Just enlarge the hole by 1/32 at a time if you can. 1/16 max.
The point is to minimize how far open the throttle has to be cracked in order to get good IAC (hot and cold start!). If you're having to adjust the throttle open more than two full turns from closed then drill larger. Don't forget to TPS relearn after each adjustment.
Of course, as Alvin mentioned, too far closed is possible.
Last edited by SiriusC1024; 05-31-2023 at 09:15 AM.
I didn't have a chance to really look over your logs carefully.
Just glancing at it looked like you need to lower your ve in the idle section.
I saw you were at 1.9 lb per minute at idle and at operating temp.
I didn't have a chance to see much more between the logs. Could you post the tune file that created those three logs?
You can open up your throttle blade some more before you have an issue exiting the idle routine and before drilling that hole. When I get back to my computer and have a chance to look I'm curious what the RPM is set at for idle? How low have you lowered the idle rpm and still have stability with that camshaft? It's a big cam, but you might be able to tighten up your under and over speed tables to control your RPM and allow you to lower your target. Depending on how much Stit you're dealing with and how close the bra is to the desired / required you may gain some wiggle room.
Idle is set at 900 rpm. To put it in perspective, this setup idled at 750 very steady and the only thing that changed was I went from an aluminum 5.7 to an iron 6.0 and 821 heads instead of stock heads. Aside from other supporting mods that was all that was done. And when I first started the car, it ran on the old tune with updated injector data and a generic 10% increase to the VE table. It drove fine until I tried lowering my IAC counts (trying to clean up the idle) because they were up near 200 fully warmed up. After that it all went to shit so I think I will be replacing the throttle body all together for a larger one so I can close my tps more. My tps voltage is at .65 at idle so I believe my issue is coming from it not being able to go into the idle routines. I drove my car on the highway for two hours yesterday while I took it to my new home and logged the entire way. I noticed after getting off the highway the idle would stick at 1100 rpm. The throttle body is stock and looked crusty as hell when I put it all together so I wouldn?t be surprised if it?s gummed up or something. I was debating on swapping it at the time but that required changing my intake setup which I didn?t want to do at the time. So I think replacing it all together is gonna yield better results than using the old tb with a drilled hole.Originally Posted by Hondaeater
But yeah my VE table is now pretty solid. Stays within 3% of target. But because the tb is open too far (Iac counts still in the high 80s to low 100s so I?d have to open it even more) and seems to not realize when it?s suppose to switch to idle routines. I?m thinking a nice 102mm tb will allow me to open the blade less but get more air while staying under the .55 tps voltage threshold. I?ll be ordering it in a few days once I?m done moving.
On a side note, I do have some questions about desired vs dynamic airflow;
After some researching and reading the forums, I found several posts that show how to get dynamic and desired airflows to line up. The equation goes along the lines of (desired air/dynamic air)*iac position. Now, I read on multiple ones that you need to make up values from 0-310. Then take the new populated iac count for that number and plug it into the same corresponding number in your tune. My questions are as follows;
1.) Why would you not just use the same iac count values that are already in your tune? Seems like that?s the most straightforward way so it would allow you to copy and paste the numbers instead of hunting for each individual number.
2.) I don?t quite remember if the posts stated this but do you do it only while at idle or do you do it while driving as well?
1.) You need to change the effective area as part of the calibration because your TB contribution has changed. You needed to open TB to increase air for the lost torque from your cam choice. Spark needs to be altered as well and there is a balance to achieve desired results. There is no plug n play numbers here. What the engine wants you have to give it. How well you do that, then the better the rest of the tables work and need less calibration.
It takes SEVERAL calibration tweaks to get the new Effective area table correct and a lot of it is in the cold start, idle warm up. It all starts with correct idle parameters and the effective area is one of the last things to do. Do not start adjusting this until the fuel calibration is complete. It's the fine tuning but it is very important.
Your dynamic air at idle is too high. Fact.
