Intake manifold research

[Dave]

Hey guys, I have a T1 intake that came off my Spirit. The elbow blew apart on it so I was thinking of cutting it open and trying to do some work to the plenum. I've seen someone on here taking a 3.3 TB and elbow and welding it to the plenum.

Just wondering what I can do to improve some performance on it.

Thanks,
-Bryan

[shadow88]

Almost anything is an improvement. Do you plan on swapping elbows? Or a whole new upper plenum?

[Dave]

I'd like to swap the entire upper plenum. I'm not sure if there is any much of a difference between the 1 piece and 2 piece intake runners. I know a lot of custom manifolds with large box plenums use a 2 piece lower plenum, but is that just for ease of fabrication?

[shadow88]

I couldn't tell you what's easier. I hacked-up a 1 piece. I think "8 valves" intake manifold from lwp used a stock(ish) lower half and a custom plenum.
Here's mine. It's kind of a step-by-step. It wasn't very easy to do but it makes a big change in the engine's power.

http://www.turbo-mopar.com/forums/showthread.php?t=3234

[Dave]

Shadow88 - thanks! That helps a lot. I think I'll go grab my good manifold and just try it out. I have plenty laying around.

Was that 6061 aluminum you used?? How thick was it? Did you do anything to the runners, or is the only thing you did was just add the box plenum?

I asked Wallace White about this and he agrees, just increasing the volume in the upper plenum helps tremendously.

[8valves]

I'm not sure what you're exactly asking for- but increasing volume will help you the most for the least effort. There is a lot more that you could do that will continue to help, but unless you have the supporting mods to take advantage of them, it may not be worth the effort.

AM

[Dave]

Aaron, I have a T3/T04E being looked over by Cindy at the moment. I'm building up a G-head with +1 valves and a mild port job. A bunch of other goodies. So I'll have the stuff to make use of it, I think.

Just trying to get some opinions of how to build a box plenum. I have a local machine shop that does tig and mig.

[Garret]

Give me a 150 dollars and that T1 manifold and I"ll make you a fancy one like mine

[shadow88]

Shadow88 - thanks! That helps a lot. I think I'll go grab my good manifold and just try it out. I have plenty laying around.

Was that 6061 aluminum you used?? How thick was it? Did you do anything to the runners, or is the only thing you did was just add the box plenum?

I asked Wallace White about this and he agrees, just increasing the volume in the upper plenum helps tremendously.

Glad it helps. I have no idea what aluminum it is. It's 1/8" think and has been pressure tested to about 25 psi. The runners are much shorter and have a nice blend into the plenum.

If this is for your caravan, you may want to consider longer runners. = more low end torque. It fits the stock 1 piece fuel rail like factory.

This with a tbi header picked up a traction limited 6 10ths and 8 mph.

[Dave]

Give me a 150 dollars and that T1 manifold and I"ll make you a fancy one like mine

Can I get pics??

[Garret]

http://www.turbo-mopar.com/forums/showthread.php?t=8505