cinergi1

no problems with idle here. We used exactly 36 in/lbs. (3 ft/lbs.) on all the bolts. We put a dab of thread lock in each bolt hole and on each screw. So, I think I should have a really good consistent seal. For obvious reasons the most important place to use the threadlock is on the bolts and screws inside the plenum.

BTW, you can buy a nice torque wrench at sears for $65 that goes from 25-250 in./lbs. There's also one for $19 but its not very accurate.

all_bark

iTrader: (5)

i also have no idle problems, i did when I had the vaccum leak but now that that is gone so is the idle problem.

chris, how bad is your idle problem? and no I did not attach a grounding wire to the throttle body.

silverstoneTT

iTrader: (1)

Too bad about those sounds at idle? Are those supposed to be normal?

Well if anything, Im anxious to hear the sound clips?

Also, don't know if it's been asked but, will I feel any difference in driving if I were to just get the plenum and not the headers?

jabroney12

Chris, you didnt really give a review on the performance gains of the plenum but rather the sound and install summary. How big of a difference did you feel with this plenum and when does it start to kick in?

crazed350z

I just picked up my Z a couple weeks ago and am thinking about going FI. Will there be an FI version of this plenum, or will this one work ok?

ChrisMCagle

I attached a ground wire from the throttle body to one of the points that my grounding kit was using and I can honestly say that the idle is better now, but not as good as it was before the plenum was installed. The only thing I can think of at this point is that the ECU just needs to re-calibrate itself.

I have updated my site with a couple extra instructions as well as attaching the ground wire (if you decide to). I figure it couldn't hurt.

I also added some more information to my review. I have not really gotten the chance to drive it much, but from the little I have driven it, I can honestly say that it is the most noticible mod (both in sound and performance) that I have installed.

I can't wait to get the CATS installed. Unfortunately there is NO way I can do it myself on ramps so I'll be taking it to Performance Nissan sometime this week.

-Chrismcagle

jabroney12

Chris, you didnt really give a review on the performance gains of the plenum but rather the sound and install summary. How big of a difference did you feel with this plenum and when does it start to kick in?

Apexi350z

iTrader: (3)

even more noticeable improvement than UR Crank Pulley? If it is, then this would be awasome!!

alphared

For the additional ground wire, how come you connected it on the other side? Couldn't you just use the ground point right in front of it? (where the other 2 gnd wire are on the lower plenum)


(see on the right hand side where the other 2 gnd wires are)

ChrisMCagle

alphared,

Well, I am honestly not even sure if the ground is necessary. I drove to work today (about 20 miles) and the idle was definitely MUCH better by the time I got to work. When I get home I am going to remove the ground wire and see if there is any diference. If there isn't I will completely do away with the ground wire and also remove it from the install instructions.

As for my reasoning for using the ground point on the opposite side of the engine rather than the point right in front... I just wanted to make sure there was a "good" ground and since there is a wire directly connected to the negative battery terminal attached to that point, I decided to connect there.

As I said, I am not sure at this point whether the ground wire to the throttle body is even necessary since all_bark and cinergi1 both said they have no idle problems and do not have the wire attached. I am just troubleshooting. I am failrly confident at this point that my specific problem is jus that the ECU needs to adjust to the change in air volume.

I am not 100% sure if my ECU was even reset to begin with though. I had the negative battery terminal disconnected for over 3 hours while I installed the plenum and when I reconnected it I went through the ECU reset procedure, but the CEL light never indicated that the reset was working (it's supposed to flash when it's working). I don't know if having the negative battery terminal disconnected for the length of time I did would reset the ECU, or if the only way to reset it is to do the reset procedure.

-Chrismcagle

alphared

I thought it was 12hr before ECU reset or do the pedal procedure. Well I guess I'll find out when I do my install

ChrisMCagle

Well I don't know but I have tried like 6 times in a row to reset the ECU with the Technosquare directions and I can't tell if anything happens. When I installed my pulleys and drained the coolant from the radiator and got everything hooked back up I got a CEL and the first time I did the reset procedure it worked and the CEL went out so I know that I am doing it correctly. But that's the only time it seems to have worked.

Do you know if the ECU will calibrate itself to changes without being reset?

-Chrismcagle

ChrisMCagle

Ok guys/gals,

A few things...

First, I updated the instructions and added some notes about using the Loktite on the screws when installing the new Plenum. I wasn't sure if it was a given or not so I decided to make sure to note it.

Second, I captured some sound clips and put them on the site as well. They are fairly large so a high-speed connection will help. [ Everyone has that nowadays, right? ]

There's one of the engine idling and a few revs thrown in for good measure. Another of a quick little 25 mph run to the end of my street and a third of a freeway on ramp run up to about 70 mph. They didn't really capture the full effect and sound, but did an okay job.

