2006 350z feels sluggish
 

My 2006 350z is feeling really sluggish lately....like not even as peppy as my fiancee's 2009 GTI which is a less powerful car. Taking it to a dyno tuner is not really in the cards in the near future.....just don't have time. Any suggestions for things I can do on my own to at least eliminate some variables? The car currently has ~54000 miles and the engine modifications are as follows:

* JWT Popcharger
* Motordyne 5/16 plenum spacer
* Motordyne MREV2 lower plenum
* (stock engine, headers and cats)
* Invidia Gemini true-dual catback exhaust


No check engine lights, weird sounds/smells, nothing. Tire pressure is normal.
I can't recall for sure, but it seems like I first noticed the change last fall when I replaced my old cat-back setup (JIC y-pipe and Fujitsubo Legalis-R) with the Invidia system. Could it be that the true-dual arrangement is sapping my power somehow? Maybe not enough back-pressure or some such thing?

I have been planning to get the UpRev Osiris Standard package and go the e-tuning route (again, no time in the near future for a dyno visit) and I'm wondering if the tuner would be able to detect any potential issues from the datalogs that I would record and send to him. If it was indeed due to an unfavorable flow characteristic from the Invidia exhaust, is that something a tune could remedy?

Sorry for all the questions. Thanks in advance for any support!

Well,the first thing that comes to mind is your car is running lean.
Are you saying that with all those bolt-ons,you have never had a tune?
You are prolly not alone.Ask any tuner about this.There are tons of cars
out there that guys slap on all these parts thinking that the car will
just figure it out and make it all work.
Not so.
Besides your air/fuel ratio being out of whack,your car is sorta like
a guy that has went to the gym,bulked up,ready to make the team.
Because of this,his appetite has grown.In your case,your car is
crying out for more fuel.
Get a tune.

^^^Agree with the above...

06 airbox > pop charger.

Thanks for the feedback guys. I like the airbox suggestion....I will reinstall it tonight and do a soft ECU reset (unplug battery + pump brake pedal) and see if that makes any immediate difference.

Airbox won't make that big of a difference. You're running extremely lean. Running an MREV2 on your REVUP makes a huge difference. The MREV2 is made from Non-Revup lower plenum cores to take advantage of the longer runners. You've completely changed the dynamics of how your original intake manifold was intended to run. I would either get tuned or switch back to your stock lower plenum

Thanks for your input. I see what you are saying, but it's strange that I've only noticed this relatively recently (within the past 6 months) while the MREV2 has been installed since ~2009. At any rate, I plan to order the UpREv Osiris Standard package today and hopefully have at least a base tune loaded up by next week to get me back on track.

HFC'S
 

If it were me,I'd install HFC'S or test pipes before you get the needed tune.
You'll maximize the power gains from the stuff that you have already installed.

I considered it, but don't want to introduce rasp so I'm stuck with either HFC's or ART pipes. At the same time, I don't really want to increase the sound level of the car....it's loud enough for me with the Invidia Gemini cat-back, so I'm afraid of how loud it could become with anything wider-open than the stock cats.

You need a tune really bad... That's the problem lol. Get a tune, you won't regret it!

I'm getting a tune at this very moment. No joke... I'll post up some numbers for you to check out.

EDIT: Ordered my UpRev Osiris Standard package this afternoon so I should at least have my base tune loaded by next weekend : )

Perfect timing! (pun realized but not intended)
Stock cats? What other breathing mods?

Mods:

Mrev2 and Spacer
Ultimate Racing HFC
MD XYZ pipe
Fujitsubo Catback
K&N drop in


Stock Run 240hp/235tq

UpRev Tune 251hp/250tq ***Sasha is still tweaking

Very nice. Looking forward to seeing your results.

If I am indeed running lean and therefore pulling timing and putting out less power (feels like less power than stock at this point), then hopefully the UpRev tune will at least get me back to "zero" even with the stock cats in place. I figure the purpose of the tune is to maximize output based on whatever breathing mods are in place. Then later if/when I decide to go with HFC or test pipes, I can get re-tuned to suit.

I will be going the e-tune route so my gains will only be measured by butt-dyno, but that's good enough for me at this point.

The tune will make a difference. You won't regret it.

Here's my final numbers... Car pulls harder, increased throttle response. I'm very happy with the tune.

Attachment 464967

Very nice, thanks for sharing! Increased throttle response is my number 1 priority, and I'm thinking even via e-tuning that should be easily achievable. Even better if I eventually end up with HFC's.