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Knock at 21 degrees of timing?

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87NAT

In Between GN's
Joined
Dec 24, 2005
Messages
3,058
Could I have knock or preignition @ 21 degrees in 3-4 gears? I usually run 25 psi with my alky set at position 4. My scanmaster says 757 and 2.1 degrees of knock. I turned my alky knob to #5 and the knock numbers went away but the problem is still there.
My boost guage needle visibly moves back and forth REAL fast between 23-25 psi when I am at WOT. It make a wierd noise...small popping noises... almost like its on a rev limiter. I feel that my timing is very conservative at 21 degrees but should I have to drop it down to 18-19. I am not sure what my problem is I am just throwing this idea out there for some feedback. My car pulls like a freight train up until this point at WOT. It just doesnt soumd like "knock" like I have heard before and I dont see any carzy high numbers on my scanmaster. I have done all of the other troubleshooting ideas, FP check, coil/ign, cam sensor, etc......
 
757 is low. You should target 780-790 minimum. If you lean out the motor, it will knock even with alky. You may get away with 757 O2 but with a lot more alky like pos 7 or 8.. but every car is different.

As to engine sounds.. could be blown vacuum hose in engine compartment. bad PCV blowing air into crankcase, turbo going out.. dunno.

Turn the alky up.. leave the timing alone. The alky is your detonation suppression.. it needs to be fed into the motor.. bringing it down in volume only creates problems...especially when the motor tells you it wants it.
 
Thanks Julio, I will turn up the alky and see what happens. I am really just getting my tune dailed in with the new 6776 and 60# inj. I had never moved the alkly knob from its setting with the old turbo. I guess its wants for more alky to add to the more air and fuel I am throwing at it.

Could I have knock or pre-ignition at a different frequency that the knock sensor is not picking up?
 
Dude thats a big turbo.. feed it meth :D

No.. preignition wont make the knock sensor go off. Also if you changed the turbo, you need to add more fuel in the chip.. lots more.
 
Should I adjust the initial knob in the box since I have this big turbo or just leave it alone and crank my 1-8 knob up?
 
dont touch the black box yet...just put the 1-8 knob on 7. I'm running straight meth also.Remember you have a big turbo and it likes to eat :biggrin: put the tt chip back to default settings and the knob to 7 set boost and work on timing then scale back fuel in chip if necessary.
 
I just pulled all of my plugs. I found the rear passenger cyl gapped at .24 while all of the others are at .32 I must have hit it when I was installing it because I am sure I gapped them all the same. I also found an IC hose clamp was not tight. I wouldnt say it was "loose" but I could move it up and down abit. I guess at 25 psi it would rear its ugly head and cause issues right? I wonder if this was my boost flutter at WOT (the IC clamp and mis-gapped plug)?? I will drive it tomorow after work and see.
 
dont touch the black box yet...just put the 1-8 knob on 7. I'm running straight meth also.Remember you have a big turbo and it likes to eat :biggrin: put the tt chip back to default settings and the knob to 7 set boost and work on timing then scale back fuel in chip if necessary.


+1 ;)
 
Any response to my misgapped plug and IC hose not being tight. Could this be a problem?
 
Any response to my misgapped plug and IC hose not being tight. Could this be a problem?


Yup.. the problem is you see a problem.. you need to fix it and retry again. My Buick crystal ball has a blown gasket :D

So you put 6 new plugs in.. tighten all your hoses.. if you still have a problem, then you know its not plugs or hose clamps ;)
 
Ditto on the meth being at 7. I run my meth at 7 for my TTA with 25lbs on a GT32 and my GN with 26lbs on a 63. I had to add fuel in the chip for the GN. The TTA was dead on with the chip from Eric and Meth on 7.
 
Yup.. the problem is you see a problem.. you need to fix it and retry again. My Buick crystal ball has a blown gasket :D

So you put 6 new plugs in.. tighten all your hoses.. if you still have a problem, then you know its not plugs or hose clamps ;)

I know its most likely a problem ...but I have a 3 year old and a 7 week old baby. My test n tune is limited to once a week if I am lucky. My cars sits most off the time. I was just trying to get some feedback to make me feel better until I have the time to fix things and test it out. Not trying to use your crystal ball for that...I would ask alot of other questions if I could.;) :D
 
Reopening this thread.

Long story short...pulled my engine and all of my lobes on my cam were worn. Previous owner installed 100 plus # springs about 14 years ago and my guess is they did a number on my stock cam. All of my rings were shot also. Motor was veeeerryyy loose. New roller installed with a mild rebuild. Car sounds and runs completely different.:) All my high rpm miss/sputters I contributed to my worn camshaft. :mad:

I always ran my alky kit at 4 on the knob...now it wants 7 and it wants a ton of fuel from the chip. I had the big turbo and heads..I just wasnt utilizing it before without a good camshaft. Thanks for all the help guys.

I will be at the track at the beginning of the new year. Hoping for mid-low 11's.
 
Thanks for the follow up. Its always great to hear what and why of things that happen.
 
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