stock BR-Z, much detonation during shifts: tune?

[Suberman]

Originally Posted by arghx7

I'm not sure I'd go that far... remember the injector issue on some of these engines and the new knock control settings from the dealer reflash.

I was just trying to point out that this is a gray area, not black and white. It's a murkier issue than "my car is definitely knocking and any knock is bad"

Well, OK if you think so. But the fact is that detonation is not harmful until combustion temperatures start melting holes in pistons.

The basic rule of thumb is if you can hear the detonation and it goes away quickly then no harm is done.

Detonation reduces bmep, ironically by increasing peak pressure (Brake Mean Effective Pressure). The harm arises when the driver is unable to detect detonation and compensates for the drop in bmep by applying more throttle. Eventually the detonation melts a hole in a piston and catastrophic engine failure results. For factory engines this hasn't happened since about 1968.....emissions compliant engines just can't do this.

[Thorpedo]

I just made this thread, but it fits quite well here so let me post:

Alright so I've read the hell out of most of the DI failure threads. It seems the common understanding is that this failure is caused by detonation, which absolutely makes sense. This detonation is caused by "fast shifts" (>0.6 sec as per defined by a Toyota) where the computer cannot compensate quick enough and the engine experiences detonation on some (or all) of the cylinders for the first few revs upon of the reapplication of throttle....

While I can hear detonation on a really quick shift, it seems I can hear it a LOT more often than that now that I am looking for it. I only use Shell VPower 91. When my car is fully warmed up, most of the time if i quickly apply throttle I will have a few knocks, whether I shift or not. (Due to my previous experience with autos, I know for sure it is detonation). In the sheet supposedly taken from Toyota which re-tuned vehicles in south africa, it claimed this issue ONLY happened above 5200 RPM where our ECU won't pull timing.)

While I have seen several threads saying my DI seals are shot if i hear this detonation, I disagree. I have only ever heard one actual "pop" from the car, and it runs great with no CELs.

SO, where should I go with this? Take it into the dealer and take a tech with me and show him/her I can make preignition happen on command? I know I have no issues now, but from daily driving this will undoubtedly lead to DI seal failure or worse...

I was thinking I would take a printout of that sheet about the tune in south africa.... My car was built in the end of last Nov. Would I have the updated ECU Calibration? Opinions?

Let me add on for you folks in this thread, for the brief second it happens it is a harsh knock. It is not a ping or light pre-ignition I am talking about....

[elefunkd]

Originally Posted by Thorpedo

I just made this thread, but it fits quite well here so let me post:

Alright so I've read the hell out of most of the DI failure threads. It seems the common understanding is that this failure is caused by detonation, which absolutely makes sense. This detonation is caused by "fast shifts" (>0.6 sec as per defined by a Toyota) where the computer cannot compensate quick enough and the engine experiences detonation on some (or all) of the cylinders for the first few revs upon of the reapplication of throttle....

While I can hear detonation on a really quick shift, it seems I can hear it a LOT more often than that now that I am looking for it. I only use Shell VPower 91. When my car is fully warmed up, most of the time if i quickly apply throttle I will have a few knocks, whether I shift or not. (Due to my previous experience with autos, I know for sure it is detonation). In the sheet supposedly taken from Toyota which re-tuned vehicles in south africa, it claimed this issue ONLY happened above 5200 RPM where our ECU won't pull timing.)

While I have seen several threads saying my DI seals are shot if i hear this detonation, I disagree. I have only ever heard one actual "pop" from the car, and it runs great with no CELs.

SO, where should I go with this? Take it into the dealer and take a tech with me and show him/her I can make preignition happen on command? I know I have no issues now, but from daily driving this will undoubtedly lead to DI seal failure or worse...

I was thinking I would take a printout of that sheet about the tune in south africa.... My car was built in the end of last Nov. Would I have the updated ECU Calibration? Opinions?

