HSV Dyno day Oct SRR
Discussion
ringram said:
9 degrees is a lot. FI on stock NA compression isnt a good recipe, its a compromise which more people are realising. This illustrates nicely the concept of being knock limited.
All FI setups on stock engines are knock limited. Even with no knock registered power gains are limited by the fact that timing is reduced to avoid knock.
Therefore timing moves further and further away from Mean Best Timing (MBT)
Very misleading Richard. Its got knock because it has a problem, not because its supercharged. Fix the problem and it will be OK. All FI setups on stock engines are knock limited. Even with no knock registered power gains are limited by the fact that timing is reduced to avoid knock.
Therefore timing moves further and further away from Mean Best Timing (MBT)
monkfish1 said:
Very misleading Richard. Its got knock because it has a problem, not because its supercharged. Fix the problem and it will be OK.
I stand by everything I said. FI on stock engine is knock limited .That's was offensive and unfair , so I deleted your remark to save you from moderator intervention of a banning nature.
Edited by RichieSlow on Monday 20th October 19:37
Information:
http://www.autospeed.com/cms/article.html?&A=1...
"The spark timing at which knock occurs is called the "knock limit". The value of the knock limit depends chiefly on the engine's compression ratio and the fuel's resistance to knock. In practice, it may not be possible to advance the spark timing to MBT without knock occurring, since the knock limit may lie either before or after MBT (ie best torque may occur at an ignition timing where knock intrudes)."
http://www.autospeed.com/cms/article.html?&A=1...
"The spark timing at which knock occurs is called the "knock limit". The value of the knock limit depends chiefly on the engine's compression ratio and the fuel's resistance to knock. In practice, it may not be possible to advance the spark timing to MBT without knock occurring, since the knock limit may lie either before or after MBT (ie best torque may occur at an ignition timing where knock intrudes)."
Mr Moderator please explain what was inaccurate about my comment that you edited?
I am 100% correct and have plenty of academic material to back up my statement.
I stated Roger was incorrect and must not understand what I am saying.
Can we please debate this properly and like adults so people can learn. Isn't that the whole point of this forum.
Banning free speech simply serves to keep everyone in the dark.
Can you please explain in factual terms what is incorrect about anything I have stated.
Thanks.
I am 100% correct and have plenty of academic material to back up my statement.
I stated Roger was incorrect and must not understand what I am saying.
Can we please debate this properly and like adults so people can learn. Isn't that the whole point of this forum.
Banning free speech simply serves to keep everyone in the dark.
Can you please explain in factual terms what is incorrect about anything I have stated.
Thanks.
ringram said:
I stand by everything I said. FI on stock engine is knock limited .
That's was offensive and unfair , so I deleted your remark to save you from moderator intervention of a banning nature.
You choose to miss my point. The bit about 9 degrees of retard and the statements about knock retard are unconnected.That's was offensive and unfair , so I deleted your remark to save you from moderator intervention of a banning nature.
Edited by RichieSlow on Monday 20th October 19:37
1 is not related to the other is it?
The gentlemans car is not performing as expected. This is because it has a problem. This needs to be fixed.
The other is about the theory of FI being knock limited.
The 2 are not related. You chose to relate the two in order to mislead. You may choose to deny it, but we both know this is true. Otherwise, why bring it up? Given your knowledge on the subject, you could have helped. You chose not to.
ringram said:
Mr Moderator please explain what was inaccurate about my comment that you edited?
I am 100% correct and have plenty of academic material to back up my statement.
I stated Roger was incorrect and must not understand what I am saying.
Can we please debate this properly and like adults so people can learn. Isn't that the whole point of this forum.
Banning free speech simply serves to keep everyone in the dark.
Can you please explain in factual terms what is incorrect about anything I have stated.
Thanks.
Try reading what is in front of you Richard. I dont recall saying you were incorrect? I am 100% correct and have plenty of academic material to back up my statement.
I stated Roger was incorrect and must not understand what I am saying.
Can we please debate this properly and like adults so people can learn. Isn't that the whole point of this forum.
