[usc335]

Originally Posted by M335i Oreo Package

suppose just suppose the dme is pulling timing b4 the onset of knock bcuz it looks for certain conditions and labeled it "here comes knock" so it just making necessary adjustments... Kinda like the theory presented about over heating a few posts back....

So, once again, the burden of proof is on those that believe this to be true.

[STONEY_M5]

Must've got a couple of you thinking...

[Clap135]

Mentioned this 10 times already and everyone ignores it. If the dme had the ability to drop timing pre knock based on iats or temps or whatever.....why doesn't it drop timing when u run high octave gas. The only parameter you are changing by running high ocean is the fuels resistance to.detonate.....everything else stays the same as before.

Originally Posted by M335i Oreo Package

suppose just suppose the dme is pulling timing b4 the onset of knock bcuz it looks for certain conditions and labeled it "here comes knock" so it just making necessary adjustments... Kinda like the theory presented about over heating a few posts back....

[STONEY_M5]

Originally Posted by usc335

So, once again, the burden of proof is on those that believe this to be true.

not necessarily. That is a what if, but what if they are right? I just said that bcuz they are basing their point off of tuning in the past when computers didn't have so much control, things and times have changed, but then again maybe they haven't...

[MDORPHN]

Originally Posted by Clap135

Mentioned this 10 times already and everyone ignores it. If the dme had the ability to drop timing pre knock based on iats or temps or whatever.....why doesn't it drop timing when u run high octave gas. The only parameter you are changing by running high ocean is the fuels resistance to.detonate.....everything else stays the same as before.

Clap -

Any chance you could state your observations/conclusions instead of posing a question?

I believe that would be very helpful to those of us with no ax to grind and who are sincerely trying to learn/undertand.

Thank you.

Neil

[InCityPhoto]

Originally Posted by Clap135

Mentioned this 10 times already and everyone ignores it. If the dme had the ability to drop timing pre knock based on iats or temps or whatever.....why doesn't it drop timing when u run high octave gas. The only parameter you are changing by running high ocean is the fuels resistance to.detonate.....everything else stays the same as before.

You have also said 40 times there is no such thing as "pre knock"

[STONEY_M5]

Originally Posted by Clap135

Mentioned this 10 times already and everyone ignores it. If the dme had the ability to drop timing pre knock based on iats or temps or whatever.....why doesn't it drop timing when u run high octave gas. The only parameter you are changing by running high ocean is the fuels resistance to.detonate.....everything else stays the same as before.

well clap I am sort of a newb but, I thought if you add higher octane gas all others being the same it wouldn't pull timing or would pull very little because the threshold was higher... Did that make sense??? Lol dnt flame me clap I'm learning... Lol

[Focus]

My question. If Dinan doesnt see a need to alter the ECU's safety paramaterswhen running their stage 3, then why should a JBtune?

Any blown engines, etc, imo are mostly brought on by user error. People who think they can slap a tune on and run 15+ psi with not IC,Meth,Stock DV, etc... and it'll be fine. People who think filling up " Just this one time " with 87 or 91 is fine then try to race someone. People who skip a couple thousand miles past their oil change schedule.

[STONEY_M5]

Sorry my post are late enjoy this from my bs phone. Lol

[STONEY_M5]

Originally Posted by Focus

My question. If Dinan doesnt see a need to alter the ECU's safety paramaterswhen running their stage 3, then why should a JBtune?

Any blown engines, etc, imo are mostly brought on by user error. People who think they can slap a tune on and run 15+ psi with not IC,Meth,Stock DV, etc... and it'll be fine. People who think filling up " Just this one time " with 87 or 91 is fine then try to race someone. People who skip a couple thousand miles past their oil change schedule.

but the very first post on this thread showed a completely stock car on stock tune.... Which again brings me back to the radiator over heating theory the car was overheating so the dme pulled timing no knock could it be that bcuz the temps were so high it was pulling timing but was trying to go back and find a happy medium? Forgive me if this was stated already most of the reading was done at 1Or2 am while in a zone...lol

[Dmacc]

There is no such thing as preknock.

Then knock sensor is going to hear that knock, and is going to pull timing as fast as it possibly can before more damage can occur.

As for the comment on what the safe knock threshold would be for knock. Im pretty sure it's simple to say that if you're knocking on the stock tune designed by bmw themselves, that is as safe as you can get as far as knocking on that psi.

and don't try to argue that more psi does not equal worse knock. It most certainly does mean worse knock by the laws of physics



in short what I'm saying is, anyone arguing that knock is bad is correct, anyone arguing that certain knock events are more damaging than others is also right. and for anyone arguing what the best knock threshold is? the answer is stock.

these points have already been made clear for the past 50 pages numerous times. time to open up everyones eyes

[Mike@N54Tuning.com]

Originally Posted by themyst

Ah, screw it, here you go Mikey:

The PROcede fakes the load signal back in to the DME based on the load target. So by design you'll never see load changes in the ignition advance and that is the same reason CPS offsets are so necessary during transitions with it.

Mike

[Jeff@TopGearSolutions]

Originally Posted by Dmacc

There is no such thing as preknock.

Then knock sensor is going to hear that knock, and is going to pull timing as fast as it possibly can before more damage can occur.

