I'm planning on a homebrew supercharger modification for my JKUR. I have a TS charger from a Mazda Millenia on the way. Does anyone know how the inside of the upper intake manifold is designed? Is it basically an open chamber with the six outlets on the bottom or are there passageways that route air from the throttle body to the six outlets? Any cross section pictures, drawings or CAD models would be super helpful.

 

Your best bet is likely going to be running over to eBay and looking at used intake manifolds and engines. I think you'll be able to get a good idea of what it looks like from there.

Best of luck with the project, we look forward to it.

 

Not sure if the JK software has provision for forced induction setup in the tune. For some reason my Chev 5.3LT engine does as I see it in the software when I am making changes for my Jeep but it is for turbocharging not supercharging. Most likely you will need to look into that in your planning as that tuning ability may have the algorithm already to ensure the transmission shifts at the right power settings with the FI. Your best bet is to get hold of HP Tuners ($299) and pay the 2 credits access ($100). I am not sure if the other FI suppliers provide piggyback cheater modules to overcome this or if they change the core Jeep program.

 

Fellas -

Thanks for the replies.

I was debating whether I should try to fab a custom upper manifold to accommodate/support the supercharger, hence my question about internal design.

After some research, I determined that the 2001-2002 Dodge and Chrysler minivans with a 3.8L used an aluminum upper manifold that is very similar to the plastic one in my Jeep. I went to a local pick-n-pull yesterday and grabbed these.


Full intake: upper and lower manifolds and throttle body

Air box and fresh air feed


My current plan is to modify the upper manifold by cutting out a section and welding on a flat aluminum plate. This will provide the mounting surface for the supercharger. I will cut a hole in the plate to match the SC outlet in order to feed the plenum. I’ll block the throttle body intake on the manifold and mount my Jeep’s TB to the SC input port. I think that I’ll only need the upper manifold, but I took the other parts from the van just in case my Jeep parts don’t directly swap over. Then I can mix/match as needed to make it work.

Here are a couple of pictures after I cleaned the upper manifold.



Before

After

After

 

I’ve talked to a local dyno shop that has Diablo about my project. The owner has experience modding Jeeps and can create a custom tune once I’ve got the mods installed.

 

Also, to close the loop on my initial question, there is not a special internal structure in the plenum. Here is a pic.

 

Best of Luck, on the project.. Keep us updated

 

This is going to be an interesting project. Definitely looking forward to following along.

 

So you said the plenum was very similar- could it be a direct bolt on and is there any reason to go aluminum over the plastic (aside from awesome looks instead of a hunk of plastic)?

 

Wait... you guys are saying the whole upper intake manifold is plastic? You sure it’s not just a painted aluminum? I’d be surprised if it were plastic and they’re holding up to thousands of heat cycles and tens of thousands of miles.