[455_regal]

I have a set of kinda cheap, dynamax mufflers, 2.5" they look like ballons, all puffed out , are these just cheeap mufflers or do I have to much back pressure? they only have about 200 miles on them.

[screamingchief]

Usually a good backfire or two causes that in my experience.

Even the welded case type mufflers like flowmasters can suffer damage from such an event,but those usually just knock the internal baffles loose causing rattles/buzzing vs. the "balloon" syndrome.

Rare is the muffler that survives that kind of occurance if it happens enough.

Soooo,had any good backfires lately???

[455_regal]

funny you said that, I did have a time when I first got the car out, was getting on it and it lost spark, then fired while I was on the gas still..I didnt have a hood on so It sounded like it came from up front,

[screamingchief]

Yep,once can be all it takes.

Of note:
I had a friend from back in my high school days who had a pretty tough '71 torino cobra,small block 4 speed car,but dont let that small block bit fool you,if anybody here is familiar with this era ford I'm sure they'll agree that those boss 351's were no simple "small block"...

Anyhow,suffice it to say here this car was stout,hot 351 boss (bumped compression,ported heads,big solid cam,holley dp,big tube headers yadda,yadda,yadda)
toploader 4spd,4.33 locker equipped 9",and visually quite striking too,shaker,blacked out hood/deck,louvers,wing,magnum 500's,man that thing was nice!

Well he was a bit of a "gadget geek",and had the bright idea to wire up the dual point distributor so he could switch between single and dual points to give it a bit of a "pick-up" performance wise...

So he tries his new toy once or twice and all is fine,does as expected,well,one night he's out running around and gets on it hard and switches it to dual points,but it goes silent for a second or two,and he decides to try switching it back...

KAAABBBOOOMMMM,there goes two perfectly fine turbo mufflers!

Blew the snot out of both of 'em,split them down the middle seam,and also nearly blew the whole backside outta them,quite impressive destruction,almost nearly as sweet as what that thing could do to motor mounts,but that's another story altogether.

Moral of this story is obvious...

Was a nice car really,but in the end it went downhill IMO,got too into the "stereo" thing and then it wound up getting a big block in it,along with a color change,all big mistakes from my viewpoint,but I digress.

[zippy]

I once had a S-10. Did head gaskets on it. Upon re-assembly, Seem's no one told me #1 cyl on a 2.8 is on the pass side LOL. ANyways, had them wired 123456, but 1 Drivers side as 1. cranked, and cranked. Ohh, coil wire off. Hit the key again while leaning in htrough the window and BOOM. sounded just like a shotgun blast. I looked at the heads, to see if they were on, looked at my chest to check for blood. Even the neighbours came running out hearing the boom. The turbo style muffler was completely anihalated.

[RS 455]

I once had a 1974 Grand Prix 400/400. It had a short in the distributor wire where it went through that little rubber grommet in the base and every once in a while it would ground briefly and then come back. Before I found the problem, I went through two sets of mufflers. I remember getting the first set for free after arguing with the counter guy at the auto supply that they were defective.

[bjohnson]

I had turned on the hwy and started accellarating aggresivley went through the gears and lifted and the throttle stuck near WOT and I paniced becuase it was on icy roads, turn the switch off and pushed the clutch in, and then the steering was locked and I paniced again turn the switch to on and I let the clutch out and BOOOOOOOM!!! Not only did I blow the back of the mufflers out, it broke three pistons.. I think I was 19 then, 1982. Learned a big lesson. $$$$$ I have never driven any of my GTO's in winter again.