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learned something about the Predator 3
- Thread starter DLeno
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Well JRG if you want to know what your peak rail pressure is I could certainly tell you if I ran it on my truck. I'm not opposed to that. However, once I finish my HP/rail pressure study I might be able to predict it with some accuracy. you tella me da HP, I tella you da pressure. something like that. Unless I find that the correlation between peak HP and peak rail pressure isn't there.
Digger: I'm working on that. I may have something worthy of a picture by end of month. If there is interest I'll see if I can get genos interested.
richard: you're not alone. you can always T-tap the wire if you want to measure the output of the pressure sender...
Digger: I'm working on that. I may have something worthy of a picture by end of month. If there is interest I'll see if I can get genos interested.
richard: you're not alone. you can always T-tap the wire if you want to measure the output of the pressure sender...
dleno, you say you want to test mfg claims of hp yet you are only dicussing fuel pressures. you have had a h@rd on for fuel pressure since day one, admit it. just put them on the dyno and post results and offer your $0. 02.
Prototype fuel pressure sensor? what is it, a radio shack voltmeter with a masking tape background and some speakerwire?
Prototype fuel pressure sensor? what is it, a radio shack voltmeter with a masking tape background and some speakerwire?
well now you all know why I've decided to stop reporting intermediate results before I have the whole study finished. The dyno runs will be among the last measurements made because of the logistics involved, scheduling, etc.
mattymac, there are many reasons for the apparent discrepancy between rail pressure and HP claims. some of it, yes, is best-gain versus peak gain.
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JRG said:OR if I have injectors?
Would be best if you got to play with it yerself eh?
Keep up on the good work, I'll look for the article, and I'll PM you when I take the truck in for service.
JRG
yea, ultimately that would be the most accurate but here's what we could do to avoid shipping costs and so I can concentrate on the actively shipping boxes
lets suppose the data shows a good correlation between peak HP and peak rail pressure on the stock truck. You've dyno'd your truck so as long as we consider differences between your dyno and mine, we could get close enough, probably, to what your truck makes for rail pressure. If you add injectors, then, that adds another variable. I'd have to think about that a bit -- what the ECM would do. seems like it would try to keep the same pressure as it does with stock injectors, but the additional flow might pull the rail down a tad, I don't know. DD I'm sure has got all that down pretty well. I think we could probably say rail pressure will be close to the same with or without the injectors, and that it might be a tad lower with the injectors.to much pressure??
My truck is in the shop currently waiting on a high pressure fuel valve. Something to that effect. It is located on the rail next to the fuel pressure sensor. They say the needle(valve) itself gets eroded away by to much fuel pressure. I have the edge ez. It was set on secret level 6 until i recieved the tst box, and some time while running witht the tst. Mark from tst said its pretty common when a pressure box added. The tech told me that anything over 26,000 psi will rapidly wear this valve. Any input??? Thanks.
Not sure as to if it would be warrantied yet. Not that I am looking for any hand outs. But if this pressure box is going to cause this I am going to look into injectors and get rid of the box. Its cheap power until some looses a pressure valve! Thanks. Lee.
My truck is in the shop currently waiting on a high pressure fuel valve. Something to that effect. It is located on the rail next to the fuel pressure sensor. They say the needle(valve) itself gets eroded away by to much fuel pressure. I have the edge ez. It was set on secret level 6 until i recieved the tst box, and some time while running witht the tst. Mark from tst said its pretty common when a pressure box added. The tech told me that anything over 26,000 psi will rapidly wear this valve. Any input??? Thanks.
Not sure as to if it would be warrantied yet. Not that I am looking for any hand outs. But if this pressure box is going to cause this I am going to look into injectors and get rid of the box. Its cheap power until some looses a pressure valve! Thanks. Lee.
Do the rail pressures mean anything in mpg? Thanks, Doc
ok, now we ARE talking about fuel pressure and stresses to the rail. I tried not to go there, but this has to be addressed.
