Was there a flowchart for the air box on these? I know the ECU is still in the front half but was that tiny hole decent? Didn't want to create a CAI as of yet and wasn't sure what to even do with the ECU(as in location) if I did a air box delete.

 

I just took out my entire air box to get to the overflow tank. Debating if I should mess with that tube or not.

 

Since we are calling the 97 99 3100 V6 "NPI" like the 4.6 fords, Gonna get me a PI air box and maybe (years from now) 3400 UIM/LIM and newer 3100 V6 heads TB swap. In reality I'm gonna gut the air box I got and see where that takes me. Thanks for letting me hold a conversation with myself

The haynes shows the air box is different for the newer Centuries.

 

I think we're the only Century guys who regularly visit the forum, unfortunately, and I don't really know a lot about this.

Can you take a picture of your air box setup? I'm curious to see if it looks different than mine.

GM changed from the L82 (like yours) to the LG8 in 2001 or 2002. The newer motor made 172hp while the L82 made around 150. I'm not sure what differences there are between the two, but I know that the LG8 3100 and the (LA1?) 3400 are identical, minus the piston size/heads, which, added around 5 extra horsepower.

 

Yeah every time I look up info for it they said upper and lower intake and heads were the difference. They also said use the LIM gasket for that intake system. After that everyone was on the 3500 swaps with cam heads and other stuff I can't justify. Already have a "project car" to get back on the road. I did pull the snorkel from the front half it was just held in place by 2 metal rivets. Tip the throttle is night and day wot is little bit louder. I would have took pics but the new firmware for my phone crippled the camera and be being able to hang up phone calls. The air box I have is in this video...

14:18 is the time in the video when he takes it apart.


There is a little snorkel that goes from the filter side right under the ecu and shops short of the sealed hole in the fender. The video doesn't give it much lighting but it's like almost 2 inches wide and maybe 4 inches long. Removing this made the hole bigger on the filtered side "before the maf" and intake noise slightly louder. Not cold air intake distinct loud but less restrictive whoosh sound that still complies with NVH of a Buick.

Slightly off topic, my coolant overflow is behind the headlight sandwiched between the air box and my washer fluid bottle is under my battery. The century book shows different air box and that style washer bottle over the battery like in that video.

 

Here is a video of a regal placing the ECU on the body where the air box once was. I wonder how it's holding up since it has padding in the air box originally to "Keep it cool".

1:49 is the time

 

Wow, yours is much different than mine. That might have been one of the things that added in the power difference when they changed to the LG8

This is basically the same as mine:




I don't really like the idea of having the ecu exposed like that. It seems like its only asking for water to get in there and start corroding everything..

 

Just looking on google images, I found this picture. Its a 1997. Its only a warm air intake, but you can't really see what he did with the ecu..

 

On my other cars the ECU is way smaller and inside the car above the gas/brake pedals. Our ECU is sealed off to the elements even the harness are screwed on not cliped on.there is drainholes in the airbox where the ECU sits. It was wet inside when I opened it to get to the coolant resivior(as seen in the service video). Yours appears to be up by the firewall. Your zip tube is also difrent with that airbox no crazy 90 degree bends and what not.

2nd review on the snorkel removal mod:

Just barely taping the gas, the car floats like a V8. It holds speed of 36-44 mph on flat land with no touch of the gas pedal whatsoever to explain my last sentence better. 3/4 to wot while already moving took a negative effect to the snorkel removal. There is some delay in responce after you hear the throttle open up. It's almost as if the powerband shifted lower in the rpms on wot like a 0-60 in a silverado. Pretty much like where it stops pulling hard after 40ish mph. I will give it a few days to see how it plays out but IMHO I took it as a deterrant to wot vs barely opening the throttle and getting clean crisp acceleration. Once I get the subaru up and running I might get a slight computer tune and swap intakes. As I was saying earlier this is gonna be a mpg daily driver but my track history shows me never having 2 completely stock cars.

 

I'm not too sure about everything to do with the intake and ecu. They are two things I don't really like messing with. I haven't really paid much attention to either, other than taking the intake apart to access my Neutral Safety Switch a couple months ago.

I do know that the transmission constantly learns your driving habits and adapts to them, so maybe if you give it a couple days, and it will act differently to what you done.

I've noticed that my car holds anything under around 40mph very easily, with little throttle action as well. Its not something i really like, because i tend to find myself speeding a little too much in town. haha