Hi all,


I just got a new 04.5, and I haven't done anything to it except put a bullydog straight-through muffler on it. It's almost stock-quiet.

Anyway, I'm interested in putting a "box" of some sort on my truck, but a conversation I had with a dealer diesel tech has me rattled. Basically, he advised me to leave the motor the hell alone. Not surprising since he's a dealer tech. He also said that almost all cummins engines they have with problems have been tampered with. Furthermore, he said evidence of the presence of a box "voids the whole warranty". I'd assume that's for the engine only. He mentioned wires with cut insulation as an example of what they look for right away. I know some boxes require splicing into wires for installation, while some do their thing through the OBDII port. I'm really concerned with keeping anything I do undetectable, and so far, I haven't heard that any of these boxes are FOR SURE undetectable. Lots of innuendo, but no facts quite yet.

I'm dying for more power, but I'm really leery about doing something that has a good chance of maybe voiding the engine warranty.

Can someone explain a few things for me, like what does defueling do? I keep seeing that mentioned as a feature of some aftermarket boxes. Another question I have is, what different ways do the boxes make power? Raising fuel pressure is one of them, and altering injection timing is another. Are there others?


One thing the tech mentioned is that raising the fuel pressure on these common-rail engines often damages the pump in a way that's usually indicative of some sort of modification. If I recall right, it's some sort of ceramic seal that blows out. (I may be off here, this is just my memory) Any comments on that?

 

First of all he is a dealer tech not one of us (Diesel bombers) You should tell him how come there are so many 4-500 HP daily driven cummins around and some in the 700 hp range?

If your in persuit for more power you need to get gauges (pyro, fuel pressure, boost, tranny temp) then you need to figure out how much power you want overall, there are some good simple plug and play boxes for your truck and some serious power makers as well that will need some additional supporting parts to play safely.

Defueling is when either the trucks computer or an aftermarket chip can sense when torque management needs to be used (mainly when leaving on boost, this is with the factory computer) or high EGT's (aftermarket chips) it just basically limits the amount of fuel being injected for safegaurds.

As for fuel pressure, there are MANY people running pressure boxes with no ill effects.

Do your homework and know what kind of power you want to end up with.

 

Lets see if I can handle a few of these for ya:

1) Thats BS. Most of the Cummins engines I've seen damaged have been due to flawed parts from the Cummins factory. Dodge and dealer techs make Cummins out to be some sort of gods, however we've seen brand spanking new heads from Cummins with deep valve seat cracks and bad warping.

2) I get the feeling he's trying to tell you it will void your complete warranty. If you add a power enhancement, they CAN void your powertrain warranty. And chances are good it would stand up in a court of law, despite Magnusson/Moss. They CANNOT void the rest of your warranty though.

3) Automatic Defueling is generally based on exhaust gas temperatures. You set your box to allow a certain max EGT, and once you get there, the box drops fueling to keep EGTs below your preset maximum.

4) Snoop around on this site, and you'll find a powerbox summary for the common rail trucks. I don't have the link handy at the moment. To be brief, the current lineup of boxes available make power in the following ways:

i) Fuel rail pressure - bump up pressure on the rail. More fuel is injected when the injector opens
ii) Rail pressure/Timing - same as above, only with timing added.
iii) Injector pulse duration - Keep rail pressure the same, but hold the injector open longer. Stay away from these. IMHO, you NEED the timing to go along with the duration box.
iv) Duration/Timing - Open the injector earlier, and hold it open longer.

5) The seal he speaks of was on the early 03 trucks, and has been superceded with a proper washer that won't blow out. A fuel pressure box would exasperate the situation, however stocker trucks were also losing this seal.

Rod

 

Here is a link to the fueling box summary Rod mentioned. It's a must read.

http://www.nwbombers.com/membersites...ox_summary.htm

 

Well, it looks like the TST Powermax may be the box for me, especially since it does not raise rail pressure or require splicing into any wires. The fact that it has its own boost pressure and EGT gauges is a big plus also.

Anybody else want to chime in with their experiences using this box, especially on the 600 engine?

 

The TST is a great box, I really like mine. It can make enough power that your stock drivetrain will not hold up especially tranny/clutch. I would reccomend it, but some self control will be required to keep your tranny intact. It is a great chip to grow into. Another chip that I have some experience with is the VA 3.2. It is adjustable and seems to be safe if you keep and eye on temps. Hope this helps