Stock air filter cover? - ZR-1 Net Registry Forums

RICKYRJ1 · 01-30-2006

Sorry guys I wasn't sure how to title my question. I bought my car w/ the Vortex air filter system already installed. As per everybodies comments I removed it and installed the stock one. MY Q. is the blk. plastic shroud that the filter housing lays on then scewed down w/the 3 round fasteners has a big hole cut out of it from the Vortex system. Is this a problem? Should a new shroud be installed? I also have one of the stock air filter housing that has been modified to make it a open system w/ K&N filter totally exposed. Should I use that one instead? Again sorry for the maybe not so clear Q.

Demps · 01-31-2006

I personally would seal the radiator shroud--or change it. It will potentially let debris and moisture in the engine compartment. I have a cut lid and K&N on two of my cars. Some people say it doesn't help. I just like it. One thing that I have noticed--a K&N filter in a ZR-1 will make the idle hang up slightly at a stop. GM put out a notice that the oil from the filter will contaminate a sensor for the automatic shift of a tranny. I'm suspecting it somehow interferes with the coast-down idle on a ZR-1 and the speed density system (either IAC valve or MAF sensor). Ted

Locobob · 01-31-2006

I wouldn't worry about it. I've got the same deal as you and it's been like that for over two years without a problem. On my car the hole for the Vortex is entirely covered by the factory air filter housing.

RICKYRJ1 · 01-31-2006

The air filter housing does cover the hole. Is it a big job to install a new shroud? Are they still available?

Tom · 01-31-2006

A speed density system like on a ZR-1 does not have a MAF (Mass Air Flow Sensor) to get coated with the oil from a K&N filter and give faulty readings. It uses a MAP (Manifold Air Pressure Sensor) which on a ZR-1 is located at the back of the engine. The MAP sensor and connections do sometimes get engine oil into them which causes erratic readings, softens the rubber parts of the connections, and makes it much easier for the connections to be forced off if you have the ZR-1 starting backfire caused by not holding the key in the start position long enough.

The K&N filter oil could possibly get in the IAC area but it is easy to remove and clean.

Demps · 01-31-2006

Oops, typo. I'm fairly familiar with the speed density system. I chased an idle issue for about three years. I've now come to the conclusion that a K&N filter is causing it.

The radiator shroud is aggravating to change. If I remember correctly, Ricky, your car has about 4,000 miles. That is why I would change it/fix it. The correct one with the stickers will be hard to come by new.

Ted

01-30-2006	#1
RICKYRJ1 Join Date: Dec 2005 Location: Tinton Falls, NJ Posts: 1,177	Stock air filter cover? Sorry guys I wasn't sure how to title my question. I bought my car w/ the Vortex air filter system already installed. As per everybodies comments I removed it and installed the stock one. MY Q. is the blk. plastic shroud that the filter housing lays on then scewed down w/the 3 round fasteners has a big hole cut out of it from the Vortex system. Is this a problem? Should a new shroud be installed? I also have one of the stock air filter housing that has been modified to make it a open system w/ K&N filter totally exposed. Should I use that one instead? Again sorry for the maybe not so clear Q.

01-31-2006	#2
Demps Join Date: Jan 2006 Location: Niceville Posts: 998	Re: Stock air filter cover? I personally would seal the radiator shroud--or change it. It will potentially let debris and moisture in the engine compartment. I have a cut lid and K&N on two of my cars. Some people say it doesn't help. I just like it. One thing that I have noticed--a K&N filter in a ZR-1 will make the idle hang up slightly at a stop. GM put out a notice that the oil from the filter will contaminate a sensor for the automatic shift of a tranny. I'm suspecting it somehow interferes with the coast-down idle on a ZR-1 and the speed density system (either IAC valve or MAF sensor). Ted

01-31-2006	#3
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Stock air filter cover? I wouldn't worry about it. I've got the same deal as you and it's been like that for over two years without a problem. On my car the hole for the Vortex is entirely covered by the factory air filter housing. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

01-31-2006	#4
RICKYRJ1 Join Date: Dec 2005 Location: Tinton Falls, NJ Posts: 1,177	Re: Stock air filter cover? The air filter housing does cover the hole. Is it a big job to install a new shroud? Are they still available?

01-31-2006	#5
Tom Join Date: Jan 2004 Location: Southern CA Posts: 108	Re: Stock air filter cover? A speed density system like on a ZR-1 does not have a MAF (Mass Air Flow Sensor) to get coated with the oil from a K&N filter and give faulty readings. It uses a MAP (Manifold Air Pressure Sensor) which on a ZR-1 is located at the back of the engine. The MAP sensor and connections do sometimes get engine oil into them which causes erratic readings, softens the rubber parts of the connections, and makes it much easier for the connections to be forced off if you have the ZR-1 starting backfire caused by not holding the key in the start position long enough. The K&N filter oil could possibly get in the IAC area but it is easy to remove and clean.

01-31-2006	#6
Demps Join Date: Jan 2006 Location: Niceville Posts: 998	Re: Stock air filter cover? Oops, typo. I'm fairly familiar with the speed density system. I chased an idle issue for about three years. I've now come to the conclusion that a K&N filter is causing it. The radiator shroud is aggravating to change. If I remember correctly, Ricky, your car has about 4,000 miles. That is why I would change it/fix it. The correct one with the stickers will be hard to come by new. Ted