Should we be doing an ECU reset after install?

 

I didn't. I've never reset my ECU. I believe the ECU will learn what changes you have made, and adapt itself to them. Many here will dissagree with me. But, I've felt every change that I have done. BTW, Doug Stewart of Crawford agrees with me, as does Jim Wolf of JWT fame.

Lou

 

Lou, You're not alone bro. I agree with you too, but resetting saves the waiting for the relearning.
I've never been able to find out how long it takes for the ECU to relearn after a mod, or learn a new driving style.... Whether it's a few drives, or more I don't know.
I'm so used to resetting now, I'd miss doing it [img]/w3timages/icons/tongue.gif[/img]. But as you say, within time, the ECU relearns.

It would be nice to get some feedback from Infiniti, but there's been nothing forthcoming in almost 2 yrs of asking.

Have a safe N/Y's

<font color=red>G</font color=red>S<font color=green>M</font color=green>
<font color=red>G</font color=red>S<font color=green>M</font color=green> <font color=black>Silverstone Coupe</font color=black>

 

shunsuenli,

I dont know why some people have the sound and some dont. It could be differences in their hearing, or variation in how Doug makes each plenum by hand. All I know is that it bothers me and I haven't been able to "get used to it". I dont like my engine sounding like it needs valve lifter repair. And it was perfectly quiet before the plenum, so I know there is nothing wrong with the valvetrain.

 

did you replace the gasket or use the old one.

-Ted


'03 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS or Vote at Online Showoff

 

Good call, he could have a leak.

Lou

 

so any of you people that dont like the plenum...are you going to sell it? id like to see firsthand if there is noise or not. cant wait to get mine.

G35S 6MT
Technosquare ECU
350Z Springs & Struts
6-wire ground kit

 

I have never heard ANYTHING weird coing form the engine.

Ted, you've seen my car many times, does it sound weird???

What could have happened is an incorrect install. Since these plenums are welded, that may cause a slight warping of the initial form. Lay it down a very flat surface and see if all the surfaces touch. Even if they don't (by small measure), that is still ok. Keep in mind that these plenum bolts must be TIGHTENED pretty hard to make sure that a vacuum is preserved.

THere is one sure way to find out if you have a problem: Get the vacuum gauge (made specifically for intake leak diagnosis), connect it to the vacuum line right in the fron of the plenum (plugged by a rubber plug) and see if the vacuum measurement is in the green. Danny of TechoSquare had this instrument and we tested it after my initial install and found out that it was leaking (this was because I damaged the original gasket). So needless to say I got a new $4 gasket, replaced it and torqued down the bolts - and PERFECT! - No leaks any more and the slight roughness in idle and low- to mid- ranges is GONE!

I strongly suggest that you do the same. I do not remember what the numbers should read on the vacuum gauge, but they should be in the "safest" part of the green (away from the yellow arch interval).

Cheers
Gurgen

 

Are you saying there is noise (diesel engine noise) before you replace the gasket? After replace the gasket, the noise is gone?

 

Never heard dieseling from Gurgen's ride.

That's why I suggested the gasket issue. I'm pretty sure you've got a vac leak there. Either the gasket is not sealing properly, or you didn't torque the plenum down properly.

One thing I learned on old iron, is never reuse bolts, belts or gaskets when installing an upgrade. Your car is worth putting off the install for one weekend or making 6 trips to the parts store in order to get it done properly.

Patience grasshopper.

-T



'03 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS or Vote at Online Showoff

 

When I saw how the plenum was made, I was very concerned about flatness and warpage, so I put it on my granite counter in the kitchen to check it. It was OK with no tilt or light coming through the edges. Then after I put it on and started the engine, I sprayed starting fluid all around the gasket area and bolts. If there was a leak, the engine would have responded from the extra vapors. It didn't. I just think the sound comes from the thin aluminum plate resonating from the pulsed air charges coming into the manifold. Either that, or its just allowing more valvetrain noise to escape since its so thin compared to the cast piece that was cut out.

 

link to Crawford clip
http://www.imagestation.com/album/?id=4289165157

The sound byte does demonstrate the sound that I tried to describe earlier. Listen carefully to the end of the clip for the "knocking" sound.

Let me know what you think. I am also curious to hear back from Crawford owners to hear their thoughts.

 

I listened to the sound clip and that duplicates exactly what mine sounds like.
It doesn't bother me because I'm almost sure that the new plenum is amplifying this already there.
As Karlhungus says, it's air intake noise that can be heard due to the increase in flow to the front 2 cylinders, and because the new plenum's walls and top are thinner.
I'm interested to hear what Doug of Crawford says too, but I'm faily sure that noise isnothing to worry about, and is not detrimental in any way.

<font color=red>G</font color=red>S<font color=green>M</font color=green>
<font color=red>G</font color=red>S<font color=green>M</font color=green> <font color=black>Silverstone Coupe</font color=black>

 

When I put mine on, I was told by Crawford that there would be more noise. This was because of the two screws in front (the ones that are capped in side the plenum) being removed. Those screws somehow interacted with the turbulant air inside the plenum, and reduced noise. They are not needed for any structual reason, nor are the rear ones, but are there for reasons releated to sound control. Doug Stewart's (Crawford's) first plenum didn't contain the middle front screw, and the noise was much louder, than on later designs. As a concession to this noise, Doug put in that center screw and spacer.

This is from my memory of four months ago concerning my discussions with Doug, when I purchased my Plenum. As for me, I really haven't noticed a difference in noise, as I previously stated, and this is the one mod I could not do without.

Lou

 

Talked to Doug today - he is going on vacation and asked me to post essentially what karlhungus already did - the sound is normal and preexisting. It is simply amplified by having the thinner plate covering the front two cylinders compared to the stock plenum. Just make sure to torque down the bolts well and get a new gasket.

Gurgen