Carbur8tr

Will do. So no more starting at 17*?

So I've been paying a little more attention to timing lately and noticed something a little odd and wanted your thoughts. Right now cruise timing is set to .1 and was settling around 17 while cruising when I first started testing this, but here lately it's been dropping around 14-15 for almost no reason. Any thoughts?

Overall yes it seems to settle but feels almost like it's hunting. Data doesn't quite point towards hunting but it feels like the power is going in and out which is not a bad thing and seems to hold fairly well. Check you inbox for the data. Little note here as well is the second run where the back down stayed the same but the boost tried to hold around 18ish.

Mmmm not always but I know what you're referring to and it's more pronounced than that. Mike, I wish I could say it was only when things were warmed up but it has happened when the truck is cold as well. @Me78569 I have 4 pulls with data that I sent you via message. It works but I think I might have discovered something that will end up being a pain in the *** to deal with. No idea how quickly the quad is able to react but I can blow through the low boost limit like no ones business. It's all in the data but I believe one time I was able to touch close to 31psi or so with only 80% throttle. Most of the pulls are towards the end of each data export. Another thing I noticed is that it would often times seem as though it would react late and still apply back down even though I had already gotten out of the boost. Not sure if this is just due to the time delay in the data or what but odd if you looks at when the backdown is applied vs when the boost is coming up. I had a thought though, is there any way that we could lower the boost max for cold mornings. Right now I think the lowest it will go is 23 which is what I had it at today. I think it would be nice to limit the truck to say 10psi on cold mornings to help with timing and head gaskets. Most common time I heard of people blowing head gaskets was on cold mornings prior to the truck being up to temp. Just thoughts.

1. Yes, the best way I can describe it would be a lope. Not a hard lope but more of a vibration that is audible like the engine has a bit of a hitch. 2. Not sure and really not sure why it would be idling so low. I believe that it is still within the window of normality but regardless I've never had a problem like this before. 3. I have the same question, not terribly convinced it's due to the Quad but 790s is definitely getting down there.

Audible only. Tach seems to be fairly steady.

@Me78569 I'll give it a shot tomorrow. Does it also pull for EGT or just boost currently? Also, I caught the lope today but I don't think the data is worth a damn. If you can find something then awesome, but I haven't been able to identify anything. The last 30 seconds of the data is where it was happening, and off and on through the short accelerations. Also my RPMs usually hover around 850 in the morning when cold then 825 when warm so 800 is a bit low which is where it's more noticeable. I know you've got a lot on your plate right now so no biggie, just wanted to get you some data one the topic. iQuad-2017-02-13-02.46.39.csv

Send it my way. Just want the boost defuel to say 35 psi? I don't get much above 1200 on a hard pull so the egt backdown might not be a good one for me to test.

I've read 20k as well but find that hard to believe considering that would be close to 5 times that of spec which is 4500 +-250(per the manual). If it was though I wonder if timing becomes an issue at that point? Also I would have to wonder how long the injector pump could sustain that pressure. You could definitely empty the barrels/plungers a lot faster which might mean more RPMS up top..... Now you really have me thinking.

I'm at .1 which is having the truck hover in the 17 degree range and so far it looks like this tank is going to come out with better mileage. Will have to fill up tomorrow so I'll let you know what I find. On another note @Me78569 and @jlbayes, I've been reading a little on the VP mainly just trying to get some more info on pop pressure and so forth and most of what I found is just hearsay. What I would really like to find is some information on "max reliable pop pressure" that's attainable. Two concerns though, 1 the pump itself and the max pressure it can provide to an repeatable injection event, and 2 the happy medium between atomization and risk breaking a tip or fatiguing the spring. Any thoughts?

@Me78569 Two questions, 1) Pump stretch, what exactly is limiting us to 1200-2200 microseconds? Have you looked any into variable stretch? 2) When you're referring to the fueling tables what exactly are you referring to? Is this stock fueling tables or something that you or quad/Spencer/whoever designed? My rough understanding is that the canbus percentage map is only for canbus fueling so ~65hp to be had there, but when it comes to the fueling tables and pump stretch I'm a bit confused after reading through a few things.

@jlbayes I've read a few injector pop threads and I don't recall anyone really determining anything that was ground breaking or helpful for that matter. I think my injectors are around 305 bar right now. I know you're no injector builder but what's the highest pop pressure you've heard of someone running in a VP? Still wish SACs were not as dirty as they are otherwise I might consider them again. Just the nature of the design though that they'll be dirty. All this said, it might be a better question for Chris or Weston, honestly haven't talked to either in a while though. On the note of the idle, manual here so I don't see having an issue. Also, I made a few changes to the macro I built for pulling max/min/averages and so forth. Pretty easy to use, no graphs just data. Quad_Data_Macro_v1.17.xlsm

I'm listening.... In all seriousness I've been tossing around the idea of getting another pair of 7x.012s here soon so all I need is one more excuse lol. Probably go with VCO this time though in an attempt to get a clean daily driver while also having the ability to fuel a larger setup. My SACs were not bad but were not clean that's for damn sure. Let me know what you're thinking, I might be able to help out with testing. On a side note, do you think Chris could do a custom or stock HO angled injector or do you think he just buys and assembles? Never heard much on how he operates. Also, I did not see any loping today so no dice yet.

If I see it happen again tomorrow I'll be sure to download a data set for you. I notice it at idle and so far I have yet to find a pattern.

