OK so in currently working with a 10psi + turbo eco running 650cc injects with stock regulated 2002 Spec fuel rail
Injector constant is at .06885 from the stock .17760
We got the low end VE table pretty much dialed in, its smoothed, a thing of beauty, no problems there, however the lowest cell is 48 which is at 0 throttle at 1000 RPM, now in order to achieve the desired AFR under boost in the high RPM table some cells are up to 15 off what they need to be.
In order to hit higher VE numbers the VE offset must be moved up from the stock 20% which would only allow for a cell of 120, this is nowhere near enough fuel, so we kept working up to 80% VE offset and this pretty much dialed in the upper end, now the problem with this is that with the VE offset at 80% you cannot make any value less than 80 in the low RPM table, this causes a rich condition all through the low RPMs and idles at about 12.0 AFR not an ideal situation at all. In fact it seems like the higher the VE offset goes the worse the car runs.
There must be some way of scaling things wider so that you can hit a wider range of VE otherwise this program is basically junk to any eco with more than 230whp because in order to provide enough fuel for top end the low end will be overly rich.
I have a few ideas of what maybe could fix the problem, playing with the injector constant a bit, or the injector pulsewidth vs vacum table (which is all set to 1s right now) per the VE tuning sticky.
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Again Matt, this is not HPT's fault, its GM's. HPT didn't pick using the VE offset, thats just the way it has to be done in the ECU.
I was rolling this over in my mind after you called last night, and there is a way to do it.
You can either use the IPW modifier at the lower MAP signals, but be warned that it may affect coastdown IPW's as well, or you can richen up the injector constant and bring the idle VE back in line.
Personally, I'd pick the latter. Size them for 500cc, even though he's using 650's, that should allow you to bring the idle back down to where you want to be, and use a lesser VE offset.
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Got ya , same thing happened to me last night I kept on thinking about it
I also was thinking same thing on the injector constant, makes sense, we'll give that a try
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Shifted wrote:Again Matt, this is not HPT's fault, its GM's. HPT didn't pick using the VE offset, thats just the way it has to be done in the ECU.
I was rolling this over in my mind after you called last night, and there is a way to do it.
You can either use the IPW modifier at the lower MAP signals, but be warned that it may affect coastdown IPW's as well, or you can richen up the injector constant and bring the idle VE back in line.
Personally, I'd pick the latter. Size them for 500cc, even though he's using 650's, that should allow you to bring the idle back down to where you want to be, and use a lesser VE offset.
Ok, but wouldn't that affect my upper rpm VE values? like 180 VE is only 180 VE on an ECU programmed for 500cc injectors.
This is just a PITA.. I sold ym fmu because I didnt want to go back to that band aid but it seems like one of the only feasible options...
Ok secondly... why would my af's get worse with the more VE we add? My pump running out of volume or what?
LE61T PTE6262 Powered 
Rodimus and Shifted I also ran into this issue when I tuned Cory's black Sunfire Ecotec with the Hahn turbo kit. The VE offset would work great in high rpms and mid range but the offset had to be raised so much the low rpm and idle fuel tables were practically undriveable. At that point in time what I chose to do was leave his FMU on the car and adjust it to have a gain under boost of about 3:1. This allowed me to account for the extra fuel we needed in the mid and top end of the rpms but also still keep the injector constant and pulsewidths close to what they are supposed to be. This allowed me to still tune in the idle and low rpm tables perfectly and we were able to also get the upper rpms into a very nice afr of high 11's. I wish there was another way to do this and if anyone knows of a way let us know. If the VE offset would still allow for lower numbers and a wider range we would be set. Anyways that was my solution to the issue, even though it still requires running an FMU that's not exactly a bad thing as long as you can still tune in your injector constant and fuel tables to obtain good AFR's throughout the rpm range as well as having near stock driveability.
"Horsepower is the Ultimate Accessory"
According to Acer his car is tuned perfectly at 15 psi and idle, although he uses the IPW's and experiences no fuel cut of in DFCO (sp?)
So I am waiting on ACER's HPT File so Rodimus and I an go over that.
Jimmy: Yeah Rodimus and I came to that same conclusion of me putting an FMU back on my car, but we want to avoid doing that in any possible way. So we might use ACER's file and just change the auto tranny settinds or whatever we have to do...
LE61T PTE6262 Powered
All of you guys hate on Chris(sweetness), but that was his plan from day one...was to keep his fmu along with hpt. So it seems as tho it isnt such of a bad idea after all eh?
i've never hated on Chris at all. His project is massive and he is building something no one has ever seen in the qaud 4 community, major respect to him. As far as the fmu goes i am running an FMU on my 2.4 right now as well, it is set to a 1:1 ratio which is what most ecu's that recognize boost see anyways. My afr are exactly where i want them now and have been pretty easy to manipulate and work with. I think it would be nice to remove the fmu altogether if possible, but leaving it on the car will in no way hurt anything as long as you figure out how to make the hptuners and fmu work together to achieve a desirable AFR. Either way it will work, good luck though guys, the ecotecs are alot more difficult to tune than the LD9's have been for me thus far. As always this is a learning process and there's still much to learn and experiment with
"Horsepower is the Ultimate Accessory"
QBE (The Boosted One) wrote:Fst Cavy wrote:All of you guys hate on Chris(sweetness), but that was his plan from day one...was to keep his fmu along with hpt. So it seems as tho it isnt such of a bad idea after all eh?
