Injector size as it relates to Quadzilla tuning

[James T]

 I purchased a set of 75 hp injectors  the DDP-ISB75 I don't know how that relates to the tunning of the Quadzilla adrenalin. 

are they a 7.010 7.012 or something else? Any guidance would be appreciated as I am new to the tunning world.

[Mopar1973Man]

7x0.0085 is typically 75 HP injectors.

 

As for injectors you have to weigh in the pop pressure the injectors are set up too. Like myself I'm 320 bar which is +10 bar over stock. This is for atomization value but comes at a cost of needing to advance timing more. Now if your below 310 bar you need to retard some because the injectors are firing early. 

 

Size injector you need to start at 85% or so for canbus fuel and ramp up. Best to have 5 to 10 PSI of 100% stock power for cruising zone. When you ramp up to 150% start your wiretap at the same PSI of boost that way gain the power of both together.

 

Bigger turbos need deeper retard to get launched and spooled. Stock turbos and auto trans can start out advanced. Like my NV4500 needs to start at 13° so it can spool up the HX35/40 Hybrid.

 

Optimal timing should produce low EGTs. For example at 55 MPH my average is 450°F EGTs and 65 MPH is 550°F. Engine load at 65 MPH is below 20%. This gives me a high mark of 28.04 MPG. That is good efficiency. If you generating heat you not setup right. Good starting point you should see 19° of timing at 2k RPMs.

 

Tires and gearing make huge impacts. Optimal final ratio should be closer to 3.73 after tires. For example 245/75 R16 tires 30.5 inch tall and 3.55 gear produces final ratio of 3.69:1. Lower ratio number than 3.55 is a huge problem. 4.10 is getting too low geared. Bigger the tire the lower the ratio number like 37 inch tires on 3.55 is 3.00:1 which is very bad ratio, creates lots of heat.

Edited December 27, 2021 by Mopar1973Man

[Royal Squire]

It’s likely that DDP injectors are more smoky than some. 

[Mopar1973Man]

8 hours ago, Royal Squire said:

It’s likely that DDP injectors are more smoky than some. 

Typically because they were popped lower and then after the break-in period the pop pressure fell more so now the droplets are larger and going to need more timing to make up but the injector is already early because of low pop pressure. I've seen this with many injectors that are popped lower for flow rates and then typically the lifespan of the injector is shorted being it falls below 293 bar (Dodge FSM minimum pressure) rather quickly. 

 

Now if the injectors were re-popped back to at least 310 bar it would most likely clean it up again. Lower pop pressure provides the most fuel but at a large droplet size. Higher pop pressure provides less fuel but at a finer droplet size and burns cleaner. 

Edited December 27, 2021 by Mopar1973Man

[Silverwolf2691]

My DAP 50s are 7x.0085 as far as I'm aware.. so his might be 7x.009..  [double checked, mine should be 7x.008 not 7x.0085.]

 

After talking with @dieselautopower for a while about injectors, its become clear why there is so much ambiguity with the horsepower rating system of injectors. There are too many variables: hole size, number of holes, spray angle, pop pressure, engine setup, turbo setup, internal injector mods.. there is just too much to just quantify injectors at a horsepower number. But since that is the "industry standard" here we are.

 

@James T, there are tuning guides in the quadzilla section under vendors to help you get started, fueling wise.

 

How long ago did you get the injectors? I heard a rumor that DDP is trying to clean themselves up from their past image (pun intended). They were known for being a dirty and hot injector because of the spray angle (I think they used a marine injector) and quality of machining if I remember correctly. I'm curious how your setup runs. @Mopar1973Man posted as I was writing this, pop pressures are not helping the issue, but they can't fix bad spray angles.  

 

I'm not familiar with the timing of an auto trans, but I have a theory I'm working on. Use your idle timing number (whole number) as your 1500 band, then go up from there +4 or +4.5. It seems to line up with what I have observed over the couple years I've been on here. My truck idles at 11.2x, so my 1500 band is 11 and I go up either 4 or 4.5. I cant remember from the last time I played with my tune. @Mopar1973Man I think idles at 13.XX and that's where he starts his timing curve (13).. Correlation maybe, but its something I've been meaning to post up about.     

 

Unless you are racing, you should copy the same timing curve into all of your tunes as well. 

 

 

Edited December 27, 2021 by Silverwolf2691

[dieselautopower]

Flow is a better measurement than  hole size/ HP rating etc.

 

We have a set of 8x.012 that flow more than 6x.020 that Drew Carter is running on his drag truck.  So far he is at 6.70 on fuel only  for 1/8 mile on a VP44 powered extended cab truck.

 

 

He had a competitors 6x.016 previously.  He spools significantly faster and makes more power with the 8x.012 we built him.

