[atlharry]

Originally Posted by themyst

The problem is many BMW owners lease their cars for 2-3 years so they really don't give a rats ass what damage they do.

THIS

You f*ckers. Seriously.

[BeenieMan]

Originally Posted by Litos

my SRT8 doesn't knock
my SRT4 didn't knock
my STi didn't knock
my WS6 didn't knock
my OTHER SRT4 didn't knock

only car that has potential to knock in stock form from a car that i own or have previously owned is the 335.

what other $35-40K performance cars knock in stock form - i'd like to hear this

my 300zx did, and it would go into safety boost... only happened in 100+degree temps after getting stuck in traffic at 15psi

[Litos]

Originally Posted by BrianMN

Remember we're mostly talking about very poor conditions, such as low octane or very hot weather. If you were to throw in some 87 into your cars, you'd likely see knock...

i would agree, but all of these cars are reccomended to run 93 octane.

my SRT8 can be tuned to run 87 with the DiabloSport, but that's retarded HAHA !!! no one wants to run 87 octane in a 400+hp car

hell, even my wife's Scion XB would run 93 octane HAHA !!!!

[roninsoldier83]

Originally Posted by vasillalov

Clap135,

I am catching a bit of a contradiction in your statements:

1. First you question my argument that timing drop does not necessarily mean engine knock.

2. Then you say that there is no direct way to capture the knock sensor output in a reliable fashion

3. Now you are saying that proper boost and ignition control are necessary, instead of relying on the knock sensor. (I agree with this BTW)

From all three, I don't see HOW you can accomplish all this given the restrictions above? I.O.W, how can a tuner company rewrite the timing tables, if they have no way of detecting knock events, since the knock sensor output is useless?

To turn this around a bit:

Say you are able to extrapolate a way to determine when knocking will occur with 100% certainty by the use of all other sensors EXCEPT the knock sensor. Say that's possible. Then wouldn't that mean that BMW would have already implemented an algorithm to pull timing when the conditions are approaching a knock threshold? :

Well, since we're unable to extrapolate useful information directly from the knock sensors themselves, a reasonable alternative would be to find or construct a set of det cans in order to physically listen for detonation while logging yourself. Or find a local tuner that has a set (I know a couple local tuners that keep det cans / electronic stethoscope on hand) and make a few pulls on their dyno while logging.

I'm assuming if a person was to do enough searching, they could likely find pinout information on the stock DME, and could likely trace down the knock sensor wire(s). Unless there's something completely out of the ordinary with the sensors on these cars, I don't see why a person couldn't simply solder in a knock light (tap the factory sensor(s)).... like the fairly inexpensive knocklites produced by TurboXS:
http://www.turboxs.com/shop/product.php?id_product=245

^^^Not sure if they run a different voltage/signal requirement than we would need for these cars, or if there's something "special"/proprietary I don't know about for BMW's, but it wouldn't hurt to give the guys at TXS a call and ask. Granted, a knock light wouldn't tell you the severity of the knock your motor is experiencing, but it would dispel the rumors on either side while logging timing & monitoring the knock light. Although a simpler solution would just be to log while listening with a set of det cans IMO...

Just an idea

[Dmacc]

Originally Posted by BeenieMan

that's a contradiction in itself. if a stock car knocks as bad shown, the best tune would just retard the timing and leave the boost stock or drop it completely lol

and I have seen a log from all the tunes that showed timing drop. you just need to know how to increase boost and not knock to keep it safe

correct, but the learning curve for the jb product is a little scarier than other products that have the ability to adjust timing.

relying on the stock knock sensor for trying to learn the right combo of boost and fuel is much scarier than using cps offsetting to make the learning process much safer.

timing is set to stock levels, so is it safe to say the knock is going to be more severe when the jb is learning compared to lets say when the procede is learning?

[Litos]

Originally Posted by Dmacc

relying on the stock knock sensor for trying to learn the right combo of boost and fuel is much scarier than using cps offsetting to make the learning process much safer.

especially seeing as it can barely do that in stock form.

[mikracer]

Originally Posted by Litos

my SRT8 doesn't knock
my SRT4 didn't knock
my STi didn't knock
my WS6 didn't knock
my OTHER SRT4 didn't knock

only car that has potential to knock in stock form from a car that i own or have previously owned is the 335.

what other $35-40K performance cars knock in stock form - i'd like to hear this

I had an MSRT8 I traded in for my 335. That thing pinged (alot) on the stock tune. Pinged almost just as much on a Predator tune as well.

[Dmacc]

Originally Posted by Litos

especially seeing as it can barely do that in stock form.

True, which raises the whole point of this thread in the first place.

why rely on it to run higher boost safely when in poor conditions it can't even run the right amount safely?

