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Discussion Starter #1
That post with the link to the PDF file was awesome! There's so much info in there I decided it was necessary to start its own thread. heh heh heh (btw I'm now officially a fan of the Yoshiyama-Tomita model)

Some seriously interesting stuff on that webpage if you decide to read it. Several things can affect the ionization sensing ability. Nictric Oxide's free electrons as it is ionized is often the bar for measuring cyllinder pressure and temp ... but Nitric and Nitrous Oxide are both ionized by platinum, which might upset the ballance in the cyllinder and certainly would make it think at least slightly more of the cyllinder was ionized than was really the case. Also ... in the Saitzkoff-Reinmann model the diameter of the electrode, and plug gap, would seem to have a great deal to do with the what the computer interprets from the signal.

In the Yoshiyama-Tomita model the tendancy for different size plugs to change the characteristics of the "thermal peak" are clearly stated. My larger copper elctrode that I installed should have hypothetically increased the sensitivity to knock. (though copper and platinum conduct differently) Yet I see more boost rather than less. (Though the car has recently decided to get a little spark missfire because of those copper plugs, so on to standard NGKs or Iriduims for me) Again showing the tendancy for platinum to exagerrate the knock sensitivity.

Also I found something very interesting in the Yoshiyama-Tomita model. As the flame front of combustion reaches the chamber walls in releases the + ions into the metal and allows for the second "flame peak". This means that hypothetically one could determine two things with the voltage chart: One, you could determind the regularity and shape of the flame front by observing how long the "flame peak" lasted. A very long and low flame peak would imply a very uneven combustion as not all of the flame wave reached the cyllinder walls at the same time. A very short peaky "flame peak" would imply a very regular combustion took place, in which all of the gas reached the walls nealy simultaneously. Knock is often described as "irregular combustion" when it is not severe, and knowing the shape of the wave front could help a great deal in increasing reliability and hp. Two, knowing the time it takes for a flame front to reach the cyllinder walls could help a lot in determining ignition timing. Knowing the speed of combustion at any peticular temperature and pressure allows you to time the ignition so that the maximum cyllinder pressure occurs when the piston is at its ideal postion. Which would be very handy when calibrating an engine with heavily modified internal parts.

I'm going to keep reading into this. Thank much for the info!! Always fun to read about new research!

Yours,
Adrian W
 

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Discussion Starter #3
Ohhhh. I like I like. Finally two years of calculus classes will actually be usefull. LOL *chants the characteristic equation for simple harmonic motion* haha

Anyone try putting the larger electrode NGK BCPR7ES-11's in their T7 Saab? Tha platinums have a much smaller electrode and the calibration for knock sensing is highly dependant on the diameter of the center eletrode. Also they have a larger gap. Original PFR6-H10's were about .035" and the NGK BCPR7ES-11's are .045". This could seriously change the ionization pickup signal under the same conditions (not that the platinum was too terribly accurate in the first place). I'm going to try the Iridium plugs as they are a very fine electrode. Their original gap is .044" but Iridium and PLatium "can" be regapped as long as you don't use a bend gapping tool. You can lightly tap on the outer electrode. The tech at the Saab dealer told me sometimes NGK sends them plugs with gaps that are too large, and that by tapping them into spec very gently it saves them sending them back. So far no problems. So I'm hoping the same will work for me. Also, the copper plugs I was experimenting with have developed a slight miss. Not at all frequent, or enough to set off the OBD II electronics, but enough to motivate the purchase of the Iridiums yesterday. I am hesitant though. I wish I knew if the Saab was calibrated for the design of the platinums, or calibrated for the design of the BCPR7ES-11's. Or perhaps it can learn new plugs? We'll see what happenes when I install iridiums. Ciao.
 

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Hi Adrian W and others, have you ran across any info of the following.

I don't know what the correct term is, but I'am looking for info about the ECU knocking advance set value. I'am sure that there is a more proper term to it, someone want to fill me in?
The question is about this value that can be read by TECH.

