What am I missing/overlooking

[TurboJim]

Put a bung in my DP and installed the O2. Set up closed loop parameters of 800rpm low 6000 rpm high, 120 enable temp and closed loop enabled, and there is 0% correction displayed at ANY time. My target AF is 14.1 and actual varies from 13.6 to 14.5. When does it start correcting? I wanna start tuning this thing. How will I know what it wants. I cant watch target/actual and grab VE areas and modify them while I'm driving.

What are "normal" VE numbers for a 231 ci motor w/stock long block? I dont know but it seems I had to make a lot of changes to the base program that comes burned on the unit. And what timing ranges do these things like on pump gas? Is it exactly the same as on a chip? Cuz the chips crank offset is like 24* and this one is 10*. Should the FAST unit be 14* lower than I do on my chip?

What am I missing or overlooking? I KNOW I'm not that close right off the bat...

 

[TurboJim]

OK RTFM (read the darn manual) and I see I have my CL high set wrong.

What about any VE/Timing hints?

 

[TurboTR]

10 deg ref angle is right since the Buick ref pulses (should) occur at 10 deg BTDC. That said, do the right thing and still double check that the actual timing is correct, which also verifies that the Bypass line is working, the interrupter wheel hasn't rotated on the balancer some, etc.

IME the supplied program is pretty much for an example only. Keep in mind that since this is speed density it's going to be very sensitive to the VE numbers you supply it with. The actual VE numbers some of us see start at around 30 or so at idle and rise to the mid 80's or so at higher MAP. The ones in yours will depend on alot of things, like what the inj constant is set to compared with what the inj actually are, what the inj response time number is set to (at idle with 160's , etc.

There's a learning curve, but in general it's a very positive experience IMO Nothing you can't lick in no time I'm sure.

TurboTR

 

[bobc455]

TurboJim-

Don't worry about the next guys VE numbers, the program that comes with it is only intended to be an example and get your car started.

For VE, be sure you have O2 Corr% on your dashboard, then just follow the bubble around the VE table as you're driving and change the VE number until you get very little correction (<6% is fine) at most of the important cells.

For timing, just keep advancing it until your knock sensor starts to tell you that it doesn't like it. (Not 100% accurate, but you're smart enough to know the rest)

-Bob Cunningham
bobc@gnttype.org

 

[TurboJim]

Originally posted by TurboTR

IME the supplied program is pretty much for an example only. Keep in mind that since this is speed density it's going to be very sensitive to the VE numbers you supply it with. The actual VE numbers some of us see start at around 30 or so at idle and rise to the mid 80's or so at higher MAP. The ones in yours will depend on alot of things, like what the inj constant is set to compared with what the inj actually are, what the inj response time number is set to (at idle with 160's , etc.

Heya Todd!

OK, then I guess I have a problem. Because my idle Base Fuel #'s are in the 50's and 60's to get it to hold a 14.1:1 idle AF and not stall. Any leaner and I get rolling and stalling when put in gear and when the cooling fan comes on. I played with idle timing etc and got it to idle at a pretty steady 900-910 wihout stalling. It still hiccups when the fan comes on or put in gear, but if thats as good as it gets I guess I can live with it. I havent started to work on part throttle yet. Just idle and off idle. Its almost as good as my chip, but has a slight hiccup when the pedal is blipped.


I wonder how much of this is due to the injector opening time parameter. Is there any place I can find out like average opening times? I am still using my 50's right now, but will be installing 65'sa next week. Theyre both Delphi injectors so can I assume their characteristics are similar?

 

[Eric Stage I]

Jim,

Here is the program I'm using. Mines a 4.1 with 52# injectors, but maybe you can get some info from it. I had a similar thing with the idle until I brought the a/f down to 13:1 to 13.5:1. It's set up to go into closed loop above 800rpm.

As far as timing, I used 18 degrees at WOT for a long time and ran 121-122mph. I bumped it up to 22 and ran almost 124 (no other changes). Right now, I've got the timing dipping down during spool to see if it will spool up faster (I can't tell if it worked yet).

