# Glass packs? **URL:** \ **Category:** General Discussion\ **Tags:** chevrolet, camaro\ **Created:** [July 16, 2017, 9:18pm UTC](https://community.cartalk.com/t/glass-packs/105956 "2017-07-16T21:18:15Z")\ **Posts on this page:** 18\ **Page:** 2
**Author:** ![B.L.E](https://avatars.discourse-cdn.com/v4/letter/b/848f3c/32.png) [@B.L.E](https://community.cartalk.com/u/B.L.E)\ **Post date:** [July 18, 2017, 12:58am UTC](https://community.cartalk.com/t/glass-packs/105956/21 "2017-07-18T00:58:44Z")
> [@circuitsmith](#): > > Put simply: what comes out depends on what goes in. > A 4 cylinder or 6 will never sound like an 8. > The more cylinders the closer are the exhaust pulses. > This makes for less of the buzzy sounding fundamental pitch and more melodious harmonics. There’s more to it than that. Because of the 90 degree crank throws of a V-8, it is impossible to have evenly spaced exhaust pulses on the right or left bank, and because the right and left banks usually have their own exhaust pipes, you always hear one bank louder than another. Here’s the pulse sequence of a small block Chevy. Left bank… pulse, space, space, pulse, space, pulse, pulse, space Right bank: space, pulse, pulse, space, pulse, space, space, pulse Notice that the engine as a whole has an even and regular firing order and if you do put 8 equal length pipes on this engine coupled to a single collector, these engines indeed do scream like a flat crank Ferrari V-8. Yamaha has started putting cross plane cranks on some of its inline fours in their sport bikes. These engines have a firing interval similar to one bank of cylinders on a V-8 and they produce a “burble” type of sound much like a V-8. Why not flat cranks on V-8 engines. The second harmonic vibration is naturally cancelled with a 90 degree crank, but not on a flat crank meaning that flat crank V-8 engines buzz even worse than inline fours, often needing special engine mounts to absorb the engine vibration. ---
**Author:** ![sgtrock21](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/sgtrock21/32/246_2.png) [@sgtrock21](https://community.cartalk.com/u/sgtrock21)\ **Post date:** [July 18, 2017, 1:51am UTC](https://community.cartalk.com/t/glass-packs/105956/22 "2017-07-18T01:51:26Z")
Nothing to do with firing orders, cylinder bank degrees, or crank angles. My 1990 Mazda GTUs stock dual exhaust had a pleasing V8 like burble at idle. RPMs above idle it sounded like a Mazda rotary. ---
**Author:** ![sgtrock21](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/sgtrock21/32/246_2.png) [@sgtrock21](https://community.cartalk.com/u/sgtrock21)\ **Post date:** [July 18, 2017, 1:58am UTC](https://community.cartalk.com/t/glass-packs/105956/23 "2017-07-18T01:58:24Z")
A long time good friend and coworker had an expensive Borla exhaust installed on his Gen2 Mazda RX7. It sounded like a poor running weed eater. ---
**Author:** ![sgtrock21](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/sgtrock21/32/246_2.png) [@sgtrock21](https://community.cartalk.com/u/sgtrock21)\ **Post date:** [July 18, 2017, 2:03am UTC](https://community.cartalk.com/t/glass-packs/105956/24 "2017-07-18T02:03:20Z")
I have had several glass packs that sounded good and were not excessively loud. Of course they were all installed on American V8s. ---
**Author:** ![B.L.E](https://avatars.discourse-cdn.com/v4/letter/b/848f3c/32.png) [@B.L.E](https://community.cartalk.com/u/B.L.E)\ **Post date:** [July 18, 2017, 2:12am UTC](https://community.cartalk.com/t/glass-packs/105956/25 "2017-07-18T02:12:09Z")
Rotary engines have an idle burble for the same reason two-stroke engines do. Random misfiring due to a high degree of exhaust dilution of the incoming charge. My old 1972 Kawasaki two stroke triple had a “dragster” idle even though it had an even firing interval. Four stroke twins with 360 degree cranks sound completely different than four stroke twins with 180 degree cranks. 360 degree crank twins: Most old British twins- Triumph, BSA, Norton. BMW boxer twins, Honda 160, 175 and some versions of the 305. 180 degree crank twins: Honda 350, 450, many of the 305’s, recent Kawasaki twins, John Deere tractors. In this video of a really slow idling John Deere, you can hear the Pulse, Pulse, pause, pause, Pulse, Pulse, pause, pause firing sequence of a 180 degree crank twin. ---
**Author:** ![Renegade](https://avatars.discourse-cdn.com/v4/letter/r/b4bc9f/32.png) [@Renegade](https://community.cartalk.com/u/Renegade)\ **Post date:** [July 18, 2017, 2:25am UTC](https://community.cartalk.com/t/glass-packs/105956/26 "2017-07-18T02:25:24Z")
That is what we use to call poppen John’s. ---
**Author:** ![B.L.E](https://avatars.discourse-cdn.com/v4/letter/b/848f3c/32.png) [@B.L.E](https://community.cartalk.com/u/B.L.E)\ **Post date:** [July 18, 2017, 2:35am UTC](https://community.cartalk.com/t/glass-packs/105956/27 "2017-07-18T02:35:28Z")
At higher rpms, the double pop in quick succession melded into a single pop that had a different tone than the pop of a single cylinder engine. Sort of a “plop” instead of a “pop”. V-12 engines do not have that V-8 burble, since each bank is essentially an in line six with an in line six firing order. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [July 18, 2017, 2:03pm UTC](https://community.cartalk.com/t/glass-packs/105956/28 "2017-07-18T14:03:25Z")
