Hey guys, I have an '03 Monte Carlo SS, the Jeff Gordon edition. It has the 3.8 NON superchargered engine. I know that engine comes supercharged in some models of cars and I would like to add one on to mine. Other than just bolting it on I know there is lots of other mods that need to be done, does anybody have any idea what these other mods are; eg. pcm change trany mods etc. Most importantly do I need to decompress the engine or replace any other internal engine parts. I am a journeyman mechanic but in heavy duty trucks so I am knowledgable and capable, just need to know the info or where to find it.

 

At least you're knowledgable, because there is a bit of work involved in order to install a supercharge on a non-supercharged 3800. Non-supercharged 3800's are known as an L36, and supercharged 3800's are known as an L67.

In order to "add" a supercharger to a non-supercharged 3800, you have to swap your heads, LIM, UIM, fuel rails, t/b, etc for all of that from an L67. This is commonly called a "Top swap". Do a search on that and you will find many people who have done it, and get loads of information. You can also find some info here: https://montecarloforum.com/forum/en...-bumpin-24896/

You will have to do some mods in order to run the stock size s/c pulley (which is a 3.8" pulley). If you installed an air intake and headers, then you will have no problem running the stock size pully. The reason why the stock size s/c pulley is too small is due to the higher compression that you will have being that you're starting out with an L36. L36's compression ratio is 9.4:1, and an L67's CR is 8.5:1. That means that you will gain MORE power then you would if you had just swapped an entire L67 in. Also, don't mess with the internals, they will be fine. Our 3800's usually do worse after the bottom end is redone and I have personally seen a Grand Prix with a 3800 that put down 385whp without nitrous and lasted 264k miles (he was almost making 450whp with nitrous).

I highly recommend doing a top swap. You will ABSOLUTELY need a PCM reflash, and a built tranny will be a must too, considering that our tranny's don't even like stock 3800's. Get a built tranny from www.tripleedgeperformance.com (they're the best with our 4T65E tranny's).

Anyways, I hope that helps. Make sure you check the links that I posted and do a search on "Top swap".

 

Thanks zip! It will be a bit before it happens, I just like to know what I am in for and research in depth so I don't get any surprises!

 

No problem. The more you know the better!

 

L32 or l67 swap. It will save you sooo much effort.

 

i have thought about a swap but my bottom end is strong and I don't mind the challenge as loong as I know the obstacles.

 

Last year my 2003 Monte SS with the L36 (non SC) was closing in on 198K miles and I was looking at a rebuild, top swap, or just swapping the entire thing. I chose the latter, partially because as I was deciding the Monte developed an issue with the pressure control solenoid in the trans - basically, it started slipping. Dealer wanted $700 to diagnose whether the solenoid swap would fix it or if I needed a rebuild.

Long story short, I chose an entire swap. With those miles and trans issues it made more sense. We took the PCM and harness, front axles, L67 (SC 3800, with 49K miles by the way) and the trans (the beefier 4t65e-hd instead of the non-hd model on the L36 like you have and I had).

I had it done for me since it was more than I could tackle - took them about 10 hours of labor to swap everything and I was on my way. I got the engine from a well known to the board Cleveland company that specializes in GM FWD. I highly recommend them if you are anywhere close. I drove nine hours each way for the motor and install. Spent the time with my wife at the Rock and Roll Hall of Fame while we waited for the car.

And yes, I drove a car nine hours to get home after having that level of surgery done on it! No issues along the way that caused any delays. Trans felt much better coming over the mountains on the way back to NJ too.

 

Hey guys, I have a line on a 3.8L SC from an '01 Bonniville with a good top end. Apparrently it blew a rod bearing or something. Will this top end work will my '03 Monte? Just want to know if it is worth checking out.

 

hay kramer241 if you are interested on doing a top swap imo i would still check the heads just to be on the safe side after that i would go all the way with the swap. what i mean is you did say the block threw a bearing it had a chance to tap one of the heads. if you do a check a a meachine shop you will have a chance to get the valve guides changed as well get them ported and polished if you want as well.

 

Hey Monte, ya I would for sure get the heads done, i can get them done for about $100 a piece. I was just wondering if there is a huge change in three years that they won't work with my car. Stuff like bolt holes for engine mounts and the A/C and alt. bracket.
Also does anybody know if I can take and get my PCM reflashed to handle the SC or do I need a whole new (different) PCM?