[Knightmare]

Can anyone and everyone who has done exhaust modifications tell me what they did, and what they noticed for acceleration and horsepower (if your car has been dynoed) increases? I've heard what they can do for sound, which is awesome. The thing is, I don't have tons of extra money lying around, so I want to know where what I do have should be spent.

 

[1mz-fe]

pics and sound would be VEEERY appreciated and VERY helpful too if it's not too much trouble.

 

[jager383]

i ripped out the stock exhaust and fabbed pipe from the cat-back to a flowmaster 40 series (not the delta series). sorry, never been to the dyno with this car, so a gain in figures is merely a guess.
short and sweet: off the line, no improvement. past 35 mph, vast improvement, you can feel it in the seat of your pants. i love the sound, my friends say they can hear me coming a mile away.
disadvantage: i did this mod for REAL cheap... the muffler cost me about 70 bucks, and the aluminum pipe cost 11 bucks...installation cost me 2 hours. a buddy of mine worked at a muffler shop and let me use a pipe bender and a welder to do the job. ill get some pics of my car up soon, sorry cant help quite yet.

 

[silver ghost]

I'll let you know on thursday, friend o mine runs an exhaust shop and we're cutting out the resonator then (the one under the seat). I'll fill you in then. He's doing it for a 12 pak!!

 

[Mopar4U]

silver ghost,
I thought the muffler was under the seat and the resonater is what has the tips in the back of the car?

 

[97purple_trep]

yea thats what i thought too, can anyone clear this up for us... is somebody 100% sure one way or the other.

 

[matt22tec]

I have decided to take my muffler off. I am taking it to a custom exhaust shop that my work deals with and have them make me a pipe. I have heard of so many different good and bad things about this that I am just gonna experiment for myself. My trep seems to move after 3000 rpm. I would like to have more low end power though. My trep just is not a tire burning car. It will squeal them but not instant smoke at all. I guess that is just the way that they are geared. When I do wind out 2nd gear I do hit 80 mph and I think that is pretty impressive. I am excited to see what the muffler does when off. If I don't like that maybe I will go to dual exhaust. All of this exhaust talk is confusing to me so I am just gonna see what happens. By the way I believe that the muffler is under the seat area and the resonator is at the back of the car. Matt 97 3.5 ES

 

[Knightmare]

Yeah, I think that the resonator is the one towards the back of the car too.
I was under the impression that if you cut the muffler off, it would actually decrease your low-end power and performance because of the reduction or complete loss of back-pressure. Sounds like we need somebody in here who really knows what they are talking about.
Help from anyone would be much appreciated, and... really... helpful.

 

[1mz-fe]

i don't know what i'm talking about but i do know that if you reduce back pressure too much you'll lose low end power. back pressure reduction is good but there's a point at which you need some pressure in the tube to keep your low end performance from decreasing.

 

[swartlkk]

Click here to go to a previous topic on this issue. Scroll down to my rather 'exhaust'ive explaination of the pros/cons and applications of the various setups.

And to clear things up, the resonator is the one at the back end of the exhaust system. The purpose of this is also explained in the other post.

later

[ August 21, 2001: Message edited by: swartlkk ]

 

[1mz-fe]

thanks kyle, i was trying to find your post to paste in here (giving you credit, of course) but i couldn't find it. ;-)

 

[Starscream]

Hey Keith. I am wanting to do the same thing. This guy has a Concorde page (as you prolly know, almost identical as trep's) and he wrote a good how-to for cheap and not so cheap performance upgrades. As a matter of fact, as soon as I read the first one about how to remove the cone from the accordion air intake hose, I ran out side took it out of my trep and smashed it and dumped out the pieces. I didn't notice any sound differences, but I guess a little extra air couldn't hurt. Here is the link: http://www.angelfire.com/sc/brun0/performance.html

I also am bidding on a steel cone air filter on ebay from a guy. The auction's website
http://cgi.ebay.com/ebaymotors/aw-cgi/ebayISAPI.dll?ViewItem&item=594546592&r=0&t=0

claims that this steel cone takes in 926CFM over the much more expensive K&N cone filter of 887CFM. Not that much of a difference, but this thing is 20 bucks, the K&N is 56 bucks at my local autozone and they're always sold out anyways for Intrepids.'

If you don't feel like getting that cone deal, do what the second thing on that guy's website says to do. I plan on doing it if I have to get a metal intake pipe for that steel cone air filter. Its the one where you take the stock air box out and drill holes in the bottom of it to allow more are to be taken in. I havn't done it yet, but its free and easy.

 

[Knightmare]

Thanks all for your info and input.
What do you think would happen if I cut off the resonator, and just extended the pipe to the back of the car, or maybe had two exit pipes from the muffler? Has anyone tried something like this?

 

[1mz-fe]

i saw those steel cone air filters. even if it does take in more air than a k&n the amount of extra airflow is negigable and also i'd feel better with a k&n cleaning the air. k&n is reputable for performance but keep in mind they clean very well. i'd be wary of particulates entering your intake with this filter.

 

[jager383]

about the backpressure thing...i think that the headers and the 3 catalytic converters are sufficient enough as far as backpressure goes. i mean, cutting out the entire exhaust system from cat back, and replacing it with a performance (or stock) muffler is nothing like making a dump (which would basically give NO backpressure at all, as the headers would be open)...what im trying to say, with exhaust mods like the ones people are talking about here, lowers the amount of restriction in exhast flow, but not enough that it would totally decimate torque.