A little off base, there John. ALL internal combustion engines, including your riding lawnmower, will benefit from the least-restricted, most direct, most laminar breathing path for the intake. It doesn't matter if it'* a YUGO or a Ferrari.

Actually, you have that exactly backwards. The modern 3800 was in fact designed by a performance engineering team. And then adapted for lighter internals and free-er revving. The LD8 is directly descended from a luxury, smooth, quiet family of engines. It is not a 'from the ground up' performance engine.

If we stopped modding based on one person trying something, and never went further, we'd have some pretty slow cars here. There is every possibilty that you overlooked something critical, or didn't notice something, or had something different in some way. We've seen some L36'* respond well to a removed MAF screen, and others not. Some do, some don't. Same principal.

Well, that'* actually for HIM to decide on his own car, since he is the owner, and not us. Considering he'* interested in the Mod, I asked him to pull it out of there AND TAKE PICS. Not go fast and loose with a dremel. I'm sure he'll be well aware of any potential risks before he begins cutting or replacing any components.

I don't recall ever accusing you of being young or naive. But at the same time, I also recall seeing some work done recently to a bunch of L36'* who aren't supercharged, and they benefited greatly from it. All the air you can get in ANY internal combustion application is a benefit to performance. The engine is an air pump. If you increase it'* efficiency and allow it to pump more, you will get more power. That is a physical law. Not a theory. The trick is identifying the largest restrictions in the system one at a time. That takes trial and error. In this particular case, I think it makes much more sense to go after the easily-accessible 'exterior' components rather than ripping gaskets apart. Again, that would be the decision of each individual car owner.

Light years? I guess the laws of physics and internal combustion engines changed after the last Northstar I owned, or the last new engine I had? Or the last two brand new cars owned by friends that were in my driveway last month for some very successful performance improvements in their airboxes? I'm not being condescending, John. I'm making a point. The LD8 is not some magical sooper-de-dooper piece of engineering that cannot be touched. It'* an engine, and it'* been around for quite awhile.


Again, John, this is your experience on your car. I think rather than throw the whole idea out the window, perhaps we should see what other cars look like, react like, and perform.

So back to the topic at hand:

As I stated above, let'* get that airbox out of his car and LOOK at it. We'll make suggestions for HIM to decide on based on our knowledge and experience. It'll be up to him to decide which path he takes, and he will fully understand there may be risks involved. This isn't rocket science, and it'* not a total departure from engine design and control. I find it humorous that the guy running Nitrous through his LD8 is concerned about damage to another from simply improving his intake design. Last time I checked, the risks of running nitrous are some of the most extreme that can be encountered in modifying engines for more power.

Gutting an airbox, should he choose to go that route, isn't going to cause any permanent damage. Potential cost? Sure. Unless he starts with one from a wrecker first. The first L36/L67 gutted boxes started that way.

And if the MAF/PCM combination is so sensitive, why do Summit and JET both offer larger wide-open MAFs for performance for the LD8? Think further and wonder if the magic combination for better flow might just be a combination of one of those MAFs and either a gutted airbox or FWI?

I think a scantool would be an interesting thing in the hands of the right GXP owner. Datalogging capability would be nice.

i think there is a variable that has not been mentioned yet.....

the actuall heat soak/ intake air Temps in a Gutted Stock AIrbox VS FWI

i am running a Gutted airbox and have seen upwards of 120-130* while the car has been turned off and left for a good 2 hours

and also the car does not cool down when the car is restarted and driven.....For instance

drive the car for 20 min on 100% highway, temps in the 70s....intake Temp 80'*
go to the store come out 30-45 min later intake temp is 130+
get back on the highway for another 20 min ride back home....temps in the 70'* intake never gets below 95*

now that being said, and we know that one of the paramaters of Ignition advance is the cars intake Temp

and also with an FWI the car will get the Lamniar flow because of the Design of the tubing.

either the GUT method or the FWI method there are improvements that can be had

Hi everyone

Interesting points you make there Pat ole buddy.. however my experience with what I consider to be the most insulated FWI on the market is slightly to the contrary. The IAT on my FWI and Travis' were both reading upwards of 120-130 after not sitting still, but merely slowing down and hitting a little traffic for under 3 minutes.

It also takes them a certain amount of time to cool back down.

However..I do not find anything to support any problems running my timing as if my intake temp was ambient, sitting still or moving. As long as the GXP boxes get air from a reasonably cool spot in comparision to engine heat temps.. they should work well.

Not seeing or knowing anything about the flow characteristics.. I'm zipped as to FWI or gut.

pictures are on the way...

Although I do not think a FWL or a gutted box is needed maybe just some modifications to the stock box are required. Maybe extending the pipe from the inlet to fill in the hole..
















I think just closing this hole off here would increase air flow... and Personally this is where I would start then go from there. I'm not going to be doing any mods untill I have my Dash Hawk.




and maybe this is the answer to DRL'*??

I have read up alot on air intakes with regards to the N*, and from what I can tell gutting or putting in a custom intake will not net you any benefits except more noise. If it had any benefits, I would have already done so on the Cadillac.

The Northstar is a performance engine, and it already has been pretty well engineered for that.

Wow, umm. I may not be the mechanical genius that some of you guys are, but that box looks like butt for airflow. Every place the air has to take a turn is open to the rest of the box and totally nondirectional. In other words, you have massive turbulence at every place the air changes direction. Even gutting is still gonna leave a lot of turbulence. I think a tubular intake would be a massive improvement. Especially over that accordian tube behind the MAF. Thathing is at an angle where the flow is going to be right along the pleats, rather than down the center of the tube.

Well you haven't looked since there are intake boxes out for Cadillacs...

I was considering putting on in the GXP but I don't think it will fit.

In a NUTSHELL, ever car in the world can be improved with respect to air intake. Will the changes cause other changes downstream? Possibly. One change usually leads to (or causes) another. There is no 'perfect' solution, but you can improve in steps if you're willing to try.

Having the attitude that "I tried and failed, so don't try" or "I heard it wouldn't work" is what causes stagnation in any idea-ridden society.

Imagine what the Wright Brother'* neighbors were telling him, or maybe even Noah'* neighbors. Good thing those three guys didn't listen.

If it'* an internal combustion engine, it needs air. If you give it a better, shorter, more laminar, or higher velocity path to that cold air, you will benefit.

Yes, they are out there, but it doesn't mean that it will work.

The whole point is not "it doesn't work so stop doing it" or "I heard it doesn't work, so dont bother". It is that it HAS been tried, and there is very little benefit to gain unless the engine has been extensively modded. The air intakes on these Northstars are very well designed and are hard to outflow stock. There is more benefit by reworking the exhaust. This is the consensus after many tests and discussions with the Cadillac install base. Here'* a couple of helpful links:

http://www.cadillacforums.com/forums...ntake-not.html
http://www.cadillacforums.com/forums...take-99-a.html

You can go ahead and try, then report back here what your findings are here. But we've already have one real world test done here so far and the finding is that there is minimal benefit.

Like I said I think I'm going to start by filling in this hole. Maybe that will smooth out the air flow into the Filter. then Maybe redo the tubing from the maf to the intake