I don't know where to start here.. I went to the dyno today at 4:30 PM. On my 1st run I lost a few HP up top compared to before. the same for my second and third run. Then on my 4th and 5th run my car went in some sort of limp mode(it has always happened once in a while) or something because I had no botom end and my top end was bad too. I decided to unplug my battery for a second. Then we did another run, I peaked out at 220.8 FWHP and 225.5 FWTQ. My 7th run was about the same. So from these results I gained a whopping 7 FWHP and I lost 5.1 FWTQ. Hmm.. not what I expected. My low end was bit lower, I lost about 5 lb's of TQ threw most of my low end. I was pretty damn dissapointed to say the least. When I got to work I studied the sheets and compared them to my last run (a few months back). All of a sudden I figured it out! My Variable intake manifold is screwed up. A regualar VIM for the 2002 has a nice smooth transition at 3600 RPM, my car on the other hand does not switch runners until 4.5K RPM and when it does the power dips down a bit and climbes up like crazy.

So now I have to figure out what the heck is wrong with my manifold.. This has to be the reason why my car is acting weird and not giving the results I suspected. I inspected my manifold and noticed that I put two of my vacume lines on backwards(I think). I swapped them and the car still does not quite feel right, I can feel the manifold screwing up still. I need some advice here and I will try to figure it out tomarrow. Take these dyno results like a grain of salt because my damn car is messed up! I wish I knew where I put the CD to my nissan ECM

Let me know your thoughts..

 

First Emax, you deserve a healthy pat on the back for all the hard work and experimentation you've done on your car to better us 2K2 owners....well done.

It sucks that in the wake of your accomplishment, your VI is screwy. I'm obviously no expert, but perhaps its a vac. hose screw up of some type. If I remember correctly, another 5th gen owner had a similar problem and that was the diagnosis.

 

doh

I guess kevina was wrong, I wonder how much more or less it will change when the MVI is fixed

 

My Variable Intake manifold was broken on my 2k. Mine wasnt engaging at around 5k rpms causing my car to be weak up top. Your seems like it is working since u can see where it engages.

 

Hey Emax, I may be stating the obvious but make absolutely sure the vaccum lines and everything else is installed correctly, then re-set the ECU. You really need to do this - you can leave the battery unplugged overnight at least.

 

Sorry to hear about your trouble, ethan

But keep up the good work

 

emax is a warrior. I have no doubt he will get to the bottom of this and figure everything out.

Also, doesnt the ECU need more than a day to adjust to the new ypipe?

 

Well congrats anyways Ethan for a good go at it. Email me an I can help you get the manifold situation squared away. But damnit, how many times did I ask you to take picture of that setup for me when i screwed mine up?? Now you need that picture to set the thing back up.

I did finally get mine working right again so I believe I can help ya bud.

 

He also seems to take all his cars apart. and then kinda break them

 

Hey Matt, thanks for offering to help. After inspecting the pics I took for you I realised I did in fact have my vacume lines on backwards The vacume lines I mislpaced where the two that come out of that black cylinder piece, one connects to a valve and the other connects to a straight golden port going into the main manifold. I put them back together and just took the car out for a spin. The manifold seems to definatly swith at about 3600 RPM now, I can hear the nice noise and the hard pull I ge again! I've been driving with them backwards for months now too, ever since I removed my manidfold for polishing I have had them on wrong. The car feels much healthier now . For kicks I hooked my car up to my G-tech and gave it a little test. After putting my supension on it always screwed up the results by about 3-4 tenths(slower). Today I managed a 5.98 0-60 on my first try! With my supension the best I ever got was 6.13 0-60.

Now I have to go back to the dyno and make 100% sure everything is all right. I will try to get in there sometime next week, I think my results will be a lot better. I am also going to get a new intake manifold gasket and intake runner gasket, just to be safe.



Also thanks for the support guys!

 

Ok guys this is what Ethan and I need.
Pics of the VQ35 top with the cover removed. My picture is just an example since my hoses have all been disturbed are probably aren't in their correct locations. Any of you that have a VQ35 and havent ever touched these vacuum line please take soem pictures and send them to us or post them on the board. This is what Ethan needs to solve his problem. Thanks in advance.



High res here and here

 

Oh you little twirp... you DID take those pictures after all. PLEASE send them to me. Thank you.

Im glad to hear you got the thing working again.

 

I took like 5 pics for you of my manifold before I ever touched it. I could have sworn I emailed them to you. Never the less, I will send them to you now.

 

I got the pics dude. Thanks a bunch. It looks like mine is setup correctly compared to yours.

I wonder if this info should be put in or made into a sticky. I know more people are going to run into this in the future.

 

Good luck finding the problem out. Keep on chugging Lil' Engine.