Now all the other "fixes" are trying to correct a problem that has been introduced not because of the modifications. IAC count is high so you need to open the TB more to lower your iac count but because the VE is too high THAT causes issues in the iac count, it's all reaction to a poor baseline..... and there may be an issue with the TB, IDK but telling the ecm you have that much VE with a cam like yours is lying to it and you've corrected the fuel side of the equation to "FIT" your incorrect airmass side of the equation. This would be the same as telling the computer you have 25 lb injectors when you really have 50 lb injectors.... you COULD alter the ve table to get an air fuel ratio so your fuel trims show the target AFR, but that doesn't make it Right, it makes an equation work.
Start backwards, begin tuning wide open throttle and changing your fuel injectors flow rate instead of your ve table and eventually you'll make the math work so that you get the right amount of fuel at wide open throttle to hit your target AFR, but that doesn't mean the injector data is now correct and this will show its ugly head in the rest of the tune file as you try to calibrate part throttle and idle.
As long as the voltage is less than 0.76volts it's fine ( I like a little headroom too )
Start by lowering the VE at idle RPMs after WARMED up to op temp, have to put that qualifying statement in there. The thing is I would like to help you tune this but since you've already done so much, telling you to lower the ve without knowing what changes were done to your injector data may not get the predictable desired results, and a larger TB may not solve your issues. If it's to get more airflow into the engine ok, but do the head flow support the need for a larger TB?
Drilling a hole or turning the set screw is NOT THE ONLY WAY to get the IAC count to move into the desired range of 30 to 40. Things like lowering your ve table, changing your spark advance, lowering your desired RPM, and much more influences the IAC.
I'll stop here or it'll become a novel.
Stay tuned.
Hope this helps.
I think my post was deleted somehow. Not sure where the hell it went but I can?t find it anymore. Weird. Anyways;
Finally finished moving. I installed my new tb and fabricated the intake for it. I did notice a dramatic change between my old one and this one. It idled much better than my old one without even doing anything. I adjusted it by opening up the tb enough to keep it running. Once up to temp I adjusted the set screw until my iac was around 50-60. This morning I went to do a full cold to warm heat cycle to get my RAF numbers. However I noticed that my counts were actually around 150-160. I didn?t touch anything and only let it cool off completely. I then went and restarted my car right away and noticed it was trying to drop 5 g/s and my iac counts drop to 60-70. Is this were I?m supposed to adjust the effective area of the IAC? Because I?m hella confused. I also still have the same issue of every time I start it up it has an afr of 20+. It?s not as bad fully warmed up, only doing it for maybe 30 seconds. The biggest issue is at cold start up where it?s sometimes as high as 22:1 and doesn?t go down to target if around 16:1 until it?s almost fully warmed up. Has no issues idling that high though so not a pressing issue.
As far as the fueling, I know the injector data is correct. I?ve verified it twice now and Deatschwerks tells me the info in there is correct for my injectors. My WOT atras max out at 140ish which isn?t too far off from the 120ish that it used to be when it had a 5.7 and ls1 heads. Now that it?s a 6.0 with better flowing 821 heads it?s not much of a stretch. Something like 15% more fuel.
PS: I got my WOT areas finished. PE kicks in and drops me down to 12.5-12.6 and holds it. I did see 1-2 degrees of knock retard around 4400ish rpm. It made me think it may be false knock after reading up on how sensitive the stock ls1 knock sensors are. I adjusted the correct tables from the posts that I read but haven?t had a chance to go for a test drive.
The IAC is computer controlled for DBC where DBW the ECM opens TB blade. When car is cold, you are asking for a higher idle RPM. This requires more air flow and/or spark. The IAC will be higher and slowly close the valve when warm. The IAC is what the ECM can control anytime more airflow is needed. Things like AC coming on, heavy alternator loads like E-fans, and when TB closes at speed to prevent stall, and idle warm up, these need more air than you get through a closed TB. The role of the IAC is to allow the ECM to control the airflow needed for those torque vs. load requirements.
