My car (in sig) was recently dyno tuned. I was assured it is a safe tune and is knock free on 93 octane with my timing retard module set to zero. This is part of a long E-mail I sent to the tuner so forgive it's longness. Just FYI my timing was observed to be 31 - 33 for most of the runs and my lowest mv's were 920 with the average being 950 ish....at the mere 5 PSI at which I was seeing the knock I can't help but wonder...WHY? It's tuned on a 12.2:1 A/F so shouldn't it be safe at that timing? The short version of this story is that I'm seeing knock retard when the retard is set at zero but I'm not seeing it when I dial in about 1 1/2 degrees per pound. I think that kind of proves it to be true knock .....kind of like when you dump in race gas and all of a sudden the knock retard is gone. What do you all think? (part of long E-mail pasted below if you're interested....look for the part about "47 degrees at low loads" in the beginning of the last paragraph at least and tell me what you think about that) :

"When I dial in 1 1/2 degrees of timing retard per pound of boost I do not get any knock retard. When I set the timing retard to zero I get knock retard every time I get to approx 80% throttle in 3rd gear at approx 4,500 RPM......when it appears it stays there and does not go away...it is not burst retard, I was starting from 1st gear. This was observed repeadedly ....time and time again, so it is definitely not a coincidence. It is not from me running the snot out of it and heating it up either ....plenty of time in between pulls to cool down. Every other pull I would dial in 1 1/2 degrees of retard and the knock would never appear, even upon transitioning to WOT all the way to 5,500 RPM. This is not burst knock....I was starting from 1st gear and the knock retard wouldn't come in until 3rd gear....and it was only when the dial was set at zero that the knock retard would appear. My theory is that once you make it to a higher gear the air intake charge is higher and high loads last longer due to wind drag and taller gearing.....creating combustion chamber temperature increase and subsequent detonation.
I am not holding you at fault for this because as you know a dyno can only tell you so much .....it is different from driving on the road. There are other variables once you get out on the road (wind drag, bumps in the road causing quick changes in load, etc). Also, my pulls were at about 80% throttle instead of the 100% throttle of which you saw no knock on the dyno. Perhaps there's a chance it could knock at 80% where it wouldn't at 100% due to timing and fuel differences. Maybe there's really just no way you can tune every load for every RPM to ensure against knock in a motor with this much static compression......I don't know. The point is there is only so much you can simulate on the dyno and I am only telling you this so you know to set the timing a little further on the safe side for your next customer who's adamant about getting a safe tune like myself. Perhaps there's a little too much timing in it for the loads that are seen at 80% throttle?...that's how it acts anyway. Now I have no choice but to run timing retard all the time or run race gas ....or a combination. The main reason I had you tune it was for it to be knock free on pump gas with the timing retard set at zero ....the power increase was a nice side benefit though. I cannot find any unleaded race gas around here and don't want to order a whole drum ....I can't use it that fast. I guess I will have to drive it with a decent bit of timing retard dialed in all the time (even at the track) until I find some race gas. This is unfortunate because it somewhat defeats your tuning ....the way these timing retards work proportionally, they take way too much out at the high RPM's....defeating a lot of power.
I have also observed one more instance in which I see true knock. Sometimes my timing will drift all the way up to 47 degrees at low loads (usually 40-42 but sometimes it really does hit 47). If I happen to stomp on it right at that moment I will sometimes get some true knock. It is true knock, gets up there and stays there....very slow decay rate. My theory on this is that even though you have less timing tuned in it for the higher loads .....it has to actually see the higher loads first before it changes over to the lower timing. Whack the throttle right when it's at 47 degrees of timing and you get a spike of true knock for an instant before the PCM changes over to the lower timing from the higher load. Many others in the computer/diagnostics forums have had this same problem ....when they lowered the timing in the low load blocks the knock retard went away."

 

31-33 degrees of timing w/ 5lbs boost and 93 seems like quite a bit. I've never tuned an LT1 w/ a blower...but I have done a buddies 5.0 with an S-Trim. We were running 14* initial (36 total) and were pulling out 1.25* per pound of boost on 8psi. That would be about 24*. If you have to pull 1.5* that would be about 24*. Probably coincidence...but that is the first thing that comes to mind.
And you are correct that the car sees a different load on the street than it does on the dyno. And you are correct that at 80% throttle the car may get more timing that it would at WOT. But anything over a certain percentage the car will go into PE mode for fueling...and at 80% throttle you're in PE mode.
You could send me the bin file and I'll pull a couple of degrees out wherever you want and you could try it. I'm sure Woodbridge would do the same though.

 

Thanks....it's good to see someone else is on the same wavelength with me. I've mailed Woodbridge about this but haven't heard from them yet. John may be sick of my car period and just tired of fooling with it. It is the holiday season though so he may be preoccupied.
In some ways it may be tuned just right for me. At first I wanted it tuned on pump gas with the timing retard set at 1 degree per pound. I figured I could set it to zero and run race gas when going to the track for even more power. In a way that's exactly how it's tuned now. The thing is, I had decided I wanted it tuned with the retard **** set at zero ......this way I would just be way on the safe side by removing even more timing than it was tuned for for 95% of my driving. I thought it would be a safer way to go since I'm running practically 8 PSI non intercooled on stock hypers. That is how I requested it to be tuned so there was no misunderstanding......I wanted it knock free when set at zero. Now it just seems like I may have gotten the tune I wanted initially; no knock on a small amount of timing retard (I don't think it would knock when set at 1.0 degree per PSI either). I bet when a 20% mix of race gas or xylene is added it will go away.
There are other factors that could be at work here too. It seems I may have some bad gas. Seeing .1 ~ .3 KR hovering around in low octane mode even when I'm driving in vacuum. Could be hot spots in the combustion chambers due to carbon buildup too ...it runs a little rich during cruise. It was tuned open loop for low load conditions and runs a little rich (closed loop just wasn't working right so the enable temp was raised out of range)

 

Don't buy that for one second. You spent your money there and if they aren't interested in customer relations after the sale...then maybe you shouldn't do business with them.
But from what others on this site say about them, I'm sure that isn't the case.