Edge came out some time ago with a recommendation to limit RWHP gains on a pressure box to ~70HP on the dyno. Their findings revealed that pressures in excess of that required to achieve more than 70HP presented a risk to the common rail pressure relief valve. They subsequently turned down their EZ pressure box so that it would not produce such high pressures. Many folks did not believe them.
My testing has revealed that this pressure is about 26,500. that is, the EZ box in standard configuration (level 4) makes about 26,500 psi on the rail. So what has happend in your case is that the EZ box itself is not at fault -- you are at fault for dialing up secret level 6. Keep the Edge box at level 4 or below and you will not have this problem. What happend is that you popped the pressure relief valve once with high pressure, and from that moment on, the valve started to etch away. the threshold is indeed at or near 26,000? psi. dern right it is.
I hope your experience will convince the pressure naysayers on this and other forums not to throw caution at the wind or convince others to do so. Some of us have been laying out the cautionary groundwork for months, keenly interested in determining what safe pressures are. The evidence is growing. Edge tells you not to go over 70HP. I'm telling you that the Edge box makes 26,500 in the standard configuration level 4 (measurement accuracy +/- 200 psi).
See TDR issue #45 (the most recent), under "technical topics". One of the things that Edge discovered is that once that valve unseats, it never again returns to OEM performance without a replacement.
We don't just report that for the fun of seeing words in print.
What will happen in your case could range from full warranty replacement (I've heard of one other case where someone dishonestly received warranty coverage for valve replacement after having used the Edge box on level 6) to a limited warranty being imposed on your VIN. the pressure relief valve, as I understand it, can only be replaced with STAR line approval, which means your truck will get a lot of attention. the stock truck just does not pop this valve, and the dealer knows this. so does STAR
So my advice is to have lots of good conversation with your service manager. If you're lucky, you wont get slapped with a limited warranty.
doc: the jurry is still out on that. the claim is that higher pressures result in better atomization and a more complete burn. But that has yet to be validated scientifically with a statistically meaningful study.
Edge came out some time ago with a recommendation to limit RWHP gains on a pressure box to ~70HP on the dyno. Their findings revealed that pressures in excess of that required to achieve more than 70HP presented a risk to the common rail pressure relief valve. They subsequently turned down their EZ pressure box so that it would not produce such high pressures. Many folks did not believe them.
My testing has revealed that this pressure is about 26,500. that is, the EZ box in standard configuration (level 4) makes about 26,500 psi on the rail. So what has happend in your case is that the EZ box itself is not at fault -- you are at fault for dialing up secret level 6. Keep the Edge box at level 4 or below and you will not have this problem. What happend is that you popped the pressure relief valve once with high pressure, and from that moment on, the valve started to etch away. the threshold is indeed at or near 26,000? psi. dern right it is.
I hope your experience will convince the pressure naysayers on this and other forums not to throw caution at the wind or convince others to do so. Some of us have been laying out the cautionary groundwork for months, keenly interested in determining what safe pressures are. The evidence is growing. Edge tells you not to go over 70HP. I'm telling you that the Edge box makes 26,500 in the standard configuration level 4 (measurement accuracy +/- 200 psi).
See TDR issue #45 (the most recent), under "technical topics". One of the things that Edge discovered is that once that valve unseats, it never again returns to OEM performance without a replacement.
We don't just report that for the fun of seeing words in print.
What will happen in your case could range from full warranty replacement (I've heard of one other case where someone dishonestly received warranty coverage for valve replacement after having used the Edge box on level 6) to a limited warranty being imposed on your VIN. the pressure relief valve, as I understand it, can only be replaced with STAR line approval, which means your truck will get a lot of attention. the stock truck just does not pop this valve, and the dealer knows this. so does STAR
So my advice is to have lots of good conversation with your service manager. If you're lucky, you wont get slapped with a limited warranty.
doc: the jurry is still out on that. the claim is that higher pressures result in better atomization and a more complete burn. But that has yet to be validated scientifically with a statistically meaningful study.
