Detonation after Vararam install
Thread Starter
Instructor
Joined: Nov 2007
Posts: 167
Likes: 18
From: South East USA
Detonation after Vararam install
Has anybody ever noticed any detonation after installing vararam? The car is an otherwise stock 2002 MN6. It never knocked prior to install. It only does it when I stand on in 1st gear. It starts out fine, but as the motor winds up above 4 grand at WOT, I hear some knocking. I have tried to make it knock in every other gear at low an high rpm, but it won't. It only happens at WOT, high rpm, first gear.
Oil and coolant temps are fine.
Currently has a tank of shell 93 octane.
Installed a set of TR6 plugs hoping one step cooler would help. It didn't.
It feels like the thing just can't take advance out fast enough. It pulls like a scalded rabbit.
Any thoughts?
Oil and coolant temps are fine.
Currently has a tank of shell 93 octane.
Installed a set of TR6 plugs hoping one step cooler would help. It didn't.
It feels like the thing just can't take advance out fast enough. It pulls like a scalded rabbit.
Any thoughts?
Burning Brakes
Joined: Sep 2007
Posts: 1,048
Likes: 300
From: FL
Are you sure it is knock and not some rattle etc.?
If so, how many miles have you driven since the Varamm install? Did you have any tuning done? The new air intake will cause cause the engine to run leaner and the PCM via 02 sensors in closed loop should add the necessary fuel. Some car go so lean that they throw a code? Any codes? If you can get access to a tuning software or maybe a handheld tuner you can see if they knock sensors are detecting knock.
If so, how many miles have you driven since the Varamm install? Did you have any tuning done? The new air intake will cause cause the engine to run leaner and the PCM via 02 sensors in closed loop should add the necessary fuel. Some car go so lean that they throw a code? Any codes? If you can get access to a tuning software or maybe a handheld tuner you can see if they knock sensors are detecting knock.
Thread Starter
Instructor
Joined: Nov 2007
Posts: 167
Likes: 18
From: South East USA
Are you sure it is knock and not some rattle etc.?
If so, how many miles have you driven since the Varamm install? Did you have any tuning done? The new air intake will cause cause the engine to run leaner and the PCM via 02 sensors in closed loop should add the necessary fuel. Some car go so lean that they throw a code? Any codes? If you can get access to a tuning software or maybe a handheld tuner you can see if they knock sensors are detecting knock.
If so, how many miles have you driven since the Varamm install? Did you have any tuning done? The new air intake will cause cause the engine to run leaner and the PCM via 02 sensors in closed loop should add the necessary fuel. Some car go so lean that they throw a code? Any codes? If you can get access to a tuning software or maybe a handheld tuner you can see if they knock sensors are detecting knock.
It's got about three hundred miles since the vararam. Never had any engine codes and it hasn't been tuned ...yet. More mods to come. I don't want to do the exhaust until I figure this out. I might not be able to hear the knocking after the exhaust.
Burning Brakes
Joined: Sep 2007
Posts: 1,048
Likes: 300
From: FL
Did you change the plugs at the same time? What are they gapped at?
If it is plug related then you may want to use the TR55s instead of the TR6s and see if that helps. I didn't think you needed the TR6s unless you had forced induction. Did you replace the plug wires as well?
If it is plug related then you may want to use the TR55s instead of the TR6s and see if that helps. I didn't think you needed the TR6s unless you had forced induction. Did you replace the plug wires as well?
Safety Car
Joined: Jun 2005
Posts: 4,977
Likes: 256
From: St. Louis Missouri
I've tuned dozens of LSx based vehicles, some of which experienced knock retard... none of which had an audible ping.
The noise your are hearing is likely something loose based upon my experience. I have a Vararam on my car and ran it on a stock tune for a couple of weeks. I had no issues with it. 2001 Z06.
You won't need colder plugs until you hit it with nitrous or forced induction. Stock replacement plugs are what I recommend.
The noise your are hearing is likely something loose based upon my experience. I have a Vararam on my car and ran it on a stock tune for a couple of weeks. I had no issues with it. 2001 Z06.
You won't need colder plugs until you hit it with nitrous or forced induction. Stock replacement plugs are what I recommend.
Last edited by Tech; Jul 21, 2008 at 09:57 AM.
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
Mine did exactly the same thing....
The Vararam leaned out the engine too much.
Until I had ECS tune it.....
Get yourself to Carlile or sned your PCM to ECS.Tell then (Chris or Doug)
What your mods are and you will be immensely pleased with the magic they work.
The Vararam leaned out the engine too much.
Until I had ECS tune it.....
Get yourself to Carlile or sned your PCM to ECS.Tell then (Chris or Doug)
What your mods are and you will be immensely pleased with the magic they work.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Your best bet is to find someone in your area with EFI Live or HP Tuners and scan your car and see if you really have KNOCK. Scanning is FREE.
That will answer the question.
BC
That will answer the question.
BC
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Burning Brakes
Joined: Sep 2007
Posts: 1,048
Likes: 300
From: FL
Not sure, but if you go over 25% lean I believe you will throw a code.
I would definitely recommend purchasing tuning software and a wideband 02 sensor. It is about the price you will pay for a tune but you can learn how to use the software and make future changes. If your car is lean just lean then fixing with software is pretty easy. It will just a take a little commitment to understand the MAF and VE tables and how to manipulate them. If you do indeed have knock then you will see it and correct for it, etc.
I would definitely recommend purchasing tuning software and a wideband 02 sensor. It is about the price you will pay for a tune but you can learn how to use the software and make future changes. If your car is lean just lean then fixing with software is pretty easy. It will just a take a little commitment to understand the MAF and VE tables and how to manipulate them. If you do indeed have knock then you will see it and correct for it, etc.
Burning Brakes
Joined: Oct 2004
Posts: 931
Likes: 35
From: Rowlett, Texas
What are your water temps?
Maybe, if you stop or slow way down, the temps will go up, then when you hammer it in low, it's hot enough to knock. When in the higher gears, the water temp comes down enough to kill the knock.
It happened to me.
DG
Maybe, if you stop or slow way down, the temps will go up, then when you hammer it in low, it's hot enough to knock. When in the higher gears, the water temp comes down enough to kill the knock.
It happened to me.
DG
Burning Brakes
Joined: Feb 2005
Posts: 1,190
Likes: 0
From: Fayetteville AR
I had the same issue after I installed my Vararam on my 01 (auto). I first replaced the plugs/wires to make sure they were not part of the problem. I still noticed some slight pinging at WOT in 1st (maybe 2nd). Then installed the Predator tuner since I wanted more control over my auto tranny (and it was on sale). I tweeked the setting from what I learned on the CF and my problems were gone and I could really feel the performance (mostly due to the improvments to the auto tranny).
Thread Starter
Instructor
Joined: Nov 2007
Posts: 167
Likes: 18
From: South East USA
Nice job ECS
I sent my PCM off to ECS for a mail order tune. After the tune:
No more detonation
Coolant temps never got above 208
No more CAGS
I have only driven it once, but I am very pleased so far
No more detonation
Coolant temps never got above 208
No more CAGS
I have only driven it once, but I am very pleased so far
Team Owner
Joined: Jul 2004
Posts: 24,652
Likes: 298
From: NJ
St. Jude Donor '05-'08
