Engine/Transmission (1998.5 - 2002) Basic Fueling/timing box questions

[Hemiless]

First off let me start by saying I know nothing about these "bombs" besides what I gleaned from "SEARCHING" the TDR web site.



My search has led me to some questions.



(1) The PE Comp and the TST PM3 operate basically on the same principle, as I understand it. I know gauges can be added to the TST PM3 but they both seem to have provisions for controlling fueling and smoke (through timing??). Please correct me if I'm wrong.



(2) I've read in numerous post that piggybacking the PE Comp before the TST PM3 will greatly improve the low end power and torque. How can Piggy backing the two controllers increase the output?



(3) And if piggybacking does help then why doesn’t a manufacture just make one box that does it all.



I'm not ready to buy any one component yet I'm just trying to figure out how they work and how they work together!



I would eventually like to get ~400RWHP out of my truck but I'm adding gauges and an e-brake before I start down that slippery slope.



Any help and information on this matter would be great.

 

[TomGolden]

Originally posted by Hemiless

First off let me start by saying I know nothing about these "bombs" besides what I gleaned from "SEARCHING" the TDR web site.



My search has led me to some questions.



(1) The PE Comp and the TST PM3 operate basically on the same principle, as I understand it. I know gauges can be added to the TST PM3 but they both seem to have provisions for controlling fueling and smoke (through timing??). Please correct me if I'm wrong.

Nathan, I can shed some light on question #1, but not on the others, as I have never piggybacked any boxes, so I have no personal experience from which to speak or even speculate on this topic.



The Edge Comp, and also the TST box I believe, alter both timing and fueling levels. Basically, the fueling levels are increased, meaning the amount of fuel that gets injected into each cylinder. The timing of course affects the smoke the most, as you can select when the fueling increase begins - meaning instantly before boost comes up (more smoke), or later on, after boost has come up, which means least smoke since the added air from the boost being high will burn the extra fuel being added.



Hope that makes sense...



Tom

 

[Hohn]

Tom--if I could, let me "piggyback" on your post.



The PMAX and the COMP do the same thing as far as increasing fueling, but the arrive at that function differently. The Edge boxes read info off the Can-Bus and effect timing by "fooling" the ECM. The PMAX does timing by looking at the last injection event and going from there. It doesn't trick the ECM; it overrules it. This is the timing difference between the two.



The Fueling each box does is also different. The TST responds to boost (MAP sensor) input and fuels based on an algorithmic response to that input. I think it also considers pedal position, but I don't know what weight it gives that input.





The Edge comp doesn't pay much attention to boost. Instead, it looks more at APPS (pedal position) input, RPM, and other info on the Can Bus and the calculates the fueling it will demand of the VP.



As a result, the TST boxes dyno higher on load dynos (higher boost), and the Edge boxes seem to dyno higher on inertial dynos (don't have to wait for boost to bring fuel).



Finally, you can't piggy back two fueling boxes, just one fuleing box and "timing" box. Once upon a time, the TST boxes had little to no timing element to them, so guys were adding timing boxes like the Van Aaken or the Edge EZ to them in an effort to get more power. I am not aware of anyone that has ever tried to piggyback the Edge Comp.



Most recent attempts to piggyback have proven to be disappointing. There's usually too much timing, and you have less power, higher temps, less boost, and more smoke!



I would just get a Comp or an PMAX and be done with it. No need to be more complicated than that.



Justin