Large Stall = knock??

[Spl170s]

I have been having issues with my car knocking alot lately when i go WOT from a 30mph or so roll. I get as high as a 15 degree retard if i do this from a roll.

When i go WOT from a dig....no knock.

Is it possible my stall converter could be to large or too loose and this could cause knock like this???

 

[bruce]

Is it possible my stall converter could be to large or too loose and this could cause knock like this???

It would seem hard to believe that could be the case. I'd rather suspect the chip, isn't just that well matched to that converter. Depending on converter, it might need ALOT less fuel and being excesively rich, could be your knock problem.

I had a calibration pretty well worked out for a Yank 10" SS converter (LU, 3000 RPM stall), and thought it would be close to a Precision 9" (LU, 3,000 RPM stall), and was shocked as to how different they were. The fuel table, and Accleration Enrichment stuff was completely different.

 

[Spl170s]

Well, i have a 93 octane turbotweak chip made that was for my stall setup and rest of the car mods, and it had the roll on knock and no knock from a dig. Got another one made and it does it as well. I would think the chip should be good?

 

[bruce]

turbotweak chip

That pretty much rules out the problem being chip related.

Other the guessing, it'd help to do a few DS logs, and see what's going on, to try and start to diagnose the problem.

 

[Spl170s]

i don't have a direct scan setup yet. Just running by scanmaster right now. my project funds have dwindled....

 

[DragulaGN]

Im having the same prob... I am using an Art Carr 9". it is sparadic also... It may pull 2-3 one time and higher the next. Then 0.0..all on the same setup

 

[Spl170s]

It is the most annoying thing isn't it? Something so sporadic that there is no easy fix to. It woudl be different if it was the same thing...everytime. What gets me is the 0.0 when going from a dig.....

 

[Eric Stage I]

Is it on a downshift? Sometimes that can be false knock. If you can put in some race fuel (or xylene), and check the results, that might help narrow it down.

As Bruce said, DS is very helpful is these circumstances. It's possible we could adjust something in the chip to help.

Regards,
Eric

 

[Spl170s]

Thanks Eric.

PMing you now.

 

[DragulaGN]

Im using 113 now on 20 psi...with alchy because I have seen the kr sky rocket to like 48.x with no audible knock. Still hit and miss.

 

[Spl170s]

WOW! I have never went that high before!

Highest i see now is around a peak of 15 at most if i roll on to WOT from around 20mph +. And it eventually goes down to 0 if i stay on it....just takes a few seconds....and i don't hear anything.

Kind of hard to hear it on my car though due to the exhaust and the valvetrain noise.

 

[DragulaGN]

I think that the scanmaster may be messed up. I am going to pull it and send it off.. I am also going to hool up with Kip and see what he thinks.BTW What part of In you in?

 

[BEATAV8]

My guess is it's probably false knock....
I get false knock often in 1st or 2nd gear from a roll. It's like traction control... she spins the tires and the knock sensor doesn't like it. If your chip is like mine (an extender) it may ignore knock for a few seconds on launches, that's why I get nothing from a dig on slicks and something from a roll on radials. Some others have had told me they get the same symptoms. That's probably why guys put the low gear knock ignore into their chips... it's common to get false knock during launch or tire spin.

basically I pay the most attention to KR in 3rd gear WOT. If its clean up there in 3rd gear, and you cannot hear anything obviously pinging when the KR pops up down low, you should be OK.

Another thing I've found is that if I start the engine with Direct Scan hooked up and running, I will get knock counts of 150+ before the engine even starts. Then I can disconnect DS and restart the engine and the knock count will be 2 or 3. Unrelated but just another example of how finicky these things can be.....