Tech, in my opinion you can't add a supercharger on a car that is not supercharged and expect to use the stock timing tables. They were meant for stock, not a blower. Although it would make sense theoretically that the stock timing tables would work, in reality I don't think it would. Plus, you have tried a lot of things except changing the timing, I think its worth a try right.

 

As mentioned in my first post, this is with and without the blower. I have a ramair hood so I'll have to do is pull the belt and slap on my air box.

I left my new KS in the block and hooked my old one up to the harness (zip tied and taped to the starter). I got ZERO knock retard. The KS is picking up something from the block that 110 leaded fuel didn't fix. I heard very mild ticking which could have just been your standard stamped rocker arms. I'm waiting for it to cool down.

High RPM, high TPS, no audible noise, KS does not pick up knock if unless it's screwed into the block. My spark plug wires come from the top of the valve cover and come no closer to the KS than the stock wires. There is no miss and no arching. What could it be?

 

my bad, forgot

 

Just reduced timing on 80+ KPA and 3000+ RPM (where I was getting knock) by 10%. Same knock retard.

Unlike I thought before, I don't think it is based upon RPM or MAP. I can put it in high gear going up a hill which produces high MAP values but no retard. Similarly, I can rap out 1st or 2nd very smoothly and get no KR. At low RPMs I can bury the throttle and make the car jump all over the place without any KR.

Any suggestions?

 

What kind of ignition box u runnin? Maybe it has gone bad or something. I remember reading a post a while back about a guy that had knocking problems that he could not get rid of and once he swapped the box it was fine. Of course you would have to have had the same box before the blower which is unlikely... Just another thought...

 

I've tried it with a 6A and just the opti. I've also had two different coils on the car.

I just noticed that my right 02 mV are always higher when I get spark retard. The difference isn't really that significant, but the right is always richer.

 

I searched the board and found a thread where Injuneer told someone to test the KS circuit. I've got 4V+ coming from the wire and 3900 ohm resistance through the sensor. Everything checked out.

 

I guess I stumped the gurus... Normally I would be happy, but my car still runs like ***.

 

I have some kind of feeling it is something completely unrelated... it must be something real dumb but not that obvious. Do any other readings other than o2 mv's look off??? Have you tried new o2's??? That's someting I gotta do soon too and I think you need them even more because of that leaded race gas. Sorry man.

 

The O2s are fine. They are just as responsive as before the gas. I replaced them last summer when I had KR and there was no change.

The only thing I noticed is one side is always a little richer than the other. The difference isn't significant, but the right is always richer.

 

This one sounds very tough to chase down. After reading all of the posts the one thing that became obvious to me is it generally happens to you at about the same amount of vibration....which is either caused by a certain amount of load or RPM. Obviously false since it's below 100 KPA and it doesn't happen when you pull hard in high gear or 1st/2nd (especially since 110 octane didn't get rid of it either).

I had a bad false retard problem with mine (and still do mysteriously once in awhile....only occasionally now thank God) .....and it turned out to be the sensor itself. When my tuner went to remove it it spun around rather than unthreading from the block....it had become loose within it's own housing, you could shake it and feel it vibrate some, so ....it was actually knocking within itself, setting itself off ....that's obviously not your problem though.

Since it's happening to you at the same load most of the time it's obviously a vibration of some sort that is very hard to track down. You can really never be sure of the exhaust as close as most systems come to our cars. Have you checked the A/C lines? They can clang around a bit and set things off. Even though it's ovbiously coming from the block from what you said about tying it to the starter ....it could be the block picks up these vibrations better than the starter. Any chance of header gasket leak?

 

Thanks for reading up on my continuing ATI install nightmare.

As I mentioned, the blower is bypassed but still bolted on the car. Someone from the LT1edit mailing list suggested that the mister nozzle for my P600B might be hitting something or that I might have a loose motor mount.

While I was under there I saw that this wasn't the case, but that the blower was actually butted up against the block. I pushed and pryed but couldn't move the blower. I assume the vibration of the motor could cause a bit of noise. The part of the blower which is touching the block is just below the water pump and on the discharge side of the impeller (near where Procharger is stamped). Is this a common thing?

At idle, I've tapped on my header and head with a long screwdriver and found that you had to hit it pretty hard to increase the knock count. I realize that the KS responds to frequency rather than volume, but I couldn't set the thing off without banging the sh*t out of it. For something to vibrate/bang hard enough for the KS to pull 10*, shouldn't I be able to hear it?

Is it normal to get some KR while free reving the motor?

Thanks guys. Your help is very much appreciated.

 

Reving the motor = no load = false knock too ....I've had this too. Isn't this $hit fun to track down .....

 

It's funny. I started losing my hair shortly after I bought the blower.

 

Jason,
I looked at the datamaster logs that you sent and e-mailed you back, but just thought I'd share what I found.

Your knock does not START at high rpm OR high map. 90% of the retard you see is in fuel trim cell 11, with rpm's at about 2800, map at about 65-70. Also throttle is between 1/4 and 1/3 (going by TPS %). Eventually you might get to a higher rpm or tps, but that is not where the knock starts.

Some of this is false knock and some of it is real.
If I were you I would track down the false knock and pull some timing out based on where the knock first starts in the logs and go from there.

Not sure what else to tell you, but I wish I could help more.