Data Logging

[45T-XR]

"Yortts post is again a classic example of cut and paste" This is what I have experience from comparing dyno tuning and tuning at the track, my experience is from Holdens and turbo 4cylinders. I made it quiet clear that the article was lifted from the net and I did so as it was written by a very experienced reputable motoring journalist not a hack journalist as suggested. The information is now everywhere on the net, those that want to be enlightened search read evaluate weigh up the varying opinions and conclude for yourself.

I am not asking anyone to agree with me or dictate my opinion to any one just offering an alternate view based on my experience.

"A smart dyno operator will run the dyno at a ramp rate that close to matches the acceleration rate of the car in the gear being tested" All I can suggest to others reading this post is next time you have your car run up on the dyno note the number of seconds it takes to do the run then go to the track and do the same test in the same gear and compare the time in seconds again, this will answer the question.

"Your point about MBT is wrong, different configuration motors will drop power sometimes before knock has been reached while others will make more power while pinging, guess which one the Ford turbo is, yes the one that making power while pinging with 98 octane fuel, so your drag mph could end up with a motor that is grenaded by tuning it that way, but what about part throttle mbt etc how are you going to do that? On 98 octane fuel and below I do not accept your premise and no one is suggesting you drive the tune past the knock threashold.

Any thing above 98 octane fuel I would agree with you as you the have the ability to light it up too early BTDC in the compession stroke and achieve maximum cylinder pressures too early ATDC and loose power.

"The ford calibrated knock sensor is far from accurate and will pull spark when there is no knock, we have proved this time after time with electronic knock detection and it also picks up knock events before the human ear will." I know the sophistfication of the Expensive Daewoo knock system and logic would dictate that Ford would be very similar and would have spent millions of dollars developing knock detection in particular for forced induction, no aftermarket system would have access to the expertise or budget ford would have.

Your comment "The ford calibrated knock sensor is far from accurate and will pull spark when there is no knock" given my above comments I can not see how any independent workshop could have access to equipment to determine this. No aftermarket knock sensing has the ability to listen through the correct window in the combustion cycle filtering all unwanted noise and listening to the specific knock frequency generated by that particular engine and accurately determine the intensity level I know Expensive Daewoo do and I see no reason why Ford would not.

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My experience is far,far less than yours, and Ratters. But in regards to the knock detection side of things, have you actually datalogged the knock retard stuff whilst using a knock box or something similar? Ive only tuned a few mates cars, one being my own, but I can tell you for certain that every single car has started to pull timing before knock was detected with the knock box. I purchased the "Knock Box" from Smiths racing service after doing the VCM suite course as they thought highly of it. I also sent it up to Dave at CPV for him to test as his had sh*t itself and he was testing a few. His feedback was quite good said it was hard to beat it in terms of dollars/simplicity. The only gripe I have with the knock box is the fact it cant log straight to laptop like a few of the other ones do....but I intend to use my own car as the test mule and use the knock box to reduce sensitivity of the stock ones if needed to calibrate them correctly. Then once I know they are working I can log with the knock sensors confidently. I think Mick referred to doing this also earlier and doing this for each and every car is just one of the time consuming things that contribute the time spent on a tune blowing out. I can just about guarantee that the normal price for a custom tune would not leave much of a profit margin due to the length of time Mick spends on his tunes judging by the comments made. And interms of a business making money from custom tuning probably wouldnt be as profitable compared to something like servicing???

[ratter]

Thank you for the comments and yes what you have posted is 100% correct in my case, I have thought about doing tunes in a couple of hours like some others have posted in the past is all their tuner takes, this would start to give me a reasonable wage, but I want my jobs to be done to the best of my ability, no matter how basic or modified the car is, I could do better by doing servicing and replacing brakes etc rather than spending time like I do, let alone the cost of equipment.

[Yortt]

My experience is far,far less than yours, and Ratters. But in regards to the knock detection side of things, have you actually datalogged the knock retard stuff whilst using a knock box or something similar? Ive only tuned a few mates cars, one being my own, but I can tell you for certain that every single car has started to pull timing before knock was detected with the knock box. I purchased the "Knock Box" from Smiths racing service after doing the VCM suite course as they thought highly of it. I also sent it up to Dave at CPV for him to test as his had sh*t itself and he was testing a few. His feedback was quite good said it was hard to beat it in terms of dollars/simplicity. The only gripe I have with the knock box is the fact it cant log straight to laptop like a few of the other ones do....but I intend to use my own car as the test mule and use the knock box to reduce sensitivity of the stock ones if needed to calibrate them correctly. Then once I know they are working I can log with the knock sensors confidently. I think Mick referred to doing this also earlier and doing this for each and every car is just one of the time consuming things that contribute the time spent on a tune blowing out. I can just about guarantee that the normal price for a custom tune would not leave much of a profit margin due to the length of time Mick spends on his tunes judging by the comments made. And interms of a business making money from custom tuning probably wouldnt be as profitable compared to something like servicing???

I guess the question I ask myself how do you determine if an engine is knocking and which is more accurate for determining this, the manufactures knock sensing hardware/software or an aftermarket one or the human ear with a listening device.

My money is on the manufactures hardware/software which is calibrated for the specific engine type. It looks for knock in a narrow window of time in relation to the ignition cycle, it is looking for a specific frequency based on cylinder size and then filters all unwanted frequencies, it is looking for the intensity of signal generated by the knock sensor and depending on intensity of the signal from the knock sensor the level of knock is determined. This is then compared to preset parameters in the tune program from development work done by engineers for that specific engine, below these preset parameters it is considered not to be knocking above the preset parameters it is considered to be knocking.

While aftermarket knock sensing is definitely better than nothing (noting VCM suite does not report knock) I believe that no aftermarket knock detection system can match the manufacturers knock detection sophistication.

Edited 17/07/12 11:50 AM by Yortt

[IH8TOADS]

Interesting convo. In regards to the knock sensing, take a BA XR6 and a BA F6 calibration.....everything from the window detection length, sensitivity, the gain etc are quite different, despite very minimal changes in engine design. This is evidence that minor changes to design and the greater engine calibration require large changes to the knock sensing calibration. My bet is that although the sensing technology is quite advanced no tuner would have the engineering expertise, equipment and.....time to (let alone access to ALL calibration tables) to be able to make the knock sensors work like they did from the factory. For this reason the simplest method is to use knock ears to set an acceptable level of engine noise.