According to Mr Jusnes, the MagnaFlow muffler adds more power than a FlowMaster due to the difference in back pressure...

So...does anyone run a glasspack(s)? Since they are also a straight thru muffler, wouldn't they do the same thing as a MagnaFlow for a lot less money?

Also, there is a restriction at the merge...two 2-1/2 pipes into one 2-1/2" pipe. Cat backs make the change to 3" after the merge. I know that FlowMaster makes a true 2-1/2 into a 3" merge collector. Has anyone tried this?

 

Out of MagnaFlow and Flowmaster, I'd rather the magnaflow for the sound and design.

I'm about to do some exhaust work of my dad's 04, and I will be using a (12" or 18") glasspack and then a Y pipe after it into 2 pipes.

If you want to put a cat back, for better flow I'd think the 3" pipe would be better after the 2 2.5" pipes come together, but I've heard people didn't like this set up..... No personal experiance with cat backs though.

 

A glasspack will probably perform as well as a magnaflow, but sound like complete crap, haha.

Youre right though about the merge, even the cat back bolt on systems come after that merge, because anywhere before that wouldnt be a "true bolt on" system. If you want to do custom, do yourself the favor and cut it before the Y and run it true duals, just make sure you have a crossover somewhere in the system to balance the pressure. This is why I always recommend the Magnaflow DIDO mufflers, since they have the crossover core built right in.

On these trucks, a good rule of thumb for piping is single 3 inch, or dual 2.25 or 2.5

 

I grew up in the glasspack era...it oughta sound sweet...!!!

I figure that since I already have a FlowMaster 3" catback, by switching out the muffler with a same length glasspack and adding the FlowMaster merge collector, I should see some improvement. The merge is about 40 bucks, and a glasspack is pretty cheap, as well.

It oughta be louder...that may be the downside...!!!

 

Hmm, i may be able to get you a merge for cheaper than that. Let me check. You said you were looking at a flowmaster merge? got a part number?

 

I'd rather a glass pack over a flowmaster anyday.
Heck, I like glass packs and straight pipes more than magnaflow or any others too. I'm a bit younger, so I still like it loud now, latter who knows.

 

I could get you the magnaflow stainless one for about $35 shipped

 

Hey, I wont bash on glasspacks too much, I did have them on my Torino I just sold. And Im still young myself Ive just decided to have a truck with about as much bite as bark nowadays, and use magnaflow on everything.

 

Just to set this thread back on the right foot.... backpressure isnt the cause of power issues directly. It is exhaust velocity, which has an integral connection with backpressure. Anyways, Ive never been fond of Flowmasters due to their baffled design. This does not allow for straight through flow. The Bassani (and I assume others), use much more efficient designs that allow for much higher flow rates. To compare to other manufacturers, Bassani use a straight through design, with perforated tube for the exhaust gases to muffle at low rpms, but act similarly to a straight pipe at higher RPMS by forcing the air through/over. YMMV.

 

Exactly right. Thats something I have brough up in other threads, why I dont like chambered mufflers, like the Flowmaster and IMCO. They sound good, but some people report a LOSS of power using them.

Bassani is a great straight through design, and other manufacturers have similar designs, including Magnaflow and Borla. For these trucks at least, the straight through design of these mufflers is the best way to go for performance.

 

FLO-Y250300 is the part #...(Summit) they call it a scavenger series "Y" collector. This particular one is a 2-1/2" primary tube(s) to a 3" collector...161/2" long aluminized steel weld on.

 

Yeah, I cant beat that flowmaster price. Good deal on the Magnaflow one I posted above, though. Esp for Stainless metal.