Lastly... shine on attaching a ground wire onto the throttle body. I took it off when I got home and there is no difference in the way the car runs so I removed it completely. I also removed that step from the instructions so "fugitabowdit".

all_bark

iTrader: (5)

so whens the dyno coming????????????!!!!

ChrisMCagle

Soon grasshoppa'

I think that I'll wait until I get my Cats installed to get it dyno'd. I need to call Jeff and set up an appointment, hopefully for Saturday or sooner. Plus, I dropped pretty much all my available cash into the plenum and cats so I can't afford to dyno it for a while unless there is a good cheap place to go get it done around here (Orange County)?

manrey

the idle problem is concerning me as I wait for my plenum. if your idle rough as you said after the install, then its a vacuum leak on the plenum, or some sort of lost ground stemming from the change in materials. Dont just shrug your shoulder, there are many things going on in the engine, the idle should be dead steady, IF its not, then a sensor is not working, or there is a small vacuum leak. IfF you have a vacuum leak, the engine is going to detect higher pressure in the manifold, therefor it will need to add more fuel to compensate, dont know how it relates to the maf sensor not detecting incoing air, but the increased pressure in the manifold has to be compensated for, this throws everything off the loop. your car is not normal now. better find that leak.

Put the original manifold back on and see what happens,m if the idle goes back to steady, you have a vacuum leak. maybe you should take a feeler gauge verify the plastic manifold isnt warped.

ChrisMCagle

Well, perhaps I am not describing the idle problem very well. Let me try to explain it a little better.

When I start the car (cold) the rpms stay fairly constant between 1100 and 1200 rpms. after about 2 or 3 minutes (once the car gets warm) they rpms slowly go down to around 750 rpms. They stay fairly steady at around 750 (+ or - about 20 rpms). It will stay at this rpm for about 30 seconds to a minute and then the engine will make a noise kind of like when it's running and you turn on the A/C or something and the enging slows down a bit (I hope I am describing this clearly enough). When this happens, the rpms drop down to between 500 and 600 rpms and stay there for about 30 seconds, but then the engine speeds back up and the prms go back up to around 750. This cycle repeats itself over and over.

That is what I meant by a "rough" idle. I would say that 75 to 80% of the time it idles at around 750 rpms. It's just when it drops down to the lower rpm that is sounds "rough". I do notice that after driving it for a while (to and from work for example) that it stays pretty much at 750 all the time.

Perhaps if there is anyone in the Orange area that is knowledgeable in how these engines should normally sound when they run, I could bring it by and they could listen and see what they thought. Or if that occasional "bog down" is normal, then I guess it's not a problem.

all_bark and cinergi1,

How are your idles?? Do your cars do the thing that I described above?

-Chrismcagle

StrictlyZ

Chris,

What your describing really sounds like a vacuum leak. We had the same problem when we were getting ready for a car show last year and installed a polished plenum at like 2 or 3

We were smart enough to install the plenum on top of the oil filler rubber gasket. You might want to try using something like WD 40 with that straw ofcourse and spray it around the edges where the gasket is. If it stumbles that means thats the source of your leak.

It could be something entirely else but thats what it sounds like, but its hard to tell without seeing the car.

cinergi1

My car's idle does as you describe but when it gets to 600 rpms it just stays there. It doesn't jump back up then down again.

StrictlyZ,

what do you mean by "stumbles"? Do you mean that if you spray the WD40 at a point on the edge of the gasket and the idle starts to get rough or do you mean that the WD40 will kinda bubble up around a possible leak area? I would like to try this just to see if I find anything unusual.

ChrisMCagle

StrictlyZ,

Thanks for the info. I will defiinitely do that when I get home today. However, I am curious to know (as cinergi1 also asked) what you mean by "stumbles?" Do you mean that when I spray the WD40 if there is a leak somewhere that the car's idle will get really bad??? Or do you mean something else entirely?

Also, I'm not sure if this matters, but the car drives perfectly fine. It does not sputter, or seem like it's going to stall at any time. The Plenum came with a cork gasket already attached to the bottom and I also left the stock gasket in place too. I saw the prototype plemum when it was first installed (actually have about 30 minutes of video on it too) and there was most defiitely a leak there and I could see how the car would barely idle (actually not much) and mine is nothing like that. What I should have done was actually consciously started my engine before I did anything to see how it sounded and what it did "stock". THEN swap out the plenum and see if there was a difference. Unfortunately hindsight is always 20/20, as they say.

-Chrismcagle