B&B bullets question
Thread Starter
Instructor
Joined: Aug 2008
Posts: 163
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From: Duncannon, Pa
B&B bullets question
When I went to get my car tuned at Cartek in NJ they told me I was getting knock and not from the motor. It was coming from the exhaust actually hitting the rear sub frame on the left side. Now I have the B&B bullets on and was just wondering if anyone else has had any clearence issues with the exhaust. They showed me where it was hitting and you can't even get a finger in between the pipe and sub frame. Anyone else notice this when installing their b&b bullets? They told me the only way i could increase space between the two would be to grind down some of the metal. I will take a picture tomorrow of what i'm talking about.
Update pictures done. You can see from where my finger is at, is the place that has barely no space in between
the pipe and sub frame. I think this is an issue that all Bullet owners should take into consideration if getting your car tuned. Under acceleration this could become an issue causing the car to retard timing and loose horsepower. That is what Cartek was telling me.
Update pictures done. You can see from where my finger is at, is the place that has barely no space in between
the pipe and sub frame. I think this is an issue that all Bullet owners should take into consideration if getting your car tuned. Under acceleration this could become an issue causing the car to retard timing and loose horsepower. That is what Cartek was telling me.
Last edited by Number 23; Jul 27, 2009 at 01:08 PM.
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From: Machineguns, because I don’t compromise
They are a good shop, and I'm only wanting to ADD to the possibles...
Yes, the exhaust is bad and you can get knock from the hitting.... of course grinding the cradle or some other monkey business will create clearance.
You mentioned "they said the knock was NOT from the engine"
Any knock they see is from the knock sensor(s)... hence the engine, it may well be from the catback, but another reason may be carbon buildup in your combustion chambers from oil sucked through the PCV.
I had false knock on my '01 Zo6 and it turned out to be oil being sucked in, and baked onto the piston tops.... a treatment of SeaFoam got rid of the carbon (do a search).
You can grind the subframe, but I wanted to leave you with the idea that carbon can also cause knock.... which will show up on the dyno computer just like a [mechanical] knock.
Yes, the exhaust is bad and you can get knock from the hitting.... of course grinding the cradle or some other monkey business will create clearance.
You mentioned "they said the knock was NOT from the engine"
Any knock they see is from the knock sensor(s)... hence the engine, it may well be from the catback, but another reason may be carbon buildup in your combustion chambers from oil sucked through the PCV.
I had false knock on my '01 Zo6 and it turned out to be oil being sucked in, and baked onto the piston tops.... a treatment of SeaFoam got rid of the carbon (do a search).
You can grind the subframe, but I wanted to leave you with the idea that carbon can also cause knock.... which will show up on the dyno computer just like a [mechanical] knock.
Thread Starter
Instructor
Joined: Aug 2008
Posts: 163
Likes: 2
From: Duncannon, Pa
They are a good shop, and I'm only wanting to ADD to the possibles...
Yes, the exhaust is bad and you can get knock from the hitting.... of course grinding the cradle or some other monkey business will create clearance.
You mentioned "they said the knock was NOT from the engine"
Any knock they see is from the knock sensor(s)... hence the engine, it may well be from the catback, but another reason may be carbon buildup in your combustion chambers from oil sucked through the PCV.
I had false knock on my '01 Zo6 and it turned out to be oil being sucked in, and baked onto the piston tops.... a treatment of SeaFoam got rid of the carbon (do a search).
You can grind the subframe, but I wanted to leave you with the idea that carbon can also cause knock.... which will show up on the dyno computer just like a [mechanical] knock.
Yes, the exhaust is bad and you can get knock from the hitting.... of course grinding the cradle or some other monkey business will create clearance.
You mentioned "they said the knock was NOT from the engine"
Any knock they see is from the knock sensor(s)... hence the engine, it may well be from the catback, but another reason may be carbon buildup in your combustion chambers from oil sucked through the PCV.
I had false knock on my '01 Zo6 and it turned out to be oil being sucked in, and baked onto the piston tops.... a treatment of SeaFoam got rid of the carbon (do a search).
You can grind the subframe, but I wanted to leave you with the idea that carbon can also cause knock.... which will show up on the dyno computer just like a [mechanical] knock.
They told me that they actually heard it on the dyno and it was coming from the rear of the car.
ok well i will try loosing the clamps and moving things around a bit. Also I'm not sure of the procedure for the seafoam on the vette. I know with my 240sx with SR20DET I poured about 1/3 of it down a break booster type hose. I'd imagine it's the same for the vette almost. Followed by a couple WOT passes and some white smoke. LOL
I've already done about a 1/3 of the bottle into the fuel tank when I filled up here the other week at Sunoco.
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