Well I have finally gotten around to getting a dyno since I installed some Injen long tube intakes on my Z. I never got a baseline on the car, but the blue lines are with just a TurboXS cat-back (y-pipe design) exhaust. The red lines are with the exhaust + the intakes. Both are on the same dyno and both were at a dyno day. For what it's worth, based upon my observations I would say that the dyno was reading about 3 whp lower on the recent dyno day (when I had intakes) than the day when I only had exhaust. It's a Dynojet. Enjoy!



Overall I was skeptical about the intakes right when I installed them. They were a pain in the butt to install, and since I had to wait for the ECU to learn a little.. I didn't feel anything really. But once the ECU got the hang of them, I was very happy and definitely noticed a power gain up top. However, I also definitely noticed a slight drop in low end power. Both of these feelings are confirmed with the dyno results.

In the end, I am very happy with them. First and foremost, the sound they make is great. Without the intakes I hated how stifled my engine sounded. That's gone with the intakes and now it roars. On top of that, the gains are there on the dyno, at least to a small extent, about what I expected honestly. Clearly the stock intakes are fine until you are at extremely high RPMs, where they start to restrict a little.

But in my opinion, intakes aren't a dyno-queen mod. They will perform much better in the real world where my hood is closed and the car is moving. Stock intakes aren't hurt as much on a dyno where the hood is open because there is less ambient hot air in the engine bay, so that helps them. And the long tube intakes aren't helped as much on a dyno because the car isn't moving and there isn't cool air slamming into the cone filters. The way I see it, these intakes produce even better gains than this in real world applications. Just my two cents..

And for good measure, a video of the runs. First run is just exhaust, second video is exhaust + intakes.

<iframe title="YouTube video player" width="640" height="510" src="http://www.youtube.com/embed/WnoVYasHpuU?rel=0&amp;hd=1" frameborder="0" allowfullscreen></iframe>

<iframe title="YouTube video player" width="853" height="510" src="http://www.youtube.com/embed/m9GXa31SLig?rel=0&amp;hd=1" frameborder="0" allowfullscreen></iframe>

Cheers!
John

 

Nice last pic!

 

I love that last pic! Car sounds real nice.

 

Thanks for the videos. I like the sound of the Z on the dyno. Any Z.

 

Looks pretty lean with the intakes.....word of warning the turboxs is extremely loud if you add test-pipes.

 

OH S*** you stepped on the yellow line....jk nice Z

 

nice, looks like my numbers

 

nice pic

glad i never spent money on intakes

 

Thanks everyone for the comments.

Yeah I noticed that too.. but those AF's are just with the sniffer, which I've heard is quite inaccurate. Still, do you think it's cause for concern? A tune is in the eventual future regardless.. but how bad really is ~12.5?

Also, do you speak from experience on the test pipes? I've always been on the fence about them.. because I don't want rasp.. and I love how the car sounds right now. But the power is so tempting. If the exhaust is going to get extremely loud and the note is going to go crap.. I won't bother. That being said I have a set on the way right now.. lol. I figured I could always install then uninstall if I didn't like them. Or should I save myself the trouble? I hear it's actually quite a pain in the butt to install on these cars for whatever reason.

 

Nice last pic. Now you just need to get test pipes and a tune. If you're concerned about the loudness I've heard the ART pipes weren't raspy at all. Just pricey.

 

12.5-13.0 AFR would be ideal


Yeah 03threefiftyz is not kidding about the TXS exhaust being stupid loud with test pipes (this is the setup I have). The TP's are a pain to install on the 07-08 cars but they were worth it for me since the gains off idle - midrange was VERY noticeable. You will get a CEL (most likely) if you don't have a tune.

 

Frosty,

Do you have any rasp with the test pipes? Any before/after videos by chance? I actually have a set of Berk test pipes on the way.. should show up at my door some time today haha. I'm wondering if I should bother installing them though, not only because of the sound, but also because now I'm afraid I'll be too lean with them. And I can't afford a tune right now. =/

 

It is raspy at low rpm (its pretty much unavoidable in loud I-6, V-6, and V-12 engines). I wont be able to get a vid until the weekend. The low & midrange gains are very worthwhile if you correct the AFR (yours will probably in the low 14's - mid 15's after installation).

 

Thanks!

 

saw your video on youtube with the test pipes **** sounds good!

 

Haha thanks man.

Just an update. I have been using Cipher to datalog the car and my A/F trims are actually very different than what the dyno sniffer thought. I was super rich with just intakes and cat-back exhaust, and now even after installing test pipes, the car is still just a tad rich.. so I'm happy to know I'm not going to have problems there. Well, sort-of. I must say that with intakes, test pipes and cat-back, the car has some hiccups sometimes, and I noticed that whenever I go from partial throttle to WOT, the AF ratios spike to extremely lean for fractions of a second before they richen back up. This worries me, so a tune is in my near future.

Lastly, Frosty wasn't lying. These test pipes are just too loud for my tastes, so I have ART Pipes on the way, which hopefully will be a good bit quieter. 8)

Check out my other threads for more info.

 

is that at WOT? it might be different at WOT

 

Yes those AF trims I speak of are at WOT.

Correct me if I'm wrong, but Z's are open loop at partial throttle so no matter what bolt-ons you have you should be getting ideal AF ratios (this is how it was for me when I datalogged). But at WOT Z's are closed loop, giving fuel based upon a table that Nissan developed. When you tune the Z, this table is what you mess with.. so you're really just tuning WOT. This is why people say Z's lean out when you add breather mods (bolt-ons), because there is more air in the system and the car is no longer going by the MAF.

However, as I said, my Z was VERY rich from the factory and still is relatively rich with full exhaust and intakes. I am starting to come to the conclusion that HR's actually came from the factory tuned relatively rich, richer than the DE's were. Who knows why Nissan did this (if I'm correct, that is), perhaps for reliability concern with the new engines. This factory rich tuning could explain why HR guys seem to get such great power results from untuned bolt-ons..

Anyways, that's just my two cents, take it for what it's worth.

 

Glad to hear then...

 

Have any pics of the intakes?