[ExpensiveTaste]

Originally Posted by Clap135

So what are they, Do i think BMW would do this? Yes, every car does this. It relies on the knock sensor as a last resort in shity conditions. They will not detune every single car because a few run 6000 feet above sealevel in 100 degree temperatures.

Clap, why are you acting like if a tune is created, the knock sensor is no longer needed? Even with modified timing tables, the ECU will still use the knock sensor output to lower the timing in daily conditions. When you tune a vehicle, do you advise the customer not to drive in humid conditions? The point being that in most conditions, every tune will knock without meth.

[Litos]

Originally Posted by Mike@N54Tuning.com

There is no evidence in this thread. Simply hypothetical talking points and FUD spreading. The same stuff that have been said countless times before over the years. If you want to be conservative just keep it on map 1 and enjoy the car for years to come as many thousands with the JB3 have before you. If you want to optimize it for more power test out the new Map5 autotuning under development.

Mike

nope.

i should be happy with Map 1 for the price i paid for the tune.

here's one last question to ease my nerves: will a fmic reduce knock !?!?

[Mike@N54Tuning.com]

Originally Posted by KennyPowers

Ok....

If the ECU works by advancing timing until either A) it reaches the set maximum value, or B) the knock sensor detects an event and reduces timing, then why drop the maximum set timing UNLESS you believed that under the higher boost conditions of the 335is situation B would occur more often unless the set maximum was decreased? And by dropping the set maximum timing values, situation B (timing retard by virtue of knock sensor detection and reaction) would be limited.

BMW has their own objectives in mind which are not always the same as performance tuners. They want to limit how much motor output can be had with higher octane fuels for example.

Mike

[Clap135]

Originally Posted by ExpensiveTaste

Clap, why are you acting like if a tune is created, the knock sensor is no longer needed? Even with modified timing tables, the ECU will still use the knock sensor output to lower the timing in daily conditions. When you tune a vehicle, do you advise the customer not to drive in humid conditions? The point being that in most conditions, every tune will knock without meth.

I believe I just said the knock sensor is used as a last resort in shitting conditions. This is kewl for a stock car. On a tuned car, the less u use the knock sensor, the better off you will be.

[Jeff@TopGearSolutions]

Originally Posted by ExpensiveTaste

Clap, why are you acting like if a tune is created, the knock sensor is no longer needed? Even with modified timing tables, the ECU will still use the knock sensor output to lower the timing in daily conditions. When you tune a vehicle, do you advise the customer not to drive in humid conditions? The point being that in most conditions, every tune will knock without meth.

Not true... I tuned my last car one time for ignition.

It never knocked ONCE, from 20 degree weather, to 100 degree weather.

Again, the difference is, tuning a specific car, VS tuning a car to be used around the world. Also having the full control for compensation tables. I.e. Gear dependent ignition and fuel. IAT compensation, Oil temp compensation, ECT compensation and the like.

With all of those defined (as well as some others im probably forgetting), you can make a tune acceptable in all conditions, and knock free.

They key to the equation is control.

[Mike@N54Tuning.com]

Originally Posted by ExpensiveTaste

It is definitely knock, but that's how autotuning works. It is the ECU pulling timing because it was a little too aggressive. The big question is how bad the knock event was. The real question that I have with the JB4 is how it manages the autotune boost setpoint when the timing curve is changing all the time. Will it eventually drop down to near stock boost over time when the ECU tries to reach the timing tables?

The algorithm is still early in development but it hones in on a performance level that can be supported with minimal drop outs for a given car/octane/mods/conditions. Coming next it will monitor the knock sensors directly so the learning is happening on all 6 cylinders and not just cylinder 1 as is used now.

[Clap135]

IMO: You should consider who you listen in thread based on the following
1. You have people in this thread who develop tunes
2. You have poeple in this thread who sell tunes and make money of you
3. You have poeple in this thread who have experience with all tunes
4. You have idiots

Imo you should rule out 2 of the 4 before making your mind up.

[SennaZ]

Originally Posted by Mike@N54Tuning.com

BMW has their own objectives in mind which are not always the same as performance tuners. They want to limit how much motor output can be had with higher octane fuels for example.

I think it's even more basic than that, BMW wants to protect itself against the idiot who runs regular (87 octane) in the engine either by accident or ignorance.

[shifterboy45]

this link is to lighten the mood a bit

[ExpensiveTaste]

Originally Posted by JPSlick

Not true... I tuned my last car one time for ignition.

It never knocked ONCE, from 20 degree weather, to 100 degree weather.

Again, the difference is, tuning a specific car, VS tuning a car to be used around the world. Also having the full control for compensation tables. I.e. Gear dependent ignition and fuel. IAT compensation, Oil temp compensation, ECT compensation and the like.

