morWhy can ECUs produce e/less power than others?

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Mar 10, 2006 | 12:06 PM
  #1  
Ive often wondered why this is the case.....for example, same identical spec would make more power on GEMS ECU than an ECutek?

I would have thought that if the engine is the same spec then logic says that they should have the same theoretical maximum power no? the limiting factor being the weakest part of the chain....

Can anyone explain this? Im just curious as i am sticking with a TEK3 on my 2.5 build (as to be honest i cant afford the ecu upgrade right now anyway) but even if i could is there any real fundemental reason why i need to upgrade? or is it simly that the processing power of other ecus is that much greater than the stock subaru unit?

Any answers would be interesting
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Mar 10, 2006 | 12:07 PM
  #2  
whoops buggered the title there!!!
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Mar 10, 2006 | 12:48 PM
  #3  
good topic appalling title

I would be interested to see peoples views on this, especially different mappers
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Mar 10, 2006 | 05:01 PM
  #4  
anyone?
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Mar 10, 2006 | 05:02 PM
  #5  
Watch this with interest
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Mar 10, 2006 | 05:52 PM
  #6  
different ecu's allow other options which may not be available on the remapped ecu, my ecu will get rid of the maf and it has anti lag and launch control, it also allows more tuning over the cams as far as im aware. who maps the ecu is also a main factor in the power you make
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Mar 10, 2006 | 07:36 PM
  #7  
How the ECU is mapped has a big effect, the other factor will be the driving of the ignition system, better quality spark will make a little more power. The problem with some ECU combinations, is that they have inherent restrictions which must be worked around, and this takes time which detracts from normal mapping.
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Mar 10, 2006 | 09:01 PM
  #8  
have you got any examples of those types of restrictions of an ecutek ecu paul?
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Mar 10, 2006 | 09:20 PM
  #9  
Maf rescaling and large injector rescaling spring to mind as being a pain. But with Ecutek, you also have ignition and fuelling compensation that you don't have 100% control over too. There is also an inherent benefit in mapping speed that comes from a live mappable ECU, the more mapping you can do in a reasonable time, the closer you can get to ideal.

On the other hand having an ECU that is live mappable, but has problems with idle and light throttle can be equally frustrating.
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Mar 10, 2006 | 09:43 PM
  #10  
i see, so a large part of it is raw processing speed of the ecu, thast understandable.....

what im less clear on is where you say rescaling, i presume that if you use a larger bore intake that makes no difference to the maf rescaling?

also with regard to ecutek, and injectors, a realistic max is a 740cc, would that be right? to make sure that it can control it well enough to make a usable car...
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Mar 10, 2006 | 09:44 PM
  #11  
Quote: have you got any examples of those types of restrictions of an ecutek ecu paul?
an MD195 springs to mind
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Mar 10, 2006 | 09:47 PM
  #12  
Quote:
also with regard to ecutek, and injectors, a realistic max is a 740cc
nah injectors are totally different on newage car as compared with classic shape as my old car had 740cc injectors and could cope with near 600bhp the same type of injector for a newage does not seem to perform as well
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Mar 10, 2006 | 09:50 PM
  #13  
Quote: an MD195 springs to mind
shut it!....the car is built for the future....
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Mar 10, 2006 | 09:51 PM
  #14  
Quote: nah injectors are totally different on newage car as compared with classic shape as my old car had 740cc injectors and could cope with near 600bhp the same type of injector for a newage does not seem to perform as well
I was referring to the subaru ecu's ability to control that size injector well. You used a PFC on your classic, hence why it could....
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Mar 10, 2006 | 09:55 PM
  #15  
i have autronics now and i still need larger injectors £50
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Mar 10, 2006 | 09:56 PM
  #16  
well you know where they are matey....
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Mar 10, 2006 | 10:10 PM
  #17  
it has very little to do with processing speed of the ECU.

A new ECU will not mean you can get more flow out of a given set of injectors!
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Mar 10, 2006 | 10:53 PM
  #18  
Quote: nah injectors are totally different on newage car as compared with classic shape as my old car had 740cc injectors and could cope with near 600bhp the same type of injector for a newage does not seem to perform as well
No problem with new age injectors Steve, 800's are available and will run up to 600+bhp on the OE ecu once mapped.
Ecutek mapping of a Denso ECU (MY01 onwards) makes it capable of really big numbers, the Denso is superior in many ways to the Apexi I run on my race car for instance.
As Paul mentioned, one drawback can be the time requirements to map in large bore mafs and fine tuning of the complex ignition strategy.
That aside there is no reason why an aftermarket ECU would make more power.

Andy
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Mar 10, 2006 | 11:01 PM
  #19  
andy

im saying in my opinion you need bigger injectors to run similar power on the newage cars !!
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Mar 10, 2006 | 11:04 PM
  #20  
Quote: As Paul mentioned, one drawback can be the time requirements to map in large bore mafs and fine tuning of the complex ignition strategy.
That aside there is no reason why an aftermarket ECU would make more power.

Andy
Thanks Andy/Paul i think thats what i wanted to hear.

So would you agree that where possible, you should keep the intake the same bore or as close to stock as possible to help eliminate some of the issues of maf rescaling?
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Mar 10, 2006 | 11:38 PM
  #21  
Up to the airspeed limit of the maf sensor Neil, then you need a bigger bore housing in order to slow the airspeed down so it is still on the scale.
Std size maf housing is good for up to approx 400bhp

Steve, I don't think so. I had 329bhp out of my 380's running at 100% on increased fuel pressure. My 650's now run approx 73% at 380bhp. Some tuners run the new age cars much richer due to the tighter clearances on some models, maybe thats where the bigger injector thing comes from ?

Andy
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Mar 11, 2006 | 10:14 AM
  #22  
i think ill leave messing with this until the times comes to go rotated.

Thanks again guys.
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Mar 11, 2006 | 05:07 PM
  #23  
While the denso is quite capable, it's only as capable as the features that Ecutek have managed to unlock, which may be more or less depending on what code versions you can run.

800cc injectors are not easy to get running properly, by that I mean adequate cold and hot starting, idle quality and cruise fuelling. Some are sold as "duel flow" or some such mish-mash, in reality they have much larger lag times which means at low opening times (like idle and light cruise) although the ECU is opening them for a "normal" amount of itme, the actual time spent flowing fuel is much less. This effect ranges from just a few % at max power to say 50% at idle. Max power tuning isn't really an issue, but the finer points become more difficult. Going to a larger blow-through maf should fix a lot of problems, but I can't say I've personally tried it.

Up to 400hp the OE ECU ought not to be a problem.


Quote: No problem with new age injectors Steve, 800's are available and will run up to 600+bhp on the OE ecu once mapped.
Ecutek mapping of a Denso ECU (MY01 onwards) makes it capable of really big numbers, the Denso is superior in many ways to the Apexi I run on my race car for instance.
As Paul mentioned, one drawback can be the time requirements to map in large bore mafs and fine tuning of the complex ignition strategy.
That aside there is no reason why an aftermarket ECU would make more power.

Andy
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