The adjustment of the TB blade is to get the IAC count to 30-40 count. (let me qualify that... engine MUST be at full operating temperature to set the baseline of TB opening). That IAC 30-40 count allows the ECM enough authority for stable operation while providing MAJORITY OF AIR FROM TB. Think about what would happen if the TB was fully shut but the IAC was able to provide enough air for idle, ANY opening of TB would cause a huge pressure difference in manifold and overall poor results. We want that TB open as much as possible and keep an eye on the TPS voltage channel. If you reach 0.76volts, not likely with your new TB size, but if it does you would need to figure out; is the idle is higher than needed, is the injector offset correct for the combo you have, is the RAF correct, is the BRA table correct, a few things need qualification before drilling a hole or slotting the TPS mounting plate. Should not be an issue on your project but be sure to log TPS voltage channel when adjusting IAC count after it's completely warmed up. Not just into CL but at full operating temp. Keep hood open too so you don't get IAT above ambient.
Very lean start up is easy to fix. WHY it is lean as it warms up will determine what to adjust. A light throttle drive thru the gears up to about 3200RPM and a parked idle after that drive for about 1 minute or so at operating temp should help identify what table(s) are needed to be calibrated.
This was NA build and VE is 140's?? That probably means something is wrong in the calibration.
https://atgtraining.com/atg-volumetr...cy-calculator/
Run the numbers to check. Use dynamic airflow channel for MAP air mass box in that link.
Stay tuned.
I wont need to drill a hole or clock the tps sensor as im seeing about 35 iac counts at .33 v tps. I decided to swap out the TB because I have an LS3 intake and was using an adapter to get my stock tb to work. I did a RAF log this morning to get my numbers but that was when my IAC counts were about 140 or so at full warm up which is 187 degrees. I did notice that after plugging in those numbers and restarting the car it was trying to pull an additional 1 g/s for some reason. I am supposed to be at 11.9 g/s but was at 12.3 for some reason. Not sure why though but I will do another RAF log tomorrow now that I know my IAC counts are within 30-40.
As for the lean start up, im not really sure what tables to adjust. I dont like adjusting tables without knowing. As for the VE being 140 at WOT idk what to tell you. I know the injector data is correct because it was supplied by the manufacturer. I didnt come up with those values and im 1000% sure they are correct because deatschwerks even verified it after showing them my tune. I will probably contact them one more time just for shits and gigs but If I take fuel out it starts to go lean and I really dont want that. Truthfully I think its because of the increase in displacement plus the increase in air flow of the 821 heads and the increase in air flow of the LS3 intake. I was having slight knock retard around 4400 rpm after putting back some timing. I suspected that my knock sensors are too sensitive after reading up on some other threads. What I believe to have been the issue now is the fact that I was still using cheap tr5 spark plugs which ive read is not cold enough for my power level. I have since switched to TR6IX spark plugs but have not had a chance to test them yet. I will be doing that later today after I get off work. Ill attach a log of the RAF I did this morning just keep in mind the IAC was too high and have since adjusted it down to 30-40. But you can see where my AFRs are reading around 20:1 and then dropping down to just below target at around 150 deg. I will also attach my tune file in case you want to reference it. Thanks for your help will keep you updated.
So I figured out the link you sent me. The VE came back as 146.54%. Is that what you are referring to? Im assuming that means a 146 in the VE table is what that translates to? It also says my flywheel horsepower is 642 and wheel horsepower is 546?? That cant possibly be right.
Also, after verifying that I had set my tps voltage to allow enough air in to drop my IAC counts to around 35 fully warmed up yesterday, I did another RAF log this morning. For some reason my IAC counts went only as low as mid 110s when fully warmed. What gives? I changed nothing. Could my IAC motor be sticking or something? The car idles and drives great though. I had a weird scenario while out for a drive where my car lost all power for a couple seconds while doing a U turn. Sounded like I had turned off the key for a couple seconds and turned it back on while the motor was still spinning. It cant be my battery terminals because they are new. Very strange honestly, im wondering if I may have a bad ground somewhere? *shivers*
How do you have AEM hooked up?
