learned something about the Predator 3

[DLeno]

Been playing with the Predator stage 3 and learned that their approach is to raise the nominal (steady state) rail pressure significantly from the stock level at the same power levels. At 65 mph and 10 lbs boost, the stock truck runs all day at about 12,000 psi rail pressure. With the predator box, the truck runs at 21,000 lbs rail pressure all day (same speed and boost)



what this means to me is that the box has forced the ECM into lowing the injector duration, yielding a shorter, higher burst of fuel for the same power output. not sure yet if that is good or bad -- I'm just reporting results



Of course, in addition to the rise in nominal rail pressure, the box generates 27,000 lbs psi rail pressure for peak horsepower output, AND rail pressure floats up there even for high RPM runs at less than full output. dern box just loves high pressure!

 

[GWoody]

Doug, I'm curious as to how you are seeing rail pressure??

 

[DLeno]

I have a prototype gauge that reads directly in psi and connects to the fuel pressure port

 

[realsquash]

I have a prototype gauge that reads directly in psi and connects to the fuel pressure port

You should now plug it into the connector coming out of the predator and see what it reads



Andy

 

[GWoody]

I have a prototype gauge that reads directly in psi and connects to the fuel pressure port

You got that gauge in the cab with you???????????

 

[Gypsyman]

Doug,



Have you tested the EZ for the 03's yet?



-Richard

 

[DLeno]

Andy: that would be fun -- to see how big of a lie the predator tells! one story that was posted a while back told of a dealer tech riding with his scanner plugged into the OBD port with a Bullydog box on. If memory serves, the ECM read 11,000 psi at WOT, and we really know that the Bullydog is in the 26,000 region.



Gwoody. yup, got the gauge in the cab. way cool. I get to look at rail pressure as I drive just like boost and EGT. how fun is that! I'm hoping to have one worthy of a pic later this month



richard: I have the EZ on the truck now. its much milder than the predator in the most-driven region, making more like 15,000 psi when the predator makes 20,000. Haven't graphed it out yet, though, so those numbers are approximate. peak rail pressure is 26,000.



I'll try and attach a graph of actual rail pressure as a function of boost for both the predator and the stock truck. I collected data up to about 23 psi boost to capture the most driven region.

 

[DLeno]

rail pressure as a function of boost

This is predator vesus stock

 

[bpenrod]

Doug,

Do you think the injection duration has been shortened or is there just more fuel cycling back to the tank??

 

[DLeno]

I think injector duration has been shortened. this is probably where Dr. P gets his modified "plume" claim which of course is possible with any pressure box and not unique to Predator. That said, Predator may be one of the most aggressive pressure boxes out there (meaning it may run a higher nominal pressure at cruising speeds). I'll know the answer to that question in a few weeks.

 

[Loaded 45]

ez - 65 hp - 70 hp - predator stage 3 - 100 hp - why even try to compare ?

I have ran predators & one ez - I will take the predator in any flavour over the ez.

The ez I had at level six to make what I think is decent power - otherwise At the lesser settings the ez sucked a** - at level six about 80 hp - rail pressure for the ez?

I will take rail pressure + tst to take truck past stock slug status anyday.



These trucks need at least an extra 100 hp - Quadzilla, Ramifier,volumizer - cheap power !!



Otherwise its just Grandma,s grocery getter .

 

[DLeno]

well I'm not sure what your point is, but I can tell you the reason why it is important to compare boxes -- its to put a reality check onto the mfgs claims, to understand the relationship between rail pressure and peak horsepower, to discover the way each box makes power in the low end, how high the rail pressure actually goes, and how conservatively or creatively the power claims are stated.

 

[Loaded 45]

compare 100 hp - to 100 hp module , Tst to banks 6 gun or new( juice) in 2 weeks

65 - 65 hp modules - put them on a dyno - the same dyno for the real numbers.



Its no secret that the higher hp fuel module the higher rail pressure. I still say big deal - rail pressure - but thats ( MY OPINION ) you want real power to the ground its tst all the way dollar to dollar. New Quadzilla also (sounds) good.



No matter what you put on that increases power dramatically - Something is getting stressed - no matter what!!! - Why just pick on rail pressure ? Thats the least of my worries.

