theprodigy79 wrote:Can't go wrong with it bro... Looks beautiful, all stainless (not polished chrome plated BS that rusts and falls off after a couple years), weighs literally a bit over a third of the factory muffler (that thing is HUGE!!) , straight pass-through design (breathes very easily), and sounds pretty tight (not too loud, nice deep purr). The factory muffler design is a bit odd... not really necessary if you ask me. They could have efficiently muted the exhaust using a lot smaller and more breathable design from the start... prolly a lot cheaper too... go figure...
-James
Hey there everyone.
Sorry I've been offline for a few days. I'm on vacation with the 'fam in Japan. It's been killing me not to have internet access. The past three days we've been on Miyajima Island staying in a 200yr old Ryokan. (Japanese Inn) This is one part of Japan where technology stands still.
Today, we're a few hundred meters from the Himeji Castle. Jackpot, the hotel has highspeed wireless internet access! (I'm addicted!!)
Back to the subjects:
1) Differences in the TRD Mufflers
2) The OE "Muffler in a muffler."
1) Differences in the TRD Mufflers
I haven't personally seen any TRD authorized round mufflers before. If this is TRD product, it may be an early version. If you just received it, I would personally return it and ask them to try and get the oval version.
Honestly, this is just asthethics. The oval TRD muffler has a straight through tube which is bent in two places to go from the offset inlet to the center position outlet. Yes the two bends have a slight positive effect on acoustics versus a straight through (no bends) design. The results may be too slight to notice by ear. IMO, the oval just looks better. The round looks like a "buzz box" put on by a muffler shop.
Before I get flamed for being wrong, there are differences in muffler chamber volume when comparing oval and round. The more volume, the better for acoustics. In this case, the
oval will have more volume. However, in the case of these two mufflers, they both should have the perforated innerpipe wrapped in stainless steel wool. (AISI430 or AISI304 depending on the innerpipe material.)
(One comment on the chrome plating) May years ago, chrome plating was pretty popular. Nowadays, with the availability of good 304 stainless steel and many "low cost countries" willing to provide inexpensive labor for polishing, chrome has gone the way of the dodo bird. (Notice, cars of today have very little chrome anymore.) Chroming in the US is a pain with the EPA restrictions in place to prevent the release of carcinogenics (sp?) into the air.
To put it short (too late); if you get a polished muffler, I'm 99.9% sure it's made from 300 series stainless steel that is hand polished in Taiwan or China. (Before you react, I'd put Taiwan's polish quality up against anyone else in the world. I've personally delt with suppliers there and have seen their quality improve greatly in the past 5-10 years.)
2) The OE "Muffler in a muffler."
The OE Muffler design is pretty good at doing its job. It's VERY difficult to balance backpressure and sound pressure levels. Here's a few snap shots of the OE muffler and a drawing of the internals. (I've got a photo of the internals cut open, but not with me today.
There's no doubt that there are cheaper ways to make this part. However, Toyota is pretty strict on the acoustic quality. If they were not, your Solara might sound like a Hyundai. (Yuck!)
by PhreakdOut » Sat Apr 30, 2005 9:16 pm 
