HPTuners SD VE Tuning with Wideband - Commanded AFR stuck at 14.7 for cruise?
03-24-2017, 10:55 AM
#1
HPTuners SD VE Tuning with Wideband - Commanded AFR stuck at 14.7 for cruise?
So started tuning my VE table again because there have been a lot of changes that I've made in my tune over the past year, and just wanted to level set VE and MAF again. (Both were previously done by someone else on a dyno)
I have now taken 25% fuel out of my VE table 2x, and the car never pulls timing, it has gotten a little more responsive, and just driving around it feels fine, but I'm nervous. We all know things run their best before they let go! haha I know that cruising there is no pressure or heat, so things almost never let go, but just want to be safe.
So I followed the guide/link at the bottom of this post, and all was going well, but it wants to push the car to a 14.7 AFR - not 12.6-12.9 like I have set in my PE table. I know VE is a steady state table, but if you push the petal enough to get to PE enable (I think the enable TPS% is like 64% for around the 2,000rpm range), then it will go to 12.68 like I want, but just cruising around logging (1,400 to 3,500 rpm's) it wants to go to 14.7? I feel like this is too lean even for cruising around? The second you get into the throttle it will command 12.6, but I think that for some reason the car should run at about 12.6-12.9 for ALL RPM, and then lean cruise should be what leans it out...or am I wrong?
Thoughts?
Link:
http://michigansnowmobiler.com/hptun...ons%20rev2.pdf
I have now taken 25% fuel out of my VE table 2x, and the car never pulls timing, it has gotten a little more responsive, and just driving around it feels fine, but I'm nervous. We all know things run their best before they let go! haha I know that cruising there is no pressure or heat, so things almost never let go, but just want to be safe.
So I followed the guide/link at the bottom of this post, and all was going well, but it wants to push the car to a 14.7 AFR - not 12.6-12.9 like I have set in my PE table. I know VE is a steady state table, but if you push the petal enough to get to PE enable (I think the enable TPS% is like 64% for around the 2,000rpm range), then it will go to 12.68 like I want, but just cruising around logging (1,400 to 3,500 rpm's) it wants to go to 14.7? I feel like this is too lean even for cruising around? The second you get into the throttle it will command 12.6, but I think that for some reason the car should run at about 12.6-12.9 for ALL RPM, and then lean cruise should be what leans it out...or am I wrong?
Thoughts?
Link:
http://michigansnowmobiler.com/hptun...ons%20rev2.pdf
03-24-2017, 06:52 PM
#2
So started tuning my VE table again because there have been a lot of changes that I've made in my tune over the past year, and just wanted to level set VE and MAF again. (Both were previously done by someone else on a dyno)
I have now taken 25% fuel out of my VE table 2x, and the car never pulls timing, it has gotten a little more responsive, and just driving around it feels fine, but I'm nervous. We all know things run their best before they let go! haha I know that cruising there is no pressure or heat, so things almost never let go, but just want to be safe.
So I followed the guide/link at the bottom of this post, and all was going well, but it wants to push the car to a 14.7 AFR - not 12.6-12.9 like I have set in my PE table. I know VE is a steady state table, but if you push the petal enough to get to PE enable (I think the enable TPS% is like 64% for around the 2,000rpm range), then it will go to 12.68 like I want, but just cruising around logging (1,400 to 3,500 rpm's) it wants to go to 14.7? I feel like this is too lean even for cruising around? The second you get into the throttle it will command 12.6, but I think that for some reason the car should run at about 12.6-12.9 for ALL RPM, and then lean cruise should be what leans it out...or am I wrong?
Thoughts?
Link:
http://michigansnowmobiler.com/hptun...ons%20rev2.pdf
I have now taken 25% fuel out of my VE table 2x, and the car never pulls timing, it has gotten a little more responsive, and just driving around it feels fine, but I'm nervous. We all know things run their best before they let go! haha I know that cruising there is no pressure or heat, so things almost never let go, but just want to be safe.
