anybody here have a catless exhaust system on there j30?

[infinitiboyj30]

i was gonna remove my cats,mid mufflers,and resonators and go with 2.5" piping threw out the whole thing and with a megan racing muffler on back with a 4" tip what do you guys think? we dont have emissions here in chicago for 95 and older cars and i know a catless exhaust would gain me a lil hp and sound insane lol
Modified by infinitiboyj30 at 7:17 PM 2/7/2009

[Victor]

You would never pass smog test in California doing that. Plus you would be causing excessive air pollution and noise pollution.

[kbflip02]

i was gonna remove my cats,mid mufflers,and resonators and go with 2.5" piping threw out the whole thing and with a megan racing muffler on back with a 4" tip what do you guys think?

whatever pops ur pistol bro....to each his own...i ran my car w/o cats for a couple of days before i got my exhaust done and personally i hated it...the drone inside got annoying after long drives...also 2.5in pipe is a little too big IMHO...i went ahead w/ 2.25 from the exhaust manifolds back...put in magnaflow high flow cats...and replaced the resonators w/magnaflows and just piped them out the driverside rear end w/ rolled tips...it ALMOST looks stock and sounds great especially @ startup...also the sound inside was barely noticeable and the isnt raspy at all like it was just dumped before the cats...heres some pics and a short vid clip....





hope that helps with your decision a little...good luck and when ur done post some pics and a vid...wed be interested to see what itll look/sound like

[infinitiboyj30]

whatever pops ur pistol bro....to each his own...i ran my car w/o cats for a couple of days before i got my exhaust done and personally i hated it...the drone inside got annoying after long drives...also 2.5in pipe is a little too big IMHO...i went ahead w/ 2.25 from the exhaust manifolds back...put in magnaflow high flow cats...and replaced the resonators w/magnaflows and just piped them out the driverside rear end w/ rolled tips...it ALMOST looks stock and sounds great especially @ startup...also the sound inside was barely noticeable and the isnt raspy at all like it was just dumped before the cats...heres some pics and a short vid clip....





hope that helps with your decision a little...good luck and when ur done post some pics and a vid...wed be interested to see what itll look/sound like

why are people telling me a round air filter that attaches to the maf sensor will draw heat in the engine and not cold air? i dont understand how is that possible? the drop in filter is in a closed box and only getting air threw a little hole with a round filter it would be opened to all the air possible...so what do u think?

[kbflip02]

why are people telling me a round air filter that attaches to the maf sensor will draw heat in the engine and not cold air? i dont understand how is that possible? the drop in filter is in a closed box and only getting air threw a little hole with a round filter it would be opened to all the air possible...so what do u think?

the drop in filter is enclosed and only getting air through the fender well thus cooler than the air in the engine compartment...with a round filter although the opening is bigger allowing for slightly more air its exposed to the heat in the engine compartment therefore pulling in wamer air than the stock airbox would be pulling in...thats why i fabricated some dryer duct and drilled a hole so my air filter isnt sucking in air from the engine compartment but from underneath the car

[#1 Sailor Scout]

i went ahead w/ 2.25 from the exhaust manifolds back...put in magnaflow high flow cats...and replaced the resonators w/magnaflows and just piped them out the driverside rear end w/ rolled tips...it ALMOST looks stock and sounds great especially @ startup...also the sound inside was barely noticeable and the isnt raspy at all like it was just dumped before the cats.

That does sound pretty good. Almost like a 350Z. Props.

It seems that Magnaflow is the weapon of choice for the J30s...what about Flowmaster or Borla?

[J30inthe sun]

That does sound pretty good. Almost like a 350Z. Props.

It seems that Magnaflow is the weapon of choice for the J30s...what about Flowmaster or Borla?

I was getting some work done to my J today & they were working on a 300Z TT that had Borlas on it & it sounded great, nice & deep, definately not ricey sounding.

[infinitiboyj30]

the drop in filter is enclosed and only getting air through the fender well thus cooler than the air in the engine compartment...with a round filter although the opening is bigger allowing for slightly more air its exposed to the heat in the engine compartment therefore pulling in wamer air than the stock airbox would be pulling in...thats why i fabricated some dryer duct and drilled a hole so my air filter isnt sucking in air from the engine compartment but from underneath the car

will 2.5" inlet cats fit with the pipes commin down from the headers? or do i have to go with 2.25"?

[kbflip02]

will 2.5" inlet cats fit with the pipes commin down from the headers? or do i have to go with 2.25"?

they wont bolt up but regardless im assuming youre going to have them welded in so it wont make a difference

[infinitiboyj30]

they wont bolt up but regardless im assuming youre going to have them welded in so it wont make a difference

yea im gonna weld it up so it should work.

[SteveTheTech]

First off. Removing the cats may be easy but is a violation of federal law and a noise violation is a primary offense in most states allowing the police to stop and harass you if they so choose. In the states I have lived in the police had ground to impound your car for such an offense, if they desire. Just as a heads up.

Secondly, are you really asking why removing the air box and just using a filter will be less efficent? Let's try a little experiment. Open the hood after you've been driving with the engine running check the temperature around the air inlets.While the engine is under load and pulled 30-50+GPS of air it will suck in whatever air is easiest, the warm engine air (especially after the radiator) is being drawn in instead of the air intakes that are outside of the engine bay on a J. In that case it's only an aesthetic modification, you are most likely loosing power when it's hot, that's why most people who do something like this get a box for it, or at least some kind of design instead of just a filter, again especially given the location of the MAF on the J.

Putting a custom exhaust on a J although a new one to me I have to admit I kind of like the sound. Nothing I would consider doing to mine but whatever floats your boat.

Lastly Rafeal by posting numerous threads about the same thing in the same time span is what we at Nico consider spamming. While we do not discourage participation in more than one forum. You have created several threads about your exhaust options, you could have just as easily maintained one...maybe two threads but that's about it. Forums are not instant and many of us do indeed spend hours a day here, hang tight and someone will eventually get to it. This is a warning, next time you will end up with a small vacation. If you have any questions or concerns about the terms of service feel free to contact me or one of the admins.

[GerryO]

i was gonna remove my cats,mid mufflers,and resonators and go with 2.5" piping threw out the whole thing and with a megan racing muffler on back with a 4" tip what do you guys think? we dont have emissions here in chicago for 95 and older cars and i know a catless exhaust would gain me a lil hp and sound insane lolModified by infinitiboyj30 at 7:17 PM 2/7/2009

Spend some time sitting behind and inhaling the exhaust of an older car that wasn't originally equipped with a catalytic converter system, and maybe you'll better appreciate what almost every other car having one is doing for you and all of us.

[yodawill2000]

totally off subject but Stevie your Avatar just made me blow coffee out my nose !!!

Classic.