A question of exhausts
 

I have a 2011 that I just installed the K&N typhoon. The engine sounds beautiful with slight pickup. Of course I want more. Right now the dealer I work with is attempting to get a license to import akropovic, which will take a few months to get. He offered in the mean time to install headers and catalytic converters (stillen) until the the exhaust arrives. Some questions.
1. Does installing the headers/catalytic without the CBE cause any damage to the engine? Is it possible to have this setup all the time?

2. Is a tune (up rev) necessary for the above set up and if so how much does it improve the system.

3. Let's say hypothetically headers/catalytic plus the CBE gives the car an additional 30 hp how much is from the headers/catalytic alone?

4. Is an upgraded CBE truly necessary over stock when switching headers/catalytic? Or is mostly a question of sound.

Thanks

1. No, it will not hurt the vehicle.
2.No, a tune will not be required. A tune will be required for all three mods you are looking into if they are all installed.
3.Shortie headers might net 5whp over stock, most of the gains are seen replacing the catalytic converter and exhaust. Stick with stock or go the full long tube headers. The only thing the Stillen header has over the stock header is weight and a better merge collector.
4.The Y pipe and muffler on the stock exhaust it restrictive and gains usually measure about 15whp-20whp. The headers or cats you install will have a dramatic impact on the sound of the exhaust, stock or aftermarket. Use the exhaust threads figure out the sound you want.

2. Is a tune (up rev) necessary for the above set up and if so how much does it improve the system. --- A tune will be necessary if you make any changes to the CATS or Headers because a light will pop up on your dash. But really you should get a tune when all your mods, or any significant changes are made.

3. Let's say hypothetically headers/catalytic plus the CBE gives the car an additional 30 hp how much is from the headers/catalytic alone? I think from High Flow Cats & Headers people are getting around 15-20 extra hp but thats mostly from HFC, I believe.

4. Is an upgraded CBE truly necessary over stock when switching headers/catalytic? Or is mostly a question of sound. Watch this video on youtube. Its someone that kept the stock exhaust on and just got HFC. 370z Berk HFC - YouTube


If getting HFC's aren't what your looking to do- spend $250 bucks and get AAMs for the time being. You will get a great ROAR.

Simply put you're wrong. The brand on of the HFC/Test Pipe/LTH will determine if the CEL will come on. Companies such as Fast Intentions spend a lot of time developing these so that the CEL won't come on. Typically it involves a "J-bend" to get the secondary O2 sensors out of the exhaust stream.

SS firehawk. You say shortie headers gain 5WHP. So what kind of gains are long headers giving? You are saying that most of the gains are achieved through replacing cats and exhaust? Which is how much while keeping stock headers.

Nick what are aams?

If your not really concerned with big gains, then these are great. I have em on mine & a bunch of other people have them too..If you want big gains, you gotta spend more money for a full catback exhuast


AAM Short Tail Exhaust - YouTube

I do not have gains I've made with just my Long Tube Headers, but most that have them gain 20 whp on the conservative side, and 30 whp at the high end.

I made 30whp with PPE Long Tube Headers, Motordyne XYZ Y pipe with the cat option, and Tanabe exhaust. This was untuned and with a faulty O2 sensor. My baseline was 270 whp, and with the full exhaust I was at 300 whp.