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98 STS Airbox


speedyman_2

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Well I want to mod my airbox and put in a K&N filter. Like the one on here with the 4.0 Northstar. I tried the other day and it was pretty simple to remove the upper portion of it. But there is another piece under it that curves down and then back up. I dunno how many of you have seen this, but I can't get that lower part off. It's stuck in there pretty good. Seems like I would have to remove the bumper cover to access the bolt that holds it in. ANyone know how to get this thing out??

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Read this thread before you use a K&N filter

http://caddyinfo.ipbhost.com/index.php?sho...5147&hl=k&n

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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Do me a favor? Make sure you let CARFAX know that you did this, you can add 20,000 miles to the clock when you sell it... :lol::lol::lol:

Here is some data for you to review:

http://www.caddyinfo.com/airfilterstudy2.htm

K&N actually hurt performance, what you are hearing is MORE noise, which you perceive as more power. The problem with that is that you are sucking in more dirt. If you don't mind more dirt for less performance and more noise, Cool...

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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Is the PCM in the airstream in your car? On my Deville, intake air flows over the PCM to help cool it, I would be reluctant to disrupt this arrangement.

Was this piece pulling in air from behind the headlights? Are you now pulling in hot air from under the hood or did you replace that piece with a pipe that pulls in cooler air from outside the engine compartment?

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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Speedyman, it makes you wonder how a piece so benign as that could cause such a restriction in airflow. Some cars seem to respond well to removing things like that, and on some cars, it doesn't make a lick of difference. It would be nice if you could quantify how much "gain" you really got, with a chassis dyno. Seat of the pants experience leaves a lot to perception, but a chassis dyno never lies. I know you're not going to go out and spend 100 bucks just to prove to us that removing the silencer helps, but I wanted to toss the suggestion out anyway. :)

Ride on...

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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Is the PCM in the airstream in your car? On my Deville, intake air flows over the PCM to help cool it, I would be reluctant to disrupt this arrangement.

Was this piece pulling in air from behind the headlights? Are you now pulling in hot air from under the hood or did you replace that piece with a pipe that pulls in cooler air from outside the engine compartment?

Right now it's still pulling air from under the airbox. Where that piece was getting air from. I'm going to take a piece off of it to seal it from the hot air. It will be the same air it was using, if not a cooler air supply.

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Well, lets all think about this for a minute…Do you really think the engineers that designed that engine put that piece you removed from the intake there just for sh*ts and grins? Do you think they deliberatly robbed horsepower and added cost?? C’mon. Lets think some more. Maybe,… just maybe that box was designed using the best available methods and the result was a heimholtz resonator, used for equalizing the audible airflow. Would they have left horsepower on the table just for that? No. Would the engineers cut holes in the air channels and greatly increase the probabilities of hydrolock (complete engine destruction) for a perceived but unproven gain No.

What they did was spend a WHOLE lot of thought and design dollars on a system that gave the best airflow, least noise, most safety and most horsepower. More noise does not = more power.

I for one would not botch a good design. ;)

Did I mention cooling of the PCM..?

'93 STS.. opened, dropped, wide...fast.

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Well I want to mod my airbox and put in a K&N filter. Like the one on here with the 4.0 Northstar. I tried the other day and it was pretty simple to remove the upper portion of it. But there is another piece under it that curves down and then back up. I dunno how many of you have seen this, but I can't get that lower part off. It's stuck in there pretty good. Seems like I would have to remove the bumper cover to access the bolt that holds it in. ANyone know how to get this thing out??

I have had a K and N air filter in my Caddy for about 20,000 miles and have had no problems with it. I subscribe to GM Hi Tech Performance and I have seen many cars in that mag that are fast enough to suck the grill of any Caddy that I have seen and I have seen that a majority of those cars are using K and N air filters in their cars. Most of the owners of those cars have a ton of time and money invested in their car so I would think that if they knew the airfilter would damage the motor in their car that they wouldnt put it in there. If you want a K and N put a K and N filter in your Caddy, just make sure you oil it up real good when needed.

