My First Tune 12P

Tuning The Delco In Realtime
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Re: My First Tune 12P

Postby HQ355 » Tue Jul 15, 2014 9:34 pm

So AE is basically an accelorator pump on a carby ? So weight of car, diff gears and came etc etc would have different effects

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Re: My First Tune 12P

Postby Dylan » Tue Jul 15, 2014 9:50 pm

So the rumours go, ive honestly never looked at a carby but its a quick shot of juice for a smooth throttle transition.

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Re: My First Tune 12P

Postby VL400 » Tue Jul 15, 2014 10:13 pm

Dylan wrote:AE Temperature Factor VS Coolant Temp
AE Multiplier VS Engine RPM
AE Fuel Decay Factor

I dont fully understand how they all interact together yet as i have not adjusted anything yet to get a before and after log.
The decay factor im guessing is how long the enrichment lasts, The multiplier im guessing is how much the factor is multiplied by from the first table?


Correct, the initial calc starts with the change in throttle just like a carby accel pump. It then has corrections for engine temperature and RPM. The final amount of calculated AE is delivered until the value decays to zero, at the rate in the decay factor item. There are also some IAC AE settings as it can require some AE when it opens the IAC. The AE pulses are delivered between the normal injector pulses so are referred to as asynchronous pulses, normal pulses are synchronous (ie in sync with the crank/dizzy reference pulses).

The other factor to throw in the mix is manifold fuel. As you stab the throttle it rips the condensed fuel vapor off the intake manifold walls, the AE calc takes this in to account when calculating it. Conversely the DE calc allows for the change in condensed fuel as the throttle is closed. The manifold fuel items are modeled based on the intake type, its prob not worth playing with but just to know that it exists.

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Re: My First Tune 12P

Postby Dylan » Tue Jul 15, 2014 10:39 pm

VL400 wrote:Correct, the initial calc starts with the change in throttle just like a carby accel pump.


Would that be the scalar "Accell enrichment Param - AE delta throttle threshold"

Then the table AE Temperature factor vs coolant temp, what does that do in the calcs? Replace the value in the scalar?

Then the multiplier, what does it actually multiply. The current VE figure?

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Re: My First Tune 12P

Postby delcowizzid » Tue Jul 15, 2014 11:46 pm

ae temp factor just allows for cold and hot engines needing more or less a/e so keeps it even over all temp ranges
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Re: My First Tune 12P

Postby VL400 » Wed Jul 16, 2014 8:12 am

Dylan wrote:Then the multiplier, what does it actually multiply. The current VE figure?


It uses some base numbers that relate to inj PW. Based on the amount of TPS, the temperature factor, the multipler, engine vacuum, RPM and other things like the manifold fuel, IAC influence etc etc an amount of fuel to inject is calculated. This fuel is injected between the normal injection events that occur once or twice per engine cycle (single fire or double fire option flag controls this, double fire by default).

Its just like a carby accel pump where it gives a quick shot of fuel so the engine does not bog.

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Re: My First Tune 12P

Postby antus » Wed Jul 16, 2014 9:33 am

It multiplies the calculated amount of fuel to inject for AE. Once the other maths is done, it is applied. If you just want more or less fuel, adjust the multiplier table. If you want longer or shorter duration of AE adjust AE Fuel Decay Factor (such as hit the throttle, powers up ok, then gives you a rich spike and a dead spot before returning to normal, reduce this - though thats probably not likely to happen). If you find its great at 30 degrees, but stumbles when you hit the throttle in cold weather adjust AE Temperature Factor VS Coolant Temp. But as VL400 says, for most applications you should not need to touch this. Most stumbles will be more basic things like incorrect data in the VE table. So dont start with these tables, but they're there if you need them.
Have you read the FAQ? For lots of information and links to significant threads see here: viewtopic.php?f=7&t=1396

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Re: My First Tune 12P

Postby Dylan » Sun Jul 20, 2014 9:27 pm

This engine idles at 65kpa and 900rpm, would there be any need to adjust the idle map threshold? It does enter idle mode indicated on the full dash in tuner pro.
I dont fully understand this table.

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Re: My First Tune 12P

Postby VL400 » Mon Jul 21, 2014 6:49 pm

The table is used in the throttle crack algorithm. Just need to make sure your normal idle MAP is above the value, if MAP dips below the table values the ECU drops out of closed loop idle speed control.

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Re: My First Tune 12P

Postby Dylan » Wed Aug 13, 2014 11:16 pm

Ive made a lot of progress and pretty happy with how this is running. I will have a final bin in the next couple weeks.
One thing i was struggling with was a consistent idle speed between dead cold and running temp.
Desired idle rpm is 900. To get that when cold it would be maxed out on 196 IAC steps. Then when warm (90 deg coolant temp) zero IAC steps and about 1100 rpm.

I changed the (scalar from memory) max IAC steps to 256 and now i can have hot idle of 900 with around 30 steps and cold idle of 900 or higher with cold start extra RPM
and IAC steps around 230.

Is there something ive missed? Engine has aftermarket manifold, 355 cubes and big soild cam. All this have an effect needing the extra steps?
I wonder if on factory mainfold if the 196 steps has the track fully opened?

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