check for leaks. And those systems only operate at 1,500 PSI or so!

-ben
 

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Discussion Starter · #7 ·
What PSI are the "shimmed" valves reliefing at?
 

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not sure, but even with a shimmed valve, the press still wont get above 23,055 PSI unless something abnormal happends. The fuel press regulator still controls rail pressure to a max of 23,055 PSI....the problem is that when you have hot tunes, they ask for a lot of fuel quickly and so the pressure regulator closes quickly and ramps up the pressure at such a rapid rate that the releif valve "flutters" or opens prematurly, even before max rail press is obtained. With a shimmed valve, you will be able to rapidly increase the rail press with hot tunes (to the max of 23,055) and not pop the releif valve...

someone correct me if im wrong on that..

--Ben

so basically, its not that the shimmed valves are increasing the max pressure on the rail....they just dont flutter or pop as easilly. The stock valves are weak and have been known to start dumping as early as 21,000 PSI. Ive seen mine do that (watching rail press with a Tech 2)
 

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Mine pops right at 24000 stock. It is a PITA. I have been trying to tune it out, but not having much luck. Right now I am trying to minimize fuel rail spikes on shifts.
 

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max rail pressure on the 2001-2005's is 23,055 PSI or 160 mpa.;) :)

-ben
that is before you shim the RV i was talking about it being shimmed or removed all together it would be like 24000+ PSI dont you think but i could be wrong
 

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yeah to be honest, im not really sure...my valve is not shimmed and if I command MAX rail pressure at idle with the Tech 2, it only goes up to 160 mpa (thats the most you can manually select with the T2). But I think when everything is operating normally, fuel rail pressure is more controlled by the fuel press regulator than by the releif valve simply dumping pressure... Thats why shimming a valve on a stock truck wont do anything and does not ahve a "Duramaximizer" effect, if you understand what im getting at
 

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yeah to be honest, im not really sure...my valve is not shimmed and if I command MAX rail pressure at idle with the Tech 2, it only goes up to 160 mpa (thats the most you can manually select with the T2). But I think when everything is operating normally, fuel rail pressure is more controlled by the fuel press regulator than by the releif valve simply dumping pressure... Thats why shimming a valve on a stock truck wont do anything and does not ahve a "Duramaximizer" effect, if you understand what im getting at
i understand that shimming a stock truck wont do anything because their is nothing that has changed the fuel pressure of the truck been when you put a programmer that increases the fuel pressure it makes it raises over the 23000psi that the stock truck makes that is all im trying to say
 
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