For an example orginal 9-3 LTT has the value set at 29. Maptun stage III has the same, but SpeedParts stage III is set at 40 for the same car?

From the internet I found the following, but I'am not sure if the question is about the same value.

"One of the main units is the addition unit that takes several variables as inputs, adds them up and give an output that is used for comparison against a SET VALUE. This comparison will at any moment be a representation of the "stress level" imposed upon the engine compared to the factory set acceptable level. If it is exceeded, the output circuitry will be given directions to lower the stress by lowering the boost pressure."

So, according to this text it seems that by raising this set up value the engine will tolerate more underlying knocking before the ECU takes any action.

Does anyone have a clue of the scale, what does it exactly mean in practice if the value is raised by 10, like SP/BSR has done?
 

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Originally posted by Vigge:
[qb]Does anyone have a clue of the scale, what does it exactly mean in practice if the value is raised by 10, like SP/BSR has done? [/qb][/b]
I thought Speedparts Stage III was made by MapTun ?!?
 

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On a slightly related note: I am running an early DI system (the stand alone DI from the '88 DI 9000 Turbo, only available on some markets) with a late (black T7) DI cassette. My dealer (well, they used to ba a main dealer until late 2000) said the DI cassettes are backwards compatible, i.e. you can run the later cassette with the earlier systems but not vice versa.

Now I still have a running problem or two to be sorted out and I was wondering whether the spark plugs are mated to the DI cassette or to the system controlling it? Right now, I am running BCPR7-ESII as specified for DI systems -should I try the platinum plugs for which the T7 system/cassette was designed? Or does it matter altogether when my DI system does have a combustion signal, but does not sense knock?
 

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Discussion Starter #9
Noooo ... platinum is BAD for DI cars. I've had sucess with NGK Iridiums, and others have had sucess with the plugs you're using now. I say you stick with them. I can't imagine the T7 was "designed" for platinum at all. Seems some accountant likely shoe horned them into the equation, as they are not really comaptible.
 

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Discussion Starter #10
With response to Vigge's comment:

Knock sensing is one of those real tricky things. To be honest, I would imagine in 90% of the curcumstances, knock is knock, and I would be very very weary of anyone who altered the knock sensitivity. I can't imagine any upgrade involved in a stage III that would change what level of detonation the engine could take. Even forged pistons only change that level slightly, and lowered compression just makes it harder to knock, which doesn't change how much knock it can take. In fact, if you increase the boost, you should make the car MORE sensitive because "quieter" knock can cause progressively more and more damage as the temps and boost go up. Perhaps 40 is actually a "more sensitive" setting?
 

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Originally posted by Adrian W:
[qb]Perhaps 40 is actually a "more sensitive" setting? [/qb][/b]
Adrian you're wrong on this.

A friend of mine dropped in on a saab dealer yesterday and asked them if they have info about this. They could not provide the info I'am looking for but the guy took my friend to the repair shop, where they had a 9000 turbo with pistons demolished due to knock.
They repair guy showed my frined one of the pistons and told "this happens, when the knock set value is too high"

So, by raising the number the car is not more sensitive to knock...
 

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Discussion Starter #12
lol Vigge I "asked" if 40 was a more sensitive setting. I figured it wasn't. I just couldn't think of any other reason why they would change it. You should never under any circumstances tamper with the knock setting.

" ... and I would be very very weary of anyone who altered the knock sensitivity. I can't imagine any upgrade involved in a stage III that would change what level of detonation the engine could take...."

I just didn't know for sure if 40 was lower or higher, and have not heard of anyone demolishing pistons with this peticular upgrade. Of course you realize that in a Saab T7 system the "knock" is detected by the ignition system AND a traditional knock sensor. Perhaps (I'm not saying this is true but rather asking again) they merely lowered the setting on the standard knock sensor because the higher boost generates higher "noise" and MIGHT set off that knock system even when there isn't knock? I doubt it.