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Those cars are not Northstars are they? You may not have had a problem, but I doubt you had any gains either. At least none that can be proven (it feels more responsive, doesn't count). I have also heard of people having drivability problems. Turned out that the oil coated the MAF sensor. The air filter is not the restrictive point in this intake system. It will flow all that is needed.

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Well I want to mod my airbox and put in a K&N filter.  Like the one on here with the 4.0 Northstar.  I tried the other day and it was pretty simple to remove the upper portion of it.  But there is another piece under it that curves down and then back up.  I dunno how many of you have seen this, but I can't get that lower part off.  It's stuck in there pretty good.  Seems like I would have to remove the bumper cover to access the bolt that holds it in.  ANyone know how to get this thing out??

I have had a K and N air filter in my Caddy for about 20,000 miles and have had no problems with it. I subscribe to GM Hi Tech Performance and I have seen many cars in that mag that are fast enough to suck the grill of any Caddy that I have seen and I have seen that a majority of those cars are using K and N air filters in their cars. Most of the owners of those cars have a ton of time and money invested in their car so I would think that if they knew the airfilter would damage the motor in their car that they wouldnt put it in there. If you want a K and N put a K and N filter in your Caddy, just make sure you oil it up real good when needed.

Did you read the links I posted above fully? If you didn't please read them and if you still have your opinion post again. One of the links I posted showed less performance with the K&N.. If you can show data to support your opinion that would be helpful, I posted data, quite a bit of it... Make sure that you see that the K&N filter passes more dirt and that the oil has fouled the MAF sensor as Ranger noted. Personally I don't care who uses them, if I don't see dyno data, it means nothing, and to date, I have never seen dyno data. When I was a kid, I used to take the air cleaner off my Dads 429 Caddys (no comments please) to let that Carter AFB roar, did it make the car any faster, probably not, did it sound cool, sure did, did it sound faster, oh yea, it wanted to suck the hood in, did I set fire to the hood insulation, sure did! :lol:

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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Well, lets all think about this for a minute…Do you really think the engineers that designed that engine put that piece you removed from the intake there just for sh*ts and grins? Do you think they deliberatly robbed horsepower and added cost?? C’mon. Lets think some more. Maybe,… just maybe that box was designed using the best available methods and the result was a heimholtz resonator, used for equalizing the audible airflow. Would they have left horsepower on the table just for that? No. Would the engineers cut holes in the air channels and greatly increase the probabilities of hydrolock (complete engine destruction) for a perceived but unproven gain No.

What they did was spend a WHOLE lot of thought and design dollars on a system that gave the best airflow, least noise, most safety and most horsepower. More noise does not = more power.

I for one would not botch a good design. ;)

Did I mention cooling of the PCM..?

well lets think about this for a minute. on every car i have ever seen that had a aftermarket intake installed on they make more noise and make more horsepower. lets take the exhaust system for another example. adding a flowmaster muffler or a free flowing exhaust of some sort or another, builds power or torque or both on just about any car out there. other than very expensive supercars. and those exhaust systems make more noise. all because horsepower is left on the table to make it quiet. and any car out there that has had either of these done to it and did not make and increase in horsepower, torque or both. then the computer needs to be reflashed. you dont just strap a car to a dyno and just look at what the bottom line performance #'s are you have to look at the all important air to fuel mixture printout from the dyno run. if you dyno a car bone stock and it made whatever but made a/f curve of 12:1 all the way up and then put on a intake and exhaust that a/f ratio is going to be probably like 11:1 or lower which is going to loose power or have a very small increase or i have seen them start off at 9:1 and end up at 16:1 just from those mods on various different cars. now if you go back into the computer and adjust that a/f ratio to have a smooth curve of the orginal 12:1 that power is going to go up by alot more. if you guys are installing k&n air filters or other modifications and are loosing power then u need to address that a/f ratio. i would like to thank everybody for reading this i hope this will be of further help in your pursuit for horsepower. by the way this is not speedyman_2 this is his friend pro94 of rangerpowersports.com.

