Tuning 304 11p 424

[RalphusGalkinsmelter]

Just posting to get some feedback off some gurus.
First time trying to adjust the VE table after logging a few drives. I have a pretty standard 304 / 4L60e. 304 has flat top pistons and Comp Cam 282-000-5. I believe the cam is close to stock apart from the 0.464" lift (214 duration on Inlet and Exhaust with 110 lobe sep).
I wanted to throw up a log a have done with my current bin just to see if anyone notices anything I haven't yet. Or whether I'm on the right path or not.
I've experienced a couple of stalls after 10-15min of driving, so I've kept the test drives reasonably short in-case I breakdown too far from home.
I also played around with the spark tables, but I didn't get too carried away apart from matching the idle spark and the main spark tables around idle kpa.
What I have noticed is that when I come off the pedal/ downshifting when coming to an intersection, my wideband jumps all over the shop, mainly leaning out into the 16-18 afr, and also drops below 13 afr on take-off / upshifts. I don't quite understand the AE and DE side of things but is that something I should look at early in the VE table mapping?
Any help would be appreciated.

[pman92]

What I have noticed is that when I come off the pedal/ downshifting when coming to an intersection, my wideband jumps all over the shop, mainly leaning out into the 16-18 afr

DE and / or DFCO. It will lean out under decel, and cut full completely under hard decel.

and also drops below 13 afr on take-off / upshifts.

AE. It will richen under load.

Log your target AFR along side the actual AFR from your wideband.

Dialing in the VE table requires steady state conditions at all the different RPM/load points. So you dont have these enleanment / enrichment effects at play.

[immortality]

You can disable DFCO whilst tuning and take that variable out of the equation for now.

[Deuce]

You can disable DFCO whilst tuning and take that variable out of the equation for now.

Also turning off lean cruise helps get VE dialled in better.
Also the histogram spreadsheet speeds things up a bunch.

[RalphusGalkinsmelter]

Sweet ill have a look into those!

Also separate from that, I just found out I could customise a histroy table for CalcVE? Is this a hack?

[immortality]

No, no hack. Some people really thought this through when they created 11/12p.

[Deuce]

Sweet ill have a look into those!

Also separate from that, I just found out I could customise a histroy table for CalcVE? Is this a hack?

CalcVE is what the ECU has calculated it to be based on its position across your VE map (ie between cells).
It is not anything to do with your Wideband readings unfortunately.
Use the spreadsheet.

[antus]

Thats not correct, it is tunerpro calculating a new VE from the existing VE, target AFR and difference in offset to wideband as measured in the real world while you drive. The downside is that it does not ignore AE and DE, and there will be some small lag between the bang in the cylinder that its measuring the the exhaust gas measurement getting back to the PC. In general, if you start with a smooth VE it'll make a right mess of it turning it in to a porcupine as you go if you copy paste the whole calcVE histogram back in, and as the VE gets more rough, so does your injection, and in turn makes the calcVE even less accurate and more porcupine like so you end up going backwards.

What it is good for is observing trends. If you look on the monitor page at target AFR overlayed with wideband AFR, then you can scroll through the logs for where the widest differences are, look at the TPS and RPM and see if the car was under AE or DE, and then you can see where your biggest problems are, and see the trend for part of your VE being too high or too low, as well as closer to where it should be from calcVE. Then you can use that information to offset an area of the map up or down closer to where it needs to be and test again. Example if you can see TPS was at WOT, then went back to zero and rpm started falling, you'd expect to see wideband and calcVE go super lean, and that is not a problem or a correction that needs to go back in to your VE. If you see cruising at 30% TPS and you see VE is say 80% and calcVC is 70% then you might want to apply a correction in that area. Without calcVE you can still see the offset between wideband and target AFR and know where to correct and in which direction, but calcVE helps give you a suggested number.

For it to work your wideband needs to be properly calibrated. A wideband with a gauge and analog to the ECM is useful because you can look at the two side by side and see if there is an offset. If there is you can modify the wideband high and low volts scalars to offset one or the other end of the scale a little to get the wideband reading correctly first.

[RalphusGalkinsmelter]

Cheers Antus I have been doing that slowly and it has proved positive results. As for the main spark map, is that something I should mess with without going on the dyno? I don't have knock sensors for safety and a little apprehensive

[antus]

Its a good question. For absolute max power, I would say no. But I have put this computer on a completely different engine, so we did not have a good spark map to begin with and my mate took it to the track and he could feel flat spots here or there. And we did give it a bit more timeing in those areas until it felt right. We did not destroy the engine. But, you do need to know what the engine knocking sounds like, listen closely, preferably with knock ears though I have not done that part myself, and if you don't notice much or any power gain adding timing pull it back to where it was. You have probably reached max torque and are at the dangerous point where it is starting to knock but you cant hear or might not notice it yet. This won't kill the engine immediately, but it will over time. I've noticed the last 2 or 3 degrees before knock tend to make no 'butt dyno' noticeable power difference, and if you don't get any gain its not worth taking the risk of damaging the engine. Back it out a bit and be safe. At the end of the day there is risk, you can gain, but you can also damage your engine and how far you want to push it is up to you. I've also noticed dyno shops often don't tune spark, only fuel, I guess because they want to see cars go out the shop performing better, which they will with better fueling, and not take the risk on spark. In general the shape of the spark map should be similar to the VE table and if you know things like RPM that has peak toque there are calculators online that can give you a generated spark map. This is often a good way to get good usable timing on an engine conversion without taking the risk to find the absolutely best spark everywhere in the map.