What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Doubeleive]

Yours was the previous generation Altima, mine is the L31 platform that is basically a Maxima with different sheetmetal.
I have 250k on mine and it still runs perfectly.
Too bad Nissan quality went to crap when they were bought out.

I like the maxima's too but not a CVT, give me a clutch and a 6 speed.

 

[gooffeyguy]

My 2002 Altima has an adjustable intake manifold where a vacuum actuator opens and closes portions of the runners depending on engine load, rpm and other crap.
I removed that and just have a plate covering the hole where the actuator went.
Not a singe time I've had it smogged has any tech ever questioned the plate.
The plate isn't small, it's at least a 6 in by 4 in aluminum plate with the name of the manufacturer embossed into it.
My guess is they are clueless about the intimate details of the VQ and since I have never been flagged to see a referee, no one has ever had the spec sheet out while looking under the hood.

View attachment 435836

I don't know anything about Nissan engines. Why did you bock it off? Is that system generally a problem?

Long runners move the power band lower in the rpm range while shorter runners move it higher in the rpm range. Having both and the ECM controlling a valve for which one it uses for best performance for certain conditions would be a neat bit of engineering. Did it not work correctly?

 

[Doubeleive]

I don't know anything about Nissan engines. Why did you bock it off? Is that system generally a problem?

Long runners move the power band lower in the rpm range while shorter runners move it higher in the rpm range. Having both and the ECM controlling a valve for which one it uses for best performance for certain conditions would be a neat bit of engineering. Did it not work correctly?

sounds like it has some type of vacuum advance, I had a old mazda with it and was working on it one time and inadvertantly locked it open/forward (I guess) hotdam that thing ran good! lol
ended up having to sell it as a "deal" with the judge after I had been in minor accident without insurance. I just asked the judge if I could sell it instead of having to get insurance and he agreed lol. sold it and Just went out and bought another car.
that was back when I barely had 2 cents to rub together, that dam mazda held up though, stripped out a sparkplug thread in the head once and put a insert in it but it was too short and it blew the spark plug out lol, 2nd time was a charm though. I did some shit to that car lol took it to a shop one time and they flat out told me we can't work on that! they were scared they were going to be held liable.

 

[kbuskill]

My 2002 Altima has an adjustable intake manifold where a vacuum actuator opens and closes portions of the runners depending on engine load, rpm and other crap.
I removed that and just have a plate covering the hole where the actuator went.
Not a singe time I've had it smogged has any tech ever questioned the plate.
The plate isn't small, it's at least a 6 in by 4 in aluminum plate with the name of the manufacturer embossed into it.
My guess is they are clueless about the intimate details of the VQ and since I have never been flagged to see a referee, no one has ever had the spec sheet out while looking under the hood.

View attachment 435836

So does this just open the whole manifold up, both short and long runners, or???

 

[89Suburban]

So does this just open the whole manifold up, both short and long runners, or???

hi!

 

[kbuskill]

hi!

Howdy!

 

[Grady_Wilson]

I don't know anything about Nissan engines. Why did you bock it off? Is that system generally a problem?

Long runners move the power band lower in the rpm range while shorter runners move it higher in the rpm range. Having both and the ECM controlling a valve for which one it uses for best performance for certain conditions would be a neat bit of engineering. Did it not work correctly?

From what I read from performance manufacturers, the entire mechanism only restricted flow and was mainly a mpg deal and not really a performance enhancement.
Without the assembly the car has a pending code for the system but it never throws a MIL so it still passes smog OK.
Removing it was supposed to help high RPM performance but sacrifice a small amount of low RPM performance.
The car has always ran great and had tons of power for what it is.
For awhile, it was the fastest 4 door family car you could buy.
I never ran mine on the track but I saw bone stock 3rd gens run low 14's in the quarter mile.
I saw 3rd gens with just bolt ons and a tune run low 13's.

It is still a great car to drive, which is why I have never sold it but I will sell it before I finalize my move to WY.

 

[j91z28d1]

sadly many difference manufacturers have tried the variable intake runner length thing. the 90s zr1 LT5 went as far as giving each runner its own set of injectors for each set of runners. 16 total.

while I don't know know about around town drivability, they all alway go faster full throttle by removing it all and just using a short runner manifold. shame really because in theory it should be a good thing. but kinda the same for our vvt. you might see it on a dyno chart but no one misses it in the real world delete.

 

[Charlie207]

1st oil change on the new engine.

However, I've spent hours trying to find the answer to whether there is a signal or reference difference between old & new MAP sensors, other than the difference in their physical shapes.

 

[j91z28d1]

1st oil change on the new engine.

However, I've spent hours trying to find the answer to whether there is a signal or reference difference between old & new MAP sensors, other than the difference in their physical shapes.

that's going to be a hard one.. you could either just install it and see what happens? Just ve table to the different map.

or if you have a 5v power supply.(use charger or Amazon) power it up, put a meter across the signal pin to ground. pump up a vacuum with one of those hand pump bleeder that has a gauge. log the voltage of both at different vac levels and compare?