I'm going to try to do some exhaust work this summer but I need to know the inlet/outlet sizes for the Fiero muffler.
I'm leaning considerably towards a Spintech Sportsman SplitCase 300SC muffler but Spintech's site lists multiple different sizes for the inlet/outlet pipes and I want to make sure I don't order the wrong muffler by accident.
..2 inch inlet ,2 inch exhaust always mount the muffler in the stock position mounting muffler in cat position loses horsepower & torque cut old muffler out as close to body as possible so the pipe is as long as possible file grind down welds. the pipe that goes into the muffler is the most important for length use pipe adapters from auto parts store & clamps you can drive to shop to have welded ,match mark pipe to muffler good the thickness of the muffler should not exceed 41/4.it is a tight fit. the width should not exceed 93/4 inch the length of the muffler body should not exceed 14,or a tad over 14 the muffler should have inlet & outlet 2 inch long at least to work with I prefer a single outlet for performance & MPG & ease of install I omit horns & use a down turn outlet the muffler should mount perfectly to pipe comming to rear,, the pipe will fit inside the muffler paint muffler clamps if used to prevent rust BEFORE you install you can use L brackets ,T,s & turnbuckles to mount muffler using the stock springs
..I recomend the dynomax turbomuffler #17730 for best price to horsepower for the V6. the #17730 is a tight fit It will fit ,it is about the biggest you can cram in there this is single outlet has nice sound not as loud as spintech Borla is best for horsepower there are as many favorites as there are mufflers all the Horse power camparison test are for ford & chevy V8,use lower RPM Ratings to get approximate V6 horse power rate the Dyno max turbo had good horse power ratings make sure you port exhaust manifolds ,,V6 fieros have severe manifold blockage which restricks horse power & holds back RPM, you run into a wall
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10:04 PM
Mar 28th, 2012
88RedFormula Member
Posts: 83 From: Cedar Rapids, Iowa Registered: Aug 2010
Yes, BTW, I don't like the standard C clamps. They crimp your pipe. I have used band clamps successfully but with those tight bends it is best to weld them.
Arn
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04:37 PM
NEVERDONE Member
Posts: 1088 From: ft worth, tx Registered: Sep 2011
always mount the muffler in the stock position mounting muffler in cat position loses horsepower & torque
i just got a new exhaust and i have a flowmanster 40 series mounted in place of the cat with 2 1/4" mandrel bent tubing from the downpipe back. if anything the motor feels stronger and more free reving. sounds great too.
NEVER ,Never mount your muffler where the cat was ,,this hurts power out put. this is basic 101 hot rod gearhead stuff.. maximum power on a single pipe Fiero would require a neck down in the area where the cat entrance was(im still guessing where) I love glass packs but they kill horse power.. the smoother your exhaust pipes the more power.. once you go over 130 horsepower you need a 2.5 pipe & 2.5 turbo muffler a good turbo muffler turns out more power than a straight pipe. low power engines like the 60o V6 need smooth bent pipes all the way to the muffler,I have the truelo header now "magneficique' ..I have found that with a good exhaust system,turbo muffler, ported stock exhaust manifolds the fiero V6 will rev freely & much to quickly to valve float.. you can gain up to 15 horsepower by carefully modifying the exhaust system, this is a whole pea potfull for a V6 ..My car finally gets the MPG I want with a 4 speed not spectacular,but 22 /23,up from 18 around town taking it easy,& great acceleration in 3rd & 4th.. Hwy MPG better but still sucks 28/30 MPG,,maybe 32 in the slow lane.. You want the biggest turbo muffler you can cram in the stock location. ..........................attention class Im ready for questions & slams
[This message has been edited by uhlanstan (edited 04-02-2012).]
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09:42 PM
Apr 3rd, 2012
Rickady88GT Member
Posts: 10649 From: Central CA Registered: Dec 2002
I'm going to try to do some exhaust work this summer but I need to know the inlet/outlet sizes for the Fiero muffler.
I'm leaning considerably towards a Spintech Sportsman SplitCase 300SC muffler but Spintech's site lists multiple different sizes for the inlet/outlet pipes and I want to make sure I don't order the wrong muffler by accident.