With all of those defined (as well as some others im probably forgetting), you can make a tune acceptable in all conditions, and knock free.

They key to the equation is control.

Lets bring this back into the context of the ECU at hand. This ECU is programmed to be used around the world. Correct me if I'm wrong, but the N54 ECU doesn't have custom tables for all of these conditions and relies on the knock sensor to get the "best tune" for the conditions.

[roninsoldier83]

Originally Posted by Clap135

with a v8 and 9.3 compression ratio....Boost pressure doesnt really mean much, 21psi from a tdo3 and 21 psi from a gt42r is still 21psi, but not the same amount of air or pressure in the cylinder.

+1

The absolute pressure means little when we're not looking at the CFM's / lb/min the compressor flows at "XX"psi. The peak boost pressure also doesn't begin to show the IAT's/BAT's (air temps entering the manifold) which make a difference when it comes to knock resistance. The previous poster also didn't think to consider IC size or efficiency. I agree with you.

Originally Posted by Litos

and the only real thing i took from that is the cold hard fact that the 335 knocks at stock boost on the stock tune, which ideally gives me the impression that the car is complete garbage, inefficient and a grenade waiting to happen EVEN in stock form.

I wouldn't go that far... you would be surprised how many cars have knock events from the factory, especially at higher elevations, on lower quality fuel. The fact that these motors aren't blowing left and right, but are able to adapt to conditions so readily is kind of a testament to the overall versatility of the DME and strength of the motor.

If you would like to see garbage, look no further:
http://forums.nasioc.com/forums/show....php?t=1312689

^^^Due to increased emissions & fuel economy regulations Subaru tuned bone stock 2007 STI's very lean under full load, which has resulted in countless blown motors. These aren't DI cars with overly sensitive ECU's... yet, it's commonplace on the '07's to hear of cracked ringlands, even in stock form.

Originally Posted by JPSlick

I never tuned any specific STi's, just Honda/Acura.

For N/A applications I tuned in the 13-13.2 Range
For Forced Induction 5 PSI or less they were tuned to 12.0-12.5

5PSI+ 11.7 AFR

10 PSI+ 11.5


Anything involving race gas tunes and excess of 20 PSI I rarely touched but I would likely put then in a low 11's AFR if I did.


I'd imagine I would tune any STI in the mid 11's.



Its common sense....

It doesnt need Data. Its physics my friend.

Most WRX/STI's are tuned in the mid 11's, tapering to the low 11's up top. Boxer engines don't dissipate heat as well as an inline, and as a result you typically see slightly higher EGT's than you would in an inline-4, and they're a little more prone to knock. As such, most tuners run them a little richer to help cool the heads/stave off detonation.

[Clap135]

Originally Posted by Mike@N54Tuning.com

The algorithm is still early in development but it hones in on a performance level that can be supported with minimal drop outs for a given car/octane/mods/conditions. Coming next it will monitor the knock sensors directly so the learning is happening on all 6 cylinders and not just cylinder 1 as is used now.

Does not seem like it is stable at all, the ignition is all over the place in the same gear at lets say 5k rpm. It knocks, lowers it, next time, it back up again, next pull it low again. Does not seem consistent what so ever. And this because the ecu is trying to hit preset ignition, and this is only at 12.5 psi.

[Litos]

Originally Posted by ExpensiveTaste

Lets bring this back into the context of the ECU at hand. This ECU is programmed to be used around the world. Correct me if I'm wrong, but the N54 ECU doesn't have custom tables for all of these conditions and relies on the knock sensor to get the "best tune" for the conditions.

from what i've read, it doesn't do a great job at it.

[Litos]

Originally Posted by roninsoldier83

Most WRX/STI's are tuned in the mid 11's, tapering to the low 11's up top. Boxer engines don't dissipate heat as well as an inline, and as a result you typically see slightly higher EGT's than you would in an inline-4, and they're a little more prone to knock. As such, most tuners run them a little richer to help cool the heads/stave off detonation.

mid 11's is perfect for most pump gas turbo'd cars - STi included.

i was 12.2 on M1 Meth.

[Jeff@TopGearSolutions]

Originally Posted by shifterboy45

this link is to lighten the mood a bit

Lol I liked the last one

[shifterboy45]

Originally Posted by JPSlick

Lol I liked the last one

itll kill you if you dont laugh in this business ...

[Jeff@TopGearSolutions]

Originally Posted by ExpensiveTaste

Lets bring this back into the context of the ECU at hand. This ECU is programmed to be used around the world. Correct me if I'm wrong, but the N54 ECU doesn't have custom tables for all of these conditions and relies on the knock sensor to get the "best tune" for the conditions.

I dont personally know what custom tables are available if any for compensation. I would HOPE there would be some.