Banning free speech simply serves to keep everyone in the dark.
Can you please explain in factual terms what is incorrect about anything I have stated.
Thanks.
I have reread the comment you quoted squire Keys and the entire piece is talking about FI on stock engines being knock limited.
That is the statement you said was misleading. However it is not.
The knock retard is a symptom of the problem. Lower octane fuel is only exacerbating the issue. With high octane fuel the issue is still there. Timing is set well away from MBT to avoid knock. That has a follow on effect of reducing power from the theoretical level.
Intake temp also further aggravates the issue. I refer you to page 2 of the article. It states the factors all of which were present in the car on the day which lead to knock retard.
But Im talking about being knock limited in general. Not the knock retard on the day. That was the statement you quoted and has nothing misleading in it at all. Can you point out the specific statement or error please as I would genuinely like to know.
Mr ARAF for your elucidation the answer is in black and white above. I have typed what the issue is and linked to a detailed article explaining not only MBT and Knock Limited theory. But also factors that affect knock and mitigations etc. The fixes and answers are all there.
That is the statement you said was misleading. However it is not.
The knock retard is a symptom of the problem. Lower octane fuel is only exacerbating the issue. With high octane fuel the issue is still there. Timing is set well away from MBT to avoid knock. That has a follow on effect of reducing power from the theoretical level.
Intake temp also further aggravates the issue. I refer you to page 2 of the article. It states the factors all of which were present in the car on the day which lead to knock retard.
But Im talking about being knock limited in general. Not the knock retard on the day. That was the statement you quoted and has nothing misleading in it at all. Can you point out the specific statement or error please as I would genuinely like to know.
Mr ARAF for your elucidation the answer is in black and white above. I have typed what the issue is and linked to a detailed article explaining not only MBT and Knock Limited theory. But also factors that affect knock and mitigations etc. The fixes and answers are all there.
ringram said:
Cars are tuned for a specific octane mate. Thats why they all recommend a specific rating.
9 degrees is a lot. FI on stock NA compression isnt a good recipe, its a compromise which more people are realising. This illustrates nicely the concept of being knock limited.
All FI setups on stock engines are knock limited. Even with no knock registered power gains are limited by the fact that timing is reduced to avoid knock.
Therefore timing moves further and further away from Mean Best Timing (MBT)
Running hightest octane possible will help a bit, but it cant fix a fundamentally limited configuration.
Yes but the base spark map, if kept stock, isn't going to be 2billion degrees less. Its all conjecture without seeing the tables but unless the FI's are "really" sensitive to knock, I doubt the 2 to 4 RON points is going to be that much of an issue. Looks like more than just s9 degrees is a lot. FI on stock NA compression isnt a good recipe, its a compromise which more people are realising. This illustrates nicely the concept of being knock limited.
All FI setups on stock engines are knock limited. Even with no knock registered power gains are limited by the fact that timing is reduced to avoid knock.
Therefore timing moves further and further away from Mean Best Timing (MBT)
Running hightest octane possible will help a bit, but it cant fix a fundamentally limited configuration.
t fuel, for the record I did test so often between 95, 97 and 99 and neither showed a direct reduction in knock as there wasn't any even with 95, that was on an LS1 and an LS3 admittedly not FI but still fk all difference and enough to save a small fortune... of course I use SUL simply because it makes me feel better but the run on Saturday was on 95...it would be really nice to see the tune tables
RichieSlow said:
I removed a comment that was ill-judged and insulting. I won't do you any more favours.
Im not sure how making a statement that I dont believe someone understands what I said is "Ill-judged" or "insulting" Its simply intended to act as a point for clarification. Perhaps it was something in my MBT statement or the way I phrased it that made no sense? How else can one suggest that another misunderstands without stating it?Anyway, hopefully Roger will continue to discuss this with me as Im more than willing to explain anything that I have said that is unclear, vague, misleading or otherwise. I believe the principles discussed are very relevant to everyone's preferred configurations and journey to understanding engines and horsepower etc.
Im more than willing to learn myself where Im wrong. Everyday is a learning day afterall.
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