JimMueller

iTrader: (9)

So on the EOIT, the previous discussion on the HPTuners forum years ago had spreadsheets to fill out these tables based upon comparing stock tables & stock cam valve events vs aftermarket cam valve events. Would using the valve events also be a viable tuning method in lieu of the subjective smell test?

https://forum.hptuners.com/showthrea...highlight=EOIT

ChopperDoc

I was actually trying to keep it simple on this one, since there are so many considerations. I do believe going off of the spread sheet is a start, and probably better than the smell test. However, the considerations simply don't end there. I thought about putting that stuff into the video, but decided not to. Primarily because "most" folks out there are doing it to correct the raw fuel smell and nothing more. I have read that thread in it's entirety years ago, and there is definately lots of discussion on it, but no solid agreement other than many say do it just for the smell and call it a day.

The other things to consider are RPM, stroke, VE, valve open time, rocker ratio, transients, air density, vacuum, and so on. Also modified heads will most likely transfer heat differently, and may be hotter or colder than the stock ones. Modified engines making more power will also be hotter, typically, by nature. Now how all that relates to the injector timing becomes the question. If considering all of that into it, is there a magic number or process? Probably not, and a read into that thread even a few pages takes you down a very complicated road beyond what "most" folks need to concern themselves with.

I however do enjoy the physics and trying to figure these things out. I still have a few formulas I worked on to try and develop a method of measuring this. Building a table to tell you the valve open time in milliseconds is actually really easy, but things get a lot more complicated when you start thinking of how this messes with transients. Then I tried to match that to my injector pulses to see if they were getting shorter or longer. Mixed results lol. I put those things into the "fine tuning" area, so it's not going to break the tune backing the timing off a touch.

This is simply a way of explaining it in simple terms to save keyboard time (like all my vids lol) because I have seen so many "How to clean up the smell" kinds of threads asking about it. Some had trouble with emissions after new cams too. Not sure if this would fix that, but worth a shot nonetheless.

I wanted to avoid what I have written below, as far as complexity for beginners lol.

Out of pure curiosity and to see if it can be useful I work on all kinds of random experiments and maths in the scanner.

Next month I am going home finally for a bit, so I will have some time to experiment with some other ideas, like trying to backwards calculate the temperature bias for air calcs. In doing so, I have realized the formula is wrong for it in my one video (needs to be half the bias, borrowed that from Marcin's blog) or (IAT+(ECT-IAT)*(Bias/2)) to work right in real calculations. Maybe that's why the table goes from 0-2 instead of 1, which is why that dawned on me. I need scans with some different parameters to actually get some workable math to mess with it. I started down that road on transients too, but have been unsuccessful in identifying what the values for the transients actually are, aka, units. Maybe someone out there knows? I started going through some thermodynamics formulas to try and decipher it, but I simply don't know what the units are to be worked into anything useful as of yet. That will likely result in me revisiting the injector timing as well. Perhaps there is a formula out there we could develop for use in this. With the scanner the possibilities are literally endless.

Here, I will put up some of my current work with this stuff, or where I left off. If any of you want to get more into really understanding this stuff, here is a spreadsheet I made dealing with airmass, and the beginning of my transient research as well. Feel free to add to that part and post it back up if you want to take a shot at it.

JHZ28

iTrader: (3)

anybody know why my iac hangs at 210 counts?

ChopperDoc

Appears to me that your IAC effective area table is the cause here. My camaro often "sticks" at 310 on cold starts, because this table decides what that limit is. 310 is the max in my case. 210 is as high as yours goes. It looks like the table has been shifted far over to the right. The PCM is asking for the max airflow on the startup, 40 g/s.

My suggestion would be, return the IAC effective area table to stock values, then get the AFR right using the VE table (on hot engine/operating temp). Then go ahead and plot the dynamic values for your BRAF table (Base Running Airflow) without touching the throttle on a cold start, (following day). Once all this is done, then adjust the blade itself to get the counts down to the 40-60 range, though other numbers can work, higher or lower, just depending on what your car likes.

After all that, then you can go about messing with the effective area table. I made a video on a way to do this using the scanner and math instead of shifting it. The more range you can give it the better. I don't mess with the upper limits, and leave that number alone (again, 310 in my case, which is stock). The rest of the table is adjusted to this using the math I show in the video. Remember you might have to redo the BRAF table a few times, which basically defines what the values are on the effective area table.

