Hey guys, I am pre-planning the exhaust and I need to know if it's possible to setup the exhaust on a fiero with a 3800 without cutting the trunk that is not unbearably loud. I have clearance from the local exhaust shop to get the exhaust installed minus a cat. Can I install an exhaust system that doesn't make my ears bleed at cruising speeds without cutting the trunk, and if so what type of setup would you recommend?

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It seems that Darth Fiero has convinced me into a single in dual out muffler as opposed to a dual-glasspack setup. Has anyone else had good experiences with holley's flow-tech terminator mufflers? I'm specifically looking at a single 3" in, dual 2.5" out.

I am using a Flowmaster 2.5 in dual 2.5 out....Its a little loud, but not so bad it drives me crazy !

Would that be an 80 series, and did you have to modify it?

Yes, 80 series. Nope didnt modify the muffler, just enlaged the area it fits into on the cradle. Not much to make it fit.

Magnaflow part # 12158 is a single 2.5" in dual 2.5" out replacement muffler for the Camaro that is 4 inches shorter so it fits nicely.
It is a little loud but nothing that will get you pulled over and will fir with the trunk left fully intact. Dan

The Magnaflow looks like the exhaust enters on the single side and exits from both ports on the other side. How do you plumb that? Dont you need the "in" on the side with the duals?

quote Originally posted by FIEROFLYER: Magnaflow part # 12158 is a single 2.5" in dual 2.5" out replacement muffler for the Camaro that is 4 inches shorter so it fits nicely. It is a little loud but nothing that will get you pulled over and will fir with the trunk left fully intact. Dan

This has been my muffler of choice, but I cut the trunk each time.

Very good highway manners, but quite loud when you are hammering on it.

I too am looking for a good 3800 muffler. I mainly want something that has little drone on the highway with my getrag.

http://www.summitracing.com/parts/BIG-50363FLT/

Same size as stock but bigger inlet and outlets

ride, is that the muffler that you're using?

Yessir, have numerous times

Sounds good, no drone, can be a little loud when you get on it, but it's definitely not bad

When I mash the throttle I hope it will be loud, sounds like the muffler I've been looking for at a great price! Thumbs up to you

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Darth did my exhaust using the flow tech muffler. Did alot better than most pro exhaust shops and used all mandrel bent pipe 3".This is with a 3.4, FOCOA headers 2.25" cross over into a 3"y and a glasspack where the cat use to be and Hooker dual resonator tips. I wouldn't want it any louder.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

Gonna keep this thread in mind.. I'll need this advice eventually!

spintek muffler all the way.

quote Originally posted by RideZiLightning: http://www.summitracing.com/parts/BIG-50363FLT/ Same size as stock but bigger inlet and outlets

This is what my 3800SC swap uses . Flotech Afterburner 3" in and dual 2 1/2" outs. Flows well but is just a bit loud. Can be made a bit more mellow with a pair of Heddman Hot Tips Dual resonators. Best benefit is that this muffler fits without any cutting or modifcations to the trunk

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

how was the back side header pipe fabbed to not hafta worry about cutting up the trunk?

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First LX9 Fiero GT, 1987 | My Fiero Fuel Economy | MPG Display for OBD I
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If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
screw paying those bastards. im not going to become rich by paying for things.....

WCF headers & Exhaust with Spintech:










Trunk is intact!

Regards,

David

In response to Jame's comment about noise, the muffler is a specially made Spintec that is a bit larger and quieter and we added Cherry Bombs just before the exhaust tips because the tips have a megaphone effect



Regards,

David

[This message has been edited by MountainHiBlue87GT (edited 06-29-2010).]

quote Originally posted by MountainHiBlue87GT: In response to Jame's comment about noise, the muffler is a specially made Spintec that is a bit larger and quieter and we added Cherry Bombs just before the exhaust tips because the tips have a megaphone effect Regards, David

I would love to hear a clip of this exhaust. Is it quiet? I'm looking for exhaust that's not much louder than the stock 2.8.

Tommy

quote Originally posted by Dennis LaGrua: This is what my 3800SC swap uses . Flotech Afterburner 3" in and dual 2 1/2" outs. Flows well but is just a bit loud. Can be made a bit more mellow with a pair of Heddman Hot Tips Dual resonators. Best benefit is that this muffler fits without any cutting or modifcations to the trunk

Have it on my Indy. Go without resonator tips if you want "really loud".

Flowtech Afterburner muffler PN 50363FLT
Hooker resonator tips PN 21430HKR




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I just ordered the Flowmaster 80 series. I plan to come out of the manifold, 90 to the driver's side, 180 down to the inlet.
Outlets will remain at the top and will exit through factory tips.
It probably won't sound like a sleeper, but it will look like it anyway...

I'll take pictures as I go and let you know how it turns out.

This is what I ended up with at a local muffler shop. 2.5" mandrel bent stainless.

[This message has been edited by JamesCurtis (edited 07-26-2010).]

quote Originally posted by JamesCurtis: This is what I ended up with at a local muffler shop. 2.5" mandrel bent stainless.

Thats gotta be loud?

quote Originally posted by JamesCurtis: It seems that Darth Fiero has convinced me into a single in dual out muffler as opposed to a dual-glasspack setup. Has anyone else had good experiences with holley's flow-tech terminator mufflers? I'm specifically looking at a single 3" in, dual 2.5" out.

Concerning DRONE...

I just completed a swap using this Terminator muffler and WCF headers and factory megaphone tips (no cat, resonators, or cherry bombs). The owner of the car was concerned with the amount of interior drone noise produced by the exhaust at highway speeds - as was I since this seems to be an ongoing issue with 3800 Fiero swaps when performance mufflers are used.

I tried something new with this latest swap I just completed. In the past when using factory manifolds, I ran 3" pipe from the manifold to the muffler using some 3" mandrel bends and a flex joint. Then I used 2.5" and mandrel bends out to the tips. In swaps where WCF headers were used, 2.5" tubing was used from the headers' y-pipe to the muffler since that is the max size of the y-pipe collector anyway. Still used 2.5" tubing from the muffler out to the dual tips. Always got lots of drone noise with either of these setups when using any performance muffler other than the Magnaflow 12267 (which does require a small amount of trunk cutting/modifying to fit).

The solution to the problem seems to be using smaller size pipe from the muffler to the tips. In this latest swap, I used only 2.0" dia tubing w/ mandrel bends out to the factory tips. There does not seem to be a lot of interior drone noise with this setup, certainly much less than compared to what I have heard before using the larger pipe from the muffler to the tips using any muffler other than the Magnaflow 12267. But I can tell you the amount of noise that exits the rear of the car seems to have increased. At least maybe that's my impression since less drone noise is now being transmitted to the interior of the car. This build has very light mods (pulley, induction, and exhaust - engine is otherwise stock), so I'm not overly concerned with the small outlet piping being too restrictive. On a heavier-modified swap I might be concerned about it.

So far the Magnaflow 12267 is the quietest muffler I have ever tried on a Fiero 3800 swap (even using the larger dia. outlet piping). The only drawback to this muffler is that it is too thick to fit between the trunk and the cradle which can be remedied if you notch the trunk (move the trunk wall facing the cradle in away from it by about 1" or 2" which is actually pretty easy to do; but welding is required. When doing this full trunk depth is retained, you just lose some area from front to back at the bottom of the trunk).

EDIT: To add a pic of the Magnaflow 12267 based exhaust system I built for a previous car...



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7+ years on this same swap -- NO engine or transmission failures...

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[This message has been edited by Darth Fiero (edited 07-28-2010).]