What Is The Typical Knock Reading For Rb With The Vipec Ecu?

[9krpm]

I've recently changed my ECU to a V88. I am still fine tuning the tuner's initial tune to make it safer.

It's pretty much a new tune with new ECU and new fuel injectors so I want to keep an eye on the knock reading before I track it.

I noticed that the knock target table has been adjusted to 400-500

I have a Ruzic Engine Monitor that reads knock but it's very hard to pay attention to that during full boost. The EMII is programed to warn if knock reading exceeds the knock target. Since the knock target is so high I don't get any warning light from the EMII at all.

I tried the previous Vipec logging software but that was not very user friendly and I did not get very far. The Vipec Data Logger downloader was not able to download the internal log. The freshly released Vlogger did not connect to the ecu for me either. I've used AEM EMS and FC data loggit softwares in the past but some how I was getting problem with the vipec. I will have to try it again when I have time. On top of that QLD had a lot of rain last weekend. So I did not have much luck at all so far

My power FC normally has around 50 knock counts, with occasional off throttle valve noise of around 70 (which produces a CE light). I have fairly bigg duration and lift cams.

The current settings on the vipec are

The Gain channel is 1.5x

The frequency channel is 9kHz

Does anyone know if the knock reading on Vipec = power FC ie should I expect 50 knock counts?

Has anyone else had much success with the Vipec's knock count log/graph? Could you provide some tip?

Edited April 14, 2009 by 9krpm

[TiTAN]

the knock levels range from 0 - 1020, 0=0v, 1020=5v

so 400-500 is around 2v if there is any knock it should jump to that or beyond.

see here for more info on the knock control.

 Knock Control is a feature designed for reducing engine damage caused by detonation.  Detonation occurs due to sharp increases in cylinder pressure usually caused by the ignition event happening too early (too much advance), or excessive compression pressures (eg too much boost).  Other factors can cause detonation including excessive engine temperatures, low octane fuels and lean mixtures.



 Detonation can cause irreparable damage to an engine, including burnt pistons and broken ring lands.  In almost all cases detonation can be avoided by reducing the amount of ignition advance for a given load.  The Knock Control function allows the ECU to detect detonation and automatically reduce ignition advance until detonation no longer occurs.



 Timing removed by the Knock Control function remains removed until next time the ECU is shut down.  For safety reasons, the ECU will not attempt to put the timing back into the engine.  Timing removed will be reset when power is cycled to the ECU therefore timing changes are NOT permanently stored.



Warning:  Knock Control should be used as a safety feature only.  It is not design as a tuning aid to help determine optimum ignition timing!



Knock Mode



Knock Mode selects the operating mode of the Knock Control function.  The following modes are available:



· OFF - Knock Control is disabled. 

· ON - Knk I/P - Knock Control is active.  The knock signal is measured by the onboard engine noise detection circuitry.  Note that not all ECUs have on board engine noise detection circuitry. 

· ON - An Volt - Knock Control is active.  The knock signal is measured from an analog voltage input from an external engine noise measurement device. 



Knock Target Table



 The Knock Target Table will become visible when Knock Control is activated.  This table sets the allowable engine noise for a given RPM/Load.  Each engine will have different noise characteristics.  Engine noise is generated by mechanical clearances, valve train noise and even valves closing against the seat!  Knock control will reduce ignition advance when the actual measured level of engine noise is above the value in the Knock Target Table.  This table must be manually filled out for a particular engine.  Knock Target values can range from 0 (minimum noise) to 1020 (maximum noise).  See the Knock Control setup procedure below for more info on entering values into this table.



 Use the Table Axis Setup menu to adjust the Knock Target Table axis parameters and change rows/columns.



Knock Ign Trim Table



 The Knock Ign Trim Table shows the amount of ignition retard caused by the Knock Control system.  Each time the actual engine noise level exceeds the Knock Target value for that particular RPM/Load 0.5 degrees of retard will be decrements from a cell in this table.  The Knock Ign Trim Table can be used to determine where excessive engine noise has been detected as each cell that has its retard value changed will turn blue (only when this occurs while the ECU is connected to Vi-PEC Tuning Software).



 The Knock Ign Trim Table is cleared when the ECU is turned off.  Ignition changes made by the Knock Control function are NOT stored permanently.  The Knock Ign Trim Table can also be cleared by setting Knock Mode to OFF, then back to ON.



 Use the Table Axis Setup menu to adjust the Knock Target Table axis parameters and change rows/columns.



Knock Retard Limit



 The Knock Retard Limit sets the maximum amount of ignition timing in degrees that will be removed (or maximum amount of ignition retard).  This limit avoids the ECU removing too much timing if the value in the Knock Target Table is set too low.