I also went ahead and ported my IAC out to 3/8" on the outlet because I have a FAST 102, and the port was just super small. That made a big difference in how much I could drive the idle down. I was successful in getting my camaro to idle at 700 RPM, and lower when playing with the scanner. 600 sounded awesome lol. The cam I have in it is a 244/252 .634/.634, 114+4 LSA. So if I can do it, most out there can also do it.

Once it idles nice and returns to idle (which is more spark related) then call it good. The numbers don't all always have to look nice and match up, as you may find to be the case down the road as you look at the corrected IAC or BRAF numbers using dynamic. Only time you need to mess with stuff is if it's having issues.

Check out my vids on idle tuning and the IAC fix. Hopefully they are helpful.

AINT SKEERED

iTrader: (2)

Some one needs to do videos on efi live.
Lots found for hp tuners

ddnspider

iTrader: (26)

I almost exclusively use efi live, but have used HPT enough that I can "translate" most stuff. If you have specific questions on efi live lemme know.

AINT SKEERED

iTrader: (2)

Most of it I also understand. Just would be nice to see videos

ddnspider

iTrader: (26)

I gotcha.

LSX Power Tuning

iTrader: (4)

Unfortunately the business model efi live chose wasn't in the best interest of gas tuners. So many of us that tune for a living that used efi live (were alot of us years ago) for years had to have both and mostly use hp tuners now especially for the newer vehicles. Efi Live is still great, we still have and it and use it but your not going to see the support. write ups, or videos like you will for hpt or forums. More people have hpt and also more companies out there are teaching hpt so you will always see alot more info on it IMO.

AINT SKEERED

iTrader: (2)

I understand. Both great tools,I do pretty good on my own just see more support for hpt.

JHZ28

iTrader: (3)

I put the stock iac table in my tune so it now goes to 310. I run a cheap ebay throttle body just cant seam to get it to idle lower than 1,000-1100 rpm. il try to open up the iac port

ddnspider

iTrader: (26)

If the idle is high then opening the iac will only make it worse. Try adjusting the idle set screw and make sure the desired airflow is right.

ChopperDoc

That's a start, as far as getting the numbers for the IAC looking more correct. Is the IAC closing to 0 now and asking for less air? If you have your idle RPM set lower than the actual, the PCM will close the IAC. When it runs out, then it's all in the blade.

Spot on correct. Don't bore it out unless you need too. I found it helped on my camaro, but I'm sure airflow needs are far different, as they always are from engine to engine. I didn't like how loud it was at 310 on cold start and as it warmed up. Howled like crazy. Still does it, but not quite as loud now. Also I realized my car needed more air than 310 could deliver, and at hot idle my counts settle around 30 typically. That was my reasoning.

Start with adjusting the screw, closing the blade will lower the idle and thus increase IAC counts. Make sure you do this when the engine is hot, as just getting idle is hard enough. Don't get to bent up if it doesn't cold start for the moment without help.

Spark is something else you could look at to reduce the RPM. If you have too much, but be running a little too efficiently. You can pull spark in the scanner a few degrees at a time and see if that helps any too. Just something else to look at as well.

JHZ28

iTrader: (3)

i'm starting to close the throttle blade and it is helping my iac counts when hot will go as low as12. I believe I have to continue to close the throttle blade. I have the idle rpm speed set to 950. I did notice it doesn't cold start as easy as before but still doesn't need any throttle input to start. my timming is set at 18 mite try lowering that also

tsench

iTrader: (15)

subscribed

AINT SKEERED

iTrader: (2)

You will have to log and set desired idle airflow from cold and it should help that

JHZ28

iTrader: (3)

all I did is lower the timming to 16 at idle. now iac counts way high?

ddnspider

iTrader: (26)

Timing change will directly impact torque and efficiency and can require a different amount of idle air.

ChopperDoc

Your numbers (other than IAC) look great for a cammed car. And yes timing can have effects on airflow needs, as less timing will typically raise the MAP, therefore lowering vacuum. Your goal is to reduce the RPM correct? Try doing it in the scanner by commanding the RPM change, and see how low it lets you take it. You might find that at your target idle speed, say 700 or something, the IAC will probably close a lot more.

If it still cold starts okay and everything else is to your liking, I'd say don't mess with it too much. Once you find an idle speed you like using the commands in the scanner, just change it in the tune accordingly and write it in. Another thing you can do is use the IAC guide and apply that to your IAC table. This is provided your RAF table is good to go. This will definitely change the IAC position after you make the changes.

ChopperDoc

Updated the MAF tuning guide, to a newer easier to follow version. Also, I split the video up and made the MAF baseline in SD it's own video.