So I followed the guide/link at the bottom of this post, and all was going well, but it wants to push the car to a 14.7 AFR - not 12.6-12.9 like I have set in my PE table. I know VE is a steady state table, but if you push the petal enough to get to PE enable (I think the enable TPS% is like 64% for around the 2,000rpm range), then it will go to 12.68 like I want, but just cruising around logging (1,400 to 3,500 rpm's) it wants to go to 14.7? I feel like this is too lean even for cruising around? The second you get into the throttle it will command 12.6, but I think that for some reason the car should run at about 12.6-12.9 for ALL RPM, and then lean cruise should be what leans it out...or am I wrong?
Thoughts?
Link:
http://michigansnowmobiler.com/hptun...ons%20rev2.pdf
03-24-2017, 07:31 PM
#3
Thanks for your reply. I figured that 14.7 would be ok for cruising, but I just wanted to double check because I was nervous with how much fuel I was pulling out. BUT with that said, I remind myself the car always sounds like it's drowning, it's GUZZLES fuel, and when the exhaust is so rich it will burn your eyes...also before starting I added 15% to the VE table just to be safe, so, after thinking about it a while it makes sense.
And yes, MAF is disabked and its forced to run in OL.
thanks for the help, and straight answer!
And yes, MAF is disabked and its forced to run in OL.
thanks for the help, and straight answer!
03-29-2017, 02:33 PM
#5
car is running FAR better though, and it best of all the exhaust doesn't burn my eyes near as bad!
03-30-2017, 11:05 PM
#6
Racer
What modifications do you have to the vehicle? Unless you upgraded injectors and/or modified the MAS sensor substantially (or are forced induction) there is no way you should be pulling 25% of fuel.
Also the VE table is more for how the motor runs, it is a lookup table. It really sounds like you may have some parameters or settings off as a baseline.
You can also target a different open loop target AFR table for partial throttle, but I'd suggest 14.7 for open loop and lowering the PE threshold to a lower level, 64% is asking for some throttle IMHO.
What are you using for a wideband? Is it calibrated?
Also the VE table is more for how the motor runs, it is a lookup table. It really sounds like you may have some parameters or settings off as a baseline.
You can also target a different open loop target AFR table for partial throttle, but I'd suggest 14.7 for open loop and lowering the PE threshold to a lower level, 64% is asking for some throttle IMHO.
What are you using for a wideband? Is it calibrated?
Last edited by niterydr; 03-30-2017 at 11:05 PM.
03-31-2017, 12:04 AM
#7
What modifications do you have to the vehicle? Unless you upgraded injectors and/or modified the MAS sensor substantially (or are forced induction) there is no way you should be pulling 25% of fuel.
Also the VE table is more for how the motor runs, it is a lookup table. It really sounds like you may have some parameters or settings off as a baseline.
You can also target a different open loop target AFR table for partial throttle, but I'd suggest 14.7 for open loop and lowering the PE threshold to a lower level, 64% is asking for some throttle IMHO.
What are you using for a wideband? Is it calibrated?
Also the VE table is more for how the motor runs, it is a lookup table. It really sounds like you may have some parameters or settings off as a baseline.
You can also target a different open loop target AFR table for partial throttle, but I'd suggest 14.7 for open loop and lowering the PE threshold to a lower level, 64% is asking for some throttle IMHO.
What are you using for a wideband? Is it calibrated?
i will have to look up what the stock PE enable value is and set it back to there.
car is a H/C/I car with larger injectors, LS7 TB and LS7 MAF.
Car was previously taken to a Dyno shop for a tune but it always seemed super rich. If you let it idle in the garage (door open) it will burn your eyes it was so rich.
Before i started i I increased the table by 15% just to be safe for putting it into OL. So part of the 25% I took out was that. Otherwise if you were to give the car a lot of gas in a high gear it would get so rich it would miss! Haha that is gone now luckily, but the amount that I've leaned it out does make me nervous too.
im using a innovate LC-2 WB (no gauge) and just have it plugged into my HOTubers
03-31-2017, 09:27 AM
#8
nskyline34, I strongly suggest you take your car to someone who's got some experience successfully tuning. You are grasping at straws, and often looking to make changes that are opposite of what you say you are trying to do.
