Max rpm our 7.3's can effectively turn

[Charles]

This.

Ever looked at a torque curve? As Rpms go up it drops off right?

If torque was always a constant number then you'd be right. But it's not. After a certain rpm it drops off faster then the rpm rises. Therefore less horsepower

As for shifting, ever heard of "the perfect shift"?
Lets say your engine makes 400ft_lb of tq, @2000 rpm.
And to makes things easy lets say you drop 500rpm every shift.
The perfect shift would be shifting at exactly 2250rpm, then your rpm would drop to 1750rpm. Doing this through all the gears would be the fastest way to take off. Because your stayin at the peak torque of the engine for as long as possible.

Revving a motor to redline then shifting is not the fastest way to accelerate.

Switch the word torque for power and you'd have it.

 

[golfer]

Idm can do a lot more than the PCM will allow. If someone can ever unlock that door the 7.3 would surprise the sh!t out of a lot of people. Then a lot of injectors would have to be reworked.

I have seen nearly 6K logged. But that doesn't mean squat.

I'll politely disagree

 

[ChattyCathy]

^hell, there's a reason 90% of our snow-plows, agricultural departments, and local contractors have Fords hooked to something that holds their gear:biggun:

Yep because they have unlimited tax payer dollar to fix them.

 

[85_305]

Yep because they have unlimited tax payer dollar to fix them.

I mean privatized... the state/counties uses internationals, macks and peterbilts.

 

[Meniacal_Mark]

What is it? Is he the guy thats doing a CR 7.3?



Yes, that def. makes sense to me



Was it still making power @ 5200?



What do you mean unlock the door of the IDM? Is there a lot to the IDM that we dont know? I was under the impression that the Swamps IDM had a pretty decent door unlocked?

Yeah, he's the one with the CR 7.3 drag truck built at Swamp's. 2 k16's mounted on the front cover, 6.4 injectors, and I'm sure there's other special stuff.

 

[Tim @ P.I.S.]

I'll politely disagree

Dave I am always open to learn something new. But when the IDM is taken out of the equation here, we can put out a hell of alot more fuel.

I'm not saying the IDM cannot benifit from upgrades as well. We have modded our own and taken a bone stock 96 7.3 with no muffler from 155RWHP to 167 with just swapping in our IDM.

 

[Chvyrkr]

Truth!

:bigger-smile:

 

[Charles]

Dave I am always open to learn something new. But when the IDM is taken out of the equation here, we can put out a hell of alot more fuel.

I'm not saying the IDM cannot benifit from upgrades as well. We have modded our own and taken a bone stock 96 7.3 with no muffler from 155RWHP to 167 with just swapping in our IDM.

What hypothesis do you suppose accounts for the above? Higher voltage and less dwell mid event cracking the injector on faster and holding it on a bit longer?

If so, how is that more effective than adding a proportionate amount of timing and pw in the PCM signal heading to the IDM?

In other words, all the IDM could possibly do was begin injection sooner with higher voltage snapping the armature up... and hold injection on longer by not letting the armature drop out too soon.

Right?

 

[Hotrodtractor]

:bigger-smile:

That is a CR flow sheet that represents the latest in CR 2.6 tech.

 

[Tim @ P.I.S.]

What hypothesis do you suppose accounts for the above? Higher voltage and less dwell mid event cracking the injector on faster and holding it on a bit longer?

If so, how is that more effective than adding a proportionate amount of timing and pw in the PCM signal heading to the IDM?

In other words, all the IDM could possibly do was begin injection sooner with higher voltage snapping the armature up... and hold injection on longer by not letting the armature drop out too soon.

Right?

Two seperate statements. A: the IDM will handle more than the PSM is allowing.

B: the idm in stock form can be improved upon.

And yes you also have a point, that is why with the truck tuned it did 190, and with our idm it did 197. Only a 7 hp gain.

On a mustang dyno, for the record

 

[Hotrodtractor]

Two seperate statements. A: the IDM will handle more than the PSM is allowing.

B: the idm in stock form can be improved upon.

And yes you also have a point, that is why with the truck tuned it did 190, and with our idm it did 197. Only a 7 hp gain.

On a mustang dyno, for the record

If you are insinuating that the IDM can deliver more PW than the PCM can tell it to do - that might be true due to the limitations of the FDCS signal - but the longer PW is useless when you only have a certain number of crank angle degrees to inject the fuel for an effective burn to make power - and that number of crank angle degrees is fully capable of being met with the current IDM setup with the existing FDCS signal.

While I won't disagree that things can be done to the IDM for improvements - a longer available PW than the FDCS signal can maintain is NOT one of them. Increasing the voltage as everyone does - changing the operating frequency as Swamps does - altering the peak and hold (not sure if anyone is implementing this as something that can be bought) are all good things that can improve upon the strength of the solenoid and allow you do to things with the injector not possible in other ways - but ultimately there is only so many ways to skin a cat and those improvements can only get you so far.

