Transitional knock

[ES1]

Has anyone had any luck getting rid of the transitional knock with the higher timing chips?
I have tried lowering my turn on point but it is still there.
Has upping the fuel pressure helped anyone?
This is with a 100 octane chip. No problem with a 93.

Thanks
ES

 

[blackbuick87]

Get an RJC power plate, it seems to help eliminate it.

A dual nozzle system can help sometimes, but it usually comes on too late also.

A variable timing chip is used by the guys that run really fast on alcohol

 

[Mr URL]

If alchy comes on too soon it will bog or cause slower spooling. What I did to fix it on my cars is keep the chip programming WOT timing low until 4,000 rpm + which gives the alchy time to come on and be effective so you can take advantage of the high timing safely.

 

[DMan]

A little transitional knock won't hurt anything.

 

[Steve Hill]

I second Dman

 

[ES1]

How much would y'all consider as to much?

 

[Steve Hill]

knock can be so quick as to not even increment a knock count.
IMO, this type can be ignored.

As to your question, personally, I don't get real excited within the 5-7 degree range, as long as it is just one hit.
I've also seen waaaay more than that, on many occasions. Not that I think that is good, but we really push the boost, everyday running at 27lbs with occasional trips to 30. On pump gas.
Well, that's what it takes to push air through the sh*t heads.
We've found the stock long block is more rugged than you might think, and a good w-a system is your best ally.

Dman and I have the option to force knock ignore, but we *never do that because there is gonna come a time when that feature will save your butt. It's better to take the small performance hit from retard.
Usually we get full timing back within 2-3 secs.
And, btw, there is a significant hp difference between 22 degrees and 28 degrees in timing. Right, Dman?

 

[ES1]

I am at the position that a 93 chip gives no transitional knock but the 100 chip does.
Instead of paying with the alky turn on points have you had any luck with getting the transitional knock down with raising the fuel pressure?
These are Jay Carter VT chips.

 

[Steve Hill]

>"have you had any luck with getting the transitional knock down with raising the fuel pressure? "<

no

 

[ES1]

Thanks for the help & info!

 

[DMan]

Yeah 28 degrees makes a diff all right.

But as you say, transitional knock isn't really affected by FP. Its a very strange beast.

 

[blackbuick87]

Its caused by too much timing for pump gas before the alcohol kicks in and raises the octane back into the safety range. That is why FP does nothing to prevent it, because you are short on octane, not fuel. Variable timing chips and a power plate are about the only way to prevent it

 

[Steve Hill]

I think you're about on the money ;-)