The G should get the red X to follow the active bin.

Then by taping the Q or W to raise or lower that point. The ECU reacts but needs to be burned in to retain.

No typing involved, you get lost doing that. I have had my share of Motec, type enter type enter, keeping up on a Dyno was horrible with that.

OK, the B&G code apparently highlights the active bin automatically, but I haven't seen a red "X".... so I'll try the Q and W to see if that works.

As I raise or lower the value, what should I use as a guide for the proper tuning point? Highest rpm as with a carburetor? Most stable AFR? And should I begin with the VE table or AFR table?

Frank

It will guide you to the settings in your AFR table.

The default tuning screen should have what you need there otherwise you can change all the guages to get what you need.

OK, I found the red "X" on the 3D scale. When the MS manual says to generally tune for "lowest MAP", are they referring to the 3D graph.... or Manifold Air Pressure? I tuned it to lowest manifold air pressure in about 3 bins and burned those. The idle is now very smooth from 650-1100 rpms and AFR is generally around 13.5, so it was cycling up and down because it was lean.

What I don't yet understand is why the EGO correction is above 100% - sometimes 170% and why the VE values that I've now saved are not evenly interpolated between bins.

I need to deal with the oil leak before I go much further. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

Frank

Hate to suggest this, but what about a different throttle body that has direct support for the MS, like the 3.8 GM supercharged unit ( added bonus a good flowing MAS built on )?

It would have a much sturdier IAC setup that is easier to find & cheaper to replace.

Ed

Ed, that may be a very good idea, if this one doesn't do what I like. Thanks.

Frank

Charlie, I've been chewing on this a bit and am curious if I have it right:

VE tables are for the range of a given bin - say the 500 rpm spread from 1000-1500, where operation is between those rpm levels. Fuel needs (and VE) are dependant upon - and counted by - the number of ignition events (rpms), so VE would be significantly different at 1001 rpms from what it would be at 1499 rpms.

So, if I want the 3D plot to look smooth from bin to bin - and to give the best chance of the ECU reacting correctly through a bin at all rpm levels, I really need to tune the bin at the mid point between the limits. In the above case of a bin range of 1000-1500 rpms, I should tune at 1250 rpms to best cover the spread range.

Am I on the right track here?

Frank

The ECU will interpolate between the bins.
Such as if your highest bin is at say 5500 rpm, you can still run the engine up to 7000, the ecu will use the last bin it was at. Also different code versions do there lookups in different ways so this varies some.
When I am mapping I work a session and then go back when allot has been done and smooth the curves. Then tune again and check to make sure the engine was not asking for something we consider weird.

On of what takes awhile to grasp is that we can not tell the engine to do what we want. We just need to respond to and give what it asks for. My previous paragraph of going in and smoothing the numbers contradicts this and that is whey we tune again to check if it is right to have changed them.

B&G code uses very odd ways for filtering the O2 input. You can work with the settings and get it to respond better. It may also be set to work at higher revs for when you start tuning the driveability.
Are you going to be able to get on a dyno or are you road tuning?

If road tuning, readup and get the auto tune working.

I've spoken with a local dyno tuner who has never worked with MS, but tunes a lot of race cars that use other ECUs. His dyno is not a steady-state type, but he claims it makes no difference. When I asked if he thought he could tune the MS, he said that every ECU he has seen is similar, so he thought he could. When I asked how he could tune ignition timing across all of the individual bins without a steady-state dyno, he said "timing's timing.... doesn't matter".

These answers seem a little "seat-of-the-pants" to me, but I don't know enough about the procedure to separate BS from fact.

I'd like to get it running well enough to drive cautiously (no boost) so I can drive it to a shop for larger exhaust work before going on the dyno.... then I won't have to tow it. I guess I should use auto tune so I can drive to the exhaust shop and dyno.

I also need to figure out how to tune the start/warmup parameters so it'll start easily and idle without throttle input when cold.

Lots to learn.

Frank

Sounds like the wrong dyno to use.
A dyno is only as good as the operator, it makes no matter what type the dyno is. You are paying for the guy that operates the dyno, not the dyno itself. The dyno tells you nothing, it only give a report. One must decipher what it is saying.
Every engine I have tuned is down on power when I leave the dyno. The operators go, come on two more pulls, lets get the timing up there and make some power. Drag race mentality. on a road course the last 3 HP does not matter if the engine does not last a 1/2 hour session. I have NEVER lost an engine to tuning. Many of my Subaru customers loose the engine on the dyno, just short of torque peak. Detonation every time. I am glad they are not my engine builds, I only do chassis work on Subarus.

Your timing curve will need some fiddling but looked safe, in the long run it will need more timing at low KPAs for economy. Essentially it is lacking vacuum advance.
You will need to find where the torque peak is, that is the most critical spot. Then readjust the RPM settings so you have a row of bins corresponding to the peak. The engine will have a fuel curve climb to torque peak and then taper off after peak up to rev limit.
The timing will be similar but may climb or decrease after torque peak. It will say what it wants.

I have engines that are road tuned running MS, you can have a full functioning vehicle that never spun a dyno. The dyno is just faster and safer.

I use throttle stops on a dyno, It can be a slow pull with only 20% throttle. Most unknowing dyno operators just want to open the throttle on the first pull. Do not do that.
I hate the phone calls, oh the oil pump failed. No it didn't, the bearings were hammered out from detonation and the debris got picked up by the pump! Damn Subarus.