[acannell]

90 daytona 2.5 turbo
big intercooler
hybrid T3/T4
stage 3 computer
14 psi

im using an otc monitor 2000 tool to watch the output of the knock sensor

under full boost it says it detects knock and that its changing some of the timing on some of the cylinders (a few degrees)

is this acceptable?

if the computer detects ANY amount of knock is that unacceptable?

im planning on going to 25 psi (add +40's, stage 5 computer, 3 bar, AFPR, 3" exh). should i have aboslutely ZERO knock (as detected by the computer) at 14 psi before i move on up?

 

[Sittn86]

Just melt your pistons. Then you'll know how far not to go!

 

[Sittn86]

I forgot to add... Read your spark plugs.

 

[speeduphoria]

90 daytona 2.5 turbo
big intercooler
hybrid T3/T4
stage 3 computer
14 psi

im using an otc monitor 2000 tool to watch the output of the knock sensor

under full boost it says it detects knock and that its changing some of the timing on some of the cylinders (a few degrees)

is this acceptable?

if the computer detects ANY amount of knock is that unacceptable?

im planning on going to 25 psi (add +40's, stage 5 computer, 3 bar, AFPR, 3" exh). should i have aboslutely ZERO knock (as detected by the computer) at 14 psi before i move on up?

you should have 0, dont listen to this other yahoo. What octane gas are you running? Whats your A/F? and What is your timing set at? It could be false knock(as in engine noise), so be very sure to rule this out before uping the boost(easy way would to use some better gas at the same setings and see if it goes away, if so drop your timing down a couple degrees). When the timing is retarded due because it thinks it sees knock(to try to keep it safe), this makes the EGT's go up and can melt things, so its a double edged sword.

 

[acannell]

yeah im remaining cautious. if the computer is seeing knock from the knock sensor then im worried until something convinces me otherwise.

im running 91

i only have a narrow band A/F gauge, it reads 9 bars under full boost (i have never seen it read 10 bars under any situation. it is properly installed with a good ground)

timing it set to stock

i dont know how to rule out false knock

OTC 2000 indicates the computer is retarding cyl #4 up to 7 degrees, while the other cylinders are getting at most 2 or 3. this suggests its not false knock right? cause #4 runs hotter?

plug from #4 looked almost totally normal, maybe a bit light

my EGT gauge is on runner #4. its very slow to respond but i know temps reach at least 1500F

intercooler is BIG, 19" x 14" x 3.5" core with 2.5" inlet and out let

 

[speeduphoria]

It could be false knock(as in engine noise), so be very sure to rule this out before uping the boost(easy way would to use some better gas at the same setings and see if it goes away, if so drop your timing down a couple degrees).

An easy test is bolded in my post

You could also try cleaning the injectors and swaping the order to see if anything changes. Are they new injectors?
Have you verified that your FP is staying up during boost? Is the pump new?

 

[acannell]

pump and injectors could be original for all i know, last time i checked FP during boost was at 5 psi

thanks for the suggestions...

so wait a second, im taking all this as meaning you think i should absolutely no knocking?

 

[impuresoul2k3]

Unless your really good with tuning there will probably be a few degrees of KR(knock retard), but 7 is quite a bit. My friend's GTP still gets some knock even after headers and a cold air intake, which are supposed to reduce knock.

 

[mario03SRT]

7 degrees in only 1 cylinder answers your question. Thats a crap load of retard.

If it was all cyls then that is manageable with fuel, timing etc. I see this in posts all the time with shitty old harnesses and injectors, guys thinking that these cars will go forever w/o maintenance.

Look over that cyl for obvious issues. Swap the injector another cyl and and see if the problem moves with the injector. Thow in some mega injector cleaner or better yey pull them all and get them cleaned and balanced.

FYI,
Marion

 

[acannell]

its cylinder #4, which i am pretty sure runs hotter than the other cylinders. does this matter?

 

[speeduphoria]

why do you keep saying that? we know its cyl#4, Who says its the hottest? This is nothing to do with it as this applies to everyone.

Like I said just add some better gas and go for a ride, see if its still the same, if so check that fuel injector

 

[acannell]

ive read on dodgegarage that its hotter, hence the mod to put the coolant lines right on the head near there...and since its odd man out it fits the scenario...but i totally understand it could be something else

will check the injector and add some better gas

 

[speeduphoria]

but what you dont seem to understand is what I've allready posted, retarding timing makes EGT's go up, so that KR you are seeing that pulling timing on #4 is making that EGT higher than the rest(even though you have no other EGT probes to compare to and your not measuring cyl temps either). Also if you do some more reading many people feel #3 is hottest.

 

[impuresoul2k3]

Might check your injector harness for corrosion as well.