Originally posted by bruce
I maintain that given a certain pulse width, and amount of timing at a given engine condition, there is no difference between an oem and aftermarket.
That is probably true, but the aftermarket computers can be purchased to work with MAP sensors that read to 60 psi. Shirley
you could figure out how to make the stock ECM work with a 5-BAR MAP sensor and there are prolly a dozen people on this board that could also figure it out. With the aftermarket 'puters, its already there.
There may also be the matter of better open & close injector times with one system or the other. I don't know the answer.
But I think you are either missing the point of reason for buying an aftermarket engine management computer or your statement is mis-written. People don't buy the aftermarket computers because they do a better job of computing
Xms of fuel,
Ydegrees of timing or
Zpsi of boost. They are purchased for:
- Their ease of use,
- Their relatively quick learning curve,
- Flexibility in supporting various engine combinations,
- The wide band feature with ability to tune to desired A:F Ratios,
- Their all-in-one package simplicity, and
- You have some new bells and whistles (i.e. with the Gen 7+, the "Boost Builder" function).
From the DS runs I've looked at for .25 mile passes once you reach the stall speed of the converter at launch you pretty much run between 3.7K to 6K. And other then some chips with a 3rd gear timing step the timing is a constant. Well, at least in the ones I've seen, and that includes some 9 sec passes.
I would agree that the timing should vary by gear (albeit minimally), but this is getting pretty nitpicky in pursuit of the "perfect tune." The arguments here about a quarter degree of timing resolution are also quite nitpicky, IMO. Cars ran pretty fast for years on wieghted distributors.
Now in some cases folks might be using a MAF and those can drop the HP some. But, with the ME MAFless, or going to a blow thru with a Translator, you approx having a MAP system.
That is correct. But with the aftermarket systems you usually have the option of running a MAP or a MAF based system at the click of a button. At least my 'ol Electromotive TEC has this.
Now we have the Tunercat RT that gives real time tuning, and numerous aftermarket WBs, those issues are mute. Unless you LIKE TUNING with a feedback WB with NO REDUNDANCY.
Not sure what your last statement means there.
The aftermarket systems do make adjustments while you are going down the track and the 'puter records them. Yes, you have to take the recorded adjustment values and alter your VE table manually, but the people at Accel did that on purpose so people do not overly rely on the system.
And like I've mentioned before you can use the TurboLink Boost Sensing Harness and incorporate it, so then you can have a boost sensing MAF/MAP set up.
Again, how many people really know how to incorporate this into the chip altering ROM code? With an aftermarket system, it is all included.
Yes, I'll admit to the aftermarkets having pretty screens and sort of friendly software, but where is the real performance gains?
As has been stated many times here before me, the performance gain mostly comes from the ease of use to get the motor into a better state of tune. Whether you have an Accel Gen 7+ or a Bruce Plecan-modded ECM with 8-Gig of memory
and every feature under under the sun, neither will tell you the best A/F Ratio for the current weather conditions and your motor's capabilities...but most people can
easily get their aftermarket system setup to easily change A:F Ratios at various RPM/Load levels. The screens don't excite me much. Numbers are numbers.
So someone please tell me, FACTUALLY what I'm missing. Leave the opinions at home, and let's discuss facts. What can an aftermarket ecm do that the GN ecm can't or can't be made to do?
I've tried to limit my comments above to the facts. It is not so much what can the aftermarket systems do that the GN ECM can't (because we have now seen for years that both chips and ECM ROM code can be altered heavily), its a matter of what do the aftermarket systems already do so I don't have to learn ROM code changes. I haven't seen Tunercat, but will bet that it doesn't have little radio buttons for switching between a MAF and a MAP, buttons that turn on or off some features like Lean Cruise (for instance), scalability of axis points for the main tuning tables, or the ability to control the ECM to run in Batch-fire mode, Bank-to-Bank, Phased Sequential or true Sequential. Am I right?
I would also assume that with your knowledge you could add some code to the ECM to mimic the Boost Builder funtion of the new Gen 7+. This feature, which originated with the MSD DIS-4, is a God-send for Heads-Up racers. As stated before, how many people could really do this to the ECM ROM code?