Here's the file:
http://home.kc.rr.com/erm/eric52inj.gct

Eric

 

[TurboJim]

Well, I troed base timing at 20ish, made the car idle like crap. Hunted real bad, almost sounded like it was loading up althojugh AF was falling to 15.6:1+

Put it back where I had it and idles MUCH better. Next step is to verify the crank offset I guess.

Attached is my gct file which is running decent, Off idle is "good", idle is "ok" (seems to still wander a bit at 850 or so, dead steady at 910 :shrug part throttle seems to run well, I havent touched the higher areas yet. I figger its best to leave em fat for now. although I still have some work to do. Todd, I gotta try that overlay thingy...? Wouild be nice to see a cursor instead of going to the log, ok, 148kpa and 3700, 3800, 3900 etc

http://www.turbojim.com:231/jim/jim525.gct

Any opinions/tips are appreciated

 

[TurboTR]

Well I'd say the a/f ratio going that lean at idle is why it's not doing well, not because idle timing is in the 20 deg range. That's where I've always idled mine anyway, and the stocker idles in that range too.

The overlay, basically all you do is log data, then go back to the VE table and hit "o" for overlay.

TurboTR

 

[Eric Stage I]

Jim,
I noticed in your file that you're using timing trim for idle speed correction. I always had a wacky idle if I used that table. I ended up zeroing it out. It also looks like you don't have closed loop coming on until 6000rpm (maybe you've already changed that). One last thing, the program is set for a 2 bar sensor instead of a 3 bar (unless you're running a 2 bar sensor).

Eric

 

[TurboJim]

Oops, looks like I didnt save yesterday. I'll save the tables today and re-upload. Yes, I put my 3 bar MAP in there yesterday and changed that. I changed the CL high and low parameters, but will zero out idle timing trim and see what it does. I just altered the base cal to see if it would help.

Dont you think my base fuel map is kinda high from 0 to 70kpa and 0 to 3000 rpm though? Much lower in the idle region and it stalls, rolls, sputters, correction goes nuts etc. This is a stock long block mind you. No 250+ inch stage motor.

 

[Eric Stage I]

If it makes you feel better, mine wouldn't run at all on the demo file. It would immediately stall. I had to increase the ve's in the idle range to the 50-60's. Your's does seem alittle high.
What kind of o2 correction is happening when the car is fully warmed up? Does it start pulling fuel?
Just for kicks, I may load your program into my car today and see if I can recreate your condition (I'll change the inj constant and engine size to match mine).

Talk to you later,
Eric

 

[TurboJim]

Idle correections for the m,ost part are under 1%, it does pop to -3.9% for a little bit.

http://www.turbojim.com:231/jim/526idle.log

 

[norbs]

Hrmm,

Drive the car and use the L key on STEADY state drving conditions, to set the Ve close to where it should be. THis only shoud be used on steady drving, not hard accelerations. While driving press the space bar to keep the active cell in the cursor and press the L key, keep doing this for different rpms on steady condtions. Car has to be in closed loop and warmed up. BTW if the high Cl rpm is over 6k, you better have an INDY 14k rpm motor.

 

[Eric Stage I]

Jim,
I guess our cars are too different to compare programs. I loaded in your program and changed the injector constant and engine size. It would barely run. The o2 correction was always at -25%. Oh well.
I don't think you're that far off anyway. Once you start driving the car around more often, you'll get it tweaked in. I still tweak mine after months of driving to try and get that "perfect" program.

norbs, does the L key work with the windows version, or just dos?


Eric

 

[norbs]

As far as i know it only works in DOS. Too many people were trying to tune the car under acceleration or heavy throttle, and were ending up with bad results (including me). So i guess they decided to leave it out. However, if your map is way off in cruising, it is kinda neat to watch the o2 correction, decrease almost to zero, with this feature.