Well, Today was my 1st time at the track this year since the last season. last year, with just the Warpspeed Y, i ran a PB of 15.0 @ 94 spinning off the line, the 60' was 2.38(my PB=2.24) My other runs last year werent slower than a 15.1


This year, i have a 00vi and a JWT ecu(wasnt tuned for vi FYI) with a raised rev limit to 7200.

I got 12 runs in today and most the the day was about 85-95degrees and humid. My PB today was a 15.208 @ 91 with a 2.38 60'

Now i understand the fact that the humidity and heat can kill the time but i was thinking, wouldnt i ATLEAST run a 15.0 with the added power?

I tried SO many different methods,
ran with JWT ecu,
ran twice with the stock ecu
ran with no air filter
ran with a funnel going from the MAF to the removed corner light
hooked up a vaccum hose to the dampener on the fuel rail
tried shifting at 6.5k instead of 7.2k


and YES, I'm SURE the powervalve is working.

my trap mph was between 89-92.


Anyone who has done the 00vi swap, even though there are studs coming out the block to mount the LIM, do you think there is ANY way that the gasket shifted THAT bad and is possibly making the port diameter smaller?


Can anyone tell me what i might be experiencing or could the weather just have been the main problem?

Because as of right now, 3.5 is looking like the only way out.

 

Your losing power b/c you don't have anything to control the VI. When the VI is closed your low to mid range is good but the top end sucks b/c your not using the short runners. When you have the VI open your low to mid range is bad and your top end is good. You might have benefited if you shifted earlier in the rpm instead of going to red line or over during your shifts.

 

If you're not controlling the VI then that's it right there. Otherwise, something is definitely wrong. I would think you'd see some kind of gains despite the warmer weather. I went from trapping 91.5 to 96.1 with 00vi and catback as the only difference, and I have stock ecu. I don't think your LIM gaskets could have shifted if everything was in place and you torqued it correctly.

 

Tear it apart and find out. You should definitely see some gain, if not in 1/4 mile time the trap speed should definitely be up.

 

Did you put a catback on? If not I found that to be a major bottle neck with the 00VI.

 

I have a 2 position switch connecting the vi wire to 12v. So, yes i can control it and i open it around 4800. i've tried every rpm between 4500-5000 and it seems best around 4800-4900...

I will DEFFINENTLY do that to see if anything was wrong and i will torque it down to spec this time :$



Nope, still running stock cat and b pipe.. Maybe thats my problem. I'm about to go outside now and tear it apart and re-install it. If nothing gets better, I'll do a catback before i call a quits on this motor...

 

Before you do that make sure that it isn't sticking only when warmed up. Drive your car around for a good 20-25 minutes and ground out your vias selenoid and make sure you can see the actuator rod open and close smoothly and quickly.

 

what do you mean "sticking"? staying open, or only opening partially? I know its staying open because sometimes i close it at 6400 right before redline to make sure its open and you can hear the intake tone change once i close(flick) the switch

 

wow ... iam amazed when people beat there cars in that heat .why????

ive lost 5-7 tenths in heat like that. i wont even go if the temps over 70F

i only go a couple times a year heat like that is a huge waste of time and money

 

wow, you give me hope. 5-7 tenths. i might be a mid 14sec car. only thing that also gives me hope is the fact that a ran a auto 350z one night who had a PB of 13.8 but a 14.1 that night i believe and it was VERY close.

Ill get a catback and go next weekend at night, it suppose to be 68degrees friday night so.. We'll see

 

K sounds like it's all good then. Do you know the conditions when you ran that 15 flat?

 

last year, it was the end of the season but i ran 15.0 almost all the time, it was fall/winter though. My lowest time was at 9:30pm at night and between 30-45 degrees outside

 

YOU desperately need a tune..

fyi with my 00vi (w/ dek injectors) + headers + B-pipe + 5thgen muffler, I had fuel correction varying from as low as -12 to +3 at various rpms. after the AFR was 13.3 - 13.5 Flat, the car felt ALOT better..
the hp seemed the same but there was considerably more torque felt. it also helped get wrid of a power Bog at 4-4.5K and 5K-6K (waaay too much fuel here), the car revved faster and more freely..

look into tuning the AFR, as I am 99.9% sure you are running rich (too much fuel) due to the bigger injectors..

 

In my 03, I made over 230 fwhp with the stock catback.

00VI isn't a true dual runner set-up. It's an inverted MEVI.

 

well, you just shot my kite out of the nmex. Now my motor has no hope again...I'll get a A/F tune and probably get an adjustable FPR before its done


im going to change my MAF and Intake Temp sensor too before i give up

 

vipervadim had the best suggestion of the bunch. Also, PM me as I have a Nismo AFPR F/S.

 

Id double check that, i had almost the same problem your talking about and took a bit to realize it because with how I tuned the car it was harder to notice, but the vias wasnt opening (or at least not all the way) and I was getting some 1/4 times I wasnt very happy with

personally, hot out or not, you should be running much better than that w/ your mods, something isnt right

 

did you say the oovi is activating at 5000 rpms? if its not working you wont do jack. i tested mine with just oovi and nothing to activate it, i was slower and mph lower. its 2:10am will swing back by and read the thread.

bottom line, when setup correctly you cant lose with oovi, when its on, this setup rocks !

