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ECU knock discussion (was silver supra)


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Guest Terry S
If there is any knock happening I will get the FBW reinstalled on the car to eliminate it. Mark at owen assures me its not a problem just time consuming and it will cost me an extra £300

 

I think you'll find its not a simple as that Chris

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the Motec knock control system is not all it's knocked up to be. As I understand it, all the system does is listen to the engine and compares the noise coming from it with the noise of a pre-programmed standard engine, and any excessive frequencies/amplitudes that are heard are deduced as knock and the timing on the offending cylinder is backed off accordingly. The system is theory is great for a road car, but from what I am lead to believe it has limited use at full power/full load due to the racket that comes from the engine in the first place. The knock sensing side of the ecu is actually as complex as the engine management side, so only the most sophisticated ecu's have the capability to run it effectively.

 

The M800 does not have knock control, but it is, in theory, possible to put in safeguards to eliminate the need for it. We can run with exhaust gas temperature compensation (too high = more fuel & less timing), engine temp comp, air temp comp, etc. we can use wide band Lambda control (which the factory ecu does not have)to ensure ideal fuelling at full throttle.

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Guest Terry S

The M800 does not have knock control, but it is, in theory, possible to put in safeguards to eliminate the need for it. We can run with exhaust gas temperature compensation (too high = more fuel & less timing), engine temp comp, air temp comp, etc. we can use wide band Lambda control (which the factory ecu does not have)to ensure ideal fuelling at full throttle.

 

Nothing new here except it confirms it doesnt have Knock control!

 

I assume those arent your words Chris

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Just an observation guys (Terry, Usmann).......... :shrug: but some of the comments come accross a liitle patronising rather than being helpful :thumbdown

 

I know you all are pretty cool guys how know your stuff but a less "school teacher" approach would be better. :thumbs:

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Guest Terry S
Just an observation guys (Terry, Usmann).......... :shrug: but some of the comments come accross a liitle patronising rather than being helpful :thumbdown

 

I know you all are pretty cool guys how know your stuff but a less "school teacher" approach would be better. :thumbs:

 

Sorry if it does, just clarifying points as people will read threads like these in a years time and expect to know what is actually happening with the ECU, so it is very important the full picture is given. Also from Chris' point of view it is important that he knows the limitations of his car/systems:thumbs:

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Just an observation guys (Terry, Usmann).......... :shrug: but some of the comments come accross a liitle patronising rather than being helpful :thumbdown

 

I know you all are pretty cool guys how know your stuff but a less "school teacher" approach would be better. :thumbs:

 

:yeahthat: still an interesting read though :thumbs:

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Guest Usmann A

\\My apologies too, just wanted \Chris and others to know- what the motec actually does and notwhat some tuning company has fed him.

 

its helps everyone else too.

 

excuse the tpying, justspilt coffe on my keyboard so, :)

 

\M\otec can take any square.sine wave pattern and adapt it, but it doesnt have the software to use it.

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Guest Terry S
If it's mapped properly and reasonably conservatively it won't knock in the first place...

 

Absolutely, but if its overboosting, or you get crap fuel it will...

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Just put a boost limit in the unit. I think the chances of buying crap fuel these days is very low indeed. I don't trust knock sensors, once you move away from the spec of the engine they, and the software reading them, are tuned for their output becomes pretty meaningless. IMO. Those with access to the programmes for road cars using knock sensors with a stock ecu will tell you that they are listened to over such a narrow RPM band that once you move peak torque somewhere else they don't really operate properly.

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Guest Terry S
Just put a boost limit in the unit. I think the chances of buying crap fuel these days is very low indeed. I don't trust knock sensors, once you move away from the spec of the engine they, and the software reading them, are tuned for their output becomes pretty meaningless. IMO. Those with access to the programmes for road cars using knock sensors with a stock ecu will tell you that they are listened to over such a narrow RPM band that once you move peak torque somewhere else they don't really operate properly.

