730 ECM -- 8D
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Author:  Hawk [ Fri Oct 12, 2007 3:28 pm ]
Post subject:  730 ECM -- 8D

Ok, for those wanting to tune the 730 ECM, aka- 8D here is some basic's along with pic's from the chip in my own car Just to get you going, you can fine adjust it from there

For starters, manualy adjust your TPS sensor and IAC before you start tunning, I also like to run my Fuel Preasure at 45PSI at idle, but thats a personal choice, I like the fuel atomization at this PSI

I like to start with the main Constants to get you running and work down the list

First thing, adjust your
Cylinder Volume

Cylinder volume is per cylinder. To calculate divide the total displacement by the number of cylinders. Example 350 in^3 =5.7 liters/8=.7125l/cyl X100 = 712.5

Next I'll set my Rev. Limiter, I think these are pretty self explainatory
Fuel CutOff Engine Speed
Fuel Resume Engine Speed
Then my Govener, this is great if you will have any children that might drive the car ;)
Fuel CutOff Vehicle Speed
Fuel Resume Vehicle Speed

Injector Flow Rate I have Ford 30# SVO Injectors
Spark Advance Initial Thats your Distributor Setting, stock for the TPI is 6*
Spark Advance Max This is the Total from the Initial Spark Advance, the main Spark Tables and the PE Tables.

Author:  Hawk [ Fri Oct 12, 2007 7:55 pm ]
Post subject: 

Ok now we'll start in the tables that you will need to play with to get running.

We are gunna start with the VE table's, aka Volume Efficiency Tables, the stock 8D has a Lower (400-1600 RPM) and a upper (1600-5600 RPM)
LTR TPI upper, Corvette
HSR upper, note how the VE tables end up resembling the powerband ;)
For Starters, what is VE? Well I think Wikipedia can explain it best

To do this we will want to shut off both the wide open throtle and the highway mode as they will effect your BLM's with both added or removed fuel and timing.

There is several ways to do this, for the highway mode, I just turn the A/F to the BLM target of 14.7 and I remove any timming changes for the highway mode, I set them all up later anyway's.

For the wide open throtle, I go in the PE tables for the TPS and adjust the throtle position when it would turn your PE mode on to 99%. Then watch during your data logging that you dont hit 99% on the TPS so you know you never went into PE mode.

Author:  Hawk [ Sat Oct 13, 2007 8:38 am ]
Post subject: 

OK, So now we are ready to start working on the VE table's themselves. So to help explain them...

One of the biggest things that effect the VE's is your cam. We will get into that abit later on.

Too start your gunna need to get some scanning softwere, there are several different one's to use for the 8D. So take your pick :)
Make sure you allow your car to warm up so you are in closed loop.

What you'll need to keep track of on your VE's is your BLM's (Block Learn Multiplier) and at what RPM and MAP so these tables are three dimensional (3D) tables. As you should already know if your tunning a car RPM's are the revolutions per minute the engine makes. These are Speed Density (SD) car's so manifold preasure (MAP) is also extremly importent, MAP is the amount of vacum the engine is pulling. The MAP readings for both tables are in kPa (kilopascal). kPa is a metric vacum measurement.
MAP signifies engine load. So the greater the engine load the higher the kPa value.
Think of it like this, when your car is idling it is pulling vacum inside the intake/plenum. As you open the throttle blades you are providing an inlet that will decrease the effective vacum right. So here is the sneaky part … LESS vacuum is represented by a HIGHER kPa value, so remember that. :wink: Lets say we are driving uphill, as you know driving uphill is more of a load on the engine. If you are driving uphill you will have your foot more on the gas and if you have the gas pedal depressed more then that means that the throttle blades are opened more. So with the throtle blades being opened more then it will result in LESS vacum and a HIGHER kPa value.
So MAP equals load were increasing load is represented by higher kPa values. So when put in context of the VE tables, we can see that as the kPa values increase from left to right, this represents increasing load on the engine, the highest kPa reading (100kPa) is to be equal to full out wide open throttle. 100kPa is atmospheric pressure, so no vacum at all.
To go over 100KPA, you would require forced air like a Turbo or Supercharger, and them we would switch to a different ECM so we wont go any farther with that right now.

