| newtuner |
| So I have been thinking about getting a new exhaust system for my car, '95 Sunfire GT. Then I thought about what kind of muffler to get and headers and all that stuff. Then I realized I have no clue what makes a good exhaust system. I look at different mufflers and stuff but, I'm not sure what makes one better than another. What are some feature or stats I should be looking at when trying to pick which parts I want to use in my system? Does the size of the piping effect the preformance of the system and the sound as well. I don't want a system that sounds like a lawn mower but something with a little rumble would be nice(if I Sunfire can make that happen?). Any pointers would be great. |
|
|
| 95IntegraRS |
| Try to minimize the amount of bends and use a large resonator if you are going to remove the cat. I would go with a 2" header that meets at a 2.5" collector that flows down 2.5" piping into a 20"+ sized resonator out to whatever sized muffler. That would sound excellent and give you the best performance possible. |
|
|
| mr_sars |
| I had always thought that removing the cat in some fuel injected cars would result in a power loss rather than a power gain. Something about the missing converter screwing up the sensors and stuff...:dunno: then again I don't know my cars as well as some other people on here. |
|
|
| SplineZ |
Nah, im pretty sure it'd just set a diagnostic code in the computer...
My car has no cat... but only 1 o2 sensor and its odb1, its not complicated enough to care what comes out after the cat :)
It might be different with a odb2 car.. you might need to put a resistor on the o2 sensor to make it think its working properly..
James Z |
|
|
| TrevorK |
quote:
Originally posted by mr_sars
I had always thought that removing the cat in some fuel injected cars would result in a power loss rather than a power gain. Something about the missing converter screwing up the sensors and stuff...:dunno: then again I don't know my cars as well as some other people on here.
If you have an O2 sensor AFTER your cat., it will throw a check engine light if the cat is removed.
There are easy ways to fool the computer into thinking there's a cat there...
Honestly - I'd go out to the meets, find guys who have the quad four like you and see if you like their exhaust. We can all tell you what would be best for performance, but in my opinion it'd be worth sacrificing 1-2HP to get the sound that YOU WANT because this is a permanent change. |
|
|
| newtuner |
| Ya I guess that is the best way for the sound. How about performance, I know Sunfires aren't high output cars. I just don't want something worse than stock. As for mufflers will anymone work on my car as long as the inlet pipe fits into it? this is one of my biggest questions. I would like a magnaflow muffler and tip but I don't know if I can pick any muffler or does it have to be designed for my car? |
|
|
| 2000z |
2.25 or 2.5" piping will work well, really up to you. If you plan on nitrous or forced induction definetely go with 2.5", I'm running 2.5" on my 2.4 and it works well. You can go with regular crush bent piping at any exhaust shop ($75- 300, depending on who you know) or get Apex Modified to weld you a stainless mandrel bent system for around $500. To me, $500 isn't worth it, but if money were no object I would definetly go that way.
I would suggest a magnaflow cat with the O2 bung built in.
Part # 91035 (2.25") or 91036 (2.5") will work and not set off the CEL. They are right around $100 at most shops, cheapest I found was Mopac at $98.50. They will also stop most annoying popping noises.
No aftermarket company makes a header but the 1989-1992 Quad 4 HO manifold is the best flowing stock piece and will bolt up. Look at local junkyards and www.car-part.com . Apex Modified will also custom make you a header out of stainless for around the $500 range.
Any muffler will fit as long as you get the Inlet size to match your piping size. Magnaflow is a good brand, I prefer Borla and they are probably the only two I would endorse. My personal preference is to use "normal" shaped oval mufflers with welded on tips but some prefer the 5" tip polished stainless cannons. This is entirely up to your tastes.
Check out this site for a lot of really useful information: http://www.quad4forums.com/
And this site for a lot of mostly useless information: www.j-body.org
Sorry for the novel but hopefully this is what you were looking for. |
|
|
| TrevorK |
quote:
Originally posted by newtuner
Ya I guess that is the best way for the sound. How about performance, I know Sunfires aren't high output cars. I just don't want something worse than stock. As for mufflers will anymone work on my car as long as the inlet pipe fits into it? this is one of my biggest questions. I would like a magnaflow muffler and tip but I don't know if I can pick any muffler or does it have to be designed for my car?
Your car will be unique - somewhat. Do you have two mufflers, or one muffler and two pipes coming out? Remember to take that into consideration.... The muffler(s) will need to physically fit under the car, and clear brake/fuel lines.