 

[Mopar1973Man]

All relates to the what you trying to do. Idle and engine load has nothing to do with it. It more about like my 5 speed there is ZERO slip once the clutch is released. The only way to make it spool quickly is to retard the timing deeply and blow more fire and expanding gases out the manifold into the turbo to spool quickly. 

 

Now most automatics and the torque converter will allow quite a bit of slippage to get RPM's up quicker so these don't require as much retard time or amount of retard to get spooled up being the slippage is part of that factor. The only other would be a lower stall on the torque converter would require some more retard to spool. This is something people tend to forget is launching and then put 15 to 16 degrees in the 1,500 RPM slider and wonder why it bucks and shutters a bunch daily driving. 1,500 should be somewhere between 13 to 15 degrees of timing typically.  Even when you go WOT there is the "Low PSI Timing Reduct" and the "Timing Reduct Scaling" this adds more retard for heavy throttle change. Then the "Max Load Timing Offset" which can retard up to 3 degree on light throttle change that pushes past the "Light Throttle Load Limit" each one has its place and time. 

 

Again when the timing is set right the EGT's and engine load should drop very low. Too much advancement will land you in "Negative Torque" where the piston is still traveling up to TDC and the fuel is ignited too early and now acting like a brake slowing the engine till it breaks over the TDC and then power comes out on the downwards stroke.  Usually the excessive advance will show up in the oil temp being the cylinder walls have more flame front and the coolant jacket is heated more so the oil cooler doesn't cool as good. My oil temp is measure at the filter housing and typically 160*F compared to 195*F coolant.Too much retard you notice the engine is VERY quiet sounding there is no rattle at all. There should be a very light rattle during a cruise state but should be a bit quieter under load. 

[Silverwolf2691]

I'm not arguing use.. There's one factor that I think gets over looked often. There are 2 factory vp44s. The SO and the HO. Both have their differences in fueling and timing. This I think is why my truck has 11 degrees as an idle state. I think the HO pump has a retarded timing curve, not advanced. Everyone says that when people switched from an HO pump to an SO pump felt a loss in low end power but gained more high end power. How else would that happen besides timing? The top end power loss could be explained with the 0.5mm smaller plungers on the HO, but that feels like only half the reason. 

 

My truck bucked taking off with 4.10s and undersized tires (for 4.10s, 285/70r17) at 13 degrees of timing. Most people would put that at enough mechanical advantage to be "effortless" on the motor. Dropped the 2 degrees and no more bucking. 

 

There are other differences between the HO and the SO truck itself as well; different factory injectors, higher compression pistons, different ECU programming.. The injectors, once swapped out, become a moot point. The ECU programming I'm not sure of. I don't know if the quad takes factory and adds/subtracts to it or if it "blocks" the signal from the ECU and puts its own in its place. The higher compression I believe should be accounted for because its nearly a full point higher, 0.7 to be exact. That would cause higher cylinder air temps and earlier ignition of the fuel. In the gas world that's the difference between regular and premium with recurved ignition timing. But I know gas and diesel don't translate well to each other in regards to mods.. take it for what its worth..

 

I'm not trying to debunk everything you have found out, I'm just trying to say that you might have only worked one angle of it, and there might be other ways of approaching this.

 

As I said in the previous post, its a theory I'm working on. Whether or not there is merit to it remains to be seen.   

[Mopar1973Man]

4 minutes ago, Silverwolf2691 said:

The ECU programming I'm not sure of. I don't know if the quad takes factory and adds/subtracts to it or if it "blocks" the signal from the ECU and puts its own in its place.

 

So to explain that...

 

If the RPM < 1200 then the ECM is in control completely. 

 

If the RPM > 1200 then the Quadzilla is control. Now when the fueling is dealt with the numbers your setting is ECM stock value times a percentage. This gives the ability to go below stock rate and set it based on a percentage. Now when the message of fueling is to be changed it will send the priority bit and then ignore all the ECM message then inject the new message with the changed fuel message. Same with timing as well. 

 

8 minutes ago, Silverwolf2691 said:

In the gas world that's the difference between regular and premium with recurved ignition timing.

Octane is the ability to resist compression ignition. Too low of octane and pre-ignition knock could occur. 

 

Cetane is the ability to promote compression ignition. High cetane will ignite easier in the colder mornings, comes with a cost of lower BTU's.

 

As stated from ASTM Labs...

 

There is no benefit to using a higher cetane number fuel than is specified by the engine's manufacturer. The ASTM Standard Specification for Diesel Fuel Oils (D-975) states, "The cetane number requirements depend on engine design, size, nature of speed and load variations, and on starting and atmospheric conditions. Increase in cetane number over values actually required does not materially improve engine performance. Accordingly, the cetane number specified should be as low as possible to insure maximum fuel availability." This quote underscores the importance of matching engine cetane requirements with fuel cetane number!!!

[Silverwolf2691]

15 minutes ago, Mopar1973Man said:

28 minutes ago, Silverwolf2691 said:

In the gas world that's the difference between regular and premium with recurved ignition timing.