The tune file you provided has CL to start at 93* but it never goes into CL. You have OL set LEAN (see pic
) and that is what you are seeing Commanded. Your PE table is lean too below 1200 rpm?
The injector data may be correct according to manufacturer, but it is not calibrating correctly in this set up. You are not somehow getting 140% VE of your 0.74999 cylinder NA. Your cylinder volume is the total amount of air that fits in 1 cylinder then *8 = engine displacement. At 140+% you are saying you have an 8.4L engine displacement. lol. If they ARE 65lb/hr injectors at 58 psi why is the injector table starting at 85 lb/hr 0 kPa? cut that 20% and it would be close to 65lb/hr and drop VE 20% gets much better table.
My aem is set up through a cable (forget what its called its like a computer cable with screw bolts on both sides) and transformed in HP tuners. I wanted to do it through the mpvi but I dont have the pro feature or something like that. I also think I read somewhere that these gen 3 computers cant do it through the obd2 port or something. Anyways, I digress.
The CL was set previously because I was having issues with them not working so they are actually unplugged for now until I figure it out later. Normally I have it set to disable LT and ST fuel trims so basically open loop 24/7. I actually changed my OL EQ ratio to 1 so that I stay at 14.7 constantly when not idling and PE is not active. I realized that having it at .93 was causing a lot of bucking and switching it to 1 got rid of 95% of it especially at low speeds. Mistakes made lessons learned I guess lol
As for the VE idk what to tell you. I used the calculator like you said and thats what it gave me. It seemed weird to me but I used the measured map in my log. As of now I wont be adjusting the VE since it seems to work. I trust the injector data from the company that makes my injectors since they do far more calibration than I could ever through messing with the tune. Besides, doesnt reducing the injector flow by 20% and reducing the VE by 20% effectively gets me to where im at now just with smaller VE numbers? Anyways.
Currently I have these small issues;
1.) IAC counts only go as low as mid 90s now for whatever reason. Previously at .29 tps volts and 190 deg coolant temp would get me right around 30 iac counts. After cooling off over night it now only goes down to mid 90s. Dont know why and quite honestly fed up with doing RAF tuning. I have a solid RAF tune in it now even though iac counts dont drop as low but it I guess it is what it is.
2.) After hard driving, my car wants to stall if coming to a quick stop. It doesnt always drop low enough to stall but more often than not I have to help it stay alive. This seems to only be an issue after pretty hard driving and does not happen with regular driving. I increased the RAF in the immediate cell after my normal operating temp cell by 1 g/s. When driving normally im at 187 deg but after hard driving im closer to 200-205 so my thought process is increasing the cell past where I normally operate in itll increase my base airflow and further prevent me from stalling during those instances. Curious what you think of that strategy.
3.) IAC Effective Area; Id like to know the full steps to getting this dialed in. Im hesitant to change it as I have before and it totally screwed up my RAF.
4.) Idle quality is not the best, seems to have a broad range and stumbles. Doesnt have a very solid lope like youd expect on a cam like mine. I know large cams dont idle so well but it seems excessive to me. Idk if thats something that will get better once I tune the effective area for the iac motor.
With that said the car drives great. I have attached a log of my VE tuning process. I had a second one done but my laptop crashed after I got home but before I could save it. Ill do a few more VE tuning sessions tomorrow.
Your VE is set incorrectly. It is a result of your injector data. Do what you want. if you look at the Cylinder air g/s you see that 1.2 g/s is too high. It is a result of the VE tbale. This will skew the spark table since cylinder g/s is the row axis it references. By misrepresenting the VE you are misrepresenting the area of the spark table you are in.
If you leave this as is and are happy fine. I am not here to argue. You seem to have a good idea of what to do so good luck on your tuning journey.
The AEM is hooked up by the serial to USB converter cable. It will work fine in a Gen3.This happens with wrong VE.JPG
Last edited by Hondaeater; 07-12-2023 at 07:16 PM.
