Things we learned on Dyno & 03 555 HO

[Ted Jannetty]

While testing an 03 Dodge Cummins 555 HO all stock except for a Banks 4" exhaust we learned that the Defueling was active during our dyno testing and reduced power below average numbers.



How we learned this, Our intention was to grab a base line run then test the Van Aaken C3 Pressure box installed but in off position, then in level 1 then in level 2.



To our surprise the Truck produced a much flatter torque curve with the Van Aaken plugged in but turned off indicating that just the addition of a 4" free flowing exhaust is enough to cause higher boost causing defueling.



The Van Aaken does Boost fooling even in the off position so the computer could not see the higher boost produced by the exhaust system.



So without boost fooling you are actually loosing power with a High flow exhaust due to defueling.



The Dyno plot below shows the difference in torque and Hp before and after the Van Aaken C3 install with switch in OFF positon.

 

[Ted Jannetty]

Also here is the Dyno plot for Stock with VA plugged in with switch in off positon then in level 1 then in level 2

 

[nickleinonen]

So without boost fooling you are actually loosing power with a High flow exhaust due to defueling.

hmm... i guess i better get tinkering on my home brew boost fooler, but the weather is too lousy right now [and i need to find a place to get them map sensor plugs]

 

[KKlepfer]

Hey Ted, great post.



So does the Edge EZ boost fool too. When you talk about boost fooling are you talking about the box fooling the computer telling it the boost is lower than it actually is?



Just to clarify what you mean by defueling. When the boost reaches a certain level the computer reduces the fueling in order to prevent damage? Or because there is higher boost and more air the fueling remains the same thus the ratio of air and fuel is different (more air and less fuel)?

 

[JEly]

What about fuel pressure-------------is it low enough where you need a pusher pump? I am wondering when a person might consider a upgrade



JIM

 

[R.M.THOMPSON]

Thanks Ted , good to know .

 

[DLeno]

HEre's how I interpret Ted's findings:



1. the ECM de-fuels at high boost levels. this we know.



2. A stock truck with airflow improvements is more likely to acheive higher boost levels at lower levels of fueling, due to faster spoolup of the turbo.



3. The ECM is more likely to de-fuel on a stock truck with airflow improvements, because it sees higher boost levels due to (2) above. apparently the ECM code has been written with stock air in mind (no kidding).



4. boost fooling is an electronic method of preventing the ECM from seeing high boost levels, even though the high boost levels actually exist. Every box I know of does electronic boost fooling. This is unrelated to defeating the turbocharger's mechanical wastegate, which is a way to get the turbo to acheive higher boost levels than its stock intent. It is the box intercepting the boost signal from the MAP sensor and then feeding the ECM a bogus version of it.



5. moral of the story: don't add air without a boost-fooling box



good data, Ted.





oh, nick: a zener diode and a series resistor is all you need ...

 

[ASchwartz]

My stock Dyno

Take a look in my album. I have some dyno runs from afe's mustang. I did not see any defueling after the addition of the proguard 7.

 

[KKlepfer]

Thanks DLeno,



I got a little worried considering I just installed a 4" exhaust turbo back. Thanks for answering my questions. It's interesting that Banks and other manufacturers don't inform the customer about defueling effects



So I take it that Edge EZ does boost fool and I guess that was my real concern

 

[Shooter]

Re: My stock Dyno

TED: Was the defuling an anomoly or repeatable.

Is the no box defuling repeatable &/ or present on a different 03 HO ???

Thanks

Jack

Originally posted by ASchwartz

Take a look in my album. I have some dyno runs from afe's mustang. I did not see any defueling after the addition of the proguard 7.

I see you have no exhaust enhancements.

Increasing intake capability does not guarranty more air will get into the engine, it is also dependant on haveing the ability to use the increase and capability to remove it.

 

[cpizz]

Finally someone proved that the larger exhaust DOES create a loss in power! I had a 5" exhaust on my '03 with no fueling box. There was definitely a loss in power in the low and mid range.