As for the comment on what the safe knock threshold would be for knock. Im pretty sure it's simple to say that if you're knocking on the stock tune designed by bmw themselves, that is as safe as you can get as far as knocking on that psi.

and don't try to argue that more psi does not equal worse knock. It most certainly does mean worse knock by the laws of physics



in short what I'm saying is, anyone arguing that knock is bad is correct, anyone arguing that certain knock events are more damaging than others is also right. and for anyone arguing what the best knock threshold is? the answer is stock.

these points have already been made clear for the past 50 pages numerous times. time to open up everyones eyes

Thank you

[Clap135]

Originally Posted by M335i Oreo Package

well clap I am sort of a newb but, I thought if you add higher octane gas all others being the same it wouldn't pull timing or would pull very little because the threshold was higher... Did that make sense??? Lol dnt flame me clap I'm learning... Lol

that's exactly right. There are two ways to prevent knock on an ignition curve that is too high. Either add fuel that is more resistant to detonation or drop timing so max timing values don't hit knock to begin with. This is assuming you want to keep the same boost pressure. If you don't then you have to drop boost. And on this car which has a timing curve mapped for stock boost. You will have to drop boost to stock....that's not tuning.

[chili36]

Originally Posted by MDORPHN

Clap -

Any chance you could state your observations/conclusions instead of posing a question?

I believe that would be very helpful to those of us with no ax to grind and who are sincerely trying to learn/undertand.

Thank you.

Neil

And the fact that you have not established there is a weakness to the timing control of the factory DME

[shifterboy45]

Originally Posted by Joshboody

any input by the dme based on outside factors will be gradual, and NOT a sudden decrease. Knock is a trigger that lowers timing x amount to run safer. incline, IAT, cooling temp are NOT "triggers", they are included into the overall formula constantly for each spark fire.

so if this is the case, what you are presuming is that the logic system in the car is adaptive in some cases, and not others..

and responds to knock sensor input alone to change ignition timing?

if for instance, the above stated circumstance took place, the throttle was nailed, the DME would without regard to other sensory input keep the timing stable? that is referred to as static timing (which is non-adaptive) -- and that is what blows engines up --

[Joshboody]

Originally Posted by Mike@N54Tuning.com

The PROcede fakes the load signal back in to the DME based on the load target. So by design you'll never see load changes in the ignition advance and that is the same reason CPS offsets are so necessary during transitions with it.

Mike

what are you saying these's a difference in faking the load target compared to scaling it, as I imagine the JB does? No difference the load the DME sees is still way below actual, giving a much higher timing map then required.

[Black Gold]

Originally Posted by InCityPhoto

You have also said 40 times there is no such thing as "pre knock"

He means "before" knock. Hence the use of the word, "pre"

I know you don't like clap, but come on man.

[BmwFanFL]

Omg, this thread is like a maze of twisty little passages, all alike....

These cars, like most, use microphones, yes listening devices, to pick up "knock." Further, only a limited frequency range is used, to suppress other engine noises, vibrations, or normal combustion noise from being interpreted as knock. They may also filter or compare over time using CPS position to increase accuracy (as they also can predict the time domain of knock event noises at any given location).

If there were such a thing as a "pre-knock" picked up by a microphone, it would have to be an physical vibration, even if sub-audible to the ear. If it is creating abnormal vibrational disturbances, the combustion event must have been abnormal as well. Hence, at best the audible sensors could see less extreme knock and more extreme knock. If the combustion event weren't ALREADY abnormal, there would be nothing out of the ordinary for the sensors to hear.

It is as if people are suggesting a physics that lets the combustion fuel/air react normally, with precisely controlled timing, wavefront, and heat/energy dissipation, while releasing an audible noise that suggests a tipping point is close - alerting the engine to treat the next, totally separate, cycle differently?

IMO, if microphones could truly pick up this hypothetical harmless "pre-knock" all cars would work that way and tuning would be different. Everyone would run as much advance as possible, just into the 'pre-knock' zone, relying on some system to keep you away from danger. If only physics were different.... Similarly, if frogs had wings, they wouldn't have to hop along the ground to find food....

Obviously, the sensitivity and reaction time of the DME has prevented serious and immediate consequences (that we know of). The long term, however, has to be worse for these unfortunate engines. Tuning adds wear to begin with, added knock events will add to the wear unnecessarily.

If you're okay with that added wear, and some added risk (the amount of risk is certainly debatable -- its presence really isn't), that is your choice.

[Joshboody]

Originally Posted by shifterboy45

so if this is the case, what you are presuming is that the logic system in the car is adaptive in some cases, and not others..

and responds to knock sensor input alone to change ignition timing?

if for instance, the above stated circumstance took place, the throttle was nailed, the DME would without regard to other sensory input keep the timing stable? that is referred to as static timing (which is non-adaptive) -- and that is what blows engines up --

this was in reference to the "what if" scenario presented that timing drops could be other factors. I believe the stock map is static based on load, but others are saying it could have adaptive measurements factored... i don't think anyone really knows 100% outside of BMW.

[Dmacc]

Originally Posted by chili36

And the fact that you have not established there is a weakness to the timing control of the factory DME

The weakness to the timing control of the factory DME is that it is only meant to handle the stock boost pressure...

doubling the boost and relying on the stock curve is NOT the right way to tune for double the psi.

Do you want Clap to explain another 100 times?

let me dumb it down for you and everyone else who is confused

Factory timing ≠ Good for double boost pressure

want to rely on it? stick with stock boost pressure

[papiti]

Originally Posted by MDORPHN

Clap -

Any chance you could state your observations/conclusions instead of posing a question?

I believe that would be very helpful to those of us with no ax to grind and who are sincerely trying to learn/undertand.

Thank you.

Neil

YEAH!! What he said!! THANKS!!