View Full Version : New exhaust, No Mufflers

09-10-2008, 11:05 AM
I was wondering what your thoughts were. I will be installing SCP 2.25 down tubes into 2.25 high flow metallic cats into a Borla Pro XS muffler in place of resonator. I am thinking of running the rest of the exhaust back 2.5 after 3 mid section out to the back with no mufflers. Anybody have this setup and do you like the sound. I could always put in borla mufflers later but I need money to get to Ohio for the Shoot Out. Will I be OK? Stephen

09-10-2008, 11:16 AM
It will be too loud. IMO.
But try it and add the mufflers later.
I have Magnaflow dual in and out, and a pair of Borla XS in the rear.
With cats.
It is just loud enough, Idle is quiet but noticeble, WOT is loud enough to get you in trouble, It could be a little more loud but I like it.

09-10-2008, 11:38 AM
I have set up like that. Instead of Borla I have Magnaflow resonator and cats. The size is exactly same.

The idle is loud but I like it. When driving 50-60 mph it's....hmmm...a little annoying.

Do your exhaust w/o mufflers and if you don't like it, add them afterwards. I did it that way...


09-10-2008, 12:34 PM



09-10-2008, 12:47 PM
I have a similar setup... no cats and no mufflers as well as a highflow resonator. I like the sound and would recommend it. The only issue I have with my exhaust, is the person who did the conversion shorted the pipe size and did a terrible job welding the stainless together.

09-10-2008, 01:59 PM
heh... you wanna talk loud... my car: gutted cats, 2.5" DI/DO cherry bomb elite resonator, dumped out the drivers side before the wheel well... it flows rather nice, made ~10hp more than another car with similar mods, but a more restrictive exhaust... but is a little too tinny up in the higher rpms for my taste...

09-10-2008, 02:59 PM
I ran mine with a single 3" midpipe and dual 2.5" in the rear - I think it was? maybe dual 2.25? - with cats and Magnaflow DI/SO resonator and it was loud. On the brink of annoying - in fact, I would have a slight buzz in my ears for a short time after a long drive. I added muffler tips and it was still loud, but more tolerable.

When the exhaust gets done on the 94, it'll probably be high flow cats, true dual 2.25" pipe with Magnaflow mid-mount and some mufflers in the rear. A local SC'er had that setup on his - before he sold it - and there was a tone difference but not loud and annoying at all :D

And Tyler - have dyno sheet to prove that exhaust alone was 10 HP difference? I assume your talking about the dyno trip when you and Jason went to the dyno. There are other things different between the cars besides exhaust - AOD vs 5spd, early blower vs later, and exhaust :p


09-10-2008, 03:07 PM
I have a Flowmaster 40-series "resonator" with nothing behind it right now (I need to weld the hangars on the rest of the exhaust). It'll box your ears in around 2800rpm.

You can do it, but it's annoying.... (loud enough where I try to keep a neutral throttle near cops.....)

09-10-2008, 03:18 PM
I have a Flowmaster 40-series "resonator" with nothing behind it right now (I need to weld the hangars on the rest of the exhaust). It'll box your ears in around 2800rpm.

You can do it, but it's annoying.... (loud enough where I try to keep a neutral throttle near cops.....)

Dumping out right under the floorpan will do that to you. If it was piped out the back, it would be a lot better.

I used to have a 1994 Mercury Sable 3.8, and the muffler fell off on a trip one day. It was loud and farty with a resonator but no back half of the exhaust. I rigged up a temporary tailpipe and it wasn't too bad like that. It was much better after I got the exhaust replaced. :) Much worse after the transmission died.

09-10-2008, 05:56 PM
my 89 sc has 2.25 from the manifolds to catco hi-flow racing cats, then to a dual inlet/outlet 80 series muffler (where the stock resonator was), then duals to the back w/o mufflers. i enjoy the throttle, but not too loud sound.

09-10-2008, 06:43 PM
i have mid length headers, high flow cats, magnaflow dual in single exit resonator, and piping 2x2.5-3-2x2.5. i really like the sound but after a long parkway drive at 2k rpm's my ears ring a little. at WOT it sounds awesome though which primarily is why i like it. idle isn't too bad either.

09-10-2008, 06:44 PM
I just replaced my exhaust system on my 91.I've got deleted cats into a single 3" glasspack.From there it goes into a 2.25" factory configuration pipe into stock aftermarket mufflers.Sounds pretty good at cruise and about 30mph.I tried running just a set of turn downs on the factory pipe and it sounded just like a John-Deere tractor plowing a field.I couldn't get to the muffler shop fast enough without getting a massive headache..........

09-10-2008, 08:19 PM
I have almost the same setup but I have SCP downtubes Lightning cats 2.5 into 3 resonator into 3 in pipe exiting after the differential. I LOVE THE SOUND. I do have a set of flowmasters waiting but I really like the muscular sound. No Buzzing noise. The long cats seem to make a difference. On a different SC I had before with 2.25 downtubes into gutted cats was annoying!

09-10-2008, 10:09 PM
I used the SCP downtubes, high flow cats and the flowmaster resonator into the stock mufflers. Slight rumble, but nice and quiet. Reduced the pressure from 12 lbs to 8. I like it!

09-11-2008, 06:05 AM
I've got stock cats, a magnaflow resonator, and mufflers deleted as well, and I like it a lot, I'm wanting to delete the cats as well really, but im affraid that it will be way to buzzy. I've also got a set of mustang headers sitting in my garage I wouldn't mind throwing on there, but again im scared of rasp.

09-11-2008, 11:09 AM
So whats your Veredic Stepen. Lots of replies.... ;)

09-11-2008, 11:42 AM
What a terrible idea

09-11-2008, 07:56 PM
Well I would first like to thank everyone for their info and opinions on their setup. I actually believe that I would like the sound with my setup with no mufflers. I always liked it kinda loud, but I am not such a young man any more, wife and two little ones. So I ordered a pair of 2.5 18 inch long glass packs. They are cheap to buy. It will probably help quiet it down a little and if I don't like the sound I can put in the Borla's when I get back from Ohio.So it really didn't hurt my Shoot Out budget . I am cutting my monthly flow close with this decision to go to Ohio but I can't wait. I just put in a new deck and remodeled my addition with a Jaccuzzi tube and new tile, so my wife is happy with me this month and letting me go. We will see what next month brings? I always seem to be in the Dog House. We will see what next month brings?:D:D Stephen