The plenum kit arrived with a 7-page instruction manual, and all the necessary hardware. I installed it on Saturday. The installation went as described, with two issues along the way.

The holes in the coolant block did not align with the threaded mating holes in the plenum. I had to drill oversize one of the holes to establish the proper alignment for the mounting screws. No big.

The plenum mounting flange hole just forward of the throttle body was not aligned properly with the plenum base, so the screw was binding within the hole in the plenum and required nearly as much torque run it in as the tightening torque-spec required. So, I had to guess when it was properly tightened. (One other hole – in the front – was a little snug, also.)

I was careful to take a few orbits around the plenum, tightening the screws gradually and waited the requsite hour+. I had no leaks.

It’s loud. Most notably when the engine is cold. Placing your hands on its surface quiets it, so there may be some material that could be layered on it to dampen the resonance. On the road, it is loudest on-and-off throttle in the 2500-3500 range. However, it reminds me of my cars with Webers breathing within an airbox, so I like it.

There may be a slight loss of power @ very low speeds: it seemed softer @ 1500-2000 on the freeway (where you might have slowed down for a clump of traffic and were accelerating back to speed without down-shifting).

The 3-4000 throttle response feels as good as before, and the over 4000 performance is noticeably better. At the autocross I attended yesterday I was amazed @ how quickly it used up 2d gear. And it sounds great.

Four Stars.

 

nice review..im thinking about ordering one in the near future...but i need to know if itll clear the greddy strut bar

 

the only strut bar it clear is the factory oem struct bar. even at that, it's a very very close..

 

funny you feel loss of power down low. my dyno's showed increases in power through out the ENTIRE rpm band!

 

Well, it could be just me. (And, for that matter, I don't care if there is a loss below 2000 rpm.)

 

Late,

Sweet! We'll need to meet up so I can test your car out and you can test the JWT Pop Charger.

 

Yayubetcha!

 

Ah, I've found that my ECU needed maybe 100 miles (more like 200 actually) to adapt to an air change like that. Note that I have not done the plenum, but when I did a cat & Borla install, it ran like poooooop for awhile, and then after 100 miles or more, it began to run absolutely great.

 

After a week with my plenum, I'll add a couple of comments. I had the front right bolt not properly aligned, but after some effort it managed to seat. Also, the bolt just in front of the throttle body didn't have enough threads to get enough bite, so I ditched the washer. LSDunique has indicated the plenum is now counter sunk at that place. Total install took 45 minutes, and I experienced zero air leaks.

Another issue was that quite a bit of sanding had to be done inside to smooth out some agressive dremelling and casting residue. Honestly, I expected a smoother finish be it during it's production or afterwards by the staff.

The plenum does deliver in the top end. For once the redline actually feel a little low. However, besides the improvements at 4K + RPM, I'm not 100% sure it's what I want. My main issue is noise, it's quite loud and I'm not convinced it's the type of sporting sound I'd like for this kind of car. IMO, it's not as nice sound as the exhaust per se. To those unaware of the modification, the car could even sound like something is broken. The "growl" can be hear in the cabin with the windows up at all RPMs. At 2500+ RPM, it's booming in the cabin and you need some very health volume on the stereo to cover it up.

My 350Z is a year round driver, so drivablility is important. My nature has always been to drive a the car with more bite than bark. Right now there's more bite, but the bark is exceeding those gains (even at idle).

Perhaps not as dramatic, but I did find the throttle a little harder to blip - to the point is may have offset the gains of the pulley, and engine braking has decreased. I'm going to remove the plenum and install the OEM to see if that makes a difference.

This is in no way a hack to Kinetix b/c their service has been excellent. I've received prompt replies to all my PMs. It's just an honest review to what I feel is a product worth getting if speed is the main goal.

 

Not to highjack Lateapex's post, but I thought I'd post a quick follow up. I swapped back to OEM plenum last night. Biggest issue was unthreading the two middle 'pillars' as they are just long narrow threaded spacers threaded into rod. Unfortunately, the rod with locktite stayed in the block, the pillars unthreaded. After some persuasion I got the rod out of the block. No cracks anywhere that I could see.

With the OEM plenum, it's dead quiet which is almost too tame now (even for my tastes). WOT sound is even less exciting although still nice with the Popcharger. I can really hear the "whistle" now - sounds like the car ate a dog's squeaky toy.

As for power, wow. It's hard to believe the Kinetix plenum only delivers 7-8 hp because above 4500 or so, the car felt really flat with the OEM. Almost shocking really. Frankly, it just wasn't as much fun to hammer.

You can all probably figure what I'm going to do tonight (hint: get some more locktite ).

 

Thanks for performing that comparison, Fritzman. Our butt-dynos often exaggerate results (even though we have real dyno charts for reference, in this case), so I think reverse A-B'ing helps validate performance and characteristics.

 

i have done a grounding kit, aem, pulley, borla dual, and now the plenum/popcharger switch, and i can say the latter might b the only one i've done that i can notice a diff.