I posted this question a while back but I hope someone will see this who can help. With both my auto xray and winaldl I can only get knock counts, but not how much timing has been taken out.
I read that with the 730 ECM you cannot determine knock retard and I wonder is the same is tru for the 8746 ECM? Is there a way to determine knock retard with my 8746ECM?? Do I need datamaster or some other software??


someone mentioned using lockers in my last post, but I don't understand what to lock.

Any one??grumpy? trax? Jon??

thanks.......................bob

 

Software like tunercat and tunerpro lets you change the settings in the ecu that relate to knock. i had a quick look in tunercat and found 6 !
knowing what to do with them is an entirely different thing.

see this graphic for a stock $61 1228746

 

I dont know if its possible to display the retard itself but you can output the timing to the aldl stream by changing the addresses outputed by the aldl. From this, you could probably see dips in the timing that would tell how much its been retarded. However, the data rate with the aldl is incredibly slow so the ecm would probably have completly restored the timing by the time the ecm sent the next frame of data.

 

On a side note, Ive always wondered about those TC tables. Is it really supposed to be %retard removed/sec? Ive always thought it was supposed to be %retard removed/msec but when a knock count is detected ive observed the engines power nose over for about a second or more before it returns.

 

Yeah, it's messed up. Timing retard in stock form sticks around for a WHILE. You almost need it to do so because you need to be sure that you don't cylce back in and out of pinging.
When I ran the 13.64 at 103 ALL of 3rd gear (which was ~8 seconds of the run) was in knock retard. After the 2-3 shift it picked up some knock either from actual knock or slipping trans hitting 6000rpm fuel cut-off rev limiter (don't ask). From that knock it retarded immediatly down 10 degrees from 32 to 20 and at the end of the run it was back to 24 +/- 1 . A few of the runs didn't even bring the timing back in, it just hung around 20 degrees through all of 3rd gear. I've tried removing timing but have yet to have the chance to do a full 2-3 shift at WOT to test if knock is gone. The only possible place in NJ to do it is pulling onto a highway and even then I can run 2nd gear out to 58mph so I HAVE to carry 3rd at least to 70 to see if I picked up any knock.
It's a battle that once won should yeild better track results. I figure a 13.4 at 105 in full street trim at STP is perfectly reasonable . Then it's slicks and some drag racing tricks to get into the high 12's. I just HAVE to get into the high 12's without touching this motor . 330ho motor, holley 670, stock GM ecm, custom chip, standard upgrades and high 12's :lala:

 

You can output ANY ram location into the aldl data stream so yes, even with winaldl you CAN display the knock retard SA. Just modify the chip with the new ram location. I would first replace the stupid eprom ID (both msd and lsd) with stuff that's useful. For example, final SA and knock SA. You'll need to convert it from hex to decimal then * 90/256 to get degrees. Also might as well replace battery voltage with desired AFR since both are /10 . Example, battery voltage in hex is FF, decimal it's 255, voltage is 25.5 , desired AFR is the same conversion so in winaldl it'll display the decimal point correctly, just wrong title.

 

[QUOTE]Originally posted by JPrevost
[B]You can output ANY ram location into the aldl data stream so yes, even with winaldl you CAN display the knock retard SA. Just modify the chip with the new ram location.

Duhhh, ok I will just ask it. How do you do this? could you guys point me to a post ??

Thanks to all for responding. Theses comments were a BIG HELP and I would sure like to get into high13s at bandimere..............bob

 

Jon, whats the ram address for the knock retard SA for the 8746? It looks like its $6D, is this correct?

 

Not Jon, however, yes, that is the correct location. The actual amount of knock retard spark will be that value divided by 2 and multiplied by 0.352 (for result in in degrees). Or just multiply that value by 0.176 (for result in degrees).

RBob.