Let me add on for you folks in this thread, for the brief second it happens it is a harsh knock. It is not a ping or light pre-ignition I am talking about....

My car is 02-13 build date, and what you describe in your post, is precisely what I can hear, save for the fact that unlike what you are experiencing, I have never heard throttle tip-in detonation... only during up-shifts.

I just went out for a spirited 45 minute drive, and I have been unable to duplicate the issue. It is a cool night of 16°C as opposed to the 30+°C days when the detonation usually occurs.

[ft_sjo]

Originally Posted by Lonewolf

Good to know that you know everything....

I really don't understand you people. Someone shares some actual knowledge, rather than repeated garbage they find on the forum/internet, and they come out with sarcastic comments. Bravo, well done, way to improve yourself.

[ft_sjo]

Originally Posted by suaveflooder

Weird. My car doesn't detonate at high RPM's and shifting fast. I am hardly a "doom monger" as I don't drive the car enough in the manner needed to cause any sort of DI failure, so it is not a concern for me. But if the OP is truly getting detonation, that is NOT normal on any car.

How have you established that your car doesn't det?

[suaveflooder]

Originally Posted by ft_sjo

How have you established that your car doesn't det?

I've heard detonation on both of my cobras when i had them tuned. Usually the tuner shut it down shortly after to fix it. I've never heard it on my FRSz

[ft_sjo]

Originally Posted by suaveflooder

I've heard detonation on both of my cobras when i had them tuned. Usually the tuner shut it down shortly after to fix it. I've never heard it on my FRSz

Heard.. how?

[suaveflooder]

Originally Posted by ft_sjo

Heard.. how?

What's the matter don't believe me? Or are you upset that I questioned you? I heard a slight "ping" on the first dyno run. Sure enough, tuner came to me after the run and told me that I had a little detonation down low and I needed more fuel.

You want to check on the tuner look up Greg at Racers Edge Tuning in Downy Ca. One of the best tuners for the Mustang Cobra.

[suaveflooder]

Originally Posted by ft_sjo

I really don't understand you people. Someone shares some actual knowledge, rather than repeated garbage they find on the forum/internet, and they come out with sarcastic comments. Bravo, well done, way to improve yourself.

You are not sharing any sort of "actual knowledge" just your opinion. As a matter of fact I was one of the few arguing against the whole mas hysteria DI issues in the other two threads.

I DO NOT think it is a major problem and I DO NOT think it will effect the majority of the GT86/FRS/BRZ cars. I feel it is foolish to think that way when there are SO few with the issue/symptoms. But when you see threads like this and he is specifially stating that he is hearing detonation EXACTLY where it should be if the DI was having some problems, then I'm going to call it like I see it. If it looks like a duck, walks like a duck, and quacks like a duck...well......

[ft_sjo]

Originally Posted by suaveflooder

What's the matter don't believe me? Or are you upset that I questioned you? I heard a slight "ping" on the first dyno run. Sure enough, tuner came to me after the run and told me that I had a little detonation down low and I needed more fuel.

I asked for you to explain the method, with "how?". I'm sorry you misinterpreted that, I just use simple English to communicate, not telepathy.

If you're talking about just using your ears to hear detonation without any kind of additional tool, then you're only seeing a small part of the picture, or hearing as it would more appropriately be. The kind of det which can put a hole through the engine you'd never hear with your naked ears.

That's not opinion, that's fact.. which leads me onto your next rant..

Originally Posted by suaveflooder

You are not sharing any sort of "actual knowledge" just your opinion. As a matter of fact I was one of the few arguing against the whole mas hysteria DI issues in the other two threads.

I DO NOT think it is a major problem and I DO NOT think it will effect the majority of the GT86/FRS/BRZ cars. I feel it is foolish to think that way when there are SO few with the issue/symptoms. But when you see threads like this and he is specifially stating that he is hearing detonation EXACTLY where it should be if the DI was having some problems, then I'm going to call it like I see it. If it looks like a duck, walks like a duck, and quacks like a duck...well......

