The main reason the 4.4L STS-V engine is a tad smaller is that the block deck and cylinder liners were made "meatier" to allow more head gasket seal surface to possibly avoid 4.6 problems with failed head gaskets when adding boost.

They're also very different engines, parts and PCM (Powertrain Control Module) calibration-wise. You would need to re-map the entire PCM engine and transmission management programming. I have no idea on the fuel/air delivery and metering systems.

That said, it would be possible to supercharge or turbo the 4.6 - given enough time, machine work, and money (lots of money).

One of our members, Mark99STS, did a turbo install on his FWD STS, ran some impressive times/speeds, played with it a while, de-tuned it and sold it. Final turbo install cost was over $18,000 about 11 years ago.

 

You can find those Northstar superchargers on Ebay. I saw a couple, a few months ago. Maybe turn down the boost to only 5-6 psi to be safe for the 4.6, get it tuned,spend money. Then spend more money when something breaks, haha. Then more money on other things. I was thinking about doing this to my STS, but decided not to. If you want a faster car, buy the V, there are some out there. Or another car entirely. Mid-to-low 14s is decently quick for a large car, I don't fear the normal Hemi Chryslers at the stop light.

 

Ok thanks that helps a ton, I just want to get a little extra power i guess i can get more hp by doing air intake and an exhaust is there any other mods that i can do to make a little extra hp. Im also curious about how much hp can the 4.6l take before stuff starts to snap, bend, stretch or blow. Is the 4.6l a good strong engine compared to other engines?

 

From what I've read, the 06 and up Northstars are pretty good up to around 7000 rpm. Not sure about your 05. The STS has a well designed OE cold air intake, the intake valves have similar flow area to 2.02 on old school Chevy 350s, with a .476 lift cam. So, pretty decent intake flow. Exhaust side, long tube headers are available if you look long enough. Those, and a PCM tune, should get you another 30-40 HP.

 

How much hp can the engine take and would it be smarter just to get the 4.4l and save the hassle of trial and error if so what would it cost to make everything work like it does in a normal stsv. I would rather not get a turbo i was never a fan of turbos and i much prefer the screaming superchargers.

 

The best and least expensive way to get your original 2005 4.6 car to run a 4.4 supercharged Northstar powertrain is to jack up the rearview mirror and run a 2005 STS-V under it.

As shown in the video the turbo Northstar, with enough expert machine work, can take gobs of power. As posted, bring money and hope you can find some aftermarket support - which, for your car, is slim and none - it's all hands-on custom.

 

Funny! STS-Vs were made from 06 to 09, with most being made in 06.

 

Yup - the 2006 model year ran from about July of 2005 to June of 2006.

There were 2440 STS-V built - total, 1306 for the 2006 MY.

Just for grins, what's your 2006-V build date on the driver's door sticker ?

 

Yup - the 2006 model year ran from about July of 2005 to June of 2006.

There were 2440 STS-V built - total, 1306 for the 2006 MY.

Just for grins, what's your 2006-V build date on the driver's door sticker ?

Just checked. Mine is 04/06.

I'll probably hang onto it for 2 to 3 more years and then move on to something with newer tech. I'll see how I feel then. It's such a great car and mine only has 57k miles now after a couple of summer road trips. Sits in the garage a lot, but I love to drive it when I can.

 

So your car qualifies for the "Late 2006" designator.