 

[vanderchevy18]

If you are insinuating that the IDM can deliver more PW than the PCM can tell it to do - that might be true due to the limitations of the FDCS signal - but the longer PW is useless when you only have a certain number of crank angle degrees to inject the fuel for an effective burn to make power - and that number of crank angle degrees is fully capable of being met with the current IDM setup with the existing FDCS signal.

While I won't disagree that things can be done to the IDM for improvements - a longer available PW than the FDCS signal can maintain is NOT one of them. Increasing the voltage as everyone does - changing the operating frequency as Swamps does - altering the peak and hold (not sure if anyone is implementing this as something that can be bought) are all good things that can improve upon the strength of the solenoid and allow you do to things with the injector not possible in other ways - but ultimately there is only so many ways to skin a cat and those improvements can only get you so far.

Isn't oil flow an issue before you ever have to worry about that?

 

[Magnum PD]

Why is it that the 6.0 can do more RPM's than the 7.3? Both have HPOP's. I'm confused.

 

[HOOV3R]

Why is it that the 6.0 can do more RPM's than the 7.3? Both have HPOP's. I'm confused.

The 6.0s utilize a spool valve instead of a poppet valve, which allows it to actuate a lot faster.

 

[Magnum PD]

Too bad they can't update the 7.3 injector with that valve.

 

[Tim @ P.I.S.]

If you are insinuating that the IDM can deliver more PW than the PCM can tell it to do - that might be true due to the limitations of the FDCS signal - but the longer PW is useless when you only have a certain number of crank angle degrees to inject the fuel for an effective burn to make power - and that number of crank angle degrees is fully capable of being met with the current IDM setup with the existing FDCS signal.

While I won't disagree that things can be done to the IDM for improvements - a longer available PW than the FDCS signal can maintain is NOT one of them. Increasing the voltage as everyone does - changing the operating frequency as Swamps does - altering the peak and hold (not sure if anyone is implementing this as something that can be bought) are all good things that can improve upon the strength of the solenoid and allow you do to things with the injector not possible in other ways - but ultimately there is only so many ways to skin a cat and those improvements can only get you so far.

Lets start with this. What does everyone feel is a good ending point for injection? 24* ATDC?? I know one or two tuners will be nice enough to give their input, and it is always appreciated. I am throwing 24 out there because alot of the research I have done is stating that. And i know probly every tuner will have his/her thoughts on SOI @ BTDC. But an ending point can give us enough info to get to the next step.

 

[Hotrodtractor]

Lets start with this. What does everyone feel is a good ending point for injection? 24* ATDC?? I know one or two tuners will be nice enough to give their input, and it is always appreciated. I am throwing 24 out there because alot of the research I have done is stating that. And i know probly every tuner will have his/her thoughts on SOI @ BTDC. But an ending point can give us enough info to get to the next step.

Personally I like all the injection even to completed well before 24* ATDC for turning RPMs due to the burn rate of diesel fuel. But lets just go with 24* ATDC for arguments sake - the IDM would be able to sustain a start of injection at roughly 39* BTDC using that number at any given RPM. (working on the assumption that the FDCS signal can support 70% duty cycle) Now for an RPM where 24* ATDC for the finish of the injection event, 39* BTDC is more than sufficient timing for the SOI.

 

[Tim @ P.I.S.]

Well it has been something like 7 years since i have had tuning software so my notes are a bit old. But 39*BTDC?? At what rpm would we use this to refferance? Seems a bit much for say 2K rpm, but maybe not so much for 5K.

But even with those figures you are still pushing past the pcm allowable limits i have writen down.

And i do realize that at say 5K rpm when need to acount for roughly 21* of delay after SOI. As compared to alittle over 8* at 2k rpm.

Disclaimer: this is not gospel., these are figures i have gathered over the years from some solid sourcing, or figures I have gathered from personal testing.

 

[DocBar]

Personally I like all the injection even to completed well before 24* ATDC for turning RPMs due to the burn rate of diesel fuel. But lets just go with 24* ATDC for arguments sake - the IDM would be able to sustain a start of injection at roughly 39* BTDC using that number at any given RPM. (working on the assumption that the FDCS signal can support 70% duty cycle) Now for an RPM where 24* ATDC for the finish of the injection event, 39* BTDC is more than sufficient timing for the SOI.

Are you saying you do not think the FDCS signal can hadlle a 70% DC? If so, why?

 

[seeyalater5.9]

Wow wow wow...I thought I knew a little about 7.3's.

Time to get the box of popcorn out, get to popping, and read this thread 100 times over..