Hey Guys,

I want to re do my current exhaust system so that I can get a more aggressive sound and louder. This is my current setup (300ci): cat back 2.5" into flowmaster 40 series 3 in dual 2 1/4 out the back with chrome tips.

However this is what I am thinking: Cat Delete (because I don't need emissions any more and my O2 sensor(s) are before the cat so they will not be effected) with 2.5" into (either flowmaster super 10 or borla exhaust) then an immediate down pipe after that.

I wanted to get some opinions on this. Also what do you think of hooker/hedmen headers? Which brand (headers) would help with the engine breathing.

As far as intake (I know that some people will suggest it) I am getting ready to drop a K&N filter in it, I cannot justify a full air intake right now.

 

The 4.9L just wont really sound that good... like ever. Obviously just MY opinion, some people might like the 6 cylinder sound (no idea why), but its just not going to have the rumble of a v8.

That being said, getting rid of the cat will give you better flow and make it louder, the cat is the most restrictive part of the exhaust. I would suggest running a tail pipe though, again just because it won't sound good loud. And contrary to the consensus of the teenagers who drive around my block all day, loud =/= good :P

The flowmaster is probably going to give you the most aggressive sound, but I personally don't like them (dronemaster). I've always liked the sound and performance of the straight through magnaflow mufflers, I have them on both my 7.5L and 4.9L.

On the 4.9 I have a Y pipe where the cat used to be, then 2.5 inch pipe the rest of the way back with an 18in magnaflow out to a tail pipe. It doesn't sound bad, but not really great either, just not loud at idle or normal driving rpm. Over 2k RPM it does get a little loud and right around 2500 it sounds exactly like a freaking airplane! Unique if nothing else I guess, but definitely not deep and rumbly and aggressive like the 7.5. The old exhaust was rotted off when I bought the truck, and the new system I have now did make a noticeable performance difference for the better.

As far a headers for the 4.9, what I have always heard is the stock manifolds are very good flowing. They do almost look like shorty headers. I can't imagine longtubes would add nothing however, it might not really be worth the price.

 

i used to own a 300, and have nothing but respect for them, and wouldn't hesitate to buy one again if the price was right. i also used to daydream about buying some more horsepower for it, but the math just didn't add up. around here, i bet i could find a beater with a good running 351 for $800, less if i am willing to wait ... instant increase in hp, torque, and sound. 1 weekend to re&re, and a load of used parts to keep or sell.

of course, if you don't have the space to do an engine swap, you can forget all of that.

 

I would leave the cat converter in place. Federal crime to remove it, and I like to breathe. It shouldn't be hurting performance, unless it is clogged. RockAuto has the Walker one for $173.

I guess I'm getting to be an old fart, and desiring a quiet truck. Maybe a Dynomax muffler ($38), otherwise pretty much stock. A 300 just isn't going to sound good being loud and obnoxious. When the inlet pipes fell out of my converter, it wasn't too bad at idle, but made a lot of racket when I got on the throttle.

The stock EFI exhaust manifolds are good. Headers add complications, make the starter just about inaccessible, and aren't really needed until other changes are made to increase power.

The air box of the 300 is shared with the 460, so changing that wouldn't really gain anything either. A clean paper air filter would be fine, not moving enough air to need a K&N.

 

I just recently replaced my full exhaust system, I used the y-pipe from the Walker catalytic converter kit, you can get just the pipe from summit racing, and it bolts straight up to the stock EFI manifolds. It's a 2.5" out and I have it ran to a 2.5" in/dual 2.25" flowmaster delta flow super 40 series, out to two black 2.25"in/3.00"out tips and it SCREAMS. I love the tone and sound levels, but it drones like crazy on the highway from around 75-80 but it's not to bad if I keep her around 65-70.

 

If you do decide to go cat-delete, Walker 45166 is what you want. But bear in mind, as stated above, it's a crime to remove the cat regardless of whatever the emissions testing is for your area.

 

My '96 4.9 had s glasspack on it when I got it it5. Gllasspack wore out, i took the truck to a muffler shop. I got a standard muffler and Ipoooo like it better now. You can still hear the engine winding up nice and strong, and I can hear my nice aftermarket stereo system a lot better now.
The 4.9 just sounds alot like a tractor no matter what.