I must say the install was fairly easy.

toughest part was removing the strut bar bolts ( I almost busted a vessel!) and getting those damn 6 internal gasket spacers to stick.

After install - I test it listed for air leaks - sure enough a high pitch sound go off as soon as I turn on the engine. shut off engine- check for loose bolts - yes, a few. test again no more sound.

test drive - HKS muffler is way louder than before. car is idling nornally at 1500, 1000, 750 rpms. So I go for a run and at the first stop light - PROBLEM - car starts to choke up a bit below 750 rpms.. in fact, it drops to 500 rpms and tries get back up to 750 rpms.... I thought the car was going to shut off.. It does this at every stop light. Seems like it does this if I am idling for more than 30 seconds.

HELP - I don't like this. what can be done to eliminate this "choking" effect?

BTW - I do have the JWT popcharger installed as well. I think my miles per gallon is going down - cause seems like it rides with higher rpms than before.

Other than that issue - car feels like it has more power.

Thanks for feedback!

 

Sounds like a vacuum leak to me. Check again and be careful not to break any bolts.

Look for areas that are not flush/sealed...maybe something got pinched and is creating an opening.

 

This happened to my car after I installed the Injen intake.

Double check that the oil filler spill guard is not stuck in there (if it was not removed during the install).

Also, it's not just a tighten till they are tight type of thing. Going in order, you need to continue to go around until they are all 61 inch pounds. 4myZ350 took me 4 passes till they were all tight.

Now if you think you have it all tight, get some starting fluid and spray it around the the plenum seam and the center bolts. If the idle goes up suddenly, that might be your leak point.

Lastly, reset your ECU as per Technosquare's website, I was not a believer in it until I did it and now I do it after every modification. Link avalible at www.hypersprite.com/z

Chris

 

Thanks for the replies - I will re-do tomorrow - And yes, I will be careful with tightening the bolts. hopefully, idle will be fine tomorrow after checking everything again.

 

did you torque the bolts to spec? usually incorrect torque spec could creat leaks
hope you get everything resolved. good luck!!

 

INSTALL IS COMPLETE AND CAR AT IDLE =FINE

2 things I discovered this morning:

1. some bolts were loose enough to untighten with hand - plenum must have sealed more after engine was turned on.

2. Part of the RUBBER BUFF around the oil cap got caught between the 1/4" space.

* also followed the order sequence to tighten
* don't know how to reset ECU - so I just discinnected the battery completely while working on the spacer again.
* checked the bolts again after a test run found three bolts that needed to tighten a tad bit #2, #4, #8. Don't have a torque wrench - so - whether have enought torque is yet to be known.

Thanks again for the replies! From them, it sounded like it would be as simple as what I found. Thus, allowing me to put it aside till this morning.

 

have fun and let us know your impressions of ur new mod!

 

Disconnecting the battery does nothing but mess up the clock on the radio.

From http://www.technosquareinc.com/350reset.htm

Chris

 

Removing power to the ECU resets the it...it just takes a while for the caps to drain on Z's...

It takes longer on my z32...

 

Good day all ! Chris did you have to retighten anything after you torqued it down at 61lbs . I ask because if every thing goes down this week I my be driving 1100 miles & then be going to Yosemite .The 1100 miles is all high speed & I don't want to die this week.

INSTALL was SAT 30th Chris did it WITH all the right tools.He for fun did it step by step off the print out he has on his web site.

 

Since I installed mine I have driven to So Cal once, did the Bodega Bay run and daily drive the thing (about 3k miles) and nothing has changed. I rechecked them about a week ago just to see if I needed to update my website about a re-torque, but they were all to spec.

I will have my tq wrench and a few tools with me (years of British cars, I can't leave home without a few things) so if anyone has trouble with their plenum's, even ones I did not help to install, we will have the tools to fix it on the spot.

Few install notes:

When I said I went around 4 times, the first three times the center 6 were loose again, the 4th time when they were all to spec.

Nissan is real particular about how this is torqued down and if it is flat, the manual devotes a page just to measuring how "true" the plenum surface is. If it was just a matter of tight enough (and if you feel 61inch pounds you realize, it's not tight at all) they would not have gone through all that in the manual either.

If you don't want to buy the wrench to do the job properly, at least go to Kragen and rent it. Overtightened aluminum will put a set in the treads that can make them seize or strip the next time they are removed (Just ask Jiffy Lube how many oil pans their monkeys have ruined).

Disconnecting the battery does not clear the ECU.

Chris

 

It did perfectly every time my ECU would throw codes for my test pipes...and it did this very often.

I once believed the same thing as you, so I would just use my laptop obdii logger to reset the ECU. One day I pulled power to the ECU for several hours to see if it was like my z32... I verified it did in fact reset the ECU and the ECU was back into learning mode.

 

why r people using 60 in.lb for the bolts?

manual says 108-120 in-lb for all the bolts that secure the uppper plenum.

 

The 350Z owners manual states 44 - 61 on page EM20, I noticed that Tony changed the directions to 5 foot pounds but I imagine this has more to do with people not owning inch pound wrenches. Hey you guys do what you want, it's your car.

Chris

 

hmmm.. i guess the g35 manual is different. kinda odd because they both have the plenum and I would imagine the same specs. i will be attaching a pic for reference.

vinh

 

edit: i see em-20...it does say 44-61 in lb, but refers to the "stud bolts".

which bolts are these and why does the diagram on em-17 show 9-10 ft lb?

 

Wow, your right, good catch.

This is good news for Foot Pound Torque rench owners

Chris

 

To convert ft-lb to in-lb, multiply by 12.

So if you have an in-lb torque wrench the required amount would be 108-120.

My ft-lb torque wrench starts at 25 and goes to 150 or 250, so it would still not work here. I just bought a 25-250 in-lb wrench from Sears this weekend for this mod.

 

I noticed that too when I read the manual. So what I did was to adjust the torque wrench to match what the bolts were set to on the car from the factory which came out to about 8 ft lbs. I think they are snug enough but 2-3 more lbs probably wouldn't cause any damage.