 

Chris, have you actually logged how a stock Car, especially the VVTi, pulls timing and in the VVTi's case closes the throttle, it is awesome and not only over a small rpm range.

 

As for crap fuel, disagree, I filled up with SUL on the way back from Jap fest with the car showing empty to brimming. Running the same boost as I had the whole weekend, the throttle would close, as the ECU was detecting knock.

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Whilst I can see you point there ..Peak torque where Knocking is most likely moves around in every gear and will always give of the same frequecy of activation noise ( at sensor) no matter what the power output . Mr Toyota has proven this in it stock ecu as it is a fantastic bit of gear which in my eyes will never be leveled by aftermarket ECU's YET ( enphasis on the YET) Shit fuel is more comon that you would think ...it only takes to be stuck out in the middle of nowhere and you have to use what you can get . Yes limit the boost and conservative mapping will put you on the safety side of no knocking .. But why live without yet another safety system in a real world road car...saftey safety safety can only lead to longevity . No one wants to limit the boost to a specific limit when on a single ( the devil is all in us ) and we would want to play so Knock monitoring can only be a good thing. I would live without knock monitoring in a race car ..but for road set up I would rather have it .

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Thread renamed :)

 

Play nice :) ECUs are the football team choice of the tuning world remember (although with less violence and death and destruction).

 

I was wondering about these aftermarket knock sensor things, are they really all placebo junk?

 

-Ian

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\\My apologies too, just wanted \Chris and others to know- what the motec actually does and notwhat some tuning company has fed him.

But that statement is just as patronising as the earlier ones. It is tantamount to saying that us mere mortals are gullible and need the wisdom of "Usman A" to put us on the straight and narrow.

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well, think what you want CJ.

 

FFS, try and help out and people start bitching.

 

:violin:

There is helping out and there is attempting to ridicule other products that dont fit into your scheme of things.

 

I will leave others to judge what they thought you were doing.

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Am I right in thinking knock occurs because of too much heat in the intake ultimately with our tuined cars... I know fuel and other things can come in to it but Im talking about the Boost we are putting through our cars.

 

thats why poeple use water / methanol injection ? To lower intake tempratures of the air after it is intercooled..?

 

If that is the case could I use say a methanol and or water injection on a progressive controler that starts injecting in the the intake manifold when I push over 1.3 bar and help to much reduce the intake tempratures that are a major factor for experiencing knock.

 

I guess Im only above 1.3 for not many seconds as I go through the RPM range so would not expect to use much water or methanol?

 

Before I get *flamed* for this by ANY of you please realise that I am NOT trying to upset you and Im going on what I have been told / learned and read over the passed two years of owning my car.....

 

I very much enjoy the challenge of making my car outperform competitors and be very reliable while doing it. Im not going to start drag racing or anything Im just really interested in it.

 

To be honest I am quite surprised by some of your reactions when I say Im interested in further tuning my car?. The emphasis on 'INTERESTED'

 

Whats the problem ? Im on this forum for advice in the best way to do things from people that may have been done it before ?

 

I never said I was a guru but the boys over the pond are literally YEARS in front of us on tuning these cars.. No mater what overstated BHP figures they are throwing up...

 

We all know it :thanku:

 

Oh one further thing, If you dont have anything constructive to add to this discussion then why bother ?

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Not that the Motec one aint any good , but i would still use a seperate Boost controller and let the Motec keep its ref point for boost so it still knows whats going on . The advantage to having a seperate boost contoller is that you can self ajust for problems or race days ..without having to fire up the laptop all the time...just a thought .

Good advice there Mig. I took my BC off but am now thinking of getting another to give me the opportunity to change the boost as and when.

 

well whatever it is isnt working, as the WG spring is 1.1 bar

I am confused here (not unusual i know) as to why the WG spring set at 1.1 would stop it overboosting? BTW, my spring is set at 0.8/9 not 1.1

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