Help W/ S/C timing....

[c5kid]

Ok I have been getting knock and this was suppose to be a super safe tune from ECS but I heard the lovely marbles in a can noise getting on it one day. Ever since then I can't get it to go away.. take a look at my current timing table vs my ECS tune...

Current...




ECS....




Currently I am only maken about 5-6 boost max...

What can be causing this?? I mean I keep lower the timing and I don't know how much lower I have to go.... It does have a slight hesitation when you start to go WOT, probaly due to the fact the timing drops off so dramatic...

no..i haven't added more fuel... i am already running 10.5 A/F at WOT.... could it just be false knock? I mean i took the car out again and was loggin some data and was still getting 10-11* of knock retard... and that is w/ no adavance at all 0* of timing...

here are some screen caps




it's being gion on for awhile... but would come and go...i don't beat the car so when i did get into WOT it was only once and a while.... i thought maybe some bad gas but lately i have been running Sunco 94

the only other thing that i can possible think would cause this is the Hurst shifter in a c5 rattles when you get to a certain RPM and how much load is on the tranny.... i have no load on the car it won't get any knock retard.... goin up a hill or mashing the gas at 2.5k will make her ping....

[MNR-0]

Jack up the AFR to 11.8, pull 5* timing out to 12* advance at WOT.

[BLOWNZ06]

I run 17-18 degrees of timing with 115 Degrees temps at the end of a 4th gear pull when it is 90 outside and don't get any knock.

My car is also a stock motored ZO6 running 7-8 psi on a P1SC

That timing table IS way safe from ECS.

Sorry bud, but you have something else wrong.

[tici]

I'm also at 17* and rarely see knock.
What kind of fuel are you using?
What is you engine - Year - mods?
Do you have an LS1Edit file to take a look?

[Chris@HPTuners]

don't run your timing so low as you will damage your exhaust system.

even with 10psi boost and a 200 shot of NOS you can still get 5-7 deg of timing. Something else is wrong with your setup. s/c noise, pulley vibration, exhaust baffles rattling etc. can all cause false knock. also make absolutely sure you aren't leaning out due to fuel pressure dropoff, dirty fuel filter etc.

Chris...

[tici]

don't run your timing so low as you will damage your exhaust system.

Chris, could you please explain this? Is it because the exhaust gasses still contain unburned fuel? Or because the combustion happens too late?

[BLOWNZ06]

Chris, could you please explain this? Is it because the exhaust gasses still contain unburned fuel? Or because the combustion happens too late?

You are effectively retarding your timing.

This will give you VERY HIGH EGT's.

This will kill your mufflers and CAT's VERY quickly.

[c5kid]

this is totally dumb... but after smashing my head off the wall for a couple of weeks trying to figure this out, I put the ECS tune back in the car and took her for a ride..

This time I HELD THE FREAKEN SHIFT KNOB!!!!.... NO KNOCK!!! the shifter is vibrating so bad that it gives it false knock and at times does sound like marbles in a can...

now to figure out how to stop it or put a different shifter in...

[BLOWNZ06]

this is totally dumb... but after smashing my head off the wall for a couple of weeks trying to figure this out, I put the ECS tune back in the car and took her for a ride..

This time I HELD THE FREAKEN SHIFT KNOB!!!!.... NO KNOCK!!! the shifter is vibrating so bad that it gives it false knock and at times does sound like marbles in a can...

now to figure out how to stop it or put a different shifter in...

Sometimes the easiet solutions are the hardest to see.

Glad you got it figured out.

[Chris@HPTuners]

this is totally dumb... but after smashing my head off the wall for a couple of weeks trying to figure this out, I put the ECS tune back in the car and took her for a ride..

This time I HELD THE FREAKEN SHIFT KNOB!!!!.... NO KNOCK!!! the shifter is vibrating so bad that it gives it false knock and at times does sound like marbles in a can...

now to figure out how to stop it or put a different shifter in...

yeah it sucks, once i installed a completely new exhaust system on a guys car and suddenly was getting major KR. After about 5 hours of WTF, it turned out that one of the baffles in the right side muffler was vibrating under load. Not an easy one to find... and unexpected on a brand new exhaust.

[c5kid]

Thanx for all the help guys