Knock Retard processing speed Stock ECU vs JS box and keeping it alive

[John at J&S]

View attachment 196893 One of the turbo TransAm guys contacted me (Kevin) and I told him besides the Universal version, he might be able to use a single channel Vampire version. I told him I would need to know the maximum dwell at red line. He checked with the D.U. I. and they said the stock 5 pin module has 34° dwell, so it's a go with a single channel Vampire. I made a drawing showing the Vampire operating principle:

 

[John at J&S]

 

[charlief1]

Yes, the B4black guys are following this thread as well John. Kevin's name here is Canadian Nascar for those that have visited our red headed step child section.

 

[CGASTON]

Eric:

The SafeGuard waits until the knocking cylinder is about to fire, then dials in the calculated amount of retard for THAT cylinder.

165432


John...

Have a question. How does the system define or tell what cylinder is about to have detonation/knock? Is it defined after the knock is detected at that cylinder that just fired? That is kinda hard to determine from a knock sensor in the back of the block. Newer motors now have them under the intakes or even two of them. How does it determine if it is cylinder 6 or 5? The knock can originate from cylinder 6 but register in 5. So it could be Cylinder 6 that hit the knock and cylinder 5 retard, which doesn't help. The factory ECM and I believe the XFI are not fast enough to determine this. Now in newer cars with OBD II, they are capable in determining where the detonation is coming from dtc (P0300 series) and programing. Maybe I am over thinking things and confusing myself.

.

 

[John at J&S]

Yes, you are over thinking it. Knock can come only from the cylinder that just fired. The software knows this cylinder will be on its compression stroke again in two revolutions, so it keeps track as each cylinder fires. When the knocking cylinder is ready to fire again, software dials in the calculated amount of retard for that cylinder. It doesn't need to know which cylinder is #1, etc.

Refer to the attached drawing showing operation on a four cylinder:

 

[CGASTON]

Yes, you are over thinking it. Knock can come only from the cylinder that just fired. The software knows this cylinder will be on its compression stroke again in two revolutions, so it keeps track as each cylinder fires. When the knocking cylinder is ready to fire again, software dials in the calculated amount of retard for that cylinder. It doesn't need to know which cylinder is #1, etc.

Refer to the attached drawing showing operation on a four cylinder:View attachment 196926

Ok.... I was overthinking and confusing myself. Now another question. Since there is a way to log the knock....... Is there a way to interface it with the XFI? Do you recommend caspers knock gauge (digital or audible) also? Is the know gauge connected to the JS box or still spliced into the factory harness.

 

[John at J&S]

The analog voltage that appears on the "ring" terminal of the monitor jack represents the amount of knock retard, not knock.

If you plug a 3.5mm stereo "Y" adapter into the monitor jack, you can use the gauge and log the signal at the same time.

 

[CGASTON]

The analog voltage that appears on the "ring" terminal of the monitor jack represents the amount of knock retard, not knock.

If you plug a 3.5mm stereo "Y" adapter into the monitor jack, you can use the gauge and log the signal at the same time.

Ring terminal is for the gauge...... You have to have the monitor for the 3.5 jack.....

 

[John at J&S]

All units have the monitor jack on the front panel. It's where the gauge plugs in. I used to call the gauge the "monitor".

 

[norbs]

I am logging with the XFI this way, and it will show knock, but it is not fast enough to determine which cylinder is knocking, you would need 300 frames per second for 6000 rpm.

 

[CGASTON]

I am logging with the XFI this way, and it will show knock, but it is not fast enough to determine which cylinder is knocking, you would need 300 frames per second for 6000 rpm.

Norbs,

You logging the JS box via XFI? I am tracking the XFI is too slow; needs 4 gigabits of ram.


Clint

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[John at J&S]

Norbs: You are actually logging the amount of retard, not the amount of knock.

To be clear, the unit is fast enough to retard the knocking cylinder, but the logger is not fast enough to tell you which one is knocking.

Another Buick guy is using an AEM AQ-1Data Logger which can do up to 1000 samples per second. From one of his emails:
"I have great results logging with an AEM data logger and syncing the cam and crank signal to know when I get an event. In fact, the cam signal wire being close to the crank signal wire in the connector going to the data logger caused the crank signal for cyl #6 (the cam signal preceding firing of cyl #1) to spike which clearly identifies the cylinder location of any knock signal. without having to overlay the cam signal with the crank signal."

 

[dr_frankenstein]

The secret is totally out now.

J&S unit works flat out. Its made Draw Thru a reality for performance

Damn.

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[John at J&S]

"The secret is totally out now."

I was (totally) telling you guys this back in '02:

http://www.turbobuick.com/forums/threads/simple-questions.37258/#post-295771

 

[charlief1]

"The secret is totally out now."

I was (totally) telling you guys this back in '02:

Some of us weren't around in 02 John.

 

[dr_frankenstein]

Exactly, I was graduating from highschool. Lmao...

I discovered the system about 2 years ago thanks to Norbs. Pretty much scrapped my original turbo control center project I had re worked for a year already! I just couldn't squeeze more processing speed from that stupid box. And once I had the J&S....nothing compared. I dont think OEM programming is as smooth as the retard and sensitivity control.

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[John at J&S]

Wow, thanks for the props!!

 

[norbs]

Can John tell us the disadvantages of this unit, now that the Buick community has seen the light after 11 years of this product on the market?

 

[CGASTON]

Can John tell us the disadvantages of this unit, now that the Buick community has seen the light after 11 years of this product on the market?

John, I would like to know this as well before I drop $600


Clint

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[kidglok]

John, I would like to know this as well before I drop $600


Clint

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It can't prevent the knock from occurring in the first place


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