Your assessment is correct. Now, I am still not entirely certain that the sound I am hearing is indeed detonation. It could be something else, that's why I am asking for more info here. I am getting from you that the timing sounds OK and I know the fuel is OK, so my issue could be something different. The more I think about the sound, it is very similar to what a diesel engine would do under load - but it is not extreme by any stretch.

 

Do you have any shop that can take a look at your car? Detonation is really more pronounce when on a Dyno, performance shop has more tool in their possession to diagnose a problem. Let us hope your engine is healthy.

 

It was like that when it was on the dyno also. It didn't sound quite right to me, but the tuners here suck. All the guy did was adjust the fuel and called it a day. I could have done that (and now I do). I think this is beyond the dealer even though the dealer here is quite good, this type of refinement exceeds their capacity. I think I'll try pulling some plugs to see if there is any evidence of trouble...

 

Just the dyno itself is kinda weird having the TQ dip like that. I think your car Detonated and pulled some timing and hence the big dip in the TQ. I would do a Leakdown and compression test first to make sure the Motor is still healthy. Your timing and A/F is already very very conservative at that boost level.

 

Most of the time I felt it and the UTEC acted before I heard anything. The only time I could hear it was when my window was down and I was out street tuning.

 

Your engine would be running safer, regardless, if it had at least the UTEC on it.

As I mentioned earlier, the certain way to determine if you are experiencing knock, is to fill up with some high octane race fuel. If the noise stops, it was knock. But based on your description, it definately sounds like it.

 

I had originally purchased a UTEC. The tuner was unable to install it because my G does not have the standard UTEC plug and play connector (early 03 was different). The knock sensor has not identified a problem, but I don't want to wait until it's too late. I'll try to find some higher octane fuel, but I was using Chevron 94 octane before and the sound is the same as with Shell 92 I'm using now. (I'm not convinced the Chevron is really 94 octane as advertised.)

 

If you don't have access to Race Fuel then a home made Octane Boost is a quick/Temporary solution . You can do a 20%-30% mix of Toluene or get some Torco Octane Booster (http://www.jbsblownc5.net/html/torco.html)

https://g35driver.com/forums/engine-drivetrain-forced-induction/186601-home-made-octane-booster.html


I doubt it will fix your problem since at low boost your timing and A/F is way low already. It is worth a try since it is quick and inexpensive way. Just curious what if the knock goes away? Will you pull more timing or add more Fuel? hhhmm maybe you logs are not accurate then... Good Luck

 

Thanks for the info - I'll give that a shot. I'm hoping some local auto supply places carry that stuff. (Good thread with the cheap alternates!)

 

updates?