BTW, if you go into the main HP tuners folder>VCM Scanner>logs that log is listed by time/ date stamp. You didn't lose it. Even if battery goes dead it's still there. It records in real-time and if you kick and disconnect the cable or battery dies it is most likely still in that tab.
I appreciate the info. Im not trying to be argumentative, im simply stating that I entered the injector data from what was calibrated by my injector manufacturer Deatschwerks. I dont know anything about tuning with unknown injector sizes which is the whole reason why I got these. I dont think its too far off though because when I had my LS1 with same cam and exhaust setup, the VE at WOT was around 120-125. Hell even the stock trans am tune from factory has the VE at 110. It makes sense after installing a bigger motor, with significantly better flowing heads, and a significantly better flowing intake, PLUS a 104mm intake lid from FTP, id expect the VE to be even higher but then again im just going off of what makes sense to me. Im curious though, what would you put for the injector data? Ill attach it below so you can take a look, maybe youll notice something I dont.
On another note, the interruption of power has to be power related. When it happened, my wideband read all dashes which is what it does when you give only accessory power. I did notice that my steering wheel has a bit of lateral slop, maybe an inch or two. Im wondering if doing u turns causes the ignition switch to disconnect sometimes and then reconnecting when I stop applying pressure. Kinda like how my old window regulator causes my window motor to move father after bottoming out and disconnecting the power wire resulting in not being able to put the window up. Ill dig into that later I suppose, it doesnt happen very often.
Aren't you running a 525lp/hr pump? Did you replace the fuel lines to larger ones? Are you using a stock fuel filter?
Your entire fuel system is probably not ideal and the injector data is data for a set of control parameters that you do not have. The data is there but must be calibrated to the specific application.
And post number one you stated 65 lb injectors at 58 PSI. I understand you have gone over this many times and I'm not trying to be a dead horse but if that's what they were rated at 58 that should be what you're injector flow rate in the table not 85 lb/hr. Just an observation.
Check your flow rate using 65 lb / HR at 3 bar and new flow rate at the 58 PSI 4 bar. It it is not what is expected.
https://www.witchhunter.com/injectorcalc1.php
Isn?t the data just a way to calculate latency, injector open times, etc? So the way a fuel system is set up should really be irrelevant as long as the pressure is maintained? I don?t think these are true 65 lb injectors, they just flow that at the gm rail pressure of 58. Here?s the link to them if you want to check them out.
https://deatschwerks.com/collections.../16u-00-0065-8
What I don?t get is why Deatschwerks verified all the data to be correct. Surely they would have told me otherwise? I even made sure to tell them my exact setup. Oh well, I guess. I?ll try reducing the flow rate and VE by 20% and seeing what it does.
I won?t be able to do any VE fine tuning until Monday so hopefully I can get it all done that day. Then I should be all set up to adjust idle parameters like iac effective area right? I?m still not too sure on that part. At least my RAF strategy to combat stalling after hard driving seems to be working so I guess that?s a small win lol
Air mass divided by AFR equals the fuel Mass.
To get the correct fuel mass the ecm uses the data programmed in the flow rate and off set and minimum pulse and calculates the PWM required to get enough fuel to make the calculation of fuel based on the air mass it's told is coming into the engine. If you're IFR is too high, then the VE or air side of the calculation is adjusted by the user, to get a target AFR to "fit". You can adjust the VE, say it is lean, since the ECM thinks there's xx amount of fuel being injected based on the tables in the injector data but in reality it's much less, the "tuner" can calibrate the VE higher, lying to the ecm that more air is entering and the injector PWM will increase for the amount of air it's told is coming into the engine and this will get the AFR target ratio to compute and it looks like the tune is going well. The problem is not that you're not getting the right fuel/air mixture because clearly the trims or WB show it as stoich or whatever the target AFR desired. No the problem is that the amount of air is being adjusted to hit a fuel delivery to get afr instead of actually how much air is entering. This again will be appearing in your g/s row axis for spark, and also the misrepresentation of dynamic air in lb/min ? 10 = crank HP.
