Well guy's i've been having fun with my g37 and i've ordered a new topspeed exhaust and dual K&N Intakes which i'll be posting a full and complete review about.

What i wanted to know is, Testpipes ? what are they and should i get them for my car since im already installing the axle back exhaust ?

I like doing small mods not to expensive . My g37x is my daily driver car so thats why any opinions would be helpful

My cars still at the paint shop because of some crazy lady hitting me with her minivan then saying i hit her ... Luckily the adjuster wrote a full report and by analysis of the damage and some physic's examples on acceleration and momentum of force i wont . Never though my engineering degree would be useful LOL

 

Test pipes will replace your Cats. They have no resonators in them. If they arent installed correctly they can throw codes in your car. They will stink and are very loud. If that is what you are looking for go for them.

Most people go with high flow cats. They will be a little quiter and the smell is more a Fuel smell then a gross almost rotten egg smell from Test Pipes.

I am sure someone will give a more detailed explaination but this is the gist of it.

 

To add to JCole's explanation, test pipes are also known as cat deletes. They remove the catalytic converters from your exhaust stream and replace it with just a plain straight pipe. They will cause a strong foul smell from your exhaust which can usually be smelled in the cabin, they cause massive amounts of raspiness and increased volume to the exhaust note. They will cause your check engine light illuminate due to the readings of your downstream O2 sensor being the same as the upstream O2 sensor since there are no cat converters anymore. This is avoided by removing the downstream O2 sensor and replacing it with a bypass which fools the ECU into thinking everything is OK with the exhaust. They add a few HP but not anything significant to a naturally aspirated car. They are called test pipes because they are often sold as being "intended for test purposes only" and also "for off road use only" in order for the manufacturers or vendors to avoid legal responsibility for selling you something that's illegal for you to use on a road car.

They are illegal for use in all motor vehicles registered for road use in all 50 states. If you live in an area where annual vehicle inspection requires emission testing or visual inspection your car will not pass. If it is discovered that you have removed the catalytic converters, you will be fined.

As to the question of should you get them, that's a matter of opinion. IMO, no you should not. If your goal is to increase performance slightly, get a well engineered cat back exhaust system that's free flowing such as Fast Intentions or Motordyne and either leave your cats alone or get high flow cats.

 

I have test pipes on you will get some rasp at around 2k to 3k at the most. they are a pain to install trust me i did it with my dad and a buddy of mine. And people exaggerate on the smell is not that bad, IMO it smells like a 2 stroke motor when you turn it on but i like it hehe. Good luck and i would recommend buying at least a 3 feet extension for the devil bolt you'll find out which one it is when you can reach it lol.

 

WOW blackbetty what a detailed explanation " again sorry for the screw up on where to post"

Alright that makes sense now whats you take on Y-PIPE
Y Pipe Decat Catless Straight Downpipe Exhaust Fits Nissan 370Z Infiniti G37 | eBay

it looks nice lol , i love the car as it is and the performance but im trying to replace small parts to make it a bit newer if that makes sense and have less original parts that are more susceptible to rust .

 

If it's a rust thing then I'd replace it when it starts to rust. If you just want to swap out various exhaust components you can. I wouldn't do that unless I had a plan of what I was doing and I was replacing OEM parts with parts of significantly better quality. Crappy Chinese eBay exhaust parts are not a good idea. I don't even care for second and third tier manufacturers because fitment, material quality, and build quality are often the reason they are so cheap. Flanges that don't line up perfectly or sit flush with one another, "stainless" steel that rusts after a few years, piping that's as thin as aluminum foil, welds that look like a 6 year old with glaucoma made them.

If it were me, I'd save until I had enough to buy a quality part. Lots of people disagree and will tell you "it's just a piece of pipe, the cheaper the better".