Ok so I've done a bit of a cross post here, I apologize, but I'd really like some more input on the topic. Here is the original thread: https://my350z.com/forum/vq35hr/5197...r-concern.html

So far I have a TurboXS y-pipe cat-back exhaust and Injen Longtube intakes on my 2007 350Z HR. Here is a dyno showing the A/F ratios, but they are only taken with a sniffer and I've heard they aren't very accurate. But as you can see, according to the sniffer, the intakes have leaned my car out some. The blue line is only the exhaust, the red line is exhaust and intakes. However, UpRev Cipher had the exact opposite to say about my A/F ratios..



I always thought that bolt-on air mods would lean the car some. I am also concerned with Cipher's reading just a tad, because according to UpRev's website:

That being said, tonight my buddy hooked his Cipher up to my car for me (big thanks to Rob aka rh_334!) and it seemed to work fine other than possibly not reading both mafs correctly.

So here's the deal, according to Cipher I am actually running very rich. I did a few WOT runs and under full throttle my A/F ratios never went above 12. In fact they started at low 11's and approached 12 as I neared redline, getting up to about 11.8. Cruising was at a nice 14.5.

I thought that exhaust and intakes would lean me out.. not the opposite?

The reason for all of this is because I would like to install test pipes but I'm afraid that it will lean it out more than I'd like, and right now I can't afford a tune. I really don't want it any leaner than it already is, according to the sniffer. But if the sniffer is bogus (which I've heard.. especially with cats), and Cipher is correct, then I HOPE that the test pipes will lean me out some so that I can run closer to the idea A/F ratio! This is very odd to me though..

Thanks,
John

 

tons of people have full bolt ons without tunes..bolt ons wont make you run dangerously lean man there just bolt ons. You should be fine..might as well get a tune thought to get the most potential

 

get a tune and stop worrying.....

 

adding test pipes will not overly lean you out. You will be just fine.

 

^ that too

 

Ok but my main question is how in the world are intake and exhaust making my car run RICH?

I would love a tune now, and it's definitely in the works, but unfortunately I cannot afford a $600 tune for a while.