[Treyesph]

Hey guys just trying to hear your thoughts on this. im leaning toward the zzp off road downpipe but not 100% im not a car junkie but i know the down pipe upgrade allows the engine to expel exhaust more efficiently so my question is spending $100 more on the 400 cell downpipe make a improvement or is the zzp off road version better im also looking for a more throatier pur from the engine and i know going with a catless exhaust achieves that.
Secondly I'm also looking to upgrade my exhaust in hopes that a one of mrbp axleback exhaust systems fit the inline 4 camero exhaust system so can anyone help me choose the right one that fit
I Apperciate everyone's help on here

[Thandel]

Running through inspection will be tough depending on your state or unless you got some shithole shop willing to aticker the thing. I’m going to run catless no mufflers straight back on mine. I’ll have a shop weld up a full stainless system straight back. I had a fiat Abarth and loved the sound. I have seen vids of straight pipes on the ATS and love it.

[Evil-Bee-NH]

The 400cell looks alot like the stock downpipe visually from below so if it's emissions and visual you'll be fine. The offroad if your state requires cats obviously you better discuss with the shop installing it if they'll sticker it as long as it passes emissions.

[Thandel]

Originally Posted by Evil-Bee-NH

The 400cell looks alot like the stock downpipe visually from below so if it's emissions and visual you'll be fine. The offroad if your state requires cats obviously you better discuss with the shop installing it if they'll sticker it as long as it passes emissions.

I’m in NJ they hook up to the ob2 and do a brake check no visual at all. But they also allow independent shops and there are plenty in the bad areas who will do anything to buy their next fix slip a dude at the shop 100 bucks and done. Other states are different. My best friend owns a shop that does inspections and he won’t do it for his personal cars it’s not worth losing the license if you get caught plus big fines.

[Evil-Bee-NH]

Well a 400cell is fine by most every state that requires cats as long as it passes emissions. Dealerships being an exception to this, i know some states are more liberal then others on the definitions. I still like my idea of contacting whoever installs it seeing if they do inspections and if they'll pass you so long as it passes emissions and whatever visual safety they may be inclined to do. Falls into that do your research and better safe then sorry column.

[DarkFangz1100]

Personally, I like the 400 Cell more. It's not as obnoxious at high RPMs. Videos posted below from my car.


Catless /MRT V3


Catted/Intake/ MRT V3

[StPeteHyper2.0]

Not that I'm a fan of RPM, but I went with their catted DP because it was a 200 cell count. I didn't want to go completely catless. I have catback MRT V2 also.

[Idriveastickmaro]

I have been running the ZZP catted for about a month and half, just under 2k miles. I have loved it, I did have my mufflers chopped off prior to adding the downpipe. It has a nice rasp to it, and you can keep it quiet when needed, ie going through a parking garage. I came from a catless WRX, and it was loud 24/7, so having the ability to just keep it quiet has been pleasant.

[dekes1]

I tried both ZZP pieces and the ECM calculated HP difference between the 400cell and straight pipe was 4 HP.
To me, the fact that you have to disable the rear O2 sensor in the tune, are risking a serious fine in most states, and the less obnoxious sound like DarkFangz mentioned, all outweigh the possible 4 HP gain

EDIT: one other note, when i ran the catless version for a few weeks, the exhaust smell was almost too much to handle. It smelled like heaven when i ran some CAM2 103 octane race fuel, but the rest of the time it gave me a headache and was not fun with passengers. However, that was on an ATS so maybe the Camaro airflow draft is different.

[Zzsteve]

in back to back testing on a bolt on ATS, i have found the HP difference to be nearly un-measurable. like literally 1 WHP or less between the 2.

as mentioned, the smell...i prefer the catted, as it keeps the raw fuel smell down.

[kropscamaro16]

i had a zzp catless on my old car (cobalt ss) and it was a good piece but catless or hi flow catted are still illegal in cali and other states so it really doesnt matter lol