Would it make sense to go with the readily available catback's now? I hear 3" piping is best for the application, but i think most available are 2.5" (like the Invidia Q300, my preference if going this route.)

Ideally, i'd like to keep the OEM exhaust set-up for a variety of reasons, but if it means significantly compromising whatever power i can get out of a "stage 1" s/c kit, and/or damaging anything, then i'm open to swapping them out.

If that's the case, i might as well swap them out now.

So, questions are:
- Will it be okay running stock exhaust with an s/c?, or
- Should i swap the exhaust out?

Thanks!

 

i d say swap

when me and my friend (who turbo'd his 350z) were installin coilovers on my car he saw our exhaust and how restricted it is. I dont think i ve heard of anyone keeping their stock exhaust after going FI.

I think fast intentions is able to make a 3'' system. i also know that GTM will help you out too if you get a kit from them

 

FI will be able to make you one. I would just talk to Tony. he should be able to tell you if the 2.5" regular catback is plenty enough. from the looks of mine i wouldnt see any issues with running 2.5" the more you increase diameter the more you increase resonance and drone. i learned that the hard way when i put the 3" magnaflow system on my mustang lol.

What SC kit are you going with?? GTM?

 

Thanks guys. So i take it, staying OEM with this isn't a good idea? That's still my preference, if possible.

Yep, looks like it's going to be GTM. We have a local installer that have worked on GTM kits so that solves my dilemma of having to drive up to the West Coast just for an install/tune.

I originally wanted the Stillen, but they're nowhere to be found and some of the 350z folks don't seem too happy with them.

 

Ya its only going to maximize the results from the SC. are you getting the Stage 1 shift kit installed as well? i know it was recommended.

Invidia is the cheapest of all the catbacks, FI is more expensive but offers more of the ability to customize your exhaust (piping size, tips, types of mufflers etc) either way you will be happy with either. our cars sound great when you put a well put together exhaust on them.

 

When going S/C, your going to need a exhaust. Their is so much restriction in the stock exhaust. You need better air flow if your going to S/C, so get an after market exhaust.

 

Yes you do need to change your exhaust in order to get the full power of the SC. I also think that 2.5 inch pipping on the exhaust is also fine there is no need to get bigger diameter pipping. I chose the stillen SC kit first but all the 370z and G37 owners had problems so I switched to GTM and when they finish testing I'll be getting the kit for my G.

 

You can use the stock exhaust no problem. with superchargers you don't need the same big diameter piping exhausts as you would with turbochargers. Obviously because turbo's need the larger piping to reduce any restriction in the exhaust to help the turbos spool faster and make more power up top. You will obviously make a bit more power going with a 2.5" catback with your SC kit but it is not required nor will it affect the engine or SC if you stick with stock.

You will however going to need test pipes, the stock cats or any aftermarket HFC's will get destroyed within months.

 

^ What he said.

3" would be overkill, 2.5" should be more than enough as an upgrade when S/C'd

 

Thanks for the input, guys, very helpful!

It just occurred to me that the Invidia's have 2.36" pipe diameter. That's not much more than the OEM, isn't it?

As for test pipes, wouldn't that make the car that much louder and make it fail emmissions?

 

2.36" may be the inner diameter, which some companies will use to measure piping. However, stock exhaust piping is 2.25" outer diameter, Stillen also measures at 2.5" outer diameter.

Test pipes alone will not increase noise that much. They'll be MUCH quieter than going with catback alone. If you don't want to fail emissions then stick with stock cats but expect them to fail within a few months of going FI. Keep in mind stock cats are very expensive. I would get test pipes for daily driving and switch to stock cats when the time comes for emissions testing.

 

just curious which SC kit you looking at GTM?