I just installed an aftermarket air filter on my '89 L98 GTA. It is an open element filter w/ a heat shield that covers the rear half of it. Ever since I put this on, the car makes a very loud hissing noise at idle, like its madly sucking air in - which is what I am guessing is what is happening and that that is what that air filter is designed to do. Sorry for the dumb question, but this is my first performance car so I am new to some of the sounds that you are supposed to hear. Let me know if this sounds right.

 

Yup. Open filters do make more noise. As far as the hissing, I've never had a TPI so I don't know, but I wouldn't be too alarmed.

 

You think thats a bad thing??? Enjoy the noise!

 

Yes, its normal.

Also so you're forewarned: I don't know how apparent this will be on yours because you have them MAF so you'll have some tubing too, but on my SD car, I had the K&N open that mounted to the TB, and when you open the throttle there was a very noticable pop.

 

Actually I never thought it a bad thing ( I think it sounds pretty cool - like its a heavy breather and waiting to go), I just wasn't sure if it should be doing that or not.

goumba, thanks for the forewarning. I was interested in that air filter right off the throttle body, but from what I understand, thats difficult to do with the MAF system. I am happy with what is on there now, except I want to replace the rubber hoses with something solid and polished so I have to explore that. Thanks for the heads up though.

Peace