Pics from http://www.precisionmuffler.com

 

Seen those before it clearly shows how restrictive the stock muffler is , however it is an excellent sound supressor. The pic shows why just about any axleback should give you 4-5 hp.

 

AWSOME.

I was thinking about hacking mine up a while back and playig around with the inside to try to custom-tune a nice deep exhaust note, but $ is always an issue. Did you trash this muffler after opening it up? Would there be a way to re-weld it shut?

 

Talk about restrictive. It's a miracle anything is able to get out.

 

thats friggin horrible

 

I wonder how much different the TRD axle-back is on the inside. Anyone have a clue? Because since the TRD exhasut came on my car, I wanted to go to a muffler shop and get the rst of the piping done from the s-pipe back to the axle. anyone know if the TRD uses 2.25 or 2.5?

 

I'll be able to tell ya in a few days, I'm getting my TRD redone (i.e. make it so it gives horsepower..hehe)...so I'll find out and post what needs to be done to get some actual gains while keeping the sound basically the same.

 

The TRD axleback uses a standard perforated core . Although it takes a sharp bend, this is done to expose as much as the sound obsorbing material as possible to the flow of gases. The result is a deeper tone and no rasp,with the stock header. Combination SS wool and other materials inside. The TRD uses 2.5" piping read the forums guys

 

Actually I just spent 20 mins measuring the pipes on the TRD exhaust and stock piping outside and they are not 2.5 inches. The inlet pipe of the TRD exhaust is about 2.100-2.130 inches (~53-54 mm) and the outlet pipe of the TRD exhaust is about 2.350 inches (~60 mm). The stock pipe after the resonator, right before it bolts up to the TRD muffler inlet pipe is about 2.125 inches (~54 mm) which makes them about the same. This was done with digital calipers that were zeroed before each measurement and checked to see if it was still zeroed after each measurement. The fact is the piping is the same size as the stock piping after the resonator so if you wanted to change the middle pipe to the same size as the TRD one then it would be the same size as stock. In my opinion the stock piping is fine with the trd exhaust and only if you change everything, will it then have a dramatic affect on power.

I hope this clears up the misconception that the TRD muffler is 2.5 or 2.25 inches because in fact it is not. Also the stock piping size after the cat but before the resonator is really about 2.35 ish inches (~60 mm) and not 2.25 inches. So it really looks like all the pipes were actually using standard metric sizes and this makes sense since our cars are actually manufactured in Japan.