Running true duals with no mufflers, I may be in "trouble" come inspection time, so I'd like your opinions on glasspacks. I want "turn-downs" so maybe I should have the glasspacks added at the very end, just before the axle, and angled slightly downward? Does the same rule apply to glasspacks as it does for other mufflers that you need at least 8" of pipe after the muffler to allow the gas to escape due to atmosphereic pressure? Do glasspacks rust out easily? Do they kill that much sound or would it be possible to some how "gut" the glasspack? I've heard of getting them hot, then running cold water over them to "break" them up, but what's inside to be broken up? Would this work on CATS? I hate the idea of having mufflers, so is their any other alternative to keep me from getting "busted"? Maybe they wouldn't even look, or I could possibly tell them that I had resonated pipe installed? TIA!!!

-AR

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2001 F-150 XLT 4x4 Off-Road, SuperCab, Flareside, Black[*] 4.6L Triton V8 HPI[*] 5 Speed / 3:55 Reg. Axle[*] Keyless[*] Premium Audio CD

Mods:[*] K&N Intake (Chopped Airbox)[*] Removed Elbow Silencer[*] 3" Cat-Back (No Muffler, Turn-Down)[*] Cranked Torsion Bars[*] APC XENON PLASMA Super Whites[*] '01 "L" Taillights[*] Bugshield[*] Bedliner[*] Ventshades[*] Taillight Covers (Slotted)[*] Removed Mudflaps[*] "Light Argent" 4x4 Off-Road Decals

Audio:[*] Clarion 6675[*] Rockford Fosgate 5x7's[*] Rockford Fosgate G360A2 Punch Amp[*] JL 12W3-D2 (Ported)[*]Viper 500 Alarm

Build Date: 8/23/00 (Kansas City Plant)

arobbins@mail.liberty.k12.mo.us

 

The glasspacks have fiberglass packing between the outer shell and a perforated inner core. It's hard to diminish the effectiveness of the fiberglass, you do better just using short ones. The same rules of law that mufflers have apply to the glasspacks. They do muffle sound and because of the shell thickness they can have a long life against rust for a steel product. Here are 2 ideas: 1) a Dynomax Race Muffler (4" bullet, 5" or 6" round), straight through design, small case with little packing, better sound than glasspacks, loud (of course not by your standards ). 2) Buy a oversized straight through muffler and run a smaller straight pipe right through it.

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2000 F-150 XL, RC, LB, 5.4L, 4R70W, 4.10LS,
Class III tow, Payload #3, & Convenience pkgs.,
4-wheel disc/ABS, Chestnut/Parchment 40/60,
Ford bedliner w/Paintsaver & gas/wheel/spare locks,
K&N F.I.P.K. w/Outwears pre-filter, Superchip,
Dynomax ultra-flow welded 3" cat-back w/ 3" Y-pipe,
Hellwig front & rear anti-sway bars, Rancho RS 9000s,
Pirelli Scorpion Zero 275/60/16s, Mobil 1, K&N oil filter.

 

IMO glasspacks do not hold back that much sound compared to straights on a 4 cat setup. I do know that a cheapie will only last about 2-3 years and then they seem to rust out. That could be because on my last truck I never washed or took care of them. As for the cats I do not believe the cold water trick would work. Different materials inside and water usually splashes up on them anyways. Hope you figure out what will work for you.

 

Thanks guys...

-AR