350Z Dyno Test 

Yeah, sure did. Turns out, I must have some sort of exhaust leak. I was still running lean, though - about 14+, so that had to be fixed. I went down to Uprev in Austin while visiting my family and had the car dyno tuned. I'll probably post some videos of the whole thing sometime. Got the A/F ratio down to 12.9 and gained 16+whp at 6600rpm. So now the car is more reliable AND more powerful. I'm loving it.

Normal A/F ratio when idling is about 14.7'ish. At wide-open-throttle (WOT), most tuners prefer to have it around 13 or just below, though there's a range in there that's relatively safe. You go too low (rich) or too high (lean), and very bad things begin happening to your engine that could absolutely ruin your car. There are various ways to get the A/F data. A common method is a "sniffer" device stuck in the exhaust pipe. Others include sensors farther upstream or simply plugging into the ecu.

@cbeck611 It was a combination of both. The car wasn't actually running as lean as the dyno "sniffer" said it was - that was partially caused by the leak. However, the car was definitely running pretty lean (14.5'ish) after the MREV2 and Spacer. Not a bad thing if you get a tune to keep it under control - it's just what happens with these cars when you open up the intake airways as much as those mods do. If it didn't lean it out, it probably wouldn't be doing its job, really.

The MREV is a plenum modification - a replacement for the stock lower collector. When combined with the spacer, it adds gobs of power in the midrange. I'm sure it did lean my car out. However, I'm not sure the numbers are accurate. I feel like my car would be running pretty badly with some obvious symptoms if those readings were correct. Fortunately, there's a guy in town who's going to help me out. Wish me luck :)

I'm taking it in tomorrow to see if there might be an exhaust leak letting/sucking air into the exhaust stream. One of the guys at Motordyne suggested that as the possible culprit. At 16:1 A/F, the car would probably be running terribly, anyway. I'm really hoping it's that simple. If it's not, I'll get an ECU tune from Uprev or someone and get this under control.

Your sound is what I'm going to try and replicate when I get my '07 soon. Although with a minor difference of 8000rpm instead of 7000 :P Anyway, I hope you can get it figured out and still keep that torque number. That's like 300lb-ft at the crank!

Yep. All the way to the 7000rpm cut-off. Thanks :)

Car sounds great. What is mrev? Is it an intake piece? Anyway, those are crazy gains for two simple mods, but that's because they leaned your car out. Hope you get it figured out.

get a fuel pressure regulator and add more fuel, simple as that

yea or you might wanna look into a VAFC so you can keep adjusting the settings as you mod your car more

Good luck! What are you revving to in this vid, redline at 7000? Sure sounds nice...

@oNAGAo so does the mrev2 and spacer cause it to run lean or was it your exhaust leak?

Did you ever get it sorted out?