I finally got under my car and did a good look. Tires aren't rubbing, tried to wiggle the gas tank, wouldn't move. Then I noticed the exhaust. It is lying on (what I guess is) the track bar brace. That is the brace under the intermediate pipe and over some other brace, right? I still haven't checked the transmission mounts yet, so it may be a combination. Could this be what is causing the noise?
BTW, what size i-pipe do I have?

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My only mod: Flowmaster 40 series

 

Cool! Yeah that's the track bar brace; below it is the track bar. There should be a hanger off the passenger-side tailpipe that anchors the system "up" to the rearmost frame rail. Of course I'm assuming you have a dual exhaust... I'm not sure how the singles ran.

I think stock pipes were 2 inches diameter. It's been a while since stock


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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I have a single inlet and 2 outlet setup. what do i need to do to upgrade to a 3" exhaust besides maybe expand the rear of the converter?

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My only mod: Flowmaster 40 series

 

Technically if it's a bolt on, you wouldn't have to extend the convertor's butt. There should be a flange between the I-pipe & cat, unless you've got a custom job there.

A 3 inch cat-back system from Dynomax or Flowmaster should cover it; that gives you the I-pipe, tailpipes, & muffler. I don't think a 2.8 needs 3" exhaust tho, the Dynomax #17493 (Super Turbo Catback) comes with 2.5" pipes all around- and it's a v8 exhaust (5.0 non-high-output). It's the same one listed for our 2.8/3.1's.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!