i have an 2003 sunfire running hahn stg 2 kit setup up directly as the manual says. except that i have a 2bar map sensor installed, cat deleted, o2 sensor deleted and a aem ugeo wideband


--i have the fake 2bar setup on HPT (following Shifted's stick)
--i did the calculation for larger injectors (following shifted's sticky) and inserted it into my injector constant
(i thought i read the stock eco injectors were 24#s...can someone verify this?) so i did the math 24/32 x stock injector constant. so it came out looking like this .17800(32/24)= .13350
--i made my IPW multiplier vs VAC all reading 1
--i turned my closed loop off by making the coolant temps set at 256
--i set my desired PE BASE AFR VS ECT to 11.8 and the MULTI VS RPM set to 1


1) when im going to be tuning this should i leave the car how it is and tune it or should i be opening the nozzole on the FMU all the way to basically bypass it as if it wasnt there?

2) again i remember reading when tuning VE table i lowering the values in the table adds more fuel? and that our motors like an AFR around 11.8:1 when boosting.

3) the VE idle table goes to 1600rpms and the VE high rpms table only starts at 3800 whats there to do about the rpms inbetween bc if the turbo is spooling up i dont want the AFR to lean out bc i dont have access to those rpms. or will the VE idle take care of the rpms between 1600 and 3799 by reading the last value in the VE idle?

4) ok whats the point of doing the VE tuning with closed loop turned off? bc i have an 03 pcm which means im always in closed loop unless its first strart up and such....and i apparently dont enter open loop at WOT. so why would i turn off closed loop then tune and just not tune for closed loop?

thanks, thats all i can think of right now im sure ill come up with other questions later.




MY 2003 SUNFIRE 15.17@90.82mph N/A....More times to come after turbo install

"A N/A ecotec is not gonna give Honda's and Mitsu's that much of a run for their
money unless their blown or bottle fed.GM is still smokin crack!"
~1QWKZ24
www.streetracing.org, 08/2001

1) I am curious why you are using an FMU if you are tuning with HPT, it is not needed.

2)if you lower the VE you will LOWER the fuel delivered

3)there should be a idle, low RPM, and high RPM (high and low octane.. so 6 tables)

4)a.you tune with closed disable so the computer doesn't adjust anything. You control exactly what you want and get it very close for your exact setup... then hopefully the PCM will only have to adjust a few % instead of 10-15%

4)b.at WOT I believe you do not enter closed loop... so you would not have to disable it for this portion. But you will likely do some WOT pulls and normal driving stuff, so we just hit all of it at once.. WOT should be tuned at a dyno and have it done by a pro... it's worth $200 to save your engine,


HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED

i know i dont need the FMU but the shop put it in anyway. ill get to take a look at it monday when i get it back. as for the daily driving and WOT driving i planned on having it run pig rich and then take away fuel as i got closer to the AFR i want to see. and i see where the low rpm charts are i guess i just skimmed past them. but what i planned on doing was just dirinvg the car around for a little bit with out the tune and just run the FMU and then get rid of the FMU after i was done the tune and it was on my PCM. i understand how the VE tuning works i was just mixed up on changing the values but now u got me squared away on that. thanks



MY 2003 SUNFIRE 15.17@90.82mph N/A....More times to come after turbo install

"A N/A ecotec is not gonna give Honda's and Mitsu's that much of a run for their
money unless their blown or bottle fed.GM is still smokin crack!"
~1QWKZ24
www.streetracing.org, 08/2001

you forgot one step in your open loop tuning file, you need to disable DCFO otherwise everytime you back off the gas you will create a false lean spot on your histogram for that rpm/tps cell

as stated less VE , less fuel delivered

the idle tables are a reflection of your high and low rpm VE tables are thats not where you should be making your adjustment, correct the high and low, and the idle will follow automatically

if you put 255 in accross the board, your in open loop WOT or not or at least as much as your going to be

as far as tuning WOT at a dyno, thats nice, but its not needed, others here will disagree and thats thier view

This is how I did things:
After doing all the steps in shifteds sticky on here about creating your open loop tuning file, bring up the low rpm VE histogram and your wideband should be constantly comparing your actual AFR vs what your PCM is commanding and then calculating the difference which you can view on your chart and make sure also to be using the average values and not the max or min, as that of course will throw off your results

Go out for a drive and hit as many cells as you can in the low RPM VE, red usually indicates a lean spot I generally aim for 0 to 5% error, your never going to get it exactly within 0% now after you have gone out for a drive and you look over things, paste in the results to your VE table , smooth, and repeat this process at least 2 more times, by then you should be in that window of 0-5% error or less, also make sure you do this all in the same day otherwise your results are not accurate as temputure factors big on how an engine computer does its job. After you have your low rpm table which is 4000rpm and under you should see a pattern.

The pattern your looking at is the VE on the bottom 2 rows there should be an upward trend that lasts until about 5-6 then goes back down slightly, you will see this reflected on the factory VE table, now at this point you start with the first few columns of the high rpm VE table and look at the differences between where your low rpm is and where the high rpm is, you can manually enter in numbers slightly greater for the first few cells say from 4-5k with an upward trend from where your low RPM leaves off, save it, go out and work the 4-5k range, if your off its not going to be by a dangerous amount. Log your run and come back and paste in your new 4-5k range values, then do the same thing for the 5-6k range and so forth

Point im getting at is dont go out and just rip into the thing all the way to redline with stock ve tables, work yourself into the higher rpm range, I dont like to use the word guess, but its essentially what your doing, your using the data collected in the lower cells to predict where your going to be in the higher ones, thats all your pcm does essentially anyway, it takes the information its given and gives a solution based on patterns. Dont be in a hurry to get done, the more time you spend the better it will be.




1989 Turbo Trans Am #82, 2007 Cobalt SS G85

well right now im running a slighty tweaked hahn tune. it read 12.0 across the board and it made 211whp and 212wtq...the tq already peaked but the HP didnt peak. he shut it down at 5500 and the HP was still building, unless it peaked exactly when he shut it down which could be a possiblity



MY 2003 SUNFIRE 15.17@90.82mph N/A....More times to come after turbo install

"A N/A ecotec is not gonna give Honda's and Mitsu's that much of a run for their
money unless their blown or bottle fed.GM is still smokin crack!"
~1QWKZ24
www.streetracing.org, 08/2001

Hypsy I believe made 224 at 7.9 psi with that kit from one of his old posts so its safe to say if it was still building you would be closer to 220

From the dyno sheets ive seen of the Hahn prototype car for that kit they were pretty flat on the power curve from 3-4 up



1989 Turbo Trans Am #82, 2007 Cobalt SS G85

Rodimus Prime wrote:Hypsy I believe made 224 at 7.9 psi with that kit from one of his old posts so its safe to say if it was still building you would be closer to 220

From the dyno sheets ive seen of the Hahn prototype car for that kit they were pretty flat on the power curve from 3-4 up

The difference in #s can easily be the fact it was done on different dynos though.


___________________________________________________________________

very true, me and QBE tried the fake 2 bar over the weekend and quite honestly all it did was make things worse

we went back to the one bar and now we are making bigger gains



1989 Turbo Trans Am #82, 2007 Cobalt SS G85