I don't think you understand what the TSB specifies, nor what the OP of this thread is describing. I'll try and break it down for you, hopefully you will understand rather than just throwing it back in my face with some kind of insult:

The TSB which describes the injector seal-killing det, explains that above 5200rpm and with gear changes faster than 600ms, transient detonation can occur. The cause identified as a lack of effective transient spark angles in the relevant tables. The fix is a revised calibration which enables the transient spark table above 5200rpm and populates the empty parts of the relevant table with useful values.

If you go back and read the OP in this thread, you will see he describes it as happening below 5200 rpm. This is completely different behaviour and I can reproduce it easily, with or without the calibration fix above. It's completely unrelated.

I'm going to take a video soon with some real-time logging on-camera explaining the different methods of achieving all of these behaviours. Hopefully people can use that as some kind of useful reference rather than just repeating crap on this forum.

I hope this helps.

[suaveflooder]

Originally Posted by ft_sjo

I asked for you to explain the method, with "how?". I'm sorry you misinterpreted that, I just use simple English to communicate, not telepathy.

If you're talking about just using your ears to hear detonation without any kind of additional tool, then you're only seeing a small part of the picture, or hearing as it would more appropriately be. The kind of det which can put a hole through the engine you'd never hear with your naked ears.

That's not opinion, that's fact.. which leads me onto your next rant..

It's called a dyno, with graphs and all sorts of cool stuff doing the "tooling"

Originally Posted by ft_sjo

I don't think you understand what the TSB specifies, nor what the OP of this thread is describing. I'll try and break it down for you, hopefully you will understand rather than just throwing it back in my face with some kind of insult:

The TSB which describes the injector seal-killing det, explains that above 5200rpm and with gear changes faster than 600ms, transient detonation can occur. The cause identified as a lack of effective transient spark angles in the relevant tables. The fix is a revised calibration which enables the transient spark table above 5200rpm and populates the empty parts of the relevant table with useful values.

If you go back and read the OP in this thread, you will see he describes it as happening below 5200 rpm. This is completely different behaviour and I can reproduce it easily, with or without the calibration fix above. It's completely unrelated.

I'm going to take a video soon with some real-time logging on-camera explaining the different methods of achieving all of these behaviours. Hopefully people can use that as some kind of useful reference rather than just repeating crap on this forum.

I hope this helps.

CSG mike was able to get it to make a fun little noise at idle just revving the motor after the problem was found.

I would love to try and recreate this like you say you can. My engine runs perfectly. No idle dip, not detonation in any range of the RPM.

I think you are just trolling for a fight.

I'm not going to argue with you on this. It's not normal and should be looked at. I'm crossing my fingers that it's nothning. It just might be and you can go feel all good about yourself. You know....warm fuzzy feelings

[ft_sjo]

See, I try and explain the facts to someone and they just reply with nonsense. Can't win either way.

[suaveflooder]

Originally Posted by ft_sjo

See, I try and explain the facts to someone and they just reply with nonsense. Can't win either way.

lol, stop being a baby. You win! You win! It's whatever you said it was, or wasn't...or .....whaterver.... you feel better? Feel like you've won?

OP, just get it checked out. With any luck it's nothing. Good news is that it's free. Or you can listen to people like @ft_sjo and do nothing about it because it is completely "normal" to have your car detonate in normal drivng conditions.

I've read some of your other posts, @ft_sjo, you sound like a charming person. We should get together and have a beeeeeeer.:happy0180: Enough alcohol makes anyone fun

[arghx7]

If you're running US 91 octane, it may really be audible knock. I can pretty much guarantee this engine was designed for Japanese fuel, which is 98 or 100 RON, or US certification fuel which is 97 RON. The lower grade fuel was an after thought.

Try putting 87 octane in and see if it gets worse.