IDM mod. Does it work?
#16
Originally Posted by cookie88
It absolutely does work.....especially if you have aftermarket injectors. Almost all of the "hotrod" PSD's you see on the boards and in magazines et.al. run 140v. IDM's. It's just that in most cases they did the mod so long ago they don't even remember to list it as a mod.
Way back when I got to ride in a truck with a switched 120/140 IDM, so I know it makes a difference...but I had never been willing to experiment on my own expensive part, nor had it been high enough on my mod list to pay the premium for somebody else to do it.
That is about to change however....last weekend I scored a 95 F-superduty IDM. As soon as my resistors come in I'll be doing a 140 conversion on it for my truck. So I'll have more better first hand for ya'.
Way back when I got to ride in a truck with a switched 120/140 IDM, so I know it makes a difference...but I had never been willing to experiment on my own expensive part, nor had it been high enough on my mod list to pay the premium for somebody else to do it.
That is about to change however....last weekend I scored a 95 F-superduty IDM. As soon as my resistors come in I'll be doing a 140 conversion on it for my truck. So I'll have more better first hand for ya'.
#17
#18
I'm installing 175's this week too- SO, running tuners will not effect the injector timing like this mod will??
So if I'm reading everything correctly, I can do this and it will safely add HP/TQ in addition to the DP tuner and new injectors?
If the above assumption is correct, is it worth it? Maybe an IDM could be found on ebay and that could be used instead of the one in your truck....
So if I'm reading everything correctly, I can do this and it will safely add HP/TQ in addition to the DP tuner and new injectors?
If the above assumption is correct, is it worth it? Maybe an IDM could be found on ebay and that could be used instead of the one in your truck....
#19
#21
I am no expert on this. I have spoken with Dave at Swamps about this as they sell modded IDMs. The general concept I walked away with was that it is basically upping the current to fully open the solenoid faster. The biggest limit of the HEUI system is the amount of time available to inject or something along those lines. Upping the current makes it upen faster and and more completely. As RPMs go up, the problem gets worse.
So in effect, it seems to me it would not change the timing of the electrical event, but might change the actual event as the solenoid would fully open against the spring pressure more quickly. That is what I think I know about it, and it could be totally out in left field.
EDIT: before posting, I see Cookie answered that. I don't think the closing is affected by the voltage as that is spring operated from what I think I know. The extra voltage makes it perform better against the poppet/poppet spring assembly.
So in effect, it seems to me it would not change the timing of the electrical event, but might change the actual event as the solenoid would fully open against the spring pressure more quickly. That is what I think I know about it, and it could be totally out in left field.
EDIT: before posting, I see Cookie answered that. I don't think the closing is affected by the voltage as that is spring operated from what I think I know. The extra voltage makes it perform better against the poppet/poppet spring assembly.
#22
#23
The pilot shot is mechanical....it is not going to be altered at all save it will be over sooner.
All this mod really does is allow the injector a tiny bit more time to empty itself. The flow path within the injector is not really relevant as it works exactly the same way for either style.
All this mod really does is allow the injector a tiny bit more time to empty itself. The flow path within the injector is not really relevant as it works exactly the same way for either style.
#24
Sorry to keep hammering on this but I'm just trying to think it completely through, I'm learning a lot here.
So the pilot shot is mechanically metered, always the same volume of fuel. It happening quicker then would result in higher pressure and possibly better atomization, right? That and a longer duration main shot.
Sounds like all positive to me then, regardless of injectors.
So the pilot shot is mechanically metered, always the same volume of fuel. It happening quicker then would result in higher pressure and possibly better atomization, right? That and a longer duration main shot.
Sounds like all positive to me then, regardless of injectors.
#25
#26
Originally Posted by clux
So the pilot shot is mechanically metered, always the same volume of fuel. Yes, this is correct for the same given ICP and FP.
It happening quicker then would result in higher pressure and possibly better atomization, right? No, your ICP and fuel pressure will remain unchanged.
That and a longer duration main shot. This is where you see the benefit from what I understand. This provides more opportunity to empty the injector. Big oil addresses this by pushing harder for the shorter or marginal event.
It happening quicker then would result in higher pressure and possibly better atomization, right? No, your ICP and fuel pressure will remain unchanged.
That and a longer duration main shot. This is where you see the benefit from what I understand. This provides more opportunity to empty the injector. Big oil addresses this by pushing harder for the shorter or marginal event.
#27
Originally Posted by Tenn01PSD350
It happening quicker then would result in higher pressure and possibly better atomization, right? No, your ICP and fuel pressure will remain unchanged.
#28
Originally Posted by clux
If you moving the same volume of fuel through the same aperature in less time, the only possible way to do that is higher pressure. So either the PI event has to have less volume or the pressure is higher.
So we are looking to move more volume out of the injector by overcoming the poppet spring quicker and holding it fully open better with higher current. The PCM timing of this remains unchanged. I can't really say much more about this as it was several months ago that I spoke with Dave about it.