I could kindof see that but you would think that it would work the opposite way being that when heat is applied to metal it will expand making the orifices smaller. The only problem I could see here is if they get so small that they cannot fire properly, doubtful though being that they stand up to a massive amount of heat and pressure during the compression stroke. Or potentially could be that the pintle is not able to move as freely so you're getting a bit of a hesitation as the pressure builds and finally pushes the pintle up at a latter point in the stroke effectively showing itself through a lope or miss. Don't you think that the EGTs would reflect your increased cylinder temperature, especially if you were thermal soaked? All of that is using the assumption that this is only when the engine is warm, but I've seen this as well with the truck under 120 degrees. I mentioned earlier that I planned to adjust my valves again this weekend and this was one of the reasons why. Just odd that there are two people seeing this now. I have to wonder is this is truly timing related though because the Smarty notoriously pushes more timing then what we are currently using on the quad and no problems at all have been recorded through the years. I'm not doubting your theory but I'm not quite convinced that the reasoning is strictly because of timing. Currently I don't really have a good idea on this one but curious to see if anyone else has noticed anything.

Trying to understand the logic. Can you elaborate a ittle Mike.

Mine does the exact same thing only now it seems to be more noticeable. Not sure what the deal is but it's almost like it wants to lope at idle.

Will do.

So general consensus is to pull Canbus up to a reasonable level with regards to smoke? Does anyone think that this could hurt gas mileage one way or another? I have the smoke tuned completely out at this point. I had a thought this evening and wanted to see if anyone had anything to add. It's to my rough understanding that the HO pump has a bit more timing advance than the SO meaning that fuel is actually going in sooner in most cases on an HO pump when compared to an SO, theoretically. It's also fact that the HO piston bowls are a bit narrower than the SO bowls. If I remember right we are talking MM, but regardless when you combine that with the aftermarket injectors which undoubtedly have a spray angle similar to that of an SO injector, you can imply that the fuel needs to be injected a little bit later in order to get the same results that you would normally see in an SO truck. Same result being, fuel being injected in the bowl while leaving enough room for the piston to compress and ignite in a similar fashion. Now there is another layer of complexity here though and that is that the HO trucks have higher compression which would in a sense work the other way because with a higher compression the ignition will start much earlier in the piston travel. Now when I say much earlier we are probably talking about micrometers or maybe even less but regardless it's something we have to compensate for. All that to say that theoretically 19-20 degrees for an HO truck (HO pump and pistons) might be too much and it might be resulting in a less than optimal ignition and burn. So now back to the drawing board. Fuel mileage seems to be steady around 16mpg at 20 degrees which I think can be much better so I'm going to back it down to 17 degrees (0 on cruise) and see if anything changes. TLDR: HO trucks = higher compression, more timing, smaller bowls. Timing might need to be pulled in order to obtain better mileage out of an HO truck. Will let you know what 17 degrees does in a couple of days.

Just my 2 cents, I've done the LMC dash replacement and it's been holding up going on 3 years now. Since you have it out I would go ahead and do both your heater core and your evaporator. Those are two things you do not want to have to deal with later down the road. I don't remember either of them necessarily being deal breaker with the price especially when you're comparing to the cost of the dash.

Wasn't aware you posted another one yesterday. File name looked the same, but I'll give it a shot. Dumb question, but where did you post it? Also no, I don't need to start that low but I was seeing similar result in fuel mileage with starting around 96 so trying to essentially force myself to stay out of it a little more. Might work might not but I have seen no where near 20 like many here so hoping that will change. Also thinking about running over my valves again this weekend and check the lash. It's been about 30k, and yes I know it's recommended every 100k but being that I have 110lb springs I worry a little more about wear and tear.

Time to kill some ponies and save the environment. Haha just kidding, but seriously hoping for some better mileage on this tune. Feel free to make suggestions. Number of PL 6 RPM Limit 3300 Valet Mode Power 40 Max Fuel Stretch 1500 TPS Pump Maximum 100 TPS Pump Minimum 35 Minimum Pump Tap Fueling % 15 Pump Low Boost Scale PSI 15 Boost Scaling 40 Fuel Load Timing 2 Low PSI Timing Reduct 3 Timing Reduct Scale 50 Cruise Advance 3 1500 15 2000 18 2500 22 3000 24 Max 26 0 PSI Scaling 85% 1 PSI Scaling 86% 2 PSI Scaling 87% 3 PSI Scaling 88% 4 PSI Scaling 89% 5 PSI Scaling 90% 6 PSI Scaling 91% 7 PSI Scaling 92% 8 PSI Scaling 93% 9 PSI Scaling 94% 10 PSI Scaling 96% 11 PSI Scaling 98% 12 PSI Scaling 100% 13 PSI Scaling 102% 14 PSI Scaling 105% 15 PSI Scaling 108% 16 PSI Scaling 111% 18 PSI Scaling 115% 20 PSI Scaling 119% 22 PSI Scaling 123% 24 PSI Scaling 127% 26 PSI Scaling 131% 28 PSI Scaling 135% 30 PSI Scaling 140%

@Me78569 thank you for the list. Reason I ask is because I have been averaging about 16 in town and only saw about 17 on the last tank that was mostly highway. I need to pull back on a few things though that can help like low boost psi and tps wire tap. Mine are way low compared to yours so bringing the fuel in quicker.

@Me78569 and @Mopar1973Man Can you give me a break down of what parameters yall are running on your daily tunes currently? Just curious to compare. @TFaoro What mileage are you seeing these days?

Awesome, and I hear you on the apple stuff. Too much tape on everything.