To sum it up, if you raise a given value in one of the VE tables you will be increasing the amount of fuel the engine receives at that given RPM and that given MAP.

Since camshafts have the biggest affect on VE (as compared to other naturally aspirated modifications), then a TPI F-Body with say an ZZ4 cam (208/221 w/ 0.474”/0.510” on a 112LSA) will need to have the VE curves for this setup changed for several reasons.
The most obvious reason is that this cam’s higher duration numbers will make this motor less efficient at the lower RPMs but more efficient at the higher RPMs, ya a very general statement for the purposes of explanation.
One of the other effects here is that bigger cams (especially those with tighter LSAs) is to pull much less vacum at idle (higher kPa) and less manifold vacum means less vacum to those devices that are connected to manifold vacum.
The fuel pressure regulator is controlled by manifold vacum that why you have to reset it. You see more pull (more vacum, smaller kPa) on the regulator reduces the effective fuel pressure and less pull(less vacum, higher kPa) on the regulator increases the effective fuel pressure. So if we install a cam that pulls less vacum at idle then the Fuel Pressure Regulator will see less vacum and the overall fuel pressure will be greater.
This results in a very rich condition at idle. The bigger the cam duration (with LSA and lift remaining the same), the less manifold vacum at idle.
What we need to do here is to re-map the lower VE table to supply less fuel at those RPMs and kPa values where the car idles. We will have to decrease those VE values.

The object is to achieve BLM values of 128 across the board at all RPMs and MAP readings. Readings of 128 indicate that the amount of fuel supplied by the injectors for a given RPM and MAP achieves a perfect 14.7 Air/Fuel Ratio.
So a BLM above 128 indicates a lean condition, the ECM is adding fuel over the base calibration. A BLM below 128 indicates a rich condition, the ECM is removing fuel from the base calibration.
The idea is to change the VE tables to get the BLM as close to or just below 128 as possible. If your BLM's over the entire range are high or low, you should probably address that first.

High BLM (using a BLM of 140 and VE table value of 65 as an example):

1. Divide the BLM value by 128, result 1.09
2. Multiply the BLM value at that RPM/kpa point by 1.09 ; (65 x 1.09) = 71.09
3. Enter that new value in the table, repeat a test run.

Low BLM (using a BLM of 110 and VE table value of 65 as an example):

1. Divide the BLM value by 128, result 1.16
2. Divide the BLM value at that RPM/kpa point by 1.16 ; (65 / 1.16) = 56.03
3. Enter that new value in the table, repeat a test run.

You will usually need to smooth out the values around that specific cell a little to make everything work. This is something that you'll develop a feel for.

Author:  Hawk [ Sat Oct 13, 2007 10:16 am ]
Post subject: 

more to come, normal driving spark tables to come next.... when I get time :oops: :lol: info for this thread was gained from all over the mighty world wide web plus good old personal exp .......

Author:  LB9GTA [ Sun May 17, 2015 7:06 pm ]
Post subject:  Re: 730 ECM -- 8D

Thanks for this!!!

Author:  cam [ Wed May 20, 2015 1:39 pm ]
Post subject:  Re: 730 ECM -- 8D

Best thread on CCFBG. Well done Hawk, you've helped thousands and saved a LOT of future typing 8)

Author:  Hawk [ Mon Jun 29, 2015 10:21 am ]
Post subject:  Re: 730 ECM -- 8D

Your welcome :) sadly this will soon be lost :(

Author:  cam [ Wed Jul 01, 2015 9:51 pm ]
Post subject:  Re: 730 ECM -- 8D

Hmmm any other tech threads you can think of we should archive?

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