On my 2.5GT ('99)? I was thinking of just tossing on a universal straight-through muffler, but if the stocker flows well, I'll just shelf the idea altogether.

 

Anyone?

 

The reason I asked is because with DOHC Neons, the stock mufflers flow quite well and are a poor first upgrade. But the stock Scoobie mufflers suck for performance?

 

you might as well get a whole catback. Those tiny pipes are not helping either.

 

Well what about the SOHC N/A Neons? The stock exhaust seems to be an ok upgrade for them.




Quote from Sport Compact Car:
"ExhaustResearch on www.neons.org proves informative. We found CNNP Racing and ordered a CNNP exhaust system, which is a low-restriction, stainless-steel chambered muffler with dual polished stainless tips. The Neon is blessed with mandrel-bent 2.25-inch tubing from the factory--plenty big enough for major power mods. The stock muffler is lame, however. Which is why the CNNP exhaust is simply a replacement Dynomax muffler from a V8 Camaro with the stock 2.25-inch tubing for the rest of the system."

From--> http://www.sportcompactcarweb.com/pr...2scc_projneon/

 

Just so things don't get confused, I currently have a '99 2.5GT and my question is about it's muffler. I used to own a DOHC Neon R/T and was using it's muffler as an example.

To comment about Neons, the stock SOHC Neon muffler is a single-outlet muffler. It indeed blows, since any straight-through rice-can shows improvements in upwards of 4-5whp. The stock DOHC muffler is actually a well-designed, decent-flowing muffler that replacing only nets you 1-2whp.

 

If you want to compair, this is a pic of the internals of a stock WRX muffler:

http://community.webshots.com/photo/...62257431ojVqil

Its considered more "free flowing" than a stock RS muffler. As you can see, most of the exhaust flow is directed through one small hole...

http://community.webshots.com/photo/...62257468IzbFTz

Major restriction if you ask me. Yes, just a straight pipe will net some gains, but the volume level will be MUCH higher of course

 

In my '01 RS, same motor as your car, I can say that there is some power to be gained from a catback. The pipe diameter has a lot to do with that. I recommend 2.25" over 2.5" if you plan to stick NA. 2.5" will work for a smallish turbo. Anyways, my car was faster with just my catback on it, which was a Magnaflow muffler and a very straight mandrel bent custom midpipe. Later, adding a header (which I did... great combo) and a catpipe will really get things moving. A proper 2.25" complete header-back with Borlas or MRT or TWE headers will get you around 190 crank horsepower. Add cams and you easily crack 200. Avoid intakes in MAF-based engines though. Not worth the hassle and risk.

Oh, and I must admit, I have yet to hear a sweeter sounding motor than my car with just Borlas and the unresonated Magnaflow that wasn't sitting in a full race car.

 

Could you explain your statement in more detail. What is the hassle and risk you speak of? I'm familiar with some MAF based intakes causing some really lean conditions. This could be offset by using a higher octane of gas though, preventing detonation and timing retardation. I know since I've seen my timing advance more after going with 91 octane (vs 87 octane while using a Minnam intake/K&N air filter combo).

 

A full exhaust for an RS will net about 15hp. For a WRX, it is alot more. Closer to 30, maybe more with downpipe/headers included in the conversation. This is the N/A forum though, so forget that

 

It's discussed in detail in the "Cold Air Intake debate" sticky in the EJ20 forum. Same principles apply.

 

I decided to do a custom system after all. My muffler should be arriving next week from Bulletperformance.com. It's just a 6" canister muffler, but it's got 3 types of fiberglass packing and a perforated core. I've gotten their stuff before--I had one on my 200hp Neon. My plan is to go with a long resonator in the straight-ish mid-pipe to keep the noise down. Thanks to all who contributed.