Octane is the ability to resist compression ignition. Too low of octane and pre-ignition knock could occur. 

 

Cetane is the ability to promote compression ignition. High cetane will ignite easier in the colder mornings, comes with a cost of lower BTU's.

 

As stated from ASTM Labs...

 

There is no benefit to using a higher cetane number fuel than is specified by the engine's manufacturer. The ASTM Standard Specification for Diesel Fuel Oils (D-975) states, "The cetane number requirements depend on engine design, size, nature of speed and load variations, and on starting and atmospheric conditions. Increase in cetane number over values actually required does not materially improve engine performance. Accordingly, the cetane number specified should be as low as possible to insure maximum fuel availability." This quote underscores the importance of matching engine cetane requirements with fuel cetane number!!!

 

Fair enough, but we have next to no control over what cetane is coming out of the pump. All we know is, at least in my neck of the woods, is it's a minimum of 40 (at least that's what the button says).

 

So removing cetane as a variable and putting a fixed number on it (say 40), would a diesel engine with 16.3:1 (SO Cummins) compression ratio light off later than a diesel engine with 17:1 (HO Cummins) compression with the same cetane?

 

After typing that out, I think I got things mixed up.. later ignition would need more retard while earlier ignition would need more advancement, right?

[Mopar1973Man]

13 minutes ago, Silverwolf2691 said:

So removing cetane as a variable and putting a fixed number on it (say 40), would a diesel engine with 16.3:1 (SO Cummins) compression ratio light off later than a diesel engine with 17:1 (HO Cummins) compression with the same cetane?

 

After watch another video about compression ratio it more or less translates to better torque number being the crank throw is longer which gives compression ratio a boost but the biggest thing was since the crank arm is longer it will provide more torque on the downward stroke. 2nd Gen 24V SO engine with the lowest compression ratio at 16.3:1 vs any other generation which could be as high as 17.5 or so. Also keep in mind that big power most builders reduce the compression ratio to allow for my boost pressure. For us daily drivers there is going to be little difference between 16.3 to 17.0 ratios being just compression test will net roughly 400 to 450 PSI cranking the engine over. Then when you calculate 30 PSI of boost the cylinder pressures could be as high as 1,100 PSI. No matter how you look at it you blowing 30 PSI of boost in a cylinder squeeze it again to 16.3 or 17.0 ratio its still going to light off at the time injection is programmed on the Quadzilla. Pressure makes lots of heat. 

Edited December 27, 2021 by Mopar1973Man

[Silverwolf2691]

Makes me wonder if/to what extent boost impacts timing then.

 

Might be more so "available" timing. Don't know yet, gotta mull this one over. TBH, completely forgot about the boost aspect.

 

The 5th gen CGI block Cummins are actually both the highest and lowest compression ratios. 16.2 is the HO and 19 is the SO. 03-18 Cummins are 17.3.

 

Just for reference

[Great work!]

I would like to see the vp44 cam donut from an HO and SO side by side to see if one has a different ramp profile. 

[Silverwolf2691]

Everyone has said something along those lines but no one has shown that..

[Haggar]

"Puff the magic Dragon lived by the sea..."

 

Very nice tailgate art.  Would love to hear the story.  You don't look old enough, but I could be wrong.  Have been many times....

 

Merry Christmas and Happy New year  from a 12 Bush.

 

Cheers!
Hag

[James T]

 I may have asked a question that I didn't fully understand and of that I am Shure of. so let me add to my confusion with this .........

my set up is mostly stock 1999 5.9 Cummins fass lift pump new injector pump I believe it to be the SO version new injectors the ddp 75 hp set new tubes and lines 

I replaced the cracked exhaust manifold and added the Banks intake. I put the Quadzilla adrenalin on to monitor fuel pressures.

it is an automatic trans that needs to be swapped out along with the Torque converter that's going to be another thread.

 as it sets now with the daily driver tune I am not seeing any smoke or issues unbecoming of the beast that lies with in 

 the tune is the starting place and i still have to learn a lot about the way the tune translates to the seat of the pants 

I did see a thread that talks about the fuel pump ecm bypass mod i will be looking into that next thing 

thanks to each of you for taking the time to shed a little light in my direction 

I am ok for now with the current daily tune and am looking forward to using the tow tune with the 1974 Avion, all 7500 lbs of it,

should not be an issue after the trans and tc get swaped out.

[Mopar1973Man]

Basically what you need is a power relay for the FASS fuel pump. 85 and 86 pins go to the ECM plug then 30 to battery power and 87a to the fuel pump. Put only a 15A fuse on the lead between battery and the relay on pin 30.

 

[IBMobile]

Check this article for wiring the fuel pump.

https://mopar1973man.com/cummins/articles.html/24-valve-2nd-generation_50/51_engine/59_fuel/installing-protective-lift-pump-relay-r501/?tab=reviews