Just food for thaught, this is the system I did for my LS4: Nothing wrong with a spintech, but you can go outside the box a little.
quote
Originally posted by Rickady88GT:
I did some work to the car today. I ned to get the correct cat in for the smog ref, but the new cat for the 5.3 V8 is smaller than the S* cat? So I was a little woried that the sound could get louder and I needed to add a muffler of some kind.
(This is the short version of the mod, it was a little more complex than it sounds) I got a 12" glass pack and cut it in half, one for each side. I welded one end to the C6 tip and closed the open glass filled "gap" on the other end then added a 90* turn.
Also shows the smaller cat for the larger engine. This was a better install/fit than the larger cat.
quote
Originally posted by Rickady88GT:
Got some work done today.
This is a short vid to show (hear) the before and after. This one is with no exhaust at all after the collector.
You can see the entire exhaust system on the ground under the car.
quote
Originally posted by Rickady88GT:
Got the cat in. This vidio shows how much it calms down the LS4.
I got the system in. It sounds more "mellow" and a slight bit of "whistle" or hiss from the glass packs. They did take out most of the "raspy" sound that most muflerless systems have.
[This message has been edited by Rickady88GT (edited 04-03-2012).]
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02:56 AM
ace5514 Member
Posts: 692 From: west long branch, nj, usa Registered: Nov 2008
Just call and tell spintek what you want. They are great to work with, ship very fast, cheaper than getting from some fiero vendors. I have them on both 3800sc cars
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09:03 AM
PFF
System Bot
Apr 8th, 2012
I FAR I Member
Posts: 366 From: Ontario, Canada Registered: Jan 2012
NEVER ,Never mount your muffler where the cat was ,,this hurts power out put. this is basic 101 hot rod gearhead stuff.. maximum power on a single pipe Fiero would require a neck down in the area where the cat entrance was(im still guessing where) I love glass packs but they kill horse power.. the smoother your exhaust pipes the more power.. once you go over 130 horsepower you need a 2.5 pipe & 2.5 turbo muffler a good turbo muffler turns out more power than a straight pipe. low power engines like the 60o V6 need smooth bent pipes all the way to the muffler,I have the truelo header now "magneficique' ..I have found that with a good exhaust system,turbo muffler, ported stock exhaust manifolds the fiero V6 will rev freely & much to quickly to valve float.. you can gain up to 15 horsepower by carefully modifying the exhaust system, this is a whole pea potfull for a V6 ..My car finally gets the MPG I want with a 4 speed not spectacular,but 22 /23,up from 18 around town taking it easy,& great acceleration in 3rd & 4th.. Hwy MPG better but still sucks 28/30 MPG,,maybe 32 in the slow lane.. You want the biggest turbo muffler you can cram in the stock location. ..........................attention class Im ready for questions & slams
PM sent....
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01:20 PM
Wudman Member
Posts: 1593 From: Sacramento, CA Registered: Jan 2001
I have to recommend Spintech. I had a tricky application for my true duals and the guy worked with me.
I have custom 7"x12" Spintechs with 3 spirals in each side. The steel is heavy guage and the welds are good and solid.
These Spintechs will likely outlast the car.
Putting a muffler in the CAT position successfully depends on the muffler design. I had the Moroso and it gave much better performance than the Dynomax Turbo.
My current true duals though, are making significantly more torque and hp because they are specifically designed for the engine, not the engine bay layout.
Many,many dyno test by G.M. ford.chrysler & muffler manufacturers have shown the further back the muffler the more power it will produce .Chrysler has done the most exhaust research true glass packs hurt performance ,has to do with the small inlet holes required (i love glasspacks) I like spintec has a good sound the dyno max turbo is easy to mount & always shows top gains in muffler comparison test. I have truelo headers & dynomax Turbo even if you have a modified fiero V6, use the chart info at 4500 to 5500 rpm on comparo test
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11:31 PM
Apr 12th, 2012
88RedFormula Member
Posts: 83 From: Cedar Rapids, Iowa Registered: Aug 2010
Can those C6 tips be found anywhere anymore? I just ordered the muffler today and I've been eyeing these tips for a while.
88RedFormula, the tips of the exhaust you pictured above look almost like the nicer, shinier (stainless steel?) C6 exhaust tips I purchased from fellow PFF member, Oslo almost 2-1/2 years ago. He is a good guy so I suggest checking with him. More specifically, I've consistently found the various used parts I've purchased from in the past to have always been in excellent condition.