[Mike@N54Tuning.com]

Originally Posted by Morpheus

Engine Block
The guys at Birds discovered that piston #5 was on its way to destruction. The piston had lost a chunk of material on the corner and the rings were badly worn. Oil had definitely been seeping past and there was also a tiny speck of plastic sitting on top of the piston crown (where that came from is anyone's guess!) The top of the piston was covered in specks of carbon and tiny bits of aluminium. The other cylinders looked ok in terms of piston wear, but the cylinder bores were all significantly scored, much more than would have been expected from a 50,000 mile engine (which is what mine has done)....The car has been running either a remap or Procede for about the same mileage as well (about three years)....

great thread BTW if you haven't seen it.

Missed this post earlier. Just goes to show you can damage a motor with a PROcede just as easily as you can with any tune. It will be interesting to see how/if Cobb is able to implement an autotuning algorithm or if every car will need to ultimately be custom tuned, and then retuned if conditions change, etc.

Mike

[Clap135]

If u are going to insult someone be smart enough not to look stupid. Psi on varying turbos is the same. Please realize this.

Originally Posted by SennaZ

So it seems you and your buddies live in a vacuum? Me, I like my 1 atm of base pressure. And of course, you guys apparently relate manifold pressure to cylinder pressure not accounting for any volumetric losses.

But going back to your original claim: cylinder pressure does not jump exponentially with 2x boost pressure which is precisely why the JBx platform can compensate for 14psi boost situations. Now, if you want to talk 600hp engines running gobs of boost (a hell of alot more than 14psi), then it's a different ball game.

[Litos]

Originally Posted by mikracer

I had an MSRT8 I traded in for my 335. That thing pinged (alot) on the stock tune. Pinged almost just as much on a Predator tune as well.

what's an MSRT8?

my car has always driven smooth with no knock at all - you might have been driving it in bad conditions or running bad fuel like all these other people are saying lol.

[roninsoldier83]

Originally Posted by Litos

my SRT8 doesn't knock
my SRT4 didn't knock
my STi didn't knock
my WS6 didn't knock
my OTHER SRT4 didn't knock

only car that has potential to knock in stock form from a car that i own or have previously owned is the 335.

what other $35-40K performance cars knock in stock form - i'd like to hear this

How often did you log your vehicles? Most stock STI's knock at some point (especially 07-08's that held near stoich AFR's under full load until ~4000-4500rpm) or another... I know when running 91 octane at my elevation (5200 ft), on a hot day when the TMIC was heat soaked, I would see an occasional count or two of knock (although never on E85... latent heat of 310 BTU/lb FTW!!). Were you using a knock light to monitor knock on all of those vehicles, or were you running around with a laptop/tuning device connected at all times?

[Black Gold]

Originally Posted by fisherbln

You still don't seem to hear what people are telling you repeatedly.

1. Many cars knock in their stock form in poor conditions, that is what the knock sensor is for.
2. While all knock is bad, a knock at low boost (stock) is not nearly as bad as a knock at high boost (tuned).

And to add

3) a car with higher boost/load requirements using the same timing set points as stock (ie not dropping timig to ompensate for higher boost) running under the same conditions will knock MORE than the stock car.

So, higher frequency of knock sensor detection events than an all else equal stock tune at higher cylinder pressures. If you still want to take your chances with that given that other tunes can alleviate this, good luck.

Hell, even mike himself said that tuning ideally should minimize these knock detection events. It is a fact that JBx is deficient in this compared o other tunes.

[drewrak]

The funny thing is, no matter what Terry or Mike do about the JB4 there will always be someone bashing each others work. Everyone speaks of controlling ignition timing and how the JB4 doesn't do it and it will blow up all our motors. However, after all the crying and whining say they do add ignition timing control all we will hear about is how the juice box ideas of ignition timing were ripped off from the procede. It will never end, and these threads are getting ridiculous.

[RambleJ]

Originally Posted by BrianMN

Remember we're mostly talking about very poor conditions, such as low octane or very hot weather. If you were to throw in some 87 into your cars, you'd likely see knock...

Exactly, we are basing this off of one persons stock car logs. Conditions and gas can plan a huge part. I would like to see some other stock car logs.
And I am not talking about a tuned car in bypass mode. Straight stock car with no tune plugged in what so ever.

[Dmacc]

Originally Posted by drewrak

The funny thing is, no matter what Terry or Mike do about the JB4 there will always be someone bashing each others work. Everyone speaks of controlling ignition timing and how the JB4 doesn't do it and it will blow up all our motors. However, after all the crying and whining say they do add ignition control all we will hear about is how the juice box ideas of ignition timing were ripped off from the procede. It will never end, and these threads are getting ridiculous.

even if that is the case, bms will have a greater group of customers with no worry, and a larger croud to appeal to.

but right now all it is, is

"knock knock knock, who's there?, stressed engine, stressed engine who? stressed engine because my learning capability sucks and I need real offsetting."

