i have an 86 z28 witht he stock exhaust. i just bouhgt a l89 engine out of an 89 corvette. my question is if i put a glass pack in the place of my catalyitic converter an dkept my same muffler in its place, will i have a louder rumble and will i have enough backpressure for the new motor?

 

Not this again. You never want backpressure. Backpressure is a myth. You're confusing it with velocity. Why would you put a glass pack in place of a cat and keep your stock muffler. Then you're running 2 mufflers, which will hinder your performance.

 

trick thing to do is put a 1 chamber flowmaster where the cat is and get a SLP loudmouth VROOOOM!

hehe, but that's probably a waste of money, so don't mind me.

 

But will putting the glass pack in do anything as far as sound or performance? if not are there any other ideas?

 

Depends on your budget. I'd say get headers first. Then a cat-back, and of course as everyone knows I'd recommend the Hooker cat-back.

 

i am preparing to do the whole exhaust system all at once. i wouldnt put a glasspack in where the cat is supposed to be either run a cat or run a straight pipe there.

 

also aren't most glasspacks have baffles or something in there that would disrupt the airflow?

 

Glasspacks have a louvered tube in their interior, with a sound-absorbing material between this tube and the muffler case. The sound absorbing material used in glasspacks is ---surprise--- fiberglass.

The primary drawbacks to glasspacks are:
1. the fiberglass will breakdown as result of heat and corrosive chemicals in the exhaust. as the fiberglass breaks down, the muffler becomes progressively louder.
2. the louvers, which direct a portion of the exhaust into the absorbing material, stick out into the exhaust stream. this restricts exhaust flow. you could install the glasspack backwards, but very little of the exhaust will be directed towards the fiberglass. this would make this muffler a lot louder but still restrictive(the louvers, even though they would be facing in the wrong direction, still stick out into the exhaust stream).
3. most glasspacks neckdown at the muffler entrance as a form of redundant noise reduction. the three primary methods to reduce exhaust noise being restriction(necking down), redirection(used in most mufflers) and absorbtion.

 

not to be redundant: but turning the "cherry bomb" around backwards will definetly enhance the overall back pressure and sound. I have learned this from experience! PLEASE LET ME VERIFY!!!!!!
1. When my uncle Gessippi got a bad case of acid reflux, he turned the bottle of mylanta around backwards and drank it through a funnel. This reverses the polarity of the charge so that it cancels any negative protons. This prevents them from breeding with the nucleus keeping a cleaner gene pool!
2. Have you tried that new Awapahi shampoo???? It has a texture like ice cream, but without the bones!

 

I agree!