 

[mattymac]

compare 100 hp - to 100 hp module , Tst to banks 6 gun or new( juice) in 2 weeks

65 - 65 hp modules - put them on a dyno - the same dyno for the real numbers.



Its no secret that the higher hp fuel module the higher rail pressure. I still say big deal - rail pressure - but thats ( MY OPINION ) you want real power to the ground its tst all the way dollar to dollar. New Quadzilla also (sounds) good.



No matter what you put on that increases power dramatically - Something is getting stressed - no matter what!!! - Why just pick on rail pressure ? Thats the least of my worries.

I agree 100%!



But also look at how the preditor line is "peaky". Doesnt look to be very smooth IMHO. Can we compare this to some other pressure boxes?

 

[Loaded 45]

What im trying to say is the cummins needs a boost - at least compare modules in thier own catagory. If were going to do a test to compare each module and validate manufactures claims - lets use a dyno. Show rail pressures if we must but dyno graph #s should not be left out.

 

[DLeno]

I can't figure out where in this thread anyone singled out rail pressure in any description of stresses caused by power upgrades. I don't even see the concepts of stress and rail pressure used together. the thread isn't evan about stresses. the purpose of the thread is revealed in its title.



Also, I don't see where anyone was holding up any particular box, or that there was any argument about how much power the TST box will make, nor was it ever a goal of this thread to show which boxes make you grunt the loudest.



if you see a mfg claim a power increase while staying within stock peak rail pressure, then its natural to ask what the relationship is between the two. so, no it is not 100% accepted that higher rail pressure = higher power, and the predator graph shows that very point -- it produces 20,000 psi of rail pressure to make the same amount of power that would normally require 15,000 psi of rail pressure. No one is requiring you to appreciate that or to be interested. But it is the subject of the thread.



here's a teaser to illustrate why its interesting to include the EZ in the pressure box investigations: it makes similar peak rail pressure as some of the others including bullydog and Quadzilla.



be careful how you interpret the graph I posted to infer peakiness. The Y axis is not HP, it is rail pressure. and rail pressure is not the same as fueling, as pointed out above and contrary to popular opinion. Some of these boxes have very peaky looking fuel pressure curves but that doesn't mean at all that the drivability is peaky. in fact the predator is smoother than the banks, and feels very EZ like down low in terms of drivability.

 

[DLeno]

What im trying to say is the cummins needs a boost - at least compare modules in thier own catagory. If were going to do a test to compare each module and validate manufactures claims - lets use a dyno. Show rail pressures if we must but dyno graph #s should not be left out.

not to worry. dyno runs on the same day on the same truck with all the boxes will come. targeted for TDR issue # 47. I can hold off reporting what I know when I learn it, though, and just wait for the article to print.

 

[Loaded 45]

Looking forward to your dyno test. And yes the TST does make me grunt the loudest & this over & over & over & over deal with the rail pressure makes me GROAN the loudest. Again this is my opinion . Buy an incab adjustable mean ass module and be done with it. End of story.



Now if you got on the best aftermarket turbo or twin turbo setup. And did your blood hound research. That would be very interesting.



Sorry to ruin your Predator stage 3 thread - nice to see someone try one. ( for the dyno run ) Have a good day !

 

[DLeno]

heh heh. well, I gotta admit that even this old hopeless analytic did a real double take to find out that conservative rail pressure Edge is OVER 26,000 psi peak rail pressure. more like 26,500. what a hoot. now we have boxes claiming 100HP and boxes claiming 65HP, all making the same rail pressure. now I gotta figure that one out... of course, a lot depends on boost, but hey, I'm testing the conditions presented by the mfgs -- an otherwise stock truck.



happy grunting indeed. I'm trying to work on the turbocharger thing. Every one of the available boxes, save perhaps the weany little VA 30 HP pressure box, requires more air than the weany little hy35-9 can provide. At a lowly 25 lbs of boost with the predator on, I measure 400 degrees differential pressure on mine! Boy that inspires me to hook up the ol' TST and beat up on the stock turbocharger! Anyway, so you know by now that I take a little more conservative approach than just to find the meanest and baddest, and that it really isnt' the end of the story -- gotta have more air!

 

[realsquash]

Was the EZ on level 4? I assume that was pedal-to-the-metal to get 26,500psi?



Andy