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How do you propose adjusting the a/f ratio on the Northstar?

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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then the computer needs to be reflashed. you dont just strap a car to a dyno and just look at what the bottom line performance #'s are you have to look at the all important air to fuel mixture printout from the dyno run. if you dyno a car bone stock and it made whatever but made a/f curve of 12:1 all the way up and then put on a intake and exhaust that a/f ratio is going to be probably like 11:1 or lower which is going to loose power or have a very small increase or i have seen them start off at 9:1 and end up at 16:1 just from those mods on various different cars. now if you go back into the computer and adjust that a/f ratio to have a smooth curve of the orginal 12:1 that power is going to go up by alot more.

Wow!...

Where to begin...

OK: Long version

This is all correct if you are running a carburetor. Or what’s know as a MAP driven fuel injection system. In these cars they are programmed from the factory to dump in a certain amount of fuel for a given RPM, temperature and engine load. These EFI and Carb systems are basically "dumb"... Carbs are long gone and I think MAP systems are only found on a handful of domestic trucks these days…

Northstars and most other modern engines (built since the late 90's or so) use a fuel injection system based on MAF (Mass Air Flow) In these cars, they actually measure the amount of air the engine is sucking in and then AUTOMATICALLY (and correctly I might add) adjust the air fuel ratio to whatever the engineers deemed optimal (usually 14.6:1). So if the new filter helps, the computer would see all of the extra air, dump in more gas and ta da more power!! Of course lots on this board argue the stock air intake system is already plenty big… And making it bigger will not help a Northstar suck more air.

OK, given that, where do we go from here? First no performance chip exists for the Northstar (at least not now... probably never). GM’s position on this engine is (as I recall from our fav pEng) that it contains too much proprietary, information to assist the aftermarket in producing chips… Of course GM’s position on the LS1 (and relatives) is 180 degrees in the other direction, but that is a different story.

Do the chips work? Yes. Usually they work by causing the engine to run a fuel ratio closer to 12:1 (the magical max power ratio) versus the 14:6:1 ratio which minimizes emissions. One hot rod trick in the early days of electronic fuel injected cars was to fiddle with the engine coolant temperature sensor… If the computer thought the engine was cold it would richen the mixed to provide for engine warm up. This ham fisted approach almost always made power… But you had no guarantee what ratio you were getting. On some engines this just wasted gas as the warm-up ratio was about 10:1 (which hurts both power and emissions)

Short version:

1) If the K&N cone helps; the Northstar computer will add the extra gas without a chip

2) If a chip exists, it would add even more gas at the expense of fuel economy and emissions and yes the Northstar would probably make even more power.

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Greg

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I understood it the other way. Our resident expert has said before that given the other conditions in the engine, they could have made more power by keeping the mixture lean at WOT, but they artificially enrichened it to protect the pistons from meltdown. He stated that many aftermarket chips (including ones for the OBD-I Northstar cars) do not necessarily enrichen the mixture at WOT, so the possibility is there to see more power, but at a hightened risk of engine damage if you use poor gas. That's also why they apparently state that you MUST use premium fuel with a lot of those chips. So you don't melt your engine down with the leaner mixtures they run.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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I understood it the other way. Our resident expert has said before that given the other conditions in the engine, they could have made more power by keeping the mixture lean at WOT, but they artificially enrichened it to protect the pistons from meltdown. He stated that many aftermarket chips (including ones for the OBD-I Northstar cars) do not necessarily enrichen the mixture at WOT, so the possibility is there to see more power, but at a hightened risk of engine damage if you use poor gas. That's also why they apparently state that you MUST use premium fuel with a lot of those chips. So you don't melt your engine down with the leaner mixtures they run.

