Thinking about a glasspack...

[ZippyBasher]

+? I gotta love my dual cat-back FLOWMASTER '08 Pony

[pedeboi364]

lol, thats pretty funny. i have a dual flowmaster catback exhaust on my '77 trans am, and it makes my 454 sound deadly. im thinking about a BMW M6 exhaust on my moms TL too...

[trev3813]

What? We put a magnaflow on a 96 Subaru Impreza Brighton, 4 banger, should do wonders on my 318 8 cyl.

[jhautz]

Man this thread brings me back. lol

back in my day we would put in bypass valves in the exaust right after the header. It was basically a pipe with a y on it. the header flowed into the main end, and one side of the Y went into the normal exaust system, and the other ran to short straight pipes that basically just lead to the front wheel well to get the exaust out from under the hood. When you wanted power you pulled the cable operated lever inside the car and the flaps opened up the straight pipes and the thing roared with no exaust restriction at all. Then you pushed the switch inside the car closed and the flaps closed and the car went back to normal sounding.

Great for street racing. Reaaly loud when open though. I did it on an old Chevy 350 in my '79 z28 and an oldsmobile 455 in my '74 cutlass. Freaking deafaning when you got on the culass with basically open headers.

Damn I miss that stuff... Now I'm just happy when my car gets me to work with no trouble.

[Tempted]

Originally Posted by jhautz

Man this thread brings me back. lol

back in my day we would put in bypass valves in the exaust right after the header. It was basically a pipe with a y on it. the header flowed into the main end, and one side of the Y went into the normal exaust system, and the other ran to short straight pipes that basically just lead to the front wheel well to get the exaust out from under the hood. When you wanted power you pulled the cable operated lever inside the car and the flaps opened up the straight pipes and the thing roared with no exaust restriction at all. Then you pushed the switch inside the car closed and the flaps closed and the car went back to normal sounding.

Great for street racing. Reaaly loud when open though. I did it on an old Chevy 350 in my '79 z28 and an oldsmobile 455 in my '74 cutlass. Freaking deafaning when you got on the culass with basically open headers.

Damn I miss that stuff... Now I'm just happy when my car gets me to work with no trouble.

Those are called "cut-outs" and are utterly pointless on any V style motor without forced induction. A V style engine is designed to scavenge the exhaust puffs from each cylinder and syncronize the two banks for a more efficient, smoother running engine that makes more power. A true performance exhaust system has both banks combining behind the headers by and X pipe for the scavenging effect. You can put cut-outs after the X pipe to decrease the back pressure a bit but you really gain no horsepower. You lose horsepower and efficiency by putting cut-outs on a V style engine before the X pipe. It causes a rough idle and an incurable inbalance in the engine. A forced induction vehicle does not require scavenging as it already has pressure in the intake and has a ton of back pressure in the turbo. Also, most cams designed for forced induction motors do not rely on scavenging and are built with a more aggressive low end powerband.

[jhautz]

Originally Posted by Tempted

Those are called "cut-outs" and are utterly pointless on any V style motor without forced induction. A V style engine is designed to scavenge the exhaust puffs from each cylinder and syncronize the two banks for a more efficient, smoother running engine that makes more power. A true performance exhaust system has both banks combining behind the headers by and X pipe for the scavenging effect. You can put cut-outs after the X pipe to decrease the back pressure a bit but you really gain no horsepower. You lose horsepower and efficiency by putting cut-outs on a V style engine before the X pipe. It causes a rough idle and an incurable inbalance in the engine. A forced induction vehicle does not require scavenging as it already has pressure in the intake and has a ton of back pressure in the turbo. Also, most cams designed for forced induction motors do not rely on scavenging and are built with a more aggressive low end powerband.

OK. Not gonna argue it was good. Just loud and fun. lol What the hell did I know I was 17. :)

[Tempted]

Haha, I know. I see it all the time. Kids go out, cut the exhaust off and stick straight pipes on and say they gained a hundred horsepower. Its the whole "louder must be faster" concept they have. Its fun to kill the ricers next to you at the light with an open header V8 at 5k RPMs. My cut-outs are electric so I just touch a switch on the center console to open it up. The cable cut-outs are more reliable, just more of a pain.

[jhautz]

And the cable ones were the only thing I think they had back then. Probably cheaper too which would have been another important reason I would have chosen them.

I remember showing my dad those things after my buddy and I installed them. Lets just say he was pissed. lol

Another thing I remember is they didnt close that well after a little while so it always had that "it needs a new muffler" sound to it.

[JThiessen]

Thanks Tempted - I was going to say something about that also. Antoher misconception is that a bigger exhaust is going to give you more power. IC motors rely on a certain amount of backpressure to give torque. So for all those that go ripping out the kitty's, do so with the knowledge that someone a heck of a lot smarter than you did many hours of research putting that exhaust system in place. Yes, in some cases they sacrificed some power for efficiency and regulatory requirements, but overall, they are sized about right.

[Metallover]

Well I just picked up a Thrush glasspack for $23.30. It's 28" and the stock is 24". I'll have to take it in to have it installed. Hope it costs under $50. At least it has the right diameter ends...

How much do you guys think it'll cost me?

Why not take a swzall and cut the old muffler off and put the new one on yourself and save you the money? Nothing hard to it at all.

[Metallover]

Originally Posted by Foxracin

Why not take a swzall and cut the old muffler off and put the new one on yourself and save you the money? Nothing hard to it at all.

I guess I could do that but I'd have to find someone that can weld...

Originally Posted by Metallover

I guess I could do that but I'd have to find someone that can weld...

Just get 2 exhaust clamps. They will work just fine and require no welding.

[Unsullied_Spy]

IMO glasspacks are loud and obnoxious but if you've got it already go ahead and put it in. If you don't like it you can always get something else. I personally don't like Flowmasters, they all seem to have the same bland sound and everybody uses them. My brother has them on his '66 Mustang with a 347 stroker and the mufflers don't do that engine any justice.

[Metallover]

How much louder are glasspacks then stock? My dad asked me if it was going to be loud and I said I didn't know..... He said it's loud enough already...