wont idle after cam swap

[intimid8rkid]

im looking up ve tables now. i thought you were talking to spray cam. like i said im new with this shit.

[intimid8rkid]

i can wrench and do body work but when it comes to this im lost. i was thinking i could change a few airflow settings and be on my way but thats not the case.

[intimid8rkid]

are you talking about the part throttle spark table?

[Spray-Cam Hell-Ram]

No doubt that you have been doing this longer than I and have more knowledge in this area than myself. And I know you are right about where ignition timing needs to be set at idle for optimal performance and efficiency. I even said so in my last post unless I'm mistaken. And you are right, in most cases, it's going to be a complete dog and not be pretty. Which was the point I was trying to make when I mentioned coming across others' tunes having this negative timing up to and past 2000 rpms in my previous post. There really isn't anything to argue here because I was never creating an argument against what you were saying in the first place. Even rereading my post again, it seems pretty clear, to me anyway, that I'm agreeing with you entirely with what you had said regarding where timing should be set for idle. And the part about having seen others' tunes where negative timing in input in their part throttle tables all the way up to 2000-2500+ rpms is just plain fact. And by fact, I simply mean that it wasn't a dream, it's something that I have in fact seen with my own eyes and although I am fully aware that this should never be done, I've had this come across my screen here when I am sent tunes from others who are in need of help... and I have seen this more than once. And truth be told, I wouldn't put, having done this myself in the very beginning before I really knew any better, past myself, though I can't say for certain if I ever did this in my own early days tune or not. But I can understand a bit why it is that I see things like this in some of these newer guy's tunes from time to time. I personally have found the hemi tuning platform to be the most difficult to crack in regard to being a newcomer and trying to get the much-needed information to even begin trying to wrap your head around Hemi tuning logic, let alone tune one of these Hemis. Fortunately, with patience and persistence, there are just enough willing and able members on here to be able to properly learn how to navigate this platform over time. The only thing you've even said that I may have a difference of opinion on was in your last post when you said that you don't see how a motor could even get to 2000 rpms with negative timing. I got to believe that the amount of negative timing at play in this scenario would have to be a factor, among several others motor characteristic factors, in your decision for whether or not a motor with negative timing could get to 2000 rpms. If I were asked this same question, my response would be... Absolutely a motor, a hemi for that matter, could get to 2000 rpm with negative ignition timing. And I do agree that the vast majority of instances would be downright ugly. But I can also confidentially say that a high compression 5.7L hemi running negative timing of -5 to -10 degrees can get to and beyond 20000 rpms and it's not even all that ugly. Not like you might expect anyway.... Unless of course you try to romp on it hard or floor it. And I didn't pick a high compression 5.7L hemi with -5 to -10 degrees timing by accident. I've ridden in the passenger seat of this very set up and recall telling the fellow I was helping once I saw the log of our drive, what the heck he was doing running negative timing, especially in the driving area of tables. But even still, with that being said, I didn't mention seeing this in others' tunes as an argument against what you are saying. It was quite literally the opposite actually. And I have a feeling that the majority of those who read my previous post would agree that I wasn't trying to argue against what you had said. I was merely agreeing with you and then attempting to explain to you and others, what it is that I've been coming across and dealing with, from a large number of others who have installed a cam in their hemi and seem more concerned about how hard it will chop above anything else. I do, however, want to better understand what it is exactly that you are saying in your last post here. As I had mentioned in one of my posts in this thread, my approach to improve cam chop is to utilize both positive and negative timing to achieve the best result in bringing out whatever potential a cam has to chop. And with optimal ignition timing being around the +15 degrees, the over under range ultimately ends up dipping into the negatives on the low or under side of this range, hence why I said I usually end up inputting both positive and negative timing for cam chop in a tune. And I do understand that its idle torque spark that's at play here. I guess maybe where I'm failing to fully understand what it is that you are saying here is, wouldn't making the over/under spark control much more aggressive ultimately put part of your spark control range to where, on the very low end, your range ends up in this "negative degrees of timing area"? And maybe I'm missing your point here all together. At least for me anyway, more often than not, when I'm done with inputting my data for cam chop, the logs that I'm sent afterwards will usually have a swing range of +20 degrees timing to -10 to -15 degrees timing, depending on the cam. And I can't seem to net the same results, as far as hard cam chop goes, when I adjust this swing range to, say 0 degrees to +30 degrees timing I'm hoping you can help me understand completely what it is you are saying here, as I can honestly say that I'm sure I have many things still to learn here with this Hemi platform. And above all else, please understand that Im not arguing your points here as I agree 100% with that of which you have said here in this thread, aside from what I expressed a difference in opinion towards in your very last post. Thanks!