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I'm afraid I haven't. My $. 02 is that this might not be such a good idea, depending on your goals, how you configure the TST, the VA setting you use, and what turbocharger you have. The VA pressure box fuels strong down low and then backs off at the high end. Similarly, the TST does the very same thing. So in that regard, the two torque curves are not complimentary -- they both have the same shape.
I have not personally experimented with pressure staking with the TST. that aside, my expectation going into such an experiment would be that a pressure box that fuels strong down low and weak at the top would not be optimum. I would think you would want the opposite -- a curve complimentary to the TST. you want more pressure up high to cool EGTs.
the only experimental basis I have for that statement comes from my work with the two VA boxes. the VA duration box is very TST like in its shape. When I stacked the duration box with it, I got large amounts of black smoke and very little benefit at the top end. thats because the VA boxs is only 25HP peak-to-peak gain (over stock peak HP)
Now I will say this: the VA pressure box on level 1 is a honey of a box for stacking. no torque rise -- almost flat. So if you want to a consistent bump across the entire RPM range from pressure, the VA C3. 1 box does it very well. Many of the other adjustable pressures boxes are also very nice on their low setting, but none has the drivability that the VA does in my opinion -- probably because of their RPM information and 3-dimmentional mapping. Its just that the bump you will get will be rather small.
Adjustability is the key to a good TST stack, in my opinion, which is why the EZ works well -- you have four positions to play with. For example, If I remember right, part of the problem stacking the TST with the RAmifier was because Ramifier is very strong down low. So the succesful Ramifier/TST stacks occured with a custom Ramifier program that backed off the low end.
I have not personally experimented with pressure staking with the TST. that aside, my expectation going into such an experiment would be that a pressure box that fuels strong down low and weak at the top would not be optimum. I would think you would want the opposite -- a curve complimentary to the TST. you want more pressure up high to cool EGTs.
the only experimental basis I have for that statement comes from my work with the two VA boxes. the VA duration box is very TST like in its shape. When I stacked the duration box with it, I got large amounts of black smoke and very little benefit at the top end. thats because the VA boxs is only 25HP peak-to-peak gain (over stock peak HP)
Now I will say this: the VA pressure box on level 1 is a honey of a box for stacking. no torque rise -- almost flat. So if you want to a consistent bump across the entire RPM range from pressure, the VA C3. 1 box does it very well. Many of the other adjustable pressures boxes are also very nice on their low setting, but none has the drivability that the VA does in my opinion -- probably because of their RPM information and 3-dimmentional mapping. Its just that the bump you will get will be rather small.
Adjustability is the key to a good TST stack, in my opinion, which is why the EZ works well -- you have four positions to play with. For example, If I remember right, part of the problem stacking the TST with the RAmifier was because Ramifier is very strong down low. So the succesful Ramifier/TST stacks occured with a custom Ramifier program that backed off the low end.
I agree with everything that you've stated. I was planning on using the lower TE settings of the TST and letting the VA help take up the bottom end a bit while helping to maintain rail pressure. If the EZ had the superior mapping and in-cab adjustability I wouldn't even be considering this. There is only one way to find out and I have my EZ listed in the classifieds. This testing is spendy but it sure is fun...
dleno- I just stopped by the dodge dealer and the vavle was replaced under warranty. However it hasn't fixed my prob. The engine really revs slow. Without the boxes there is only 10# of boost. With the tst on 7-7 it will boost to over 39 only in 4-6th gears. They tested the intercooler and hoses and found no leaks. They feel it is in the turbo. But When I had a boot come off it really didn't affect the way the motor reved out. Any Ideas? The part they replaced was a valve located on the rail itself, right by the pressure sensor. Any help is greatly appreciated! Thanks! Lee.
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Issue 128 – Digital Version
Digital Magazines
FREE!
TDR Test Drive - Digital Edition
Renew
Subscribe
Gift Subscriptions
Back Issues
Subscription Status
Address Change Form
Buyer's Guides
Ram Diagnostic Trouble Codes
The Perfect Collection
The Perfect Collection Vol. II
TSB Updates
Dodge/Cummins Historical Overview
Cameron Collection
What Makes Us Tick?
Product Showcase
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