Hello, I am wondering which muffler is a better option for my '86 GT. I am running the stock exhaust system with the CAT removed and a straight pipe in its place.

The first muffler is a single in, dual out magnaflow 2" in and 2" outs.
http://www.magnaflow.com/02...asp?partnumber=12128

The second is a magnaflow race muffler.
http://www.magnaflow.com/02...sp?zone=main&id=9408

I already found the necessary adapters to fit the race muffler and it would cost about the same as the single in/dual out one. Would the race one give a better sound or more power, or would it decrease the back pressure too much for the Fiero?

Any help would be much appreciated

..almost any of the turbo mufflers or new performance mufflers will help performance.
..when you cut the old muffler offsave as much of the pipe as possible to ease mounting..always mount the new muffler in the stock position,,mounting the muffler where the cat was hurts performance .
On any car you mount the muffler as far back as possible,, this is aproven prerfomance tip .
.. you want the smoothest flow thru the pipes back to the muffler,, the biggest bestest gains for the fiero 60o V6 come form porting and a free flow exhaust . the best modification a fiero is to have a 2 seal piston in the slave,the bestest mofification for the V 6 is to port the stock exhaust or install Headers.
I am going to list some muffler comparo test , there are no test for the fiero so I list small block ford & chevy V 8 ,you use the lower rpm horse power & torque that compare to what the 2.8 is capable of .
Titantalk.comflowchartforafewmufflers
GOOGLE BELOW TEST
hot rod magazine muffler test
CARCRAFT MAGZINE MUFFLER TEST
THE BEST MUFFLER FOR THE DUKE & V6 or slighly modified V6 is the dyno max super turbo #17730 great price from Sumit racing
there are many favorites on this forum including the Magnaflow,, the regular magna flow will produce the same power as the racing.
you must port the 2.8 exhaust manifolds to recieve any real gain, they have serious blockage.
I will get better site transfer for Titan talk, a great article on performance mufflers

[This message has been edited by uhlanstan (edited 10-13-2011).]

Define best.

Different people have different ideas about what is best, depending on their needs.

I like the West Coast Fieros modified Flowmaster. It is a direct replacement and sounds great. Louder than stock and loud enough to sound really good but not disturb the entire neighborhood . . . unless I want to. It will still set off car alarms with a hot run down the street (or parking garage) in first gear. It's a stock V-6 with a new cat so it is legal. But, if you drive it easily it's not bad at all.

Here's a video I made that will give you an idea.

http://youtu.be/jQOuETUluLk
------------------
Jim Martin
White '86 GT
Monterey, California

[This message has been edited by Jim_Martin29 (edited 10-13-2011).]

Best is the Borla ,most excellent for Fiero V6
I try to choose what is best for the average fiero owner in price, sound, & performance ,, there are many choices and many disagree with me..I have consulted with dyno max on the best muffler for Fiero,, arn did not like the dyno max he got better performance from another.
My information is for the average fiero owner
for fiero with V6 & buick V6 over 125 hp use Dyno max #17733 with 2.5 in & out.. these are single outlet
a stock Fiero has 108 to 112 hp
the glass pack hurts performance,,never run a glasspack unless you do not care about performance .
a good turbo muffler will out perfrom a straight pipe
for ease of install usethrush turbo

basically what I'm asking is which muffler will give me the best tone and performance that isn't obnoxious. I'm trying to mount it in the stock place without cutting out my trunk.

quote Originally posted by uhlanstan: Best is the Borla ,most excellent for Fiero V6 I try to choose what is best for the average fiero owner in price, sound, & performance ,, there are many choices and many disagree with me..I have consulted with dyno max on the best muffler for Fiero,, arn did not like the dyno max he got better performance from another. My information is for the average fiero owner for fiero with V6 & buick V6 over 125 hp use Dyno max #17733 with 2.5 in & out.. these are single outlet a stock Fiero has 108 to 112 hp the glass pack hurts performance,,never run a glasspack unless you do not care about performance . a good turbo muffler will out perform a straight pipe for ease of install use thrush turbo

Just for reference, the MagnaFlow, Borla and Dynomax are glasspacks, (Dynomax has a spring operated internal valve). Flowmasters and Spintech are acoustic. Flowmaster is a phase reversal type and Spintech uses internal vortices to convert the sound to heat and then dissipates the heat.

Studies have shown that glass packs actually create more back pressure than acoustic types that use phase reversal or some similar technology.

Hell yeah... I can hear it now.. I'd even put two of them together; they're small enough.. Just need enough collar to get a mig in there..... This clip, the description said not cat, 95 bronco, 3"




Here's a cut out from a seminar style show.. Different name though but I would think the same practically.

[This message has been edited by unboundmo (edited 10-14-2011).]

The best one is the one that requires the less bends to make it functional.

Let me know if Borla is still around.. Last I heard that muffler was discontinued a long time ago.

I would look into Spintech... sounds great, I think.



Oh.. Look into the direction of that first muffler you pointed out. It says that you can mount it to flow either direction but it's only one way in on one side and one way out the other side... instead of --- one way in on one side and out dual on opposite sides.. It would be hard to mount the rest of the exhaust tubing for duals out the back with tips.

I prefer 'bullet' style glasspacks or baffle tips to any mufflers.

I ordered last year a maganflow part# 12128 the one you have in mind and I had to send it back.
where on the inlet side of that muffler is on the same side of one of the outlets (please bear with me) because of the y configuration it means the flow would go in and through the muffler and straight out of the single outlet at the opposite side and not share both outlets.

thats where i went wrong as when I first look at that magnaflow muffler I thought great an almost stock perfomance muffler.

I ended up ordering a spintech muffler and have not regretted it.

jon