Since I know nothing about aftermarket exhaust stuff I have a could of questions for those who are good with this stuff.

1. I am thinking about taking off my cat on my duke.
2. How would one take it off? just take a sawzall to it?
3. How does a glass pack connect to the old exhaust system? does it just slide into the old pipes and clamp on?
(Any welding required?)
4. What size and brand glass packs are the best for this system?

All help will be appreciated
-Steve

[This message has been edited by Mcfleev-O (edited 04-22-2011).]

I bought my car with a cherry bomb muffler on it. It's a duke.

I've never hated an exhaust note more than that car.

Just my two cents.

Glasspacks produce a bad exhaust note. They are classified as "Resonators" not "Mufflers" thus they are meant to be inserted before a true muffler. They are generally very long, so sneaking one in a Fiero might be tricky unless done as a hack job. Even though they are designed to slip on, welding is the best option, and is not hard. To remove the Cat, I took a sawzall to my V6's exhuast, marked the exhaust peices to make it back to perfect, cut and welded in a delete pipe, and reinstalled the exhaust. I still use the factory muffler and it has a great tone. To make the 4 cylinder have a good tone, remove the cat, and install a muffler not a resonator. Better to have a tone then sound raspy and like a ricer.

ALSO! Before removing your Cat, check with local laws to make sure it will still pass any state inspection your state has. Tampering with emissions control devices can cause some havoc with the law in some places

[This message has been edited by Racing_Master (edited 04-22-2011).]

You might have to have a cat in your state. My V8 car had 2 shorty Cherry bombs, about a foot long and no cats. It sounded great. Prob not so good on a 4 cyl. Some people put the tip resonators on by themselves. My 88 Corvette had straight pipes from motor back and only the resonator tips and it sounded pretty good too. Quiet enough to not attract police, but loud when you got on it good on a back road.

What if I piped the cat with no glass pack. How would that sound?
or what would it sound like if the cat was gutted then replaced?

quote Originally posted by Mcfleev-O: What if I piped the cat with no glass pack. How would that sound? or what would it sound like if the cat was gutted then replaced?

Exhaust pipe will sound similar to a glass pack but louder and more "rasp".

A glass pack is a fine muffler. They are very free flowing (high performance) and inexpensive. However, they do not reduce noise as much other muffler styles, such as a baffled or a restriction muffler, and generally will not last as long (usually made from mild steel and packed with fiberglass that can break down).

They also do not modify the engine noise near as much as a baffled muffler.

[This message has been edited by LZeppelin513 (edited 04-22-2011).]

..Nothing sounds better on the duke than the cherry bomb glasspack ,,it is quiet enough at idle to sit beside a police car,,the beauty of the glass pack is when you are going thru the gears it is gearhead music

the Cherry bomb is difficult to mount in place of the cat ,,Thrush makes a glasspack a few inches shorter that fits in easier ..
you must saw the pipes off ,you will saw as close to the Cat body as possible ,then you will grind off the weld so the inlet and outlet are smooth,to give you the most pipe to hook onto..
you can drill holes in the clamps to hold the springs ,,also L bracket come in handy,,for use as spring mounts

..for the average owner it is difficult to mount a turbo style muffler in place of the stock muffler
I was a fan of Glasspacks/steel packs from the 50,s unfortunately the glasspacks kill power
this is because of the small holes in the tube to help keep the packing in .
installing a Dyno max,magna flow or flowmaster is the way to go for power ,,but the turbos take up a lot of space & are not easy to mount properly
there are some small turbo mufflers that would work better than a Glass pack ,,I have not been to thrush site in a loooog time,,..they may have some turbo mufflers shorter than 12 inch,or 12 inch long
I Have run many glasspacks.over the past 55 years .never got a ticket for pipes or muffler,& my ticket list is Loooooooonnng(mostly scooter stuff tho)

[This message has been edited by uhlanstan (edited 04-22-2011).]

The old school muscle car era glass packs were actually packed with steel wool. A trick we did to make them louder was stick a garden hose in the tail pipe and fill the muffler with water overnite. Next day it blew out the water and steelwool and you were good to go

Now what about performance? I have heard both loss and gain, so wich is it?

quote Originally posted by Mcfleev-O: Now what about performance? I have heard both loss and gain, so wich is it?

The car will be louder without the cat. and as for performance... eh.... it is a 2.5l.... you won't notice a change

(I have had two 2.5Ls with no cat.)

..I am sad to say the cherry bomb hurts performance ..I think the duke sounds like a gearhead sym phony when reaching thru the gears ,I love that sound as much as any sound a street car makes
in the 80,s & 90,s Dynomax (Walker) made a different type of glasspack ,you can ID these gless pack mufflers by the circular indentations that go around the muffler on the muffler body,, If you ever look under a salvage yard camaro and see one of these grab it ,, they equal the new turbos for power .Tony the tiger knows how they sound!
.. I love glasspacks on a duke ,,the only muffler that makes them sound good.
HOWEVER ,,MANY dyno test over the past 20 years has shown the glasspack to be WAY DOWN on the horse power scale ..
..it hurts performance to mount the muffler where the cat is ,, the muffler should be mounted where the stock muffler is for best performance
Forget the glasspacks unless you want the sound ,,it is difficult to get more horse power from the 84 to 86 4 cylinder duke,, the 87 & 88 are better, the 88 with the header style ex manifold is spirited to drive compared to the early models .
..Install a Dyno max,magaflow,flowmaster ,thrush turbo or similar muffler in place of the CAT & remove the stock restrictive muffler ,,THIS IS a lot of sawing, I do my removal and install with hand tools take your time and remove all welds so as to save extra length on the inlet and outlet tubes .
..I am in the process of mounting a dynomax with the purpose of instruction for younger gear heads to mount an exhaust system that produces 15 to 20 extra Horse power from the 2.8,3.1 & 3.4 V6 using commonly available hardware & auto parts store parts to mount ,,The muffler and mandrel bend pipe($15) being the only expensive parts,, I have been working on this the past week ,turned out not to be the double date with Scarlette Johanson & Madonna I imagine
..I will post this earlier than I planned ,,tonite or tommorow along with dyno results for different mufflers & measurements ,so wait a few hours

[This message has been edited by uhlanstan (edited 04-23-2011).]

quote Originally posted by uhlanstan: ..I am sad to say the cherry bomb hurts performance ..

I disagree. Flow tests consistently show similar sized glass pack mufflers outflowing popular chambered mufflers. A 2-1/2" 2 chambered Flowmaster will flow about 250 CFM and a 2-1/2" Cherrybomb glass pack flows about 295 CFM.

You have to look down the throat of a glasspack.
If it necks down in diameter,it will cut power.
Louvered units cut power compared to ones with drilled (or punched) hole in the inner wall.
Get the right one and there is minimal power loss. And minimal sound reduction.
Good for fine tuning the noise output.

Here we go...

quote Originally posted by Mcfleev-O: Here we go...

What?