Case in point, you say it is too rich, yet you thought running at 14.7 cruising was too lean and wanted to richen that up, when in fact 14.7 is exactly what it should be doing cruising. Regarding the rich idle, depending upon how big of a cam you are running that may just be something you have to live with. How big is the cam? What size are your injectors?
Case in point, you say it is too rich, yet you thought running at 14.7 cruising was too lean and wanted to richen that up, when in fact 14.7 is exactly what it should be doing cruising. Regarding the rich idle, depending upon how big of a cam you are running that may just be something you have to live with. How big is the cam? What size are your injectors?
03-31-2017, 09:44 AM
#9
nskyline34, I strongly suggest you take your car to someone who's got some experience successfully tuning. You are grasping at straws, and often looking to make changes that are opposite of what you say you are trying to do.
Case in point, you say it is too rich, yet you thought running at 14.7 cruising was too lean and wanted to richen that up, when in fact 14.7 is exactly what it should be doing cruising. Regarding the rich idle, depending upon how big of a cam you are running that may just be something you have to live with. How big is the cam? What size are your injectors?
Case in point, you say it is too rich, yet you thought running at 14.7 cruising was too lean and wanted to richen that up, when in fact 14.7 is exactly what it should be doing cruising. Regarding the rich idle, depending upon how big of a cam you are running that may just be something you have to live with. How big is the cam? What size are your injectors?
I agree the rich idle is going to just be the way it is, there is 16.5* of overlap so I'm somewhat stuck. Couple that with the LT's and how they cause o2's to be lazy at idle, it's not going to get perfect. I don't want to run the car in OL at idle, but I might have to. But the car is definitely better though. Had to change the injector end timing a bit to take overlap into account which helped a lot too.
Injectoes are 42# @ 43.5psi
thank you for the feedback fellas!
03-31-2017, 09:54 AM
#10
nskyline34, I strongly suggest you take your car to someone who's got some experience successfully tuning. You are grasping at straws, and often looking to make changes that are opposite of what you say you are trying to do.
Case in point, you say it is too rich, yet you thought running at 14.7 cruising was too lean and wanted to richen that up, when in fact 14.7 is exactly what it should be doing cruising. Regarding the rich idle, depending upon how big of a cam you are running that may just be something you have to live with. How big is the cam? What size are your injectors?
Case in point, you say it is too rich, yet you thought running at 14.7 cruising was too lean and wanted to richen that up, when in fact 14.7 is exactly what it should be doing cruising. Regarding the rich idle, depending upon how big of a cam you are running that may just be something you have to live with. How big is the cam? What size are your injectors?
Ive been screwing with the tune for about 14 months now (most of that has been learning HPTuners) trying to get the car drivable. I took it to a well known shop and I had to trailer it home because it wouldn't idle. So I decided to teach myself to do it. Well the car runs and drives pretty dang well now, so I'm going back through and trying to refine everything. I've been through hell with this tuning this thing. I have a guy that I'm waiting to get back from London to tune the car because I just want it done. should be back in the next few weeks I hope. But in the meantime I'm still trying to learn... Like I said, its getting closer. This weekend I'm going to recalibrate the WB and finish the VE and MAF then do a few WOT pulls (back in CL/OL) and see how it runs (timing and AFR). In definitely open to constructive criticism and please keep it coming. Haven't offended me yet! Lol but in all seriousness I do appreciate the feedback. I know everyone wants (and is) helping.
I dis did notice that the injector size in the tune is 53#.... Off hand I'm 99% sure 42# @ 43.5 psi doesn't scale upto 52# @ 58-60psi... Saw that last night.
03-31-2017, 12:54 PM
#11
We're running similar injector sizes but your cam's got close to 10 degrees more duration and quite a bit more lift than what I'm running. Unless you want to go OL on idle I think it's going to tend to idle on the rich side.