We can deduce that the car is smart enough to compensate for boost leaks, overheating temps and the like, and thus go into limp mode.

Be that as it may, this all falls back to what has been said time and time again....

If a stock car is indeed seeing evidence of timing drop outs and knock, it begs the question how a tune with 2x more boost with no proactive change in timing is an IDEAL way to tune.

Getting down the road is one thing, getting down the road the better/safer way is where i like to stand.

Originally Posted by roninsoldier83

+1

The absolute pressure means little when we're not looking at the CFM's / lb/min the compressor flows at "XX"psi. The peak boost pressure also doesn't begin to show the IAT's/BAT's (air temps entering the manifold) which make a difference when it comes to knock resistance. The previous poster also didn't think to consider IC size or efficiency. I agree with you.



I wouldn't go that far... you would be surprised how many cars have knock events from the factory, especially at higher elevations, on lower quality fuel. The fact that these motors aren't blowing left and right, but are able to adapt to conditions so readily is kind of a testament to the overall versatility of the DME and strength of the motor.

If you would like to see garbage, look no further:
http://forums.nasioc.com/forums/show....php?t=1312689

^^^Due to increased emissions & fuel economy regulations Subaru tuned bone stock STI's very lean under full load, which has resulted in countless blown motors. These are DI cars with overly sensitive ECU's... yet, it's commonplace on the '07's to hear of cracked ringlands, even in stock form.




Most WRX/STI's are tuned in the mid 11's, tapering to the low 11's up top. Boxer engines don't dissipate heat as well as an inline, and as a result you typically see slightly higher EGT's than you would in an inline-4, and they're a little more prone to knock. As such, most tuners run them a little richer to help cool the heads/stave off detonation.

Yes I'm aware, as well as the back cylinders liking to go lean.

[vasillalov]

Ok guys,

This is becoming very frustrating.

1. Ignition timing retard DOES NOT NECESSARILY mean knock! There are other factors that can cause timing retard.

2. When engine knock is detected by sensor ALWAYS results in ignition timing correction.

Please, stop saying that the stock car knocks all the time! It is ridiculous and totally unproven. No, showing graphs of timing curve DOES NOT NECESSARILY mean that it was result from an actual knock. It only SUGGESTS that a knock event could have occurred. Pulled timing COULD BE the trace evidence of a knock event, not a definitive proof!

Simply put:

BMS/Mike/Terry can prove that the timing drops are NOT related to engine knock by showing us a graph of timing AND actual knock sensor output. Honestly, I don't see that one happening at all...

At the same time, Clap135 and the rest can prove that BMS products do not have proper timing control by simply showing us a graph which distinctly represent a 1-to-1 correlation between timing drops and actual detected knock events.

Since no one party so far has presented logs with actual knock sensor output:

/thread!

[Clap135]

so what causes these no knock related timing drops?

[Mike@N54Tuning.com]

Originally Posted by Clap135

Does not seem like it is stable at all, the ignition is all over the place in the same gear at lets say 5k rpm. It knocks, lowers it, next time, it back up again, next pull it low again. Does not seem consistent what so ever. And this because the ecu is trying to hit preset ignition, and this is only at 12.5 psi.

You can see it is stable at 4 but when at 5 there is a drop out. It has nothing to do with the actual advance numbers. Those are always going to vary wildly based on gear, IAT, baro, EGT, etc. Tuning for 91 octane like this is the worst case scenario. Most of us run 93 or higher.

Mike

[Clap135]

Originally Posted by Mike@N54Tuning.com

You can see it is stable at 4 but when at 5 there is a drop out. It has nothing to do with the actual advance numbers. Those are always going to vary wildly based on gear, IAT, baro, EGT, etc. Tuning for 91 octane like this is the worst case scenario. Most of us run 93 or higher.

Mike

So why is it that a car on race gas will not vary timing based on rpm?
To me that means that the timing curve is set blow the knock threshold.
Your logs, with constantly varying timing, indicates the timing curve is above the knock threshold and no matter what you do, it iwll knock its way up and down constantly.

I am running 93 octane and my timing curve is spot on in every gear at the same rpm. Why? Because the timing curve for my car is set blow the knock threshold. Its a very simply concept

[Black Gold]

Originally Posted by SennaZ

I think it's even more basic than that, BMW wants to protect itself against the idiot who runs regular (87 octane) in the engine either by accident or ignorance.

I get that, but my question is why would the set timing maxed change on the is if their was no correlation between increased boost and increased knock sensor detection frequency assuming identcal set timig point maximums.

Bad gas concerns should be identcal for the 335i and 335is. Yet the timing maxes are different. Only reason I can see is that decreasing max timing setpoints on the 335is which runs higher boost limits knock sensor detection events.

If there is another reason, I'd love to know.