Engine Output Size (inches) Size (AN)
350-450 hp. 3/8 in. -6
450-650 hp. 1/2 in. -8
Fuel pressure and fuel volume will be different in different size fuel lines.
45 PSI in a garden hose or 45 PSI in a 2 1/2" fire hose which one do you want to put the fire out? They both have the same pressure.
How are you adjusting the VE table? What method are you using to come up with the corrections?
Would you post the latest tune file used to get the VE Retune 1 log?
What is showing up as needing corrections in the log and what the LQ9 Firebird Tune3.0 12 tune has would be very large changes.
Are you running an ac?
Yeah I get what you mean with pressure in a different size tube but for what I was running it really isnt necessary. As long as the rail maintains that 58 psi pressure you should be fine. The only problem I can see arising is if the flow of the fuel through the rail is not sufficient, youll start to lose rail pressure and cause lean issues. But really this isnt an issue on NA setups like mine unless you have some godly large engine. I will be upgrading the fuel system to a return style later on when I decide to put a procharger on it. I didnt do it now because I was already dealing with a lot rebuilding the motor and swapping it all by myself inside a small single car garage. I figured id cross that bridge at a later date.
I received a response back from Deatschwerks and they verified the injector data was correct. He explained the reason why below
Screenshot 2023-07-14 113353.png
My method of adjusting the VE table is to compare Air-Fuel Ratio Commanded to my Wideband reading and using math to get a percentage. Then I copy and paste special multiply by % half into the VE and try to fill in any missed cells sounded by corrected cells. Ill attach the tune file that got me the "VE retune 1" log.
On a separate note I may need a new IAC valve. I did a cold start today to double check my RAF was on point. For some reason my IAC stuck around 230-240 slowly dropping to 210 or so and then all of sudden drops down to 130 or so which stalled my car out. What in the fuck. I replaced it with another IAC valve that I had in my old TB and it dropped IAC counts down to 0. I had to basically almost close the TB to get the IAC counts to move up but they only managed to get up to 15 or so when TB volts were at .20. I had a log of it but accidently restarted the log and lost it.
I see the "Air flow mode" at the top row of that table. (0,4,6,8,10,12,14,16) and it's correlation with the "Mode vs. Airflow" table, but what is the pounds per hour numbers "lb/h" referring to on the top row of this table?
Where would I match that with what I idle at?
So you don't have a graph that is laid out like your VE table and let the scanner populate the % error? That may be why the I see such big errors in your afr target vs WB. I'll send you the picture of it so you'll be able to make graph if desired.
How you gather the data matters too. I don't think I saw much steady state kPa ranges and rarely steady TPS. You should use gearing and throttle to populate the graph. I hope you have good luck with this project. If a company sells a 65lb/hr injector that is actually flowing 75 then it should be sold as a 75lb/hr injector lol. Injector data is an absolute not a ball park. IF you use 75 as a flow rate @ 43.5 & then offset for 58psi you get 86lb/hr yes. Bit now when using that flow rate the VE and rest of the equation doesn't add up so either the associate made the math fit the data and claimed they are actually 75lb/hr injectors being sold as 65 (who does THAT?? for what purpose would you falsely label an injector??) But then the results don't work out. If you've ever had to dial in an unknown set of injectors then you would understand why the results you are getting are wrong. It's from the injector IFR table. But it's your baby and you didn't hire me to tune this so do what you want.
You're happy with the results so that's what matters. It's wrong and I have shown you how it effects your calibration and the misrepresentation is skewing the spark cyl g/s row axis and the engine torque the ECM uses in the background for calculations but if it works for you that's what matters. You don't know any better and it's not like you're thinking other people's cars. It's yours and you are satisfied. Cool. Besides it will run but if you're going to ever body this you need to get someone qualified. These mistakes na it will live, boosted your going to regret it.
I won't bring it up anymore ok. You've done a good job and looked up how to do a lot yourself, which is more than most of the forum members who start out here wanting instant gratification.
Mingus use Dynamic air value using lb/hr units as your lookup for mode vs airflow table. Hope that helps.
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