Dual Glass packs in seriies ou opinion

[Mont91]

If you do a flow test on a glass pack versus a straight pipe you will see that the glass pack causes a fair amount of back pressure because of the turbulence it creates, and if you were to cut that cherry bomb open there most likely would not be any packing left. Is a glass pack better than some mufflers? Yes. Is it better than a good muffler? No. Any muffler that has a zero back pressure rating would be better than a pack or the stock muffler, then the choice is do you want noise or not. I currently have a 3" with pack, the pack came with the used 3", and unless you are accelerating at high rpm, you can not hear it.

 

[69oiler]

here is how mine sounds with a single 24" Thrush glasspack. i can't say if performance is worse with a GP but i will say my engine has run as good as it ever has with a GP. i have had 2 1/2 and 3" systems with and without mufflers with no real difference in performance between any of them on my NA 6.9. i have to have the windows down to hear it and even then it's not bad. it sounds good echoing off guardrails and walls IMO.

You must be registered for see images attach

 

[big van]

I ran a 3" Flowmaster I had laying around just for fun before the Magnaflow & I'll have to say the Magnaflow is way better and Flowmaster is overrated. I never really liked it on the other truck it was on. You pay more for the name.

 

[f-two-fiddy]

If you do a flow test on a glass pack versus a straight pipe you will see that the glass pack causes a fair amount of back pressure because of the turbulence it creates, and if you were to cut that cherry bomb open there most likely would not be any packing left. Is a glass pack better than some mufflers? Yes. Is it better than a good muffler? No. Any muffler that has a zero back pressure rating would be better than a pack or the stock muffler, then the choice is do you want noise or not. I currently have a 3" with pack, the pack came with the used 3", and unless you are accelerating at high rpm, you can not hear it.

I don't know where your getting your info. After 40K miles, it looks JUST LIKE THE DAY I PUT IT ON. A little blacker inside.

There's no way a GP ads enough back pressure to effect performance. And it sounded great! Better than the Auto Jet I'm running now. I'd buy another one, but they don't make the Original Cherry Bomb in 3.5"

 

[tractorman86]

i've got a cherrybomb gp 2 1/2 on my truck just replacing the factory muffler, i think it sounds great and it is very affordable, like 35 bucks at checker. Although i like noisey stuff (i can set off car alarms without trying )! If you place it far enough back, in the factory posision, like i did u wont have much interior resonance but mine burnt the paint off half way back within the first week! Infact my truck was quieter in the cab after i did the swap, i am guessing the motor isnt working so hard (less engine noise) to push the spent gasses through the muffler. wgargan i highly recomend the cherrybomb gp!! just to throw my $.02 in

 

[Compu Doc]

at $192.00, they priced themselves out of the market. you can get a real truck straight through muffler for at least $20 less. My hillbilly truck has a car flowmaster welded in. Unfortunately, there's no way you can yell at the person sitting shotgun and expect them to hear you.

Thats why I love the Gibson muffler I have. I can hear and talk to the person next to me riding shotgun. I can even talk through my bluetooth GPS while driving.


As their website says the sound is at the end of the tailpipe and not in the cab as it should be.

 

[Mont91]

My information comes from many flow tests in performance magazines comparing mufflers, pipe size, pipe routing, the use of crossovers, the use of variable size headers, length of headers, overall pipe length and such.

GPs always increase back pressure over no muffler and properly designed mufflers because of the turbulence they create. I have looked in hundreds of GPs at muffler shops and wrecking yards and vary rarely have they not been empty inside. several times I have seen parts of the perforated tube hung in the final bend of a tail pipe. They should last longer in a diesel application because of the lack of condensation.

The pre muffler piping on an IDI is hardly free flowing so the GP will not make as much difference as it would on a well designed system. The 3" GP system now on my '91 came off of my '88. On the '88 it made a noticeable difference when installed, but no noticeable difference on my '91. Of course the '91 came stock with 3" to the muffler then 2.5". The '88 had 2.5" all the way. The only time I can really hear the GP is when there is a guard rail or rice grinder beside me, then I blast those little buzzy things right in the drivers window.

 

[dsblack]

I liked the sound the GP made on my old 6.9 turbo truck. Thinking about going back to it.

 

[wgargan]

o.k, thanks for all these replies guys (gals?)

but lets help me out a little more. I have sen a bazillian different types of glass packs out there. the type I am interested in are the Straight through types.

Mont91, are these the types you say create allot of turbulence and thus resistance?

What effect does length have on the sound? I have seen as short as twelve inches and as long as 28".

I currently have a muffler where I can hear NO engine noise, it just sounds like air blowing out. I think it is killing my top end power.

 

[86 1 tonhauler]

i have a straaight pipe with a 5" tip coming out just behind the dual tire and u can hear it unless the window are down and im on it hard then it get a glass pack type sound with out the glass pack, screw the glass pack and just run a straight pipe , the engines are so noisy anyway there almost louder than the exaust just my .02