Spark Knock !!!!!!!! Please Help.
Thread Starter
Racer
Joined: Mar 2002
Posts: 444
Likes: 0
From: Niceville FL
Spark Knock !!!!!!!! Please Help.
Took my 2000 6spd to dyno shop (MUSTANG DYNO). The dyno tech said he
could hear a spark knock @ 6000 RPM. We think this was limiting the HP
because the timing was being retarded. The HP was very erattic between
320HP and 330 HP. The torque was flat at 353 lb. ft. between 2500 to 6000.
This seems like a very good torque number for minor mods.
Car has Hyper tech * MAF * throtle body * shorty headers * 160 stat
Bassani exh. * plugs * wires * Blackwing.
There has never been a knock sensor error posted in the DIC. Can the Hyper Tech defeat this error posting? I would not think so.
If a spark knock is detected and the timing is retarded when does it go back
to normal? I have read about adding 5 or more gals. of fuel and it will reset.
Is this documented anywhere?
My shop manual states that if a knock is detected it can retard the timing
up to 20 degrees, but nothing about when or how it resets to normal.
On our dyno run it acted like it was retarding and resetting immediately, if it was really doing thie at all. It was Full of 93 octane of course.
Does anyone know how much timing the Hyper Tech adds? I have put it back to normal for now. The Hyper Tech sure seems to make it more agressive.
THANKS IF ANYONE CAN SHED SOME LIGHT ON THIS.
could hear a spark knock @ 6000 RPM. We think this was limiting the HP
because the timing was being retarded. The HP was very erattic between
320HP and 330 HP. The torque was flat at 353 lb. ft. between 2500 to 6000.
This seems like a very good torque number for minor mods.
Car has Hyper tech * MAF * throtle body * shorty headers * 160 stat
Bassani exh. * plugs * wires * Blackwing.
There has never been a knock sensor error posted in the DIC. Can the Hyper Tech defeat this error posting? I would not think so.
If a spark knock is detected and the timing is retarded when does it go back
to normal? I have read about adding 5 or more gals. of fuel and it will reset.
Is this documented anywhere?
My shop manual states that if a knock is detected it can retard the timing
up to 20 degrees, but nothing about when or how it resets to normal.
On our dyno run it acted like it was retarding and resetting immediately, if it was really doing thie at all. It was Full of 93 octane of course.
Does anyone know how much timing the Hyper Tech adds? I have put it back to normal for now. The Hyper Tech sure seems to make it more agressive.
THANKS IF ANYONE CAN SHED SOME LIGHT ON THIS.
Safety Car
Joined: Sep 2001
Posts: 4,411
Likes: 1
From: Wilmington NC
Re: Spark Knock !!!!!!!! Please Help. (speedyc5)
Took my 2000 6spd to dyno shop (MUSTANG DYNO). The dyno tech said he
could hear a spark knock @ 6000 RPM. We think this was limiting the HP
because the timing was being retarded. The HP was very erattic between
320HP and 330 HP. The torque was flat at 353 lb. ft. between 2500 to 6000.
This seems like a very good torque number for minor mods.
Car has Hyper tech * MAF * throtle body * shorty headers * 160 stat
Bassani exh. * plugs * wires * Blackwing.
There has never been a knock sensor error posted in the DIC. Can the Hyper Tech defeat this error posting? I would not think so.
If a spark knock is detected and the timing is retarded when does it go back
to normal? I have read about adding 5 or more gals. of fuel and it will reset.
Is this documented anywhere?
My shop manual states that if a knock is detected it can retard the timing
up to 20 degrees, but nothing about when or how it resets to normal.
On our dyno run it acted like it was retarding and resetting immediately, if it was really doing thie at all. It was Full of 93 octane of course.
Does anyone know how much timing the Hyper Tech adds? I have put it back to normal for now. The Hyper Tech sure seems to make it more agressive.
THANKS IF ANYONE CAN SHED SOME LIGHT ON THIS.
could hear a spark knock @ 6000 RPM. We think this was limiting the HP
because the timing was being retarded. The HP was very erattic between
320HP and 330 HP. The torque was flat at 353 lb. ft. between 2500 to 6000.
This seems like a very good torque number for minor mods.
Car has Hyper tech * MAF * throtle body * shorty headers * 160 stat
Bassani exh. * plugs * wires * Blackwing.
There has never been a knock sensor error posted in the DIC. Can the Hyper Tech defeat this error posting? I would not think so.
If a spark knock is detected and the timing is retarded when does it go back
to normal? I have read about adding 5 or more gals. of fuel and it will reset.
Is this documented anywhere?
My shop manual states that if a knock is detected it can retard the timing
up to 20 degrees, but nothing about when or how it resets to normal.
On our dyno run it acted like it was retarding and resetting immediately, if it was really doing thie at all. It was Full of 93 octane of course.
Does anyone know how much timing the Hyper Tech adds? I have put it back to normal for now. The Hyper Tech sure seems to make it more agressive.
THANKS IF ANYONE CAN SHED SOME LIGHT ON THIS.
This may be way off base but what plugs are you running? I was getting a slight miss close to redline in 3rd gear on a roadcourse. When I pulled the #!@#$%^*&! original Delco plugs 3 of them were missing the platinum inserts on the bottom elctrodes! I put a set of NGKs in and the miss is gone. Nothing showed on the DIC.
Melting Slicks
Joined: Mar 2002
Posts: 2,931
Likes: 2
From: Tx
Re: Spark Knock !!!!!!!! Please Help. (speedyc5)
I think you are getting the low octane spark advance flag/table mixed up with knock retard. The PCM uses the knock sensors and a variety of other inputs to determine how much knock retard to apply in real time. The low octane flag only gets set when the PCM determines that enough knock retard is taking place to warrant a switch to a lower base spark advance table. I’m not sure if anyone knows what exact conditions set the flag, but it sounds like you were just seeing typical (REAL TIME) knock retard.
I don’t know exactly what the Hypertech does to your spark advance, but I’m guessing it makes it pretty aggressive, which would obviously make you more susceptible to knock.
Maybe you are leaning out a bit at the top of the RPMs. How was your a/f ratio looking on the dyno?
[Modified by QuickSilver2002, 2:37 PM 11/11/2002]
I don’t know exactly what the Hypertech does to your spark advance, but I’m guessing it makes it pretty aggressive, which would obviously make you more susceptible to knock.
Maybe you are leaning out a bit at the top of the RPMs. How was your a/f ratio looking on the dyno?
[Modified by QuickSilver2002, 2:37 PM 11/11/2002]
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Re: Spark Knock !!!!!!!! Please Help. (QuickSilver2002)
Personally, I have never thought much of the Hypertech either on the C4 or the C5. I have it for my C4 and it had spark knock. Don't know of you plan to return to the dyno, but I would reload your original program and set the fans for your thermostat and try again before making any quick decisions or doing a lot of diagnostics.
