COMPACT 90 degree mufflers

[The Dark Side of Will]

It seems to me that if we could find *compact* 90 degree mufflers, we could install them in the exhaust cutout locations immediately in front of the rear fascia. This would free up a LOT of room for catalysts and generally make it easier to build exhausts for Fieros.

Does anyone know of such a thing?

[Series8217]

Packaging-wise, I like the idea.. but I think the problem with compact mufflers is that they don't do enough muffling!

[darkhorizon]

Would be a good addition to a existing swap exhaust, but I doubt anything that size would work to quiet it much. Most of us use the resonated exhaust tips to help.

I am thinking about trying to get some actuated baffles near the tips similar to the c6z.

[The Dark Side of Will]

Yeah, they don't do a whole lot, but when stacked with cats the effect would be cumulative.

99% of the sound reduction that comes from a muffler is related to the relationship of the minimum cross sectional area inside the muffler to the inlet. Thus it's impossible for tiny quiet mufflers to flow well. Mufflers that flow well and can be quiet will be quite large. That's simply the nature of the beast.

However, the cumulative effect from several sound reduction points along the way (or even from a distributed muffling factor) can be "sufficient".

[Nashco]

I think a turbo will be a more effective sound reducer. Sure, it will be a little more expensive, but obviously worth it.

Bryce

[Aaron]

Unfortunately I suck at having pictures.

On my friend's N* that has the 180* headers, I built a true dual exhaust for it, using two full size Spintech mufflers, one in each of the factory cutouts. I did have to cut away some of the plastic to make the cutouts bigger, and there really isn't room for an exhaust "tip," but they fit, and work. Eventually he plans on welding a chrome/polished oval onto the end of the muffler, then painting the muffler case flat black to hide it. Should look good enough, but function was the priority here, and this was the only place I could fit the mufflers and still keep it a true dual.

[The Dark Side of Will]

Thanks!
Do you have a part number handy?

In looking at the Spintech website and saw a 90 degree muffler there. According to their configuration chart, it's the "SCT" setup: http://www.spintechmufflers.com/images/ ... gChart.pdf

I have yet to find any of their mufflers offered in that configuration, though.

Edit:
Here we go: http://www.spintechmufflers.com/muffler ... d_865.html

The case is 4 x 9 x 13. From preliminary tape-stretching, it looks like a 4 x 7 x 13 would fit with minimal cutting of the fascia.

They also list a whole category of side exit mufflers, but not much info: http://www.spintechmufflers.com/muffler ... t_157.html
I guess I'll have to call and discuss.

[Aaron]

I don't, but I'll work on getting it.

I did not use a 90* muffler, I used a normal muffler, with a center outlet, and a right inlet (Left for opposite side of car). Then I used a mandrel bent pipe to make the 90 into it. I did cut off the inlet pipe, and welded the 3" 90* elbow right to the muffler case. The mufflers fit nicely, they just stick out a little bit. With the 2-3" outlet pipe of the muffler, it sticks out past the rear bumper by about 1 inch. Not the best aesthetically, but eventually we'll use chrome/black to exaggerate the oval tip, and hide the muffler case.

Give me a day or two for that part number. We didn't have to trim very much of the fascia, it's hard to explain. Basically where it constricts in on the sides of the exhaust tip we trimmed off so there's more width. Hardly noticeable.

[The Dark Side of Will]

Thanks! Good info. Pics of this setup would rock.

In playing with the tape in the exhaust cutout, it looked like minor trimming close to the forward edge of the fascia would clear a lot more muffler than it would stock.

Interesting info about the offset inlet. I @$$ume that a tighter bend (IE, a donut section instead of a mandrel bend) would allow you to push the muffler further forward and tuck it under the bumper where it should be.

[The Dark Side of Will]

http://www.walkerheavyduty.com/catalog/ ... Number.pdf

22021 and 22032 on page 293 look like they might be dimensionally acceptable for use as described above in a Fiero. 22021 has a 3" inlet and 22032 has a 2.5" inlet.

Walker-Dynomax lists them as "tractor" mufflers. I'm not sure what that means, but it would be difficult for them to be louder than what's on the car now.

Unfortunately I suck at having pictures.

Were you able to find pictures or part number?

[The Dark Side of Will]

Local CarQuest guy didn't have Walker-Dynomax, but his exhaust line lists cross-references for the two muffler above. I'll find out who the exhaust supplier is this weekend.
Was able to get a 22021 equivalent on the way, should arrive Wednesday, shipped from Raleigh.
The 22032 equivalent is far away and would require a freight charge to get it here, so I'll look at it if the 22021 turns out to be inadequate or inappropriate.

22021->3963
22032->3950

[The Dark Side of Will]

22021 -> 3963

Got one of these in... It is useable, but will just *barely* fit under the rear fascia. It is also basically a straight through design and would be very loud. The sticker on it says it fits a John Deere application.

Code: Select all

Part  Inlet  Shell  Shell   Ov'all  Outlet Inlet  Outlet
No    ID     Dia    Length  Length  ID     Offset Offset
22021 3 1/8  5 5/8  19 1/2  22 1/2  2 1/2  3 1/4  0

22032 -> 3950

Will have to pay some freight on this one to get it to the local CarQuest, even if I don't buy it. I'm having my dad check on that this week. The specs on this one make it look like it will fit much better, but the outlet is on the small side.

Code: Select all

Part  Inlet  Shell  Shell   Ov'all  Outlet Inlet  Outlet
No    ID     Dia    Length  Length  ID     Offset Offset
22032 2 1/2  4 1/4  14 3/4  19 1/2  2      3 3/8  0

Pics to follow

[Aaron]

No dice on the pics Will, the engine is out of the car right now (As is the exhaust). I'll try to get pics of the setup as it sits though. Sorry it's been taking so long, the car's in Texas and I have terrible ADD, so when I remember to ask about pics, I see a piece of candy and all hope is lost. I'll try to get the P/N too.

[The Dark Side of Will]

This is the one I was able to get:



Probably not much muffling going on...




The 3950 unit showed up, but didn't remotely resemble what was in the Walker catalog, so there's a transcription error between Walker's catalog and CarQuest's exhaust supplier catalog.

[The Dark Side of Will]

So somehow, along with the development of the 2.5" SS dual exhaust with X-pipe and dual cats for the Northstar, to be built *WITHOUT* cutting the trunk, a "compact" 90 degree muffler evolved into this:

I'll probably start with SpinTech when I am ready to get the prototypes quoted. Does anyone have any other suggestions?

[Series8217]

Does anyone have any other suggestions?

Needs moar heat resistance

[The Dark Side of Will]

Does anyone have any other suggestions?

Needs moar heat resistance

I expect that the prototypes will be made of stainless rather than pine.

[Nashco]

Do you really plan on retaining a trailer hitch within the scope of the project? Seems like that's a pretty simple sacrifice when you want exhaust volume on a Fiero.

Bryce

[The Dark Side of Will]

The hitch stays very close to the sides of the trunk... I wouldn't gain appreciable volume by removing it; and if I did, I wouldn't be able to pull a utility trailer with extra wheels and R-comps to the track/strip/AutoX

It doesn't cost me any mounting locations either, because the hitch mounting locations are inaccessible with the "muffler" in place.

[Series8217]

I wouldn't be able to pull a utility trailer with extra wheels, wheel bearings, and R-comps to the track/strip/AutoX

Fixed.