[Jeff@TopGearSolutions]

Originally Posted by Litos

so we can all collectively agree that unless your car is running a V5 on autotune or a JB4 on autotune or meth (even on a stock car), you're more than likely running with an unhappy car.

that's all this really boils down to.

No...

Atleast the PROcede proactively reduces ignition from the get-go on its default maps. Its always 1-3 degrees lower from the start.

Originally Posted by Litos

so in poor conditions this iconic 3-series drives like a pig, loses power and knocks all over God's creation?

Ok keep believing this.... IDK what else to tell you, either your just trolling now, stubborn, thick headed, or not too bright.

Originally Posted by Litos

my SRT8 doesn't knock
my SRT4 didn't knock
my STi didn't knock
my WS6 didn't knock
my OTHER SRT4 didn't knock

only car that has potential to knock in stock form from a car that i own or have previously owned is the 335.

what other $35-40K performance cars knock in stock form - i'd like to hear this

How do you know your other cars didnt knock? Did you log them in stock form?

All cars knock stock. Thats why there is a knock sensor. No, I didnt say the knock everyday, but they have the potential to knock.

People are REALLY losing site of what knock is, its severity during certain conditions, and what the whole point of the thread is....

Really losing site.

Im done repeating myself. DONE.

Re-read the thread.

The same 48 questions over and over, most by the same people.

Instead of asking questions here, and getting the same responses, try a 3rd party source.

Do your research elsewhere. Clearly the answers arent getting through. This goes for everyone.

Originally Posted by SennaZ

So it seems you and your buddies live in a vacuum? Me, I like my 1 atm of base pressure. And of course, you guys apparently relate manifold pressure to cylinder pressure not accounting for any volumetric losses.

But going back to your original claim: cylinder pressure does not jump exponentially with 2x boost pressure which is precisely why the JBx platform can compensate for 14psi boost situations. Now, if you want to talk 600hp engines running gobs of boost (a hell of alot more than 14psi), then it's a different ball game.

Yea feel free to read the post below, they already owned you. You can leave the thread knowing you dont know anything about physics.

Originally Posted by fisherbln

The air pressure from the turbo is not directly what is causing the increased cylinder pressure. The increased cylinder pressure is a result of more fuel being present in the combustion chamber because more air is in there. If there wasn't more fuel, you'd be running VERY lean. Because there is more air and fuel, the resulting explosion caused by the spark releases more energy. This energy increases pressure in the combustion chamber and (if timed correctly), pushes the piston down with said pressure.

This is why increased boost makes more power. More air + more fuel = greater pressure pushing the piston down with greater force. If timing isn't correct, that greater force is exerted at an inopportune time.

Thank you

Originally Posted by Clap135

If u are going to insult someone be smart enough not to look stupid. Psi on varying turbos is the same. Please realize this.

+1

[SennaZ]

Originally Posted by Clap135

If u are going to insult someone be smart enough not to look stupid. Psi on varying turbos is the same. Please realize this.

Well since you said "please" I won't attempt to insult you.

When you run 8 psi on the turbos, the effective manifold pressure goes from 14.7 psi (atmospheric) to 14.7 + 8 = 22.7 psi. Upping the turbos to 14 psi equates to 14.7 + 14 = 28.7 psi or a volumetric gain of about +26%.

Interesting that this is about what Cobb claims you can get with their tune, isn't it? Actually, you will typically get less because their are other losses in the system.

What you guys can't seem to understand is that the 60-80 hp gain achieved by this rather modest increase in volumetric efficiency (and yes, for your PV=nRT buddies, the equivalent increase in pressure) doesn't apparently tax the N54 platform. Now if we were seeing "exponential increases" in cylinder pressures, to the 'tune' of 1200-1800 psi, I can assure you the knock sensor system would be the last of your worries (think catastrophic head gasket blowouts).

The JBx system is quite capable of handing the necessary timing reduction for this relatively small increase in power, but it does so at it's own peril. The end user must be diligent in running the proper fuel and might want to refrain from excessive WOT runs in my Phoenix summer heat.

I appreciate and run the flash approach (Cobb), but I can understand that with the right end-user the JBx system will work also.

[Jeff@TopGearSolutions]

Originally Posted by SennaZ

Well since you said "please" I won't attempt to insult you.

When you run 8 psi on the turbos, the effective manifold pressure goes from 14.7 psi (atmospheric) to 14.7 + 8 = 22.7 psi. Upping the turbos to 14 psi equates to 14.7 + 14 = 28.7 psi or a volumetric gain of about +26%.

Interesting that this is about what Cobb claims you can get with their tune, isn't it? Actually, you will typically get less because their are other losses in the system.

