can you assign a ve table to each bank on a v8

[kaeman]

I posted this in the general support also, can you setup the ms3x to use a separate ve table for each bank, on a v8. and if so how do you assign which table controls each cylinder. I am using semi sequential fuel and wasted cop? do I have to be full sequential ? At low throttle openings on an itb manifold one bank flows a little more air than the other bank, in the 1% to 5% throttle opening position the drivers side runs a little bit richer. I have adjusted the center links and can balance the banks at a given position and they always flow evenly at throttle positions above 6% but most of my cruising is done in the 2% to 4% open range.at idle the banks are even and above 6 they are even again. any ideas, I have used a manometer to balance the cylinders but, but just off idle the banks flow just a little bit differently.

[Yves]

Kaeman,

I've fiddled with the same thing. As far as I know you cannot assign a table to different banks.

On my setup each bank has a set screw acting as throttle stop. When turning the screw you take up more or less slack out of the rod system actuating the throttle blades. Going to far on the screw screw makes the blades on both banks open to far.
My passenger sides bank is the one that has the tps on it. Passenger side always ran leaner than the diver side.

I considered one set screw as the main screw to set the idle tps % (pass side) I considered the other one to take up the slack in the rod.
I then adjusted the set screw ever so slightly untill they were even but keeping the tps% the same. Although mostly they are in the ballpark, they seem to vary from one moment to the other.

[nathaninwa]

Could you run a wideband in each header?

[dontz125]

You can only use a single VE table, but you can use trim tables per injector in sequential or semi-sequential.

Do you have ITBs, or one TB per bank? Either way, if your banks are up to 5% off, you need to get out the carb synch gauges and balance them!

You can run a WBO2 in each bank; under the EGO correction settings, you can specify which cyl uses which sensor.

[kaeman]

I am running a wideband in each exhaust pipe, that's how I found the difference, I have done all kinds of adjusting on the manifold but if I fix the ratios at idle then the cruising speeds are out of balance, the wide bands make the corrections but I was hoping to be able to tune the different tables and make it less o2 correction. like I was saying its just in the low part of the tps that the airflow isn't equal, I used to be living is bliss because I had single wideband but when I got the dual wideband gauge it pointed out the problem (ignorance is bliss). I was just thinking you used to be able to do the bank to bank adjustments with the older systems using the main fuel outs on the ms3 board and assigning one bank to ve 1 and the other bank to ve 2. But with ms3x I don't see that option.

[kaeman]

Is this bank to bank ve table assigning a possibility? I just want to know if it can be done. I have adjusted the butterflys in the barrels, using a manometer and even with fine adjustments I cant get even flow at real low throttle positions, I can get the flow to be even at idle, but then off idle it will be flowing just a little more on one bank that the other. I think its just the difference in air travel path at the mostly closed throttle plates, one bank opens towards the valve and the other bank opens to the opposite wall because both racks turn the same direction. after about 10 % throttle opening the flows equal out and run fairly close up to wide open.
It would just be nice to be able to easily tune this kind of situation by assigning each bank a different ve table just like you can assign a different o2 sensor to each bank.. I haven't found this solution in the manuals.

[Yves]

Why not use individual fuel trim

[kaeman]

I didn't realize that you could use cylinder trim in semi-sequential fuel mode. I will run a couple new datalogs so that I can set the rpm and kpa load bin values so that the trim will correct the fuel to match the difference in the airflow at the low load cruise throttle position. I will look into this, thanks.
If I read the info correct, since I set up the correct firing order for the injectors and ignition coils, cylinder 1 is cylinder 1 and cylinder 2 is cylinder 2, not the second cylinder in the firing order (cylinder number 8.)

[dontz125]

I didn't realize that you could use cylinder trim in semi-sequential fuel mode.

*ahem*

You can only use a single VE table, but you can use trim tables per injector in sequential or semi-sequential.

If I read the info correct, since I set up the correct firing order for the injectors and ignition coils, cylinder 1 is cylinder 1 and cylinder 2 is cylinder 2, not the second cylinder in the firing order (cylinder number 8.)

The main injectors still have to be wired A-B-C-D = 1-8-3-7 or however your firing order is arranged. The *trim tables* use Table 1 = cyl 1, Table 2 = cyl 2, etc.

[kaeman]

Thanks, that's what I thought when reading the help file and the manuals.
I will be using the trim tables after I get the data logs analyzed. Trying to determine how much trim to add and subtract and at what kpa, rpm values.

[red-racing]

In MS2 you can assign each injector bank to its own VE table.
should also work with ms3.

but the easier way should be trim as metioned

[kaeman]

the ms3 doesn't offer that using separate ve tables per bank when using semi and full sequential on the ms3x, like the ms1 and ms2, my old ms1 extra had the ability to assign a ve table to each bank when using the main board injector drivers.
Using the individual cylinder trim isn't going to be fun when the difference is such a small section of the throttle position, but with lots of data and plenty of time adjusting the trim I should be able to work around this.

[jsmcortina]

With only two O2 sensors it is an approximation in any case. You can't tell whether it is just 1 cylinder running differently on that bank or the whole lot. Taking plug readings and making better adjustments using the per-cylinder trim tables is likely worthwhile.

James

[whittlebeast]

Try swapping the widebands. See what happens.

[kaeman]

That was the first thing I tried, I changed the wide band o2 sensors to the opposite sides and the problem stayed with the passenger side, it didn't follow the sensor, I left the sensor attached to the gauge and just moved the sensors, originally bank 1 was driver side and bank 2 passenger side which was reading richer, then I took sensor 1 and put it in the passenger side exhaust still connected to gauge 1 and put sensor 2 in the driver side exhaust, then sensor 1 was reading richer, meaning the problem was with the passenger side air flow.
I also found some old info from hilborn about the low throttle position difference in air flow from bank to bank, but they didn't feel its a problem as the intake manifold was setup to be all or nothing and wouldn't be in the low throttle area of operation anyways...... granted my manifold is 52 years old. manufactured in 1963....... I guess having to trim the injectors for the low part throttle cruising is just one of the things you must do to be old school.

[jsmcortina]

While certainly no substitute for individual widebands per cylinder, I've used a pyrometer to read individual exhaust temperatures and trimmed cylinders with that. It was also helpful for adjusting throttle plate position in conjuction with a carb balancing tool.

James