 

[FDavid]

Ya, everyone kept saying that a bigger exhaust gave you so much more power on top end that it made the bottom end feel weeker and that it was all in our heads. Well i staright piped my truck (the factory 3. 5 exhaust is more than adequate, just the muffler is the big restriction) and I noticed a definite drop in power pulling from low rpms. And now finally we have the answer why

 

[BCarmicle]

When I put my DD turbo and airbox and a 4" exhaust w/ Walker muffler I dynoed at about 15hp less compared to the completely stock dyno. Then I added the Edge EZ and picked up about 80hp, peak to peak.



Brandon

 

[ASchwartz]

Originally posted by Shooter

TED: Was the defuling an anomoly or repeatable.

Is the no box defuling repeatable &/ or present on a different 03 HO ???

Thanks

Jack













I see you have no exhaust enhancements.

Increasing intake capability does not guarranty more air will get into the engine, it is also dependant on haveing the ability to use the increase and capability to remove it.

Shooter;



You are right about me not having any exhaust enhancements. I heard so much about how restrictive the stock box was and decided that afe's stage one would help out. When actual results did not show up on the dyno I was a little skeptic about there claim of a 20hp increase.



I would agree that without any other mods there is no need for the engine to gulp more air. My next mod I was planning was a 5" exhaust. This may change due to Ted's research.



Since those dyno results I have installed the torque tube and removed the silencer ring. I have an appointment to redyno this tursday. (AFE said that the trucks computer needed to recalibrate and once it did an increase would be visible. ) SO I WILL SOON SEE.



Avi

 

[Vaughn MacKenzie]

Originally posted by BCarmicle

When I put my DD turbo and airbox and a 4" exhaust w/ Walker muffler I dynoed at about 15hp less compared to the completely stock dyno.

Brandon

Was that at stock fueling Carmicle?



Vaughn

 

[BCarmicle]

Yep, stock fueling. I figured that bigger turbo would want more fuel, but didn't know if hp would actually decrease without that fuel. Looks like it did. Its kind of logical that you are goin to need more fuel when adding alot more air.



Brandon

 

[cpizz]

Some people are saying that you don't need any back pressure with the exhaust system. I think that might be true on the 1st and 2nd generation trucks. Not the case with 3rd gen trucks. For what ever reason, this new engine performs better with some back pressure. It must be something new that it monitoring. What does the sensor by the air filter monitor? I know some people think it is a mass airflow sensor, but it doesn't look like one.

 

[lmills]

Originally posted by KKlepfer

Thanks DLeno,





So I take it that Edge EZ does boost fool and I guess that was my real concern

Yeh the EZ has a boost fooler built in

 

[Ted Jannetty]

This post wasn't meant to defame 4" exhaust in any way it was to inform that the computers on 03-04 Dodge are more sensitive to changes and will pick up on them more easily.



If you study the Dyno graph you will see that Defueling kicks in around 2100 rpm, this is where the computer is detecting overboost and cutting fuel to control it.



This also proves the advantages of 4" exhaust, it wouldn't make more boost unless it was more efficient.



This can also be corrected by backing off on the wastegate adjustment by lengthening the rod by a turn or 2.



It wouldn't surprise me in the least that even stock trucks are experiencing some defueling on hard pulls up a mountain with a big trailer, this happens because as the turbo temps climb and stabalize at full temp it pumps more air.



Heat energy is what drives the turbo, and on short quick pulls alot is lost to the air through exhaust manifolds and turbine housings.



It is true that a little throttle response is lost when going to a high flow exhaust but not for the reasons that most think.



The reason has to do with the above statement, turbos are driven by heat energy.



With high flow exhaust the turbo tends to run cooler all the time so it takes a litte longer to get up to temp during the accleration process.



I think I am opening up a bag of worms here

 

[bpenrod]

cpizz,

The sensor by the airfilter is a temp sensor if I have been informed correctly.



Ted,

Thanx for all the valuable input!