 

how long ago did you install the Y pipe?

It took my car like over a week to "learn" the Y pipe, and that's with resetting the ECU.

 

I finsished the install on Thursday after noon. However I drove about 75 miles after that.

 

You didn't try a over-night battery disconnect Ewok? Well it sounds like you are going in the right direction, maybe this dyno will show the magic #'s....

 

Wasn't it already established before that the 2k2 ECU doesn't respond to battery disconnection for extended periods of time as a way to reset it but rather it goes on a continuous "learning" process. Meaning, the only way to "reset" it is to let it co-exist with the new mod for a certain period of time/miles while it learns of the optimum #'s.

 

I think we need a nice ECU modification . I think a well tuned one with my mods could easaly give a nice 10 HP gain. Maybe we will get lucky and companys will make one for the 350Z and then we can swap it

I wonder what ever happened to Leo from Weapon R


BTW I just noticed I gained 23 FWHP at 6500 RPM, I use to have 192 FWHP at 6.5K, now I have 213 FWHP. I can only amagine how much better my #'s would have been if my vacume lines where not on backwards!

So there you have it, 23 FWHP gain with a stillen Y-pipe, crossed vacume lines and a UR UDP, hehe, it's true though.

 

I gained 25 FWTQ at 6500 RPM too!

 

Send me the dyno files Ewok.

 

I don't have any dyno files on disc, the place I went to did not know how to do it(duh!). I'm working on scanning the dyno chart in and also getting the pics of my install up. I may have to wait until I see my bro again though becuase my computer crashed a little while ago and I am missing a lot of programs

BTW is there any way to figure out when my VIM swithces runners other then at the dyno? I still have my doubts about it working correctly. I had a friend rev the engine and the little valve on the VIM turned at 3K RPM's, hmm..

 

The VIM doesn't always switch over at the RPM you specified. I have noticed it does a switch based on RPM and vacuum load (engine load, throttle positions etc.) If you want to observe it by yourself then strap a ty-rap (zip tie) to the actuator arm and have the ty-rap pointing strait up. Now when your hood is open you can see the thing move.

The places i go to dyno don't really know what to do either so I just put my disc in and copy the files myself. I even got busted once because I was trying to unload ALL of his Nissan dyno files. He got kinda ****ed at me for that, oh well.

 

I should just take my hood off and watch the thing while I am driving down the road! I think I am actually going to try that tomarrow, haha. Maybe I will try connecting a zip tie to it while I am doing it.

 

Damn you Ethan... You are on your way to 13's easliy, with some good tires..URGHH, get rid of the Khumos .. .... I follow your entire mod, and it will give you great gains , for what you spent. Im just not about to start tearing up yet ANOTHER car. My wife will kill me ! I need simple bolt ons, that will not cause me to have to spend 12 hours on a weekend, messing with them and trying to figure out what I did wrong...Spent 13 years doing that, still have scars on my knuckles to prove it !

Keep us posted on those Dyno numbers !

 

yea keep us posted, btw what kind of y-pipe is it?

 

Stillen.

I think I am going to hold off on dynoing again until I get another mod. Dynoes get pretty expensive ($125 ) I know my car is quick and thats all that matters.

 

I also tend to trust the Butt Dyno ! .. what are your G tech 1/4 mile numbers ?

 

Hey Ethan, did you take any pictures of the 2000 header/Stillen Y-pipe install? Now its time to hit the track!

 

My G-tech has been slow about 3 tenths ever since I changerd my supension (I noticed this pattern on all of my cars). With that in mind I ran a 14.62 @ 101.6 MPH last night. Keep in mind this was just on a regular road and had not rubber compound on it or nothing, ha. During that run I had a bad launch too, I did 6.08 0-60. Back when my car was stock I use to get 14.9-15.0 on that same stretch with better 0-60 times.


Greg I am going to post a thread in the 5th gen forum with a bunch of pics in about 15-20 minutes.

 

$125 is on the high side. We get 3 dyno runs in Charlotte for about $45 to $50. The trick is to NOT use the wideband O2. Those things cost them about $400 and they don't last long because they use them on cars that run leaded gas. They don't reduce the charge for cars that run unleaded. So the next time you go to the dyno tell them you do NOT wish to pay for the use of the wideband and they should reduce the charges.

 

sorry to hear man, BUT good things come to those that wait.

Work out your problem and I am positive you will be rewarded. And I am sure your a hero to many 2k2 owners

 

I don't use the wide band o2 sensor when I dyno. I usually get about 7 runs in where I go so the price is not as bad as it seams. Also there are no other dynoes near me so I am kinda stuck having to go there.

 

did you find your cd if not i'll help you out

-steve

 

Cool, I will PM you tonight