Filtering



 On ECU's equipped with on board engine noise detection circuitry, signal filtering is configurable.  The following adjustments are available to configure knock signal filtering:



· Freq Channel - This setting sets the sensitivity of the ECU to a particular knock signal frequency range.  The following options are available: 

· LP Only - Knock input is sensitive to all frequencies below 7 kHz 

· 5.5 kHz - Knock input is most sensitive to frequencies near 5.5 kHz 

· 7.0 kHz - Knock input is most sensitive to frequencies near 7.0 kHz 

· 9.0 kHz - Knock input is most sensitive to frequencies near 9.0 kHz 

· Gain Channel - This setting adjusts the overall gain of the knock circuitry amplifier.  A higher gain number will result in larger Knock Level numbers for a particular signal input.  Use this adjustment to getter a better range of Knock Level numbers.  If Knock Level numbers are reaching full scale  then reducing Gain Channel will bring them back into range. 



 The required Gain Channel and Freq Channel numbers will depend on the engine type, engine capacity, knock sensor type and knock sensor location.  A Freq Channel setting of LP Only is not often used and exists for compatibility with older ECU's.  As a general rule engines with a larger capacity require a lower Freq Channel setting. 



Runtime Values



 The following Runtime values can be observed under the Ignition Runtime Values tab to monitor the state of the Knock Control function:



· Knock Level - The current measured engine noise level. 

· Knock Target - The current value as interpolated from the Knock Target Table. 

· Knock Ign Trim - The current value as taken from the Knock Retard Table.  This shows the amount of retard caused by the Knock Control function at the current RPM/Load. 

· Knock Count - Increments every time the Knock Level exceeds the Knock Target. 



Knock Control Setup Procedure:



 The following procedure is a guide to setting up Knock Control.  Unfortunately the amount of engine noise measured before and during detonation varies significantly from engine to engine, with sensor type and sensor location.  Experience is required to determine the best Knock Control setup.



 At all times during setup, make sure that an audible knock detection device is used (such as a KnockBlock with headphones).  Avoid unnecessarily causing detonation as engine damage may result!



1. Ensure the engine is tuned to its final optimum state, particularly ignition values.  Remember that Knock Control is used as a safety feature should engine operating conditions change, not to determine the final ignition values. 

2. Set Knock Mode to ON.  This will activate the Knock Target Table and clear the Knock Retard Table. 

3. Use the Table Axis Setup menu to adjust the Knock Target Table and Knock Retard Table axis parameters and change rows/columns. 

4. Set up the Knock Target Table.  The following hints may be useful: 

· Use the Knock Level Runtime Value (under the ignition runtime values tab) to monitor the current engine noise level. 

· The engine must be run at various RPM and load values to determine the engines 'non-detonating' noise characteristics. 

· The value entered in the Knock Target Table will be the amount of engine noise that must be exceeded before ignition timing is decreased.  Therefore, this value should be the 'non-detonating' noise level plus some headroom.  Typically the value entered in the Knock Target Table will be about 10-20% higher than the 'non-detonating' noise level. 

· Enter high Knock Target Table values in areas where Knock Control is not required such as idle, cruise and free revving. 

5. Set the Ignition Retard Limit to the maximum amount of ignition timing allowed to be removed by the Knock Control function.  This will typically be between 3 and 10 degrees. 

6. Perform power runs and operate the engine in all load/RPM areas where knock control is to be used.  Check the values in the Knock Retard Table.  If these values are not zero (or have turned blue) then the Knock Control function became active in those areas.  It is up to the tuner to decide if this was due to the occurrence of detonation or if the Knock Target Table values are too low.  Remember the Knock Retard Table is cleared each time the ECU loses power.

[Scooby]

Thanks Titan for posting that, it answers questions I have been asking for some time; 'how are knock values actually determined'. I suggested it was based on measuring the noise of the engine when it was known to not be knocking, which appears to be the case.

Cheers

Edited April 14, 2009 by Scooby

[Guilt-Toy]

btw, before you can download your data from the ecu you need to enable the internal logged in the software under "logging"

good luck

[9krpm]

Thanks for the info TiTan and Guilt-Toy. However I've gone through that info from the manual a few times last weekend aldready

I searched on the forum some more last night and apparently you have to go into the software, connect to ECU, turn off logging, save to ecu, open logging download, download logs, reconnect to ecu, turn logging back on, save to ecu, do a couple more test runs and restart the whole process again.

I will rigg up a Log toggle switch to one of the DI this weekend.

BTW what are the values u guys used in your knock target table? Any guestimate on how is my 50 knock reading on the Power FC compare to the vipec?

[Guilt-Toy]

i have not played with knock on my Vipec yet. i have the V44 and could not be bothered hooking up my K-mon to it as yet. i don't think i will as its not needed.