One thing I'll point out in your original post, unless you are running without MAF input, the VE table is not used for steady state operation - it's used for throttle transitions, and generally not used above 4000 rpm at all. Of course you should have values in it at the upper rpm ranges just in case of MAF failure.
One thing I'll point out in your original post, unless you are running without MAF input, the VE table is not used for steady state operation - it's used for throttle transitions, and generally not used above 4000 rpm at all. Of course you should have values in it at the upper rpm ranges just in case of MAF failure.
03-31-2017, 01:26 PM
#12
We're running similar injector sizes but your cam's got close to 10 degrees more duration and quite a bit more lift than what I'm running. Unless you want to go OL on idle I think it's going to tend to idle on the rich side.
One thing I'll point out in your original post, unless you are running without MAF input, the VE table is not used for steady state operation - it's used for throttle transitions, and generally not used above 4000 rpm at all. Of course you should have values in it at the upper rpm ranges just in case of MAF failure.
One thing I'll point out in your original post, unless you are running without MAF input, the VE table is not used for steady state operation - it's used for throttle transitions, and generally not used above 4000 rpm at all. Of course you should have values in it at the upper rpm ranges just in case of MAF failure.
Right now (for VE tuning) the MAF is off - so it's only running off the VE table. I've only been going upto 4000-4400rpm, and my high RPM enable for the MAF will probably be set around 3500 once done with both VE and MAF.
04-04-2017, 11:56 PM
#13
Safety Car
Put it back in closed loop and see how the short term trims look while driving around.
Leave the long terms off.
Create a table that maps stft against the VE table.
I'll bet it idles better with the MAF on.
Sounds to to me like you have done pretty well.
You are using HPT 3.4 correct?
Leave the long terms off.
Create a table that maps stft against the VE table.
I'll bet it idles better with the MAF on.
Sounds to to me like you have done pretty well.
You are using HPT 3.4 correct?
04-05-2017, 11:58 AM
#14
Yup the newest version of HPT.
It didnt make too much of a difference OL vs CL for idle for me - its still an idiot when it comes to that. BUT I'm hoping that this will help because I think part of the low speed surging is caused by the long tube headers making the o2's lazy and read lean - causing the computer to throw MORE fuel at it and making it surge. If this doesnt help too much, I might just try an OL idle tune and see.
I ended up putting the VE back to where it was because I did the VE table in SD, then before I did the MAF I put a hybrid tune back in it and it was really lean at cruise now. Havent had much time to look into why it went so lean at cruise in the OL/CL tune, when in the OL tune it was fine.
I mean lean - the WB read lean and you could feel the car was down on hp and was starving. So after about 10 miles I put the VE table back. I will figure it out hopefully this coming week if the weather ever clears up...
It didnt make too much of a difference OL vs CL for idle for me - its still an idiot when it comes to that. BUT I'm hoping that this will help because I think part of the low speed surging is caused by the long tube headers making the o2's lazy and read lean - causing the computer to throw MORE fuel at it and making it surge. If this doesnt help too much, I might just try an OL idle tune and see.
I ended up putting the VE back to where it was because I did the VE table in SD, then before I did the MAF I put a hybrid tune back in it and it was really lean at cruise now. Havent had much time to look into why it went so lean at cruise in the OL/CL tune, when in the OL tune it was fine.
I mean lean - the WB read lean and you could feel the car was down on hp and was starving. So after about 10 miles I put the VE table back. I will figure it out hopefully this coming week if the weather ever clears up...
04-07-2017, 05:38 PM
#15
They should be 50lbs @58psi. Do you know what brand the injectors are? Getting the correct injector data will help a lot.
How did you tune for the ls7 MAF?
Might be easier to start from scratch with a stock file if the tuner you went to messed it up that bad. Could save you a ton of headaches.
04-07-2017, 05:47 PM
#16
Just wondering, what is your PE ramp in rate?
You should run long scan and post it. Shooting in the dark with out a scan.
05-05-2017, 07:00 AM
#17
Instructor
Can you post your tune file? 14.7 isn't too lean for idle/cruising/part throttle. It's what the factory tune targets at all times other than when PE is engaged anyway.