 

Tuning is one aspect but he is using the JWT ECU. When I was tuning my TS ECU it wasn't all over the place. Yes I was losing power a little but nothing dramatic of a setting over -5. If any I was doing +2 in the lower and -3 in the higher rpms.

I think its controlling the VI. Maybe the cup on the VI is broken. Not sure. Ghost try to get it dynoed if your uncertain. Like I said the catback may be causing a bottle neck.

 

the catback is no bottle neck on the 3.0 meng. I put down 191whp-195wtq on my 3.0 tuned (only a/f), with USIM, on stock catback. Thats not your problem at all. As you may know, catbacks dont do much for the 4th gen, in the 4-8whp range really its no better than clogged air filter/ new air filter, lol.

You need to get the car on the dyno and find out where that a/f is so you can tune it, bottom line. After a VI, with different flow characteristics, and bigger injectors, your a/f wouldnt surprise me if its in the low 11:1's.

Catback= no
Tune=

(Do the catback if you want, more power is more power, but it wont solve your problem. Car ran fine with that catback on the USIM, the VI doesnt really flow THAT much more air at all, it just flow better at the upper end. So TUNE)

 

The most difference I've ever seen going from 40 degree temps to 90 degree temps was .3-.4 seconds... I've run in all temps and that's as big as he difference got for me.

You can't blame this on not having a catback - that's not it, trust me. There is some other issue at work here. I went deep into the 13s before I put a catback on my car (13.6 @ 101)

 

Yup as the other's have said there's something definitely wrong here. Catback won't change that much, and like Neal says, I've seen .3 to .4 on temps too but not much more.

I'd recheck your 00VI install/VIAS operation etc, maybe also check for something like a dead KS, then find out what your A/F and more importantly timing is.

 

It wasnt that close. I was putting cars on you and if that car wasnt in front of you it would have been worse. I say you take it apart and check everything out. You should be running mid 14's.

 

i guess ill try checking my KS. Ill try checking the VIAS again. But MAN, sometimes i wish i didnt bother the manifold.lol.

So, on the "to check list" is:

MAF
KS
VIAS
Intake temp sensor(couldn't this cause incorrect adjustments if it goes bad?)


Also, might just be a n00b question but, could not having the hose from the front valve cover connected to the intake track cause some type of power loss?

 

Air temp sensor does nothing that is noticeable, at least in my car. for a while I had on my garage shelf, forgot it was there for a good month, put it in, same thing, lol.

not having the hose hooked up to the VC, nah that wont do anything. As long as you have like a breather there, and a plug on the midpipe (because otherwise, its sucking in un-metered air behind the MAF, thus lean lean lean), you should be fine on those two points.

 

nope, no breather there, and a plug is on the midpipe

 

KS
Vias/vias cup

 

I've found,. even with the breather plugged up, it still idles lean and sometimes rough.

 

on your 00vi setup, which injectors did you use? if you used the dek ones you'll need to tune A/F.

 

my A/F before tune was anywhere from 11.x to 12.x on the de-k swap but I still wouldnt think he should be running like that. Plus that jwt ecu should be leaning things out a bit, probably not enough, but some

 

From past experiences, we have learned that AFR on JWT Maximas was near dangerously lean levels. So, it may help he has the touch larger injectors.

 

well, i do have the DEK injector. i took the JWT ECU out. car is WAY slower.. About to order this AFC now

 

Why did you do that?

 

No JWT ecu = stock timing = power loss.

 

well, the ECU was sent back to get retuned, it was my cousins.


On another note. I unplugged my KS, AND did the 470ohm resistor bypass mod... all of them felt the same... is there anyway the STOCK ECU could be bad?

 

If it were 'bad' it wouldn't work.

 

Some problems i ran into while doing the swap that my cause my problem. PLEASE let me know if these have any affect.


- the crossover tube connecting the the front and rear fuel rail has a few kinks where the tube was bent by accident. I managed to get it almost back to normal but still has some imperfections.

- My LIM had the swirl valve so when i filled it with JB i used a dremel to grind it down. there are a few nicks on the openings of the runners and on the surface of the LIM.

- From the grinding, the runners are slight different shaped on the inside (not straight, smooth. a few dings)

- I am still using the damper on the feed to the fuel line.

- 2 bolts that connect the UIM to the LIM are stripped(they arent right beside each other, they're on different sides) Ive sprayed TB cleaner around the bottom of the UIM where it it meets the LIM, not even a slight serge in idle



ALSO, if the ground for the injectors was decent but not PERFECT, could they not function properly or would they not fire at all.. Its not missing or anything but, kind of putting it in the terms or, "thick wire, more power" "Better ground,stronger firing"



UPDATE I did check my VIAS and there was a resonable amount of play... I guess i can blame it ALL on that or could the above reason also cause problems?

 

Bump........

 

Bump

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