I second keeping the stock tips - they fit the ground effects nicely, and round tips just wouldn't look as good IMHO. |
|
|
| newtuner |
| Ya I'm not a fan of the big round tips, I found a nice set that magnaflow makes that looks like the stock ones but chrome. There is a lot of room under there for mufflers but I think I will still put in the oval ones. I am going to keep the two mufflers, ya mostly for the look. Hey 2000z what a O2 bung, is that the same as an O2 sensor? What is the CEL? I think I will go with the reguar bend pipe, manderal is a little out of my range. What differance if any with using the 2.25 or 2.5 piping apart from a minor price differance? |
|
|
| TrevorK |
quote:
Originally posted by newtuner
Ya I'm not a fan of the big round tips, I found a nice set that magnaflow makes that looks like the stock ones but chrome. There is a lot of room under there for mufflers but I think I will still put in the oval ones. I am going to keep the two mufflers, ya mostly for the look. Hey 2000z what a O2 bung, is that the same as an O2 sensor? What is the CEL? I think I will go with the reguar bend pipe, manderal is a little out of my range. What differance if any with using the 2.25 or 2.5 piping apart from a minor price differance?
An "O2 Bung" is what the O2 sensor screws into - it get's welded onto a pipe so that the O2 sensor can be screwed in.
A CEL is a Check Engine Light - which will come on if you remove a O2 sensor and don't use any sort of O2 Simulator/Resistors.
I'd go with 2.5" if your use press bent pipe - you're going to face huge restrictions with it as is, so it might be best to go for the biggest size.... |
|
|
| 2000z |
Sounds like it'll be a nice set up, go with 2.5" piping. Performance difference will be minimal between the two, you'd have to dyno both to know what kind of difference there would be and I've never seen it done.
Trevor was right about all your questions, the reason I gave you those part numbers is because your O2 sensor plugs right in to the O2 bung on the cat. Usually you would need to get a bung welded into the pipe. And they're not even more expensive than a regular magnaflow cat. |
|
|
| REFLUX |
anyone heard of DYNAMIC PIPING???
Example of it would be:
2.5" -> 2" -> 2.5"
I believe it is a system that creates a vacuum in the ending 2.5" portion due to the expansion from the gases from the 2" section. There will also be an increase in exhaust gas velocity as the 2.5"->2" which theoretically should generate more flow and give some of the needed/wanted backpressure for an NA engine. |
|
|
| 2000z |
| Interesting. Do you have links to any technical articles? I've never heard of it before. Kind of makes sense but it seems like you're walking a dangerous line between creating a vaccuum to improve exhaust scavenging and restricting flow too much. I still think the best way is to properly size the piping to maintain the best velocity and least restriction. But I'd still like to look into this dynamic piping stuff. |
|
|
| TrevorK |
quote:
Originally posted by REFLUX
anyone heard of DYNAMIC PIPING???
Example of it would be:
2.5" -> 2" -> 2.5"
I believe it is a system that creates a vacuum in the ending 2.5" portion due to the expansion from the gases from the 2" section. There will also be an increase in exhaust gas velocity as the 2.5"->2" which theoretically should generate more flow and give some of the needed/wanted backpressure for an NA engine.
Definetely interesting - however I am concerned about the flow. There would appear to be a lot of disruption in flow as it goes from 2.5" to 2", which may restrict HP at higher levels....I guess the only way to know would be some proper dyno testing. |
|
|
| REFLUX |
yeah sorry no tech articles I can provide, I have only heard of it through chit chat with other respected tuners/car guys (mainly honda)
as for restricting flow, a free flowing exhaust typically improves high rpm power and lessens low-midrange.
So if you're spending most of your time near redline...go with 2.5" straight through
but if you like to use the rest of your powerband...a bit of restriction benefits the low-mid range power on NA engines
to my knowledge it is only in turbo (maybe SC?) engines that the exhaust should be as free flowing as possible because the turbo provides enough back pressure to help combustion in the engine |
|
|
| Ry96Z26 |
i got mine at alberta custom exhaust, go talk to them, they are good down there
My car is OBD-II and there is an O2 sensor before and after the cat, so just replacing it with a resonator was out of the question..i have heard of O2 sensor "simulators" though that can be bought...
if you want info on the quads thats a good forum, or try www.beretta.net, or www.bstuff.com |
|
|
|