You are correct, Sir. ;)

'93 STS.. opened, dropped, wide...fast.

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Those cars are not Northstars are they? You may not have had a problem, but I doubt you had any gains either. At least none that can be proven (it feels more responsive, doesn't count). I have also heard of people having drivability problems. Turned out that the oil coated the MAF sensor. The air filter is not the restrictive point in this intake system. It will flow all that is needed.

I'm not sure if any were Northstars I'll check my back issues, but most were street driven cars. If oil got on the MAF sensor then they probably used way too much oil. :blink:

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Most of the long time members are (I'm sure) are having a chuckle over this topic. Simply because most of us at one time or another have tried the K&N air filter (hand raised) and/or modified the airbox. What was the overwhelming conclusion you ask? Nothing.

But let's face another fact. There will always be those that think they know better or that they came up with the brilliant idea/fix. Some call it youth. Some call it being naive. If it makes speedyman2 feel better to try/do what the rest of us have already done then by all means let him have at it ;) . I know I went against the grain only to come back to the flock myself..... and many of you forgave me :lol:;) .

For real and effective power mods I believe Mark could show you the light when it comes to the N* engine. I believe the expert even gave him the nod as well.

"Burns" rubber

" I've never considered myself to be all that conservative, but it seems the more liberal some people get the more conservative I become. "

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I know I went against the grain only to come back to the flock myself..... and many of you forgave me :lol:;) .

We did? :lol:

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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http://www.jnjhome.net/cadillac/filter.htm

There is my experience with the K&N filter. To K&N's credit, the performance loss I saw (or at least the lack of performance gain) probably had as much to do with my lack of a sufficient heat shield as anything else. There seemed to be more power at redline, but there also seemed to be less throttle response at cruising speeds. I say "seem" because I don't have any dyno numbers to validate anything. The only objective result I could bring to the table is a decrease in fuel mileage...I assume because I had to use more gas because of the reduced power at lower speeds.

But performance measures aside, the one reason why I continue to not recommend cotton gauze filters like that is dirt. Go to bobistheoilguy.com. Click on the link on the front page to air filter test. It's about as scientific and OBJECTIVE of a test as I've ever seen. Yeah, of course K&N says their filters are cleaner. Take a look through them...you can look right through it. There's nothing standing between ambient air and your engine but a thin film of oil. That's not a filter.

Dig through the bobistheoilguy.com message boards and you'll find as many references to INCREASED silicon content in used oil analysis as DECREASED silicon content (silicon = dirt). To me, the extra 1hp you might get isn't worth the risk of possibly allowing more dirt into the engine. If I went through the trouble to perform a used oil analysis everytime I changed the oil to prove to myself that the filter works better than paper, sure, I might trust it. But it's not worth the hassle to me, or the cost for all those oil analyses.

Performance gain or not, I'll never have anything but a real paper air filter on any of my vehicles.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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Yeah.  I've scratched the K&N.  I'm going to get some colder air routed in and put on a new paper filter.  More fabrication to be done.  Updates later.

Looking forward to the updates.

It will be educational to hear about the documented air flow improvements you are able to develop that the vast ($$$) engineering resources of GM somehow missed.

This daily Cadillac driver is willing to give up a miniscule potential intake air flow 'improvement' when it comes at the cost of even more miniscule possibility of water ingestion.

Keep us informed.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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Yeah.  I've scratched the K&N.  I'm going to get some colder air routed in and put on a new paper filter.  More fabrication to be done.  Updates later.

I love researched info; if you can please post dyno before/after or gtech pro or similar accelerometer or track times before/after.

Mods are great if they work. I still wanna know why the SRX v6 makes 260hp and the CTS makes 255 hp; I want my 5 hp darn it.

Bruce

2016 Cadillac ATS-V gray/black

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