Average Engine Knock Retard?

[CamaroDreams76]

For those of you who data log or have gauges that are capable of monitoring knock and knock retard...... what is your average knock retard reading at WOT?

I purchased Aeroforce scan gauges a few months back and recently I've notice a good bit of knock at WOT. Usually its anywhere from 0.3-1.5 but my last two tanks of gas and a recent oil change I've seen as high as 6.8/6.9 . So I was wondering what is the normal/average knock retard for an untuned car with simple bolt-ons (CAI, PTB and HFC). Also I run 93 octane pump gas.

I realize there should be no knock retard being read at all but that's perfect scenario. I've seen knock retard hold around 6.0 at WOT and I've seen it spike at 6.8/6.9. This made me curious as to what others are seeing.


Edit: I also get about .7-.9 knock on occasion when starting from a dead stop (normal driving)

[376LS3]

Never modify a car without a tune. Get a tune. Knock is one of the worst things you can have. You want "0" at all times.

[GONIF]

Originally Posted by 376LS3

Never modify a car without a tune. Get a tune. Knock is one of the worst things you can have. You want "0" at all times.

Exactly , but you are able to get 93 octane in Florida so that will allow your tuner to give you a nice safe tune with good advance .

[CamaroDreams76]

Thanks for the responses guys but I don't believe that this is a tuned/untuned issue. I'm thinking more along the lines of bad gas. Is it possible to have knock this high due to bad gas or false knock such as exhaust rattle?

[Aries240SS]

It's possible that it was bad gas, or false knock. My car gets a little bit of false knock on cold start as the exhaust can make contact with the tunnel brace. I've seen others where the steering column just barely touches the header, and only sometimes.

[376LS3]

It is a tune issue. Say you are right and it is false knock. With a tune, you can lower the sensitivity and aggressiveness of the sensors so it doesn't happen. If you keep driving it and it's pulling 7* at any given moment, you might as well put it back to stock because you're leaving a lot of power out when it knocks. 7* is huge.

[christianchevell]

Your engine is pulling timing to protect itself because you have no tune........ A good tune allows the engines ECU to re-optimize the AFR not to have to pull timing to stop from going too lean...... your PTB, CAI and especially the HFC's have changed things, as would headers, and yes crappy gas does not help. If I were you I would monitor the other readings you can get and see if there is an correlation and for gods sake buy gas somewhere else though they all most likely get it from the same tanker, some places have tanks that are more prone to water in the gas..... You could also be due for a new set of spark plugs or cleaning the MAF etc everything can make a difference. Good Luck

[angryv6]

Since when did having CAI, PTB and HfCs require a tune?

[Unreal]

Zero is ideal. Agreed with above, tune isn't causing 6-7 degrees. If .7-.9 which can be normal and pops up, goes to 6-7 degrees, bad gas, or something happened. Rattle could easily do that, or something loose.

Funny that 99% of tunes are going to lean it out and add timing, so people saying a stock tune is unsafe is almost humorous, because for those mods a tuner is going to lean it out and add timing, so a stock tune is probably safer than a performance tune.

[CamaroDreams76]

Originally Posted by angryv6

Since when did having CAI, PTB and HfCs require a tune?

Right.

I know a tune can optimize gains of these mods but a tune isn't necessary for that simplistic of bolt ons.

Originally Posted by Unreal

Zero is ideal. Agreed with above, tune isn't causing 6-7 degrees. If .7-.9 which can be normal and pops up, goes to 6-7 degrees, bad gas, or something happened. Rattle could easily do that, or something loose.

Funny that 99% of tunes are going to lean it out and add timing, so people saying a stock tune is unsafe is almost humorous, because for those mods a tuner is going to lean it out and add timing, so a stock tune is probably safer than a performance tune.

Thanks Unreal, I was hoping you would chime in on this.

[Camaro Dude]

I have experienced KR on two occassions with this engine, bad gas, and a small vacuum leak around the TB and air filter connector junction point being the cause of it.

The former was cured by filling up a bit further down the street at a higher volume (more traffic) station, and the latter was corrected by tightening up my sloppy work when I reinstalled the CAI and the elbow pipe back on the TB .

0 KR readings ever since ; )

[CamaroDreams76]

Originally Posted by Camaro Dude

I have experienced KR on two occassions with this engine, bad gas, and a small vacuum leak around the TB and air filter connector junction point being the cause of it.

The former was cured by filling up a bit further down the street at a higher volume (more traffic) station, and the latter was corrected by tightening up my sloppy work when I reinstalled the CAI and the elbow pipe back on the TB .

0 KR readings ever since ; )

Thanks for the insight. I checked the CAI last night and checked under the car for any visible exhaust issues and there were no problems that I saw.

The previous tank of gas, with the 6.x KR was a racetrack 93 off of I-75. This tank is Speedway/Hess 93 and I don't see the 6.xs like I saw with the Racetrack gas but have seen 5.x and 4.x but mainly around the low 2.0 area WOT.

[Camaro Dude]

Originally Posted by CamaroDreams76

Thanks for the insight. I checked the CAI last night and checked under the car for any visible exhaust issues and there were no problems that I saw.

The previous tank of gas, with the 6.x KR was a racetrack 93 off of I-75. This tank is Speedway/Hess 93 and I don't see the 6.xs like I saw with the Racetrack gas but have seen 5.x and 4.x but mainly around the low 2.0 area WOT.

When you "check", a visual will not suffice. Get in there, and actually, refit, re-tighten what you have already touched in the past. You may be surprised...Maybe you already did this, but it was worth mentioning.

Here is a question that must be considered. If you were to remove your bolt-ons, particularly the cold air intake, and install the stock parts back again, would you still be getting KR???

I would try this, and since you are on a stock tune, then do a fuse pull, re-log at WOT, record KR readings.

[christianchevell]

Lots of people get CELs with just hi -flow cats. Lots of people get a bad tank of gas eventually too, as do lots of people develop a loose fitting on exhaust , as do sometimes people get a cracked spark plug or loose or bad wire, dirty Maf, there are lots of things that you could get a problem from, look at it and I would add a good octane booster to the tank/ valve cleaner and some water counteragent and figure at least it will clean the valves a little maybe. Then you could be sure you have done what you can with the fuel besides draining it, clean the MAF, check the exhaust, go through it is all you can do........ Because what else ya gonna do? at least you know your knock retard is working and that's a good thing! And you will have checked things.....