Grassroots muffler ideas?

It turns out the new exhaust system I put together for the fiat is a bit....undermuffled.

I am on a budget, had the cherry bomb and it fit (just barely). This thing is LOUD! Like un-corked harley loud. While the "loud pipes save lives" philosophy may actually apply to this tiny little car I like to be a little more considerate to my neighbors than the harley guys seem to be. I leave for work at 5AM and dont want to be the neighborhood shiny happy person. For now I stuffed a few scouring pads in the tailpipe and hoseclamped a wire over the end to keep em in. I has helped a bit but until I find the right 1.75 inlet muffler under 14" long I need a better solution

Any muffler with a giant can.

You could send the outlet of the header forward and then back towards the rear of the car and gain about 8" of length available. The larger the can in length and diameter the better. Raid the dumpster behind a muffler shop and find a diesel truck take off. Those things are HUGE and will quiet anything!

Corrugated steel piping...?

Here is an example that might help you. Since you aren't too worried about short term power loss from a restrictive exhaust, try this. If the car is running and you put you foot (with a shoe on) up to the exhaust, the closer you get the quieter it gets. If you put your foot on the exhaust it pretty much just sounds like rushing air and almost all of the loud exhaust is completely muffled. SOOO, logically the best solution is to duct tape a shoe to the exhaust tip..... seriously though, maybe that will give you some ideas.

In college I had similar exhaust on an fb rx7. The road out of my apartment complex sloped down so I coasted out of the apartment complex and popped the clutch at the end to start the car.

However, I still had the apartment complex tell me that I needed to quiet it down one time.

Go to tractor supply.

Buy tractor muffler for $20.00

Done.

Worked on my Starlet.

Shawn

Go to your favorite autoparts store and see if they sell universal. I know that autozone use to sell one like this Since you know how to weld, If you need to reduce the openings to fit your exhaust, no big deal. The closest I found at 18.95 had 2-1/4" inlet and outlets.

You are basicaly looking for a turbo muffler.

Good luck and beautiful car

Find a cap that will fit over the end of the muffler. Drill out the center of the cap to let exhaust gasses flow. Obviously, the larger you drill the hole the better it will flow.

Interestingly, it only takes a little bit of a rim at the edge to catch and block the sharp cracking sound waves. So you can drill the hole quite large and still greatly reduce the sound.

The generic supertrapp look-alike spark arrestors for VWs are usually under $35 and do an excellent job of mellowing out exhaust when used as a resonator at the tip.

I've bought from these guys in the past, always had great service, but you might hae an ACVW guy locally who'll have one on hand: http://www2.cip1.com/

I put a pre-owned stainless sport bike muffler on my Samurai, worked well. Also turn the end of the pipe down toward the pavement, that may help a bit.

Dan

The exhaust cap is probably the best and cheapest idea...I did this once on an old escort gt, the previous owner thought it would be "cool" to have a glasspack on - and I was driving 100+ miles per day on the interstate...

It does work well though, I think I ended up using a small hole saw maybe 1 inch or so to make the opening

http://www.cherrybomb.com/products/turbo

Trans_Maro wrote: Go to tractor supply. Buy tractor muffler for $20.00 Done. Worked on my Starlet. Shawn

had that on my accord, rattled the glass in the china cabinet on start up

but it should still be less loud than what you have

Add another $14 cherry bomb after that one

To be fair, the most grassroots muffler is a turbocharger. Looks like you have plenty of room too. Is that an 850 Coupe? I had an 850 Spider when I was 16. The car was a blast.

850 sedan.

I think I am going to try and machine a cap that I can drill holes into. I plan on running to the aircooled shop to look for the spark arrestors this week.

The trick is trying to find a turbo muffler small enough that doesnt sound like a hollow can.

Idealy I would buy this setup But they tend to sell for over $600 and that is rediculous for such a small system.

Would a monza style resonator tip do much?

Thinking the dual outlet would give me the cool abarth look from the rear

I would make basically a big coffee can filled with stainless turnings from a machine shop. Put it standing up like you would if it was full of coffee. Have an inlet going in one side near the top and the outlet going out the other side near the bottom. (Make sure they don't line up with eachother so the pulses have to bounce around a lot before exiting) You can tune it by adding more or less steel turnings.

I'd at least try to put a turndown on the tip to aim that sound at the ground instead of out at people's windows etc... Should help quite a bit, and you could test it without having to weld it on most likely. Cool car!

Seriously-raid the dumpster behind a muffler shop. IIRC V6 mustangs use a pair of really nice stainless mufflers. One would easily do the trick on your car. Drive that car up there and ask the shop and they will probably give you free reign.

What about using motorcycle mufflers? or better yet making one?

I did try to fit a muffler off of a Ducati M900 but it was way too long. It stuck out the back a good 10 inches.

As with most problems in life craigslist usually has the answer. I will report back later

I have to agree on the Super Turbo solution:

http://www.dynomax.com/ecat.html

That or an UltraFlow in Stainless (SS) w/Stainless steel core or Welded w/fiberglass core.

There is also the Collector mufflers they carry, but that might be difficult to fit without rebuilding the header.

Here's another option:

http://www.spiralturbobaffles.com/

http://www.moroso.com/catalog/categorydisplay.asp?catcode=35054

For the record, lots of modern motorcycle mufflers are constructed with the end caps riveted on. If you like the can and the inlet works, drill out the rivets, saw to your length, then re-rivet.

And in my experience: looser packing = less noise, at least with a straight-through muffler.

I had a Kerker on my GPz-1100 that had a choice of end caps, different diameters and exit angles. The caps were removable to service the fiberglass wrap inside. When the wrap got burned out you knew, performance and sound changed quite a bit.

These are as tunable as SuperTrapps but cheaper.

http://www.denniskirk.com/jsp/tpl/cmn/prodlist.jsp?store=Main&priceRange=35.99-120.99&category=403&brandId=417&_requestid=252332