[9krpm]

hmm thanks Tony.

I think my mistake last weekend was that after I turned off the log function I did not save to ecu. So the "vipec data logger downloader" crashed when it tried to dowload the log.

Have you guys try the new Vlogger yet?

Edited April 15, 2009 by 9krpm

[Guilt-Toy]

nah, i have not been playing around with my car too much these days, its going hard and well and have not needed to touch it. i only use the logging when i am racing these days and i like the software logging

[maximajim]

How do you like the vipec compared to the aem ems? (assuming this the American aem ems)

[TiTAN]

BTW what are the values u guys used in your knock target table? Any guestimate on how is my 50 knock reading on the Power FC compare to the vipec?

i am using 220-250 which is just over 1v and at the noisiest point my engine gets up to 0.8v (7000 rpm loaded up in 4th) so if there is any knock it should easily go over the limits and back off timing.

[9krpm]

How do you like the vipec compared to the aem ems? (assuming this the American aem ems)

Yes I have the USA aem ems but it's for my turbocharged Honda. I have not use the aem ems for my nissan so I can't comment on that. It's very good for a plug and play computer if you can search and learn how to use it from the forum. Using their phone help line is out of the question for us and thanks god I did not have to. Their software is very nice to use. I think their cpu is ??? a bit slower but the ecu has been doing what I wanted to.

I think it's a bit unfair for me to compare between the two because I've been using the the AEM ems since it first came out in ?2002 or 2003. I've learned the ins and outs of it since and I am very familiar with it's software (on the honda).

The vi-pec is still new and I am sure there will be major changes to make it better. I am still getting my head around the software layout. It's not difficult, it's just different to what I am used to. There are features that I am not used to like you have to save changes on both the ecu (Store) + laptop (save), and the logging funtcion. However, I am sure it will be a breeze once I get used to it.

I think it would be unfair for me to comment on the 2 systems. However I must say that Ray's customer support is awesome in my book. He has my support for his product

[9krpm]

i am using 220-250 which is just over 1v and at the noisiest point my engine gets up to 0.8v (7000 rpm loaded up in 4th) so if there is any knock it should easily go over the limits and back off timing.

Have you used a power FC before on your setup and if so what knock reading did you get?

What are your gain and knock frequency settings on the vipec?

[TiTAN]

the tune on my powerfc was different to the tune on the vipec, they cant be directly compared.

I run the plugin version of the V44 so i have an external amp/noise filter which filters around 6-7khz and the amplification is set via a variable resistor. (just kept turning up the sensitivity until it started to give more than 0v while free reving and then turned it down slightly)

[OzLeroy]

Knock detection with the Vipec sounds quite capable and potentially useful, a few questions though.

Does the R32 GTR plugin ('V66') ViPEC unit utilize the factory knock sensors? (both or just one?) If so has anyone set this up, and whats your feeling on its operation?

Or do you have to plug in a third party knock detection system?

Also does the plugin (GTR) unit allow signal filtering? or is this just for the V88...

Keen to see how well this works...

[TiTAN]

i run the plugin unit, you need an external amp/filter for the knock detection to work i run both knock sensors into that unit and then that unit has one output into the ecu

[9krpm]

the tune on my powerfc was different to the tune on the vipec, they cant be directly compared.

They should be comparable (ie not the same reading) unless you were getting knock with your power fc tune.

Kock sensor is only a basic and specific engine microphone after all

[TiTAN]

the ignition and fuel maps are nothing like each other, the powerFC was running slightly tweaked stock maps and the vipec is running completely custom maps with much more ignition timing everywhere.

The powerFC rarely ever showed more 3-4 knock and the vipec has never once needed to pull ignition timing that i have seen.

[9krpm]

Hmmm I guess you are right then TiTan. Your setup is not very useful as an example for me to find the relationship between the knock counts of the 2 ecu's. I must say that your engine is ultra quiet to have a knock reading of 3-4 on the power fc though.

[STATUS]

Hmmm I guess you are right then TiTan. Your setup is not very useful as an example for me to find the relationship between the knock counts of the 2 ecu's. I must say that your engine is ultra quiet to have a knock reading of 3-4 on the power fc though.

i have found good results with the new Link G4 extreme, but i prefer to swap out the factory sensors to another bosch part number (not on me), still the donut type but they ground differentley.

You cant really compare the two knock reporting systems (PFC vs LINK/VIPEC) as they report totally differrent.

i will look over a few i have setup but im sure from memory the logs were showing vastly different readings between engine families, im sure the last BMW turbo i did had a target of around 55 wheras others have been double that...

[Taso84]

Abit off topic but was wondering if the PFC takes timing out automatically when it knocks like the Vipec does?