Pro's & Con's of having a catback with no CAT???
 

I know about the problem passing immissions so I dont care about that.


I want to know about performance. Will I benefit from having a cat back with no CAT and a stock 2k mufler.

I have 2K 5spd.

i dont know im getting low 15's knocking on high 14's with that type of setup . but again im not sure, i had the other exhaust stuff first then added the racing pipe. if anything i suspect small gains up top.

I just dont want to loose power.

i felt minimal loss down low with a test pipe... but on the highway the difference is very noticable... especailly since i put my cat back on. haven't got to go to the track with the test pipe due to all the rain, but i think it will make a difference. the only disadvantage i can think of is using your stock muffler. the 5th gens mufflers are different, but on my 97 the muffler could not handle the flow of a ypipe, testpipe, and bpipe... it sounded like the insides of the muffler had come loose.

see you the 7th :)

Cons:
- Minimal gain on NA car
- exhaust will smell, very bad at times
- raspy sound

Exhaust will smell, gains on NA maxima are there, somewhat raspy sound... This is all on my car of course...

raspy is an understatement... i'm scared to put it back on since i have my magna flo muffler now. i'm currently messing with my stock intake box... but using the midpipe... but thinking of a hybrid cold air with the stock box... not sure how it will turn out... but we'll see. just looking for something a little quieter.

What type of test pipes are you guys using?

racing pipe
 

Im using the custom maxima test pipe with resonator. I have pics of the setup on the car and sound and video of the car with this setup at my webpage.

Also I have a 5 speed manual so im not sure if I would experience any low end lag. I certainly didnt notice losing any, but it was uptop at high rpms and also at high speeds like 70-90 is where I thought I was feeling the car opening up. But we are still talking about a small amount of HP that you may never be able to feel either way.

I have also almost given up on how to make the maxima sound awesome. My magnaflow is much to loud and covers up my engine noise. I think the muffler needs to be toned down and if you can get the exhaust sound to be a little bit less than the engine, then that might be the ticket for a good sounding max. But what muffler or what type of resonator could you add ? Im a 4th gen by the way.

Again, im certainly no mechanic and im learning everything here at the org. But believe it or not. When I added a midpipe and took out the stock resonator box, I was suspect for a while ?? But with the racing pipe, I sensed a gain. Im still not understanding why people even say a test pipe can hurt performance, isnt it less restrictive? I have a jwt intake, fc midpipe, ypipe, CM test pipe, b pipe and magnaflow racing series muffler. It seems to me im blowing it all out WIDE OPEN to tha MAX !

Still learning ..

http://www.myweb.cableone.net/kindre...extexhaust.jpg

Re: racing pipe
 

An N/A car requires backpressure to perform its best. When you open it up to the point it has zero backpressure you will be losing more then you have gained. Also never trust a butt or ear dyno...

funny you say its very noticable....cause i've never seen dyno's improve more than 2hp from a test pipe.
my friends max actually lost about 8hp after putting on one.

also..about backpressure, the maxima does not need backpressure...it never does. many people confuse backpressure with the velocity of flow...the faster the air travels the better.

4th and 5th gen maximas need no backpressure. The more you can open it up the better...for performance anyways.

so basically it smells bad with a test pipe with some raspy sound, and gains are little. but there're STILL GAINS. but not tat much. i am willing to pick up a budget testpipe for that extra 1-2HP. $24 for 2HP. good deal :)

although custommaxima claimed their racing pipe gains 9-10HP with intake/y-pipe/catback, but i donno. my car isn't their car so dyno would be different. and on the dyno i did not see any low-end lost. also custommaxima's test pipe is resonated and budget is not. so according to slammed and dev, more exhaust flow and velocity will increase gain. also budget is makin 2.5" inlet testpipe, which is not too big to lose power as well.

come on guys, $24 for (unknown) 1-2HP. perhaps even more? we'll c how i do on the dyno with CAI/y-pipe/test pipe/muffler.

depends on what other exhuast work your friend has ... and i just said it was noticable... no huge gains, atleast in peak power. i think if i had a stock exhaust, the result would be different. and the only time i did notice this gain was at high speeds... where exhaust flow is more important. anyway, as of right now i'm just going on off of feel. i've had my car for ~3 years and i'm pretty good at noticing small differences. but a dyno would be a better test.

inside the CM test pipe
http://images.cardomain.com/member_i...92_36_full.jpg

Save the planet, fellas. Put the cat back one. The gains are minimal at best (1-2hp) which is easily within the difference between a back to back run on the dyno with nothing changed.

It's no the late 1970s. The catalytic converters have a very long way and they're far from restrictive hence the reason why people are seeing a 1-2hp gain with them. Just because it's ugly doesn't mean it's restrictive. A Maxima with a Y-pipe has been known to pass emissions testing, but a Maxima without a cat pollutes A LOT. Chances are you'll be running richer too (hence the commonly reported smell) because the rear 02 sensor thinks your cat has failed.

If you want a good sounding exhaust, keep a large resonator on the B-pipe and run the 2k+ muffler. Straight thru mufflers haven't been shown to make anything more than 1-2hp at best.

No resonator on the B-pipe causes loose baffles in the muffler is a Maxima.org myth. Lack of a resonator causes a nasty metalliac buzzing sound that sounds exactly like your baffles are loose. Put a good resonator back on and the sound disappears.

Backpressure creates "lowend" is an automotive myth. Like others have pointed out, it's the exhaust velocity you want to keep up. The best setup for NA is actually an exhaust that starts big and ends up smaller. On the Maxima, a Y-pipe with a 2.8" outlet running to a 2.5" cat running to a 2.2" b-pipe/muffler actually increases exhaust velocity overall because it keeps the exhaust gases hot which means they will be less turbulent and will exit quicker.


Dave

what about boosted maxima's? :)

yup, you will gain some horses by reducing back pressure on a boosted car. free flow exhaust system is important in our case :nod:

if you have a fed spec, I wouldnt recommend a test pipe because there's an O2 sensor there that needs to be located after the cat.

i have a cali spec :)

and i already have a test pipe :D

I have a Fed spec with test pipe...

:thumbsup:

good to hear that you dont have any problem with it. :)

I forgot, how do I check which spec do I have? Cali or Fed?

Thanks

credit: UMD
source: 5th gen FAQ. :)

My 2 cents:

I bought the test pipe for one reason. Cost. It was $30. Any aftermarket cat is $100ish+. Putting it on (I was NA) I noticed NO difference. No difference in power, no difference in sound, no difference in smell.

Same here. When my RT cat started to break apart on the inside, I took it off and just gutted it.

As far as the pollution goes, I recently read that a 2 cycle engine like in a jetski pollutes as much in one hour as a car does in 100,000 miles.