I'm betting they just set the knock limit too high, and never ran into any knock severe enough to melt the pistons, which just means when someone runs it like that for a few thousand miles, they're the proud owner of a set of ashtrays.
 

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Originally posted by Adrian W:
lol  Vigge I "asked" if 40 was a more sensitive setting.  I figured it wasn't.         I just couldn't think of any other reason why they would change it.  You should never under any circumstances tamper with the knock setting.[/b]
Sorry, I missed the question mark, my bad.
You probably know tha a turbo engines power output is gratest when the motor is about to knock. What I'm trying to get at is if the value was intentionally set this high to achieve the promised hp readings.

" ... and I would be very very weary of anyone who altered the knock sensitivity. I can't imagine any upgrade involved in a stage III that would change what level of detonation the engine could take...."

I just didn't know for sure if 40 was lower or higher, and have not heard of anyone demolishing pistons with this peticular upgrade.[/b]
The examples I stated earlier are two different cars. I do not know what upgrade the 9000 had, but according to the service men the "setup value"
was altered too high. The 9-3 LTT SP/BSR stage III has the value set at 40. You can chech this out your self if you manage to find a car with this setup.

Of course you realize that in a Saab T7 system the "knock" is detected by the ignition system AND a traditional knock sensor.  Perhaps (I'm not saying this is true but rather asking again) they merely lowered the setting on the standard knock sensor because the higher boost generates higher "noise" and MIGHT set off that knock system even when there isn't knock?  I doubt it.[/b]
I think you're way of. If this would be the case
I could bet my money that all other tuners would raise it aswell.
 

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Discussion Starter #14
lol Which, Vigge my friend, would be why I ended the last part you quoted with "I doubt it.". lol I didn't think that was the case either. I can imagine any situation where you would want to increase it, just trying to come up with a reason for altering it (other than sheer stupidity). Seems rediculous to me to change it at all.
 

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Originally posted by Adrian W:
[qb]lol  Which, Vigge my friend, would be why I ended the last part you quoted with "I doubt it.".  lol  I didn't think that was the case either.  I can imagine any situation where you would want to increase it, just trying to come up with a reason for altering it (other than sheer stupidity).  Seems rediculous to me to change it at all. [/qb][/b]
This aplies to the older APC, but I guess it still works the same

"K - The K pot defines how sensitive the APC box is to knock - how much signal from the knock sensor is required before the system will start tapering boost. It is generally best to leave this potentiometer alone. Not surprisingly, "K" refers to Knock."

If someone on this board has a T5 9-3LTT with SP/BSR stage III, could you consult SP about this topic.

I'am pretty sure my mails wont be answered, I do not own this product and I 'am not their "favorite" customer...
 

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Discussion Starter #16
I'll try to contact them about it. I think the simple answer is that they lowered (raised the value) the sensitivity to knock because it allowed more power, and with less developement. Perhaps it harder than it looks to alter a Trionic car. And the easiest, and indeed cheapest, way is just to crank up the boost, lower the safety margin and "hope for the best". We'll just hafta see what they say when I try to mail em. SEe if their "excuse" for it holds up to any scrutiny.

Yours Truly,
Adrian W (aka Addy)
 

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Originally posted by Adrian W:
[qb]I'll try to contact them about it.  I think the simple answer is that they lowered (raised the value) the sensitivity to knock because it allowed more power, and with less developement.  Perhaps it harder than it looks to alter a Trionic car.  And the easiest, and indeed cheapest, way is just to crank up the boost, lower the safety margin and "hope for the best".  We'll just hafta see what they say when I try to mail em.            SEe if their "excuse" for it holds up to any scrutiny.

Yours Truly,
Adrian W  (aka Addy) [/qb][/b]
There is only one problem, SP does not know about "ECU's soul life" they only sell them. The correct place would be BSR to consult, since they are the people behind the product.
Mayby if you just step in the shoes of a stupid custormer who is willing to buy this product and ask about this issue, because you read something like this on the internet
 
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