Accert ECM programming

Yes, the ECM I have CAT can tell it's modified. But talking with Jerad at PDI, he can do a tune that isn't seen when doing a download by CAT for the Accerts. If he can do the same with the earlier engines? I'm not sure, but would think it's very possible.

I also know that PDI is putting extra passwords in the ECM for protection.

 

Hey Mr. Haney,

Where do the fuel and timing curves reside? Are they part of the flash file or correspond to a particular personality module?


And theoretically, wouldn't the bigger injectors advance the timing some do to the faster flow of fuel through the larger orifices?

 

Yes I know what is possible with ECM programming but lengthening injection and burn duration has about same effect no matter how it's done. With advanced timing you just get more power and less residual heat because of better efficiency. EGTs are more a problem for exhaust valves and turbo. Steel pistons don't melt but if they have too tight clearance they touch liners when expanding. Big injectors make same power with faster burn and less time for a piston to absorb heat.

 

Complicated topic this one....Mr Haney is right, it takes more than one part to add relaible horsepower. I would think you could possibly make 1000hp with those injectors, Acerts run multiple injections over something like 60 degrees of crankshaft duration so the injector has to flow a fair bit in the time its on to counter the time its off for in that 60 degrees, in theory if you turn the injector on for the whole time you should get a lot more fuel.

On the topic of duration vs timing, there is always more than one way skin a cat, so to speak. Horsepower (actually torque) is a direct result of average pressure above the piston on the power stoke (that would be net pressure when you take into account the opposing force/pressure from the compresion stroke). So the question is how do you get the highest average pressure and still hold the engine togeather? (Bosch has some great books on this topic by the way). We can do two things to increase this pressure;
1- increase the injection duration, ie turn the injectors on for longer, this holds combustion pressure in the cylinder for more crankshaft degrees as the piston travels down the bore. This does not increase peak cylinder pressure as peak cyinder pressure occurs near TDC. The limitation to this are because as the piston travels down the bore pressure drops off so quickly there gets a point were sufficent combustion pressure and heat no longer exist to burn the fuel and all you are doing is washing the bores with diesel (one of the reasons you hear horror stories about boxes). This is the method all boxes, including edited ECMs use (I'm not talking timing yet).
2- increase the amount of fuel delivered in the same amount of time. This is your bigger injectors and steep ramp cams. this method doesn't add fuel late in the stroke so you do not get the bore washing but to increase average pressure in the same amount of time means raising the peak cylinder pressure. Increasing peak pressure will ususally improve fuel economy due to some complicated thermodynamic but V8Lenny sums it up good with less duration is less time for the heat to escape into the cooling system improving efficiency. The down side is the higher peak pressure puts extra strain on everything but in particular (on a cat at least) head gaskets and big end bearings.
Timing is tied into both of these, if the factory was not bound by emmission laws there would be no real need to mess with the timing except on highly modified engines. I cant remember exactly but I think the ideal time for peak pressure is 5 degrees after TDC for maximum power and efficiency. Adding bigger injectors or cam puts more fuel in before TDC which bring peak pressure sooner, it now seems modded ECMs can do this also. Also modifying timing alone should gain horsepower as if you inject the same amount of fuel but increase efficiency horsepower will rise (to a point)
Now which is best? Really either method has its drawbacks and advantages but a combination of the two appears most successful. Also one builds off the other, If you increase the amount of fuel per degree of revolution (method 2) the pressures are higher so it takes more degrees of revolution before the presusre and heat drops off to the point were combustion cannot take place therefore you can add fuel for longer (method 1).
Of course all of this assumes you are getting enough air in the engine to burn the fuel you add. More fuel without enough air is nothing but black smoke and no extra power no matter how you add it.

Just my thoughts out loud, I'm a mechanic not and engineer after all

 

Well said for a "non engineer". Great reading Jas. Thank you

 

Yes, Well said Jas.

If only you cold find a cheap way to make all that happen.

I think We need a few computer guys on here to crack the Ecu's and alow us to tune our own trucks.

Like i do with Subaru's

The software is downloaded from the net and you buy or make a cable.
Once you have the right "offset" for the particular engine you can access anything in the Ecu, cut and paste maps from different models,alter cam timing and a heap of other really cool stuff.

PDI reflashes in the same way as does Bully Dog, but they charge a fair bit for it to recover the cost of hacking the system.

There are no computer nerd truckers out there, who just want to make more power, with out $ becoming involved.

So we trust someone else and pay the $

Tony

 

Hey tony,

Cracking the flash file so to speak must be possible but its way beond my ability for sure, guess thats why we pay so much to those who can. Now that PDI and Bully Dog can do it others will follow and eventually the price will come down. Think about what it cost to have an LS1 edited when they first were cracked, now you can buy mail order tunes for $300 on ebay.

 

Lead engineer at BD told me it took 3-4 people 2 mo working everyday to break the codes. think he said there are 5 levels of security in ECM . Cat was serious.

on the other hand , Cummins and DD were done during lunch break one day by the kid who sweeps the shop..... i think he was kidding

 

Exactly, Just like EFILive for all GM products. We need software that allows total control. Custom fuel curves, eliminate check engine lights ect. Here locally you can get a custom tune for a Chevy Duramax about $100. With software like that you could eliminate the overboost code on the bridge engines, remove the EGR system from a cummins and turn off the CEL. All of this is available for the pickups, not the big trucks. We need to pull the nerds off the "world of warcraft" for a while and hold them hostage until they come up with something usefull. haha