All?
Ive never seen hate towards him... maybe it was a while back
whatever...
QBE (The Boosted One) wrote:According to Acer his car is tuned perfectly at 15 psi and idle, although he uses the IPW's and experiences no fuel cut of in DFCO (sp?)
So I am waiting on ACER's HPT File so Rodimus and I an go over that.
Jimmy: Yeah Rodimus and I came to that same conclusion of me putting an FMU back on my car, but we want to avoid doing that in any possible way. So we might use ACER's file and just change the auto tranny settinds or whatever we have to do...
I do have 14.7 -15.0 at idle, and 11.3 under boost... i did this with the ipw box (last map under the injector constant... its the only box that gave me results when i was tuning originally..) i have no idea what table/map it actually affects, or multiplies, lol... i just kinda change it when i need to add or remove fuel for boost.... i guess if you knew what table it multiplies you can use it to the multipler to get the other table in the area and then use that other table to smoot per rpm... im not sure how it ties in map to that other table... does it mean that other table is map vs rpm vs throttle pos?
anyways... i have always had problems with my dfco.... i have to be slowing down from like 70 to get it to turn on, and then it only stays off until like 45 . . . . . . it might have to do with that ipw table, it might not, i have no idea... if i did, i would fix it!!
anyways, that table does work, and very well, its extremely sensative.... changing a hundredths changes your airfuel under boost by .5/1 a/f
|Forged 8.9:1 Wiseco Pistons|Forged Eagle Rods|HPTuners|60trim|Tial Wastegate|
|Precision Intercooler|2.5" Exhaust|2.5" Charge Pipes|630CC Mototron Injectors|
|Stock: Fuel Pump, Transmission, Manifold, TB, Head, Head Gasket, Ignition, Suspension...|
you have the most wacked tune file ive ever seen, im surprised that your car runs, you have your PE set to 7.75 AFR and you cut off about 15 degrees of timing
your DCFO has nothing to do with the injector pulse width vs vac table, the puse vs, vac table cannot read boost so your not gaining fuel under boost at all your just increasing the pulse across the board, as soon as i fix Phils Ill be sure to send you a copy
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Rodimus Prime wrote:you have the most wacked tune file ive ever seen, im surprised that your car runs, you have your PE set to 7.75 AFR and you cut off about 15 degrees of timing
your DCFO has nothing to do with the injector pulse width vs vac table, the puse vs, vac table cannot read boost so your not gaining fuel under boost at all your just increasing the pulse across the board, as soon as i fix Phils Ill be sure to send you a copy
Hey man,
I appreciate you willing to send me that file!! It will help me out a lot...
Like I said before, those numbers never really helped me out... The IPW Multipler vs. VAC table always has done the trick...
and, as for the timing issue... When im at 15LBS of boost my table is set to be at around 17 degrees of timing, people have told me that i should be at 20, and maybe i should, but im scared to push it
but 15 degrees off? That would put me at 32 degrees of timing advance at 15psi!!!! Isnt that way to much? or am I mistaken?
|Forged 8.9:1 Wiseco Pistons|Forged Eagle Rods|HPTuners|60trim|Tial Wastegate|
|Precision Intercooler|2.5" Exhaust|2.5" Charge Pipes|630CC Mototron Injectors|
|Stock: Fuel Pump, Transmission, Manifold, TB, Head, Head Gasket, Ignition, Suspension...|
No it's not unless you see knock... or elan afr's
LE61T PTE6262 Powered
since your using a 2 bar map sensor that changes everything
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Rodimus Prime wrote:since your using a 2 bar map sensor that changes everything
yep!
|Forged 8.9:1 Wiseco Pistons|Forged Eagle Rods|HPTuners|60trim|Tial Wastegate|
|Precision Intercooler|2.5" Exhaust|2.5" Charge Pipes|630CC Mototron Injectors|
|Stock: Fuel Pump, Transmission, Manifold, TB, Head, Head Gasket, Ignition, Suspension...|
QBE (The Boosted One) wrote:No it's not unless you see knock... or elan afr's
ima have to ask suncavi again then... sounds like it makes sense though...
|Forged 8.9:1 Wiseco Pistons|Forged Eagle Rods|HPTuners|60trim|Tial Wastegate|
|Precision Intercooler|2.5" Exhaust|2.5" Charge Pipes|630CC Mototron Injectors|
|Stock: Fuel Pump, Transmission, Manifold, TB, Head, Head Gasket, Ignition, Suspension...|
reason i was confused about your spark tables is i was not aware you were using a 2 bar tune
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