> [@B.L.E](#): > > There’s more to it than that. Then it’s not “put simply” any more, is it? ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [July 18, 2017, 2:09pm UTC](https://community.cartalk.com/t/glass-packs/105956/29 "2017-07-18T14:09:17Z")
I have heard several inline 6’s with dual glasspacks attached to headers with the tubes evenly spaced in the firing order. All had mufflers mid-car with substantial tailpipes to drop the dB’s a bit. It makes an exceptionally sweet sound, IMHO. Kind of a “ripping cloth” sound as revs build. V12’s just double the frequency - 2 sixes married together. That’s why Ferrari likes V12’s so much, I’d guess. My 90 degree V6 odd-fire could never create that sound and, oh, how I tried! It actually sounded a bit like a Corvair flat 6. ---
**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\ **Post date:** [July 18, 2017, 2:35pm UTC](https://community.cartalk.com/t/glass-packs/105956/30 "2017-07-18T14:35:13Z")
I recall reading an article many years ago about the Miata. Mazda acoustical engineers worked hard to replicate the sound of MGBs. Manufacturers’ engineers work hard to create desired sounds, based upon the intended market segment. In some modern cars, they even pump artificial sound into the car’s audio system (blah!). Getting a good sound out of a car’s system (induction, engine, and exhaust) is an art of its own. ---
**Author:** ![Purebred](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/purebred/32/46796_2.png) [@Purebred](https://community.cartalk.com/u/Purebred)\ **Post date:** [July 22, 2017, 3:27pm UTC](https://community.cartalk.com/t/glass-packs/105956/31 "2017-07-22T15:27:10Z")
I did that with a Sport Fury with Walker glass packs. When I would floor it instead of hearing the rumble from the pipes I heard the whoosh from the intake. ---
**Author:** ![B.L.E](https://avatars.discourse-cdn.com/v4/letter/b/848f3c/32.png) [@B.L.E](https://community.cartalk.com/u/B.L.E)\ **Post date:** [July 22, 2017, 4:03pm UTC](https://community.cartalk.com/t/glass-packs/105956/32 "2017-07-22T16:03:19Z")
When I got rid of the stock air cleaner and airbox of my 1972 Kawasaki H1B three cylinder two stroke motorcycle, and went to three K&N filter pods on the three carburetors, it made a world of difference in the sound of the bike. Two stroke engines with piston timed intakes make an incredibly loud intake honk when you open the throttles. Everybody thought I had a loud exhaust, but it was coming from the intakes. ---
**Author:** ![sgtrock21](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/sgtrock21/32/246_2.png) [@sgtrock21](https://community.cartalk.com/u/sgtrock21)\ **Post date:** [July 22, 2017, 4:04pm UTC](https://community.cartalk.com/t/glass-packs/105956/33 "2017-07-22T16:04:08Z")
So you are saying your Plymouth really sucked? LOL ---
**Author:** ![Purebred](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/purebred/32/46796_2.png) [@Purebred](https://community.cartalk.com/u/Purebred)\ **Post date:** [July 22, 2017, 9:12pm UTC](https://community.cartalk.com/t/glass-packs/105956/34 "2017-07-22T21:12:41Z")
Yup air and premium gas ---
**Author:** ![Dakotaboy](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/dakotaboy/32/21842_2.png) [@Dakotaboy](https://community.cartalk.com/u/Dakotaboy)\ **Post date:** [July 23, 2017, 12:23am UTC](https://community.cartalk.com/t/glass-packs/105956/35 "2017-07-23T00:23:42Z")
Depends upon what kind of “old school” sound you’re looking for. Basically a V6 will never sound like a V8. The V6 in your car was a major departure from prior American V6 engines in that it is a double-overhead cam engine, which inherently revs higher than an old school overhead valve engine. I seem to recall your engine was rated at something like 305 HP (which is very good for a 220 CI engine); the latest version is rated at 335 HP @ 6,800 rpm. If you live in or near a major metropolitan area, I would suggest you try to contact a local Camaro club; that would be your best source of information. ---
**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\ **Post date:** [July 23, 2017, 2:10am UTC](https://community.cartalk.com/t/glass-packs/105956/36 "2017-07-23T02:10:51Z")
> [@Dakotaboy](#): > > Depends upon what kind of “old school” sound you’re looking for. LOL, you brought up a good point; “old school” to someone born in 1980 is very different from “old school” for those of us that were postwar babies born just after WWII. 😜 ---
**Author:** ![Tomtotaro](https://avatars.discourse-cdn.com/v4/letter/t/f17d59/32.png) [@Tomtotaro](https://community.cartalk.com/u/Tomtotaro)\ **Post date:** [July 23, 2017, 2:29pm UTC](https://community.cartalk.com/t/glass-packs/105956/37 "2017-07-23T14:29:00Z")
Old-school meaning trying to get that loud rumble of the 60s and 70s muscle cars ---
**Author:** ![susan\_burk](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/susan_burk/32/11909_2.png) [@susan\_burk](https://community.cartalk.com/u/susan_burk)\ **Post date:** [May 7, 2018, 11:48pm UTC](https://community.cartalk.com/t/glass-packs/105956/38 "2018-05-07T23:48:08Z")
borla came out with a new exhaust sounds great on YouTube if it really sounds like that but only for 2016 and up. unfortunately i own a 2015 rs. [Previous page](https://community.cartalk.com/t/glass-packs/105956.md?page=1)