What you guys can't seem to understand is that the 60-80 hp gain achieved by this rather modest increase in volumetric efficiency (and yes, for your PV=nRT buddies, the equivalent increase in pressure) doesn't apparently tax the N54 platform. Now if we were seeing "exponential increases" in cylinder pressures, to the 'tune' of 1200-1800 psi, I can assure you the knock sensor system would be the last of your worries (think catastrophic head gasket blowouts).

The JBx system is quite capable of handing the necessary timing reduction for this relatively small increase in power, but it does so at it's own peril. The end user must be diligent in running the proper fuel and might want to refrain from excessive WOT runs in my Phoenix summer heat.

I appreciate and run the flash approach (Cobb), but I can understand that with the right end-user the JBx system will work also.

What you dont get is your getting caught up on the word exponential that I used earlier. Call it a Typo, however, the end result is, there is an increase in pressure nonetheless.

Where as you think 60-80HP increase is not a big deal, I'm not about to disagree, but adding that HP correctly, is a different thing.

You guys can preach all day how a stock ECU handles everything "perfect". I have to assume you guys view it as perfect, cause if you dont, that is my point. Using the stock system to protect you is not the perfect way, or the ideal way...

Said it time and time again. There are better approaches to tuning.

Que the smilie of beating the dead horse.

[atlharry]

Originally Posted by SennaZ

Well since you said "please" I won't attempt to insult you.

When you run 8 psi on the turbos, the effective manifold pressure goes from 14.7 psi (atmospheric) to 14.7 + 8 = 22.7 psi. Upping the turbos to 14 psi equates to 14.7 + 14 = 28.7 psi or a volumetric gain of about +26%.

Interesting that this is about what Cobb claims you can get with their tune, isn't it? Actually, you will typically get less because their are other losses in the system.

What you guys can't seem to understand is that the 60-80 hp gain achieved by this rather modest increase in volumetric efficiency (and yes, for your PV=nRT buddies, the equivalent increase in pressure) doesn't apparently tax the N54 platform. Now if we were seeing "exponential increases" in cylinder pressures, to the 'tune' of 1200-1800 psi, I can assure you the knock sensor system would be the last of your worries (think catastrophic head gasket blowouts).

The JBx system is quite capable of handing the necessary timing reduction for this relatively small increase in power, but it does so at it's own peril. The end user must be diligent in running the proper fuel and might want to refrain from excessive WOT runs in my Phoenix summer heat.

I appreciate and run the flash approach (Cobb), but I can understand that with the right end-user the JBx system will work also.

Soooo, what you're saying as that 28.7 psi in a cylinder is driving a piston with enough force to create ~400 hp?

Or are you willing to admit that AFTER ignition cylinder pressures are WAAAAY higher with exponential gains because of the increase in fuel/air?

JP - you were right the first time. No typo.

[Jeff@TopGearSolutions]

Originally Posted by atlharry

Soooo, what you're saying as that 28.7 psi in a cylinder is driving a piston with enough force to create ~400 hp?

Or are you willing to admit that after ignition cylinder pressures are WAAAAY higher AFTER ignition with exponential gains because of the increase in fuel/air?

JP - you were right the first time. No typo.

Reading too fast from a phone and his good use of words led me to second guess myself. Thanks.

[Clap135]

Yet again you fail to realize that psi does not mean much. A basketball for a turbo by your logic will make the same power at 14 psi. Intact it will make more cause its pushing more air at the same psi which raises cylinder pressure more. Nice try though.

Originally Posted by SennaZ

Well since you said "please" I won't attempt to insult you.

When you run 8 psi on the turbos, the effective manifold pressure goes from 14.7 psi (atmospheric) to 14.7 + 8 = 22.7 psi. Upping the turbos to 14 psi equates to 14.7 + 14 = 28.7 psi or a volumetric gain of about +26%.

Interesting that this is about what Cobb claims you can get with their tune, isn't it? Actually, you will typically get less because their are other losses in the system.

What you guys can't seem to understand is that the 60-80 hp gain achieved by this rather modest increase in volumetric efficiency (and yes, for your PV=nRT buddies, the equivalent increase in pressure) doesn't apparently tax the N54 platform. Now if we were seeing "exponential increases" in cylinder pressures, to the 'tune' of 1200-1800 psi, I can assure you the knock sensor system would be the last of your worries (think catastrophic head gasket blowouts).

The JBx system is quite capable of handing the necessary timing reduction for this relatively small increase in power, but it does so at it's own peril. The end user must be diligent in running the proper fuel and might want to refrain from excessive WOT runs in my Phoenix summer heat.

I appreciate and run the flash approach (Cobb), but I can understand that with the right end-user the JBx system will work also.