Hello, i'm trying to program an 808 ecu and I need a little help to get me started. How do I work out Volumetric Efficiency (VE) as a function of MAP and RPM and also Main Spark Advance vs MAP and RPM also is there a way to work out the BLM Is there any easy way of doing this. If there is a formula available that would help. Know of any good sites to find some info, I've had a look around but haven't found much so far. I'm new to all this and i'd like to learn it as it is very interesting. Thanks

Alright the following is what I came up with while using Desktop Dyno 2000 now all I need to do is work out how to put that into a proper VE table and do the Spark Advance. Could someone help me out? I'm willing to do it myself I just need to know where to begin.

Also why does it start at 2000rpm? My engine redlines at 5500rpm do i need to worry about the rest above 5500?

Thanks

Hopefully i'm on the right track.

Well, FWIW -

If it were me, I'd first get a copy of TunerCat editing SW, and a copy of the def file for your ECM. I've found that the 3-D spark & fuel tables in TC's GUI make them pretty easy to understand. (Assuming here that the 808 has 3-D tables, I've never looked at it.)

Then I'd find a .bin file for a similar engine, and compare and contrast the existing design to the one you propose to run. That should get you pointed in the right direction...

Using DD2000 is a good way to see how the VE curve is shaped, but it only shows you the 100 KPA line - the rest has to be interpreted form engine data. Looking at what you posted, are building a Jeep or a tractor of some kind? It doesn't look like you are going to need to worry much about what the curves look like after 5500 rpm... HTH

Well I have a copy of winbin and the required ecu and bin files for the 808. Winbin does do 3D tables but I still don't understand it. It looks to be very similar to Tunercat in what it does.

Any idea how I can interpret the data from DD2000 so I can have the full VE range?

The engine i'm building is a 202, it's a 3.3lt inline 6. It only makes about 83KW standard.

Isn't there a manual way to work out the VE?

Thanks

You have to run the engine at all thise rpm and map points then determine if the engine needs more or less fuel to achieve your desired a/f as programmed in your runA/F table.

No simple way to do it but get on a dyno ( or lots of datalogging on the road) and get tuning

thanks for your reply. Is there any data logging available for the delco without going to the expense of kalmaker?

Also what should the Spark reference angle be set on? How can I find out which value my engine requires.

I noticed that you are located in WA, have you had any experiences with 202's running the 808 ECU?

At the moment i just wan't to be able to have the engine running with the 808 (it doesn't have to be perfect). Which other settings would I have to modify. I've been told that spark reference angle needs changing. Is there anything else? I'm using a V6 bin file.

Thanks

Answers:

1. I don't use winbin, so can't help there.

There are a number of reference posts at the top of this section about tuning MAP systems. They are pretty thouough in explaining VE & how it's determined empirically.

2. You can't.

3. If I did the conversion right, that matches the ~120 HP shown on DD.

4. That's an interesting queston. VE is nothing more than actual pumping capacity/theoretical pumping capacity. With enough time and money you can model anything - However, most people just use a scanner to measure it. Diacom & Datamaster scanning SW work well for the 727 ECMs - you need to look around and see what works for an 808.

Also: Here, GM ECMs of that vintage use somethijng like a 6 deg BTDC mechanical spark angle. The exact value is non critical if you are doing a custom tune.

Try Winaldl for scanning software.

Distributor Refence Angle is different to base timing , base timing on the 808 $5D cal is 10 deg.

Spark Reference angle is dictated by the design of the distributor and module you are using.

I norammlly setup a dizzy by Placing the rotor in the centre of the electrode at 25 deg , then I mechanically move the reluctor to get the engine to run in backup mode at 10 deg - this way the engine will fire on startup at 10 deg then when the ecu takes control it will advance to where I programmed it to.
Then I adjust the spark reference angle so the timing I programme in is what it is getting.
On a Chev HEI dizzy Spark reference angle is 10 deg . on a Holden V8 its 60 deg - it all depends upon the design of the dizzy and the setup.

VE tuning can only be done on a running engine by going to all the load points - dependent on your injector sizing and the Volumetric efficiency of your motor

Tuning , tuning , tuning lots of work required

I will be using the standard blue HEI dizzy and i'm going to lock the reluctor plate so it can't move, and lock the mechanical advance on the shaft. I'll also be replacing the standard bosch ignition module with an item from the camira.

Stock base timing for my engine is 6 degrees BTDC. I take it the 808 doesn't need to know about this? Because i cannot find anything that refers to it in winbin.

I'd say the spark reference angle would be about 10 degrees at a guess?

Also is there any sites out there that would explain what all the settings to do with the 808 or similar ecus do? There seems to be quite a few. Some of them I have no idea what they do.

base timing is programmed into the code so when you go into diagnostic mode you time the engine to 10 deg , then you set your desired idle timing in the approproite table.

Be wary of .ecu files found on the net , some are missing stuff entirely and others are completely wrong !
What makes you guess the spark ref angle will be 10 deg ??? only way to find out is on a test bench or testing in the car , Mopar motor I did a while ago was 85 degs , lt1 was 43 deg it varys on setup


read the archives , look for programming 101 on the net