I currently have a stock 2004.5 Enthusiast Z. I will be adding the following shortly:
Injen CAI
Injen SES or Borla TD exhaust
DC Sports Headers(I hear they usually pass emissions tests)
Skunk2 or Motordyne Spacer
And a reflash if deemed necessary.

I am going with a real dual exhaust because I'm going to S/C it in the future. However, my question is, after I spend a couple G's on this bolt-on stuff, what kind of RWHP and Torque gains can I expect? I have read a lot and heard that I could lose some from the CAI and exhaust but I figure with the whole setup I will get at least some gains, plus it will sound great. Also, is there any impact(negative or positive) on gas mileage? I live in Seattle, second only to Cali in gas prices and I have a terrible commute to work every day. Thanks for any input you have!!! And yes, I have an alternate mode of transportation when it gets bad: I have an SV650.

 

you will net around 20whp. maybe 22 with a reflash.

 

Thanks!!!! I was hoping someone would respond without saying "Do your research" cuz I have, and I don't really trust Manufacturers claims. I have heard the SES and Borla exhausts, and I already bought the CAI, so I'm pretty set on what I'm getting, I just wanted to know what to expect. I think 20hp is certainly worth it, since I'm also going to have a Z that sounds pretty sexy.

 

I never understood why people think headers affect emissions.

can you explain your logic behind that statement?

 

and please do not support Skunk2, buy a motordyne spacer. Tony is active on the boards and has supported the Z/G platform.

Skunk2 is for Hondas.

and get a reflash if you can afford it.

 

I cannot help with horsepower, but my pre and post-mod ET is listed here: https://my350z.com/forum/drag/233840-top-25-1-4-mile-times-for-tt-st-supercharger-nitrous-bolt-ons-stock.html

 

Since you posted a very well organized post I will take the time to respond.

I have installed the following and tuned, and made +25hp over stock as determined by before and after dynos, with a lot more area under the curve as well (not just peak hp gain)

Links here:
https://my350z.com/forum/engine-and-drivetrain/224832-e-manage-ultimate-tuned-pics-and-dynos-inside.html
https://my350z.com/forum/showthread....t=mrev+touring
If you add up both before+after dynos, the gain is about 25hp on a dynapack. So this might translate to +20-22whp on a dynojet.

JWT popcharger
MREV2
5/16" spacer
Kinetix HFC
Emanage Ultimate Tuned
Cipher used for +2 degrees timing

Tony @ Motordyne thinks I can get about +15hp with addition of an exhaust, but I am still on the fence about it. It would have to be a well-designed exhaust system.

You want my opinion, ditch the CAI, get the stillen intake. Sounds great like you want and it won't lose power like a long tube. Also comes with a nice heat shield, better than the JWT.
Assuming you have a non-revup, get the MD 5/16" spacer. And go for the injen exhaust over the borla...much superior design.


The biggest effect I've felt from modding my car so far was tuning. I don't recommend any N/A bolt-ons to anyone unless they have plans to get tuned somehow.

Go with a reflash after you finish your bolt ons. Best bang for your buck.

 

I'd say around 20 HP. Once your done spending the money on everything the HP gained wont stretch far.

I have Injen CAI and Borla TD and love both of them. I wouldn't say the Injen is a "better" exhaust because i dont care for the sound it produces but it does have improved design over the Borla. An exhaust debate could go on for weeks, so its really up to you, but the mods you listed seem to be a good start.

I have intake, headers, HFC's, and exhaust and saw a 1.6mpg increase from city driving. Take into affect this could be influenced by a lot of things, but on an average i would say 1-2mpg with better exhaust flow. (you can gain that much by correctly airing your tires)

 

Well, most of the headers I have read about state that they are "not CARB legal" or that they aren't guaranteed 50 state legal. I couldn't give you a reason besides that. I guess I really don't know how any exhaust/header system would effect the emissions unless I replaced the cats, which I don't plan on doing. Besides being worried about emissions in Washington, I'm pretty environmentally friendly and would rather not have my car billow un-catalyzied exhaust into the atmosphere.

 

Another question:
I'm living in a very temperate climate, and in a about a year and a half, I will be moving to Houston for a while. Should I worry about getting the iso-thermal kit for the plenum spacer, or will the spacer itself do well?

 

get the iso thermal.