[Spray-Cam Hell-Ram]

Did you try revision 4? I cleared your random misfire code from setting at any point below 2500 rpms and adjusted all of your timing to stay in the 12-15 degree range during idle to see if it would smooth your idle out. Or if your misfire would still be present?

[Spray-Cam Hell-Ram]

If you look at your VE tables from revision 1 and compare them to revision 4 you'll see I took out about 8% across the board to help with your -20% LTFTs. They should be quite a bit less running rev 4 and you look at your log after running rev 4

[Spray-Cam Hell-Ram]

Went through all of your tables pretty deep this time. Made some better guesses across your entire VE table. Hopefully this gets you close at least. Also believe I have addressed your hgard warm start issue on this last revision. If you still think you have a misfire somewhere then go inmto your scanner this next round and log injector pulse width for 1-8 and log fuel mass delivered for 1-8. This can help rule out a potential injector issue.

[edcmat-l1]

Went through all of your tables pretty deep this time. Made some better guesses across your entire VE table. Hopefully this gets you close at least. Also believe I have addressed your hgard warm start issue on this last revision. If you still think you have a misfire somewhere then go inmto your scanner this next round and log injector pulse width for 1-8 and log fuel mass delivered for 1-8. This can help rule out a potential injector issue.

Comparing your last 2 revisions, you're changing way too much stuff at one time. And the key changes that should be made, you aren't doing. You barely made any change at all to the VE when it needs to be changed drastically. Need to plot the trims in a VE histogram like the screen shot I posted then copy/paste/multiply by 50%.

I'd start over from the base file again and start with the most basic changes. Idle speed, airflow, VE, etc. NOTHING else as far as adder tables, etc. should be touched until the VE is very close to final product. Need to get the trims well under +/- 10%. Once you get the VE spot on you'll notice you have to change very little as far as your adders, startup, etc.

[intimid8rkid]

dumb question here. can i enable NN and let that deal with ve tables? ive never heard of NN until i started this tuning adventure.

[intimid8rkid]

way better spray cam. goes into neutral reverse drive good. now just have to deal with this ve table stuff. i have entered into my scanner correctly. b1 and b2 ( i believe)

[intimid8rkid]

coming up to stop signs it shakes a little bit. have to read up on ve tables now.

[intimid8rkid]

OK i did the ve histogram copy and paste multiply by 50%. will check it out tomorrow.

[edcmat-l1]

OK i did the ve histogram copy and paste multiply by 50%. will check it out tomorrow.

You'll need to do the same process multiple times. Make sure you reset your adaptives before your next drive.

[Spray-Cam Hell-Ram]

The reason for that was one revision was done with the intent of solely making a few changes in the spark and airflow areas just to help with stalling. I initially wasn't intending to go over the entire tune but did so in the last revision after seeing his last log and seeing how bad the fuel trims were, so then I went ahead and went through his entire tune file and treated it as if I were creating a base tune from scratch with the intention of having only the fuel trims left to dial in. I had to make those changes to the adders prior to dialing in the fueling because it wasn't even drivable, so I made adjustments to the adders to get it drivable so that he could drive it to make logs so we could dial in his fueling. Any time I do this, I'll go back after dialing in fueling and pull back on those adder adjustments I previously made to make it drivable for logging. I'll certainly approach it with the intent of dialing in fueling before playing with adders anytime I can. And I hadn't made any major changes to VE in the first few revisions because we were initially focused solely on keeping it from shutting off so fueling could be logged and then adjusted. In revision 3 or 4 I went in and changed his VE tables entirely to a table that would be a bit closer to one from a previous tune with a similar mod list. Then in revision 5 (this last one), I noticed from his long that the E values were still a bit too strong, so I took out 6% across the board, and that is as far as we have gotten thus far. But by this point, once he loads revision 5, I expect it will be drivable at least to where he can log VE histograms so fueling can be dialed in. This is just how I approached it and wanted to share this particularly given that this started out as just an idle/surge issue and has kind of transformed now up to this point, into an all out tune.My approach would be much closer to what you have described above had it just been a forum member asking me to tune their build.

[intimid8rkid]

i drove it yesterday to work. still had a little surge so i bumped up the rpms. that seemed to help. this morning was 20 degrees and she fired rite up. thought for sure it was gonna give me problems. hot starts are still giving me a little problem. have to tap the throttle to get her going. im hopping to get the truck titled and registered tomorrow so we can start working on the fuel trims.

[Spray-Cam Hell-Ram]

Make sure you reset adaptives and fuel composition after loading the tune. Open your scanner and hit the Circle within a circle icon at the top of the scanner screen and your reset adaptives and fuel composition both will be right there to reset. Your log starts before the key is turned with -25% fuel trims. Load rev 6 and drive that to work and see if anything improves.