Is 31.6 degrees of knock retard too much?

[Low Budget]

Originally posted by 8UWITH6
I think it was simply just a lack of octane.......and obviously too much boost. However, that high of a reading, check the obvious false knock stuff.

Ok, I admit I have no idea what the actual octane of the 116 and 93 blend was. I guess I'll have to put a cell in the trunk for next year like I have been considering. (Anyone want to share how they set their's up?) The chip I had in is 27 deg timing and 24# of boost at 112+ octane. It seems to me that one extra pound shouldn't cause a net timing of -4.6.

I haven't found any cause for false knock yet. I'll check better next time it's on a lift. Would that be likely since the peak was at 92mph?

Still waiting to hear....is it even possible to NOT hear this much knock?? I know what it sounds like. Kinda like dipping a red hot piece of steel into water, or dropping a basket of fries into hot oil, or 10,000 tin soldiers drumming really, really fast.

Obviously I have more unknowns here than knowns. Anyone have a formula for figuring what my octane was?

 

[V6POWER]

(2.5 x 93) + (3 x 116) / 5.5 gals. = 105.5 octane.

 

[Low Budget]

There you have it, now we know.

Originally posted by Look Quick
(2.5 x 93) + (3 x 116) / 5.5 gals. = 105.5 octane.

Thanks for the formula. I figured it was simple, but even I can do this math. Cool!

So it has been established for certain that my octane was too low.

Now what about the little tin men?

 

[1badTTA]

Not sure about you, but I can't hear anything short of a blown headgasket with a helmet on. 30 degrees of retard should pull the timing so much that it isn't knocking anymore so listening for it after you the car falls flat on its face/ seeing it on SM, is pointless and if you do still hear it it is probably false knock you are hearing since it would be nearly impossible to get knock with timing at 3deg ATDC unless it is so lean it is igniting itself

 

[Low Budget]

More concrete information. Keep it coming guys!

Originally posted by 1badTTA
Not sure about you, but I can't hear anything short of a blown headgasket with a helmet on. 30 degrees of retard should pull the timing so much that it isn't knocking anymore so listening for it after you the car falls flat on its face/ seeing it on SM, is pointless and if you do still hear it it is probably false knock you are hearing since it would be nearly impossible to get knock with timing at 3deg ATDC unless it is so lean it is igniting itself

Quote:
Not sure about you,
Heh, heh..I'm not sure about "me" either.
I didn't have a helmet on for that very reason. I too find it hard to hear the engine with a helmet on. Then to make matters worse, I always seem to get lined-up next to someone with open exhaust and twice the horsepower.

Quote:
30 degrees of retard should pull the timing so much that it isn't knocking anymore, so listening for it after the car falls flat on its face/ seeing it on SM, is pointless.
Ahhhh.....I see. That makes sense. So how does the computer know when to let the timing come back to the chip setting? Must it see idle TPS voltage or specific O2 numbers or what?

So, I could have missed a short burst of audible knock during the excitement and noise. (...along with the voices in my head ) Then before I could percieive the knock, the timing was pulled out. Does that sound plausible?

Thanks,
Jeff

 

[growler]

Did you get your knock problem figured out yet?

 

[orion]

I have the same problem with false knock. Being my daily driver and in need of a good tune up i rarely floor it. I can't remember the last time i drove the car at WOT.

There is no noise, no loss of performance, my scanmaster will read 12 degrees of knock and it accelerates smooth with no loud noise. When i added 6 gallons of 110 to an empty tank last fall i had no knock, which leads me to belive that it isn't false knock. Am i correct in assuming that?

on another note, when i have the wheel turned hard to the left and accelerate quickly i hear a disgusting noise, sounds like very expensive things slamming repeatedly very hard, but it shows no knock! what could this be?


- thanks in advance.

 

[Low Budget]

Originally posted by orion

There is no noise, no loss of performance, my scanmaster will read 12 degrees of knock and it accelerates smooth with no loud noise. When i added 6 gallons of 110 to an empty tank last fall i had no knock, which leads me to belive that it isn't false knock. Am i correct in assuming that?

Yes

on another note, when i have the wheel turned hard to the left and accelerate quickly i hear a disgusting noise, sounds like very expensive things slamming repeatedly very hard, but it shows no knock! what could this be?

Check the rear shocks and springs. It sounds like when I had loose parts in this area. Really loud and scary.

 

[Low Budget]

Originally posted by growler
Did you get your knock problem figured out yet?

Nope. Just turned the boost down and the lions share of the knock with it! Will be looking into alky soon I think. The track bomb I had on that 31.6 degree run was probably just not enough octane.

 

[1badTTA]

Originally posted by Low Budgit
Nope. Just turned the boost down and the lions share of the knock with it! Will be looking into alky soon I think. The track bomb I had on that 31.6 degree run was probably just not enough octane.

Too much boost, not enough octane and quite possible not enough fuel.

As far as when timing returns, I believe it is a factor of time more than anything. The more Knock the ECM sees, the more timing it pulls. Once it isn't seeing any more Knock, it waits a bit then slowly returns the timing to normal. This is why I like Direct Scan, you can watch all of this in real time instead of every 1.4 seconds.

 

[jetmech]

5 or 6 gallons of gas is not enough. Run at least 8 gallons so on launch you dont undcover the pump and suck some air. And run less pump gas and more race gas. I usally run on 93 to the track very low and add 7 gallons of 110. but my timing is not that high. Shoot Joe Lubrants race chips are 116 octance and 26 degrees. Get your octane up or run less boost.

 

[TurboJim]

Re: I know

Originally posted by Low Budgit
The tank had maybe 2 1/2 gallons of 93 with 3 gallons of 116 on top. (Last time when I ran the 13.0, I had about 2 1/2- 3 gallons of 93 plus 3 gallons of 112.) No scan tool that time though, but it sure didn't pull this much timing out and run 6 tenths and 5mph faster than today! I need help tuning, but I've had enough for this year I believe.

5 gals of gas isnt enough in the tank. You prolly uncovered the pickup and went lean.

 

[Low Budget]

Re: Re: I know

Originally posted by TurboJim
5 gals of gas isnt enough in the tank. You prolly uncovered the pickup and went lean.

Prolly so Jim. It won't happen again, that's for sure! The gauge was reading half a tank if I remember right, so if it wasn't the pick-up, it was the octane of the mix.

Hey Jim, when are we gonna get together on my other troubles?
Shoot me an e-mail when you can please.
Jeff