Hello all. Now that my warranty is up on my car I wanted to maybe change out the cats on my Z.

I have the S-Tune exhaust and after doing a bunch of research I have found that most HFCs and TPs will crack when paired with the S-Tune, or the Y-pipe will crack. I definitely do not want to risk breaking my exhaust for a few extra hp, but was wondering if a certain brand works with the S-Tune.

I would prefer a HFC to a TP as my last car had a TP and the smell got annoying over time.

Also, apparently Nissan changed the S-Tune at some point to strengthen it due to this type of cracking. Not sure if it is true but I bought my exhaust new from the dealership around the end of 2010.

Any help would be appreciated.

 

i would look into something that has the brackets for oem cat brace. i had the kinetix cats and they didnt have them and i cracked a cat. i guess worst case scenario you could have a shop weld tabs on the cat or TP.

 

In theory, I would think Megan's resonated test pipes would work since they have a flex joint on them.

 

The brackets do seem very important so if I do get something I will make sure they have brackets.

I don't think I would ever get Megan products. Even when I had my Civic I refused, so I would definitley not put that on my Z. Any other companies make it with flex joints?

 

Just look for some that have flex pipes in them. You should be good then.

edit - just looked through CZP's exhaust section, and i dont see any HFCs with a flex joint. Only test pipes.

 

I might be blind but I did not see any test pipes with flex joints on CZP. I might consider test pipes but I am wary of the rasp and also the smell.

 

The smell isn't as bad as you would think. If you're driving aggressively with your windows down, you might catch a whiff coming to a stop. Otherwise, you will barely notice it.

 

My Civic was pretty bad, but probably worse since I needed a tune as I was running pretty rich when it was boosted. My B13 has no cat and it is also pretty bad. That car stinks!

 

With the ART pipes, I barely noticed the smell, if anything it would be one in 100 drives where I would smell it.

On a side note, the ART's got me +8.17whp, +11.59tq, two runs with rather similar conditions on the same dyno.

 

I don't notice any smell at all. However I have been driving a Z with test pipes for the past 4 years lol. So I'm extremely used to it.

 

So Megan is the only company to make TPs with flex pipes? If a better company made them I would buy them in a heartbeat. Any other company makes them with the flex pipes that I am missing? Decided I would go for test pipes over HFCs.

 

Megan test pipes with the flex joint are still garbage. Both of my test pipes were cracked all the way around. One was even welded before. I'll try to dig up a picture.

 

 

squalz.... do the ART pipes. I cracked a Kinetix HFC, and i have yet to have a problem with my ARTs

 

Are you running the s-tune y? How long have you been on this setup? Thanks if ARTs work I would love that since I have read such good things.

 

no sir, i am motordyne all the way. but i do have a buddy that has the s tune with kinetix cats and he has never had a problem. i think the s tune with ART would sound amazing though.

 

In theory it sounds good, but having 4 flex pipe sections make your exhaust flap around under the car doing more damage to the pipes as they eventually shake themselves to death.

I really do not understand why the Z33 likes to break exhausts. My Z32TT has NO play in the exhaust with 0 flex sections anywhere. 0 leaks for about 6 years.

 

Actually putting the windows down creates a vacuum in any car and air comes into the cabin from the cabin vents inside the quarter panels, and the exhaust gas usually gets temporarily trapped at the back of the car and gets sucked in through those vents. This is a problem on the 03-06 G35 sedan since the cabin vents are located at the very bottom of the quarter panels because the bumper doesn't cut all the way to the fender wells to allow those vents to be placed midway inside the quarter panel, like it is on every other car. It is also a problem that the EVAP canister is next to the right/passenger cabin vent, though that was not a problem on my 04 G35 sedan and that car had pristine cabin air quality. The diffuser for the Evap canister actually has a hole in front to scoop air and one in the rear to shoot out the vapors not caught by the canister... lawsuit..

Leave the cats on, unless the car burns oil. Did anyone see the tolerances between the oil rings and cylinder walls in the FSM? The pistons are cast and they expand pushing the rings against the walls causing them to wear prematurely, especially true since the VQ is prone to heat soak because in Japan they hate cold-start emissions - I did not know this until I saw it happen and ran without a t-stat in the summers. They changed the casting process on the HR and VHR so oil consumption is not as common. But this is problem for Toyota and even Honda, though they will never admit it.

You can see here how exhaust gets trapped at the back of almost any car. http://www.gtrblog.com/wp-content/up...tr35-2-010.jpg Probably not a good idea to sue the EPA.

 

you should ditch the stune y-pipe. the shape and style is the same as the old de y-pipes just larger diameter which are inferior. get an xyz pipe or if you want it more muted just go with the hr y-pipe. you will get some hp as well as not have to worry about cracking test pipes / cats