Prototype Two Piece Intake?

I have seen one other intake similar to this one, but it was more traditionally finished. When I saw this one recently for a good price, I knew I had to have it. There are differences everywhere on the intakes and I'll try to point out some of them which are more interesting to me. If anyone has information about this piece, please post up. I would love to know about the history of two piece intake development, or perhaps some crazy situation which caused a small number of these to be made by a different supplier.

From afar, they look nearly identical with the exception of the wrinkle black on the production intake.
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First thing that will jump out at most people is the lack of a 4th rib on the intake. Sure, there's the infamous 5 rib, which is better than the four, but is the three worse than the four? We'll get to that in a bit.
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When it comes to the main body of the upper half, there is a noticeable lack of a parting line. There is also no provision for a 3/8" NPT hole on the front side either. The finish on the "prototype" unit is significantly more smooth than on the production piece. This isn't just the lack of a wrinkle finish either.
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At the front of the neck area, there are a host of differences. One can see that the proto unit is set up to have a PCV pipe attached to the boss in the production unit that was threaded for use in holding the support bar that bolts to the head. The opening is slightly larger on the proto unit for the TB, but the flange has much more meat around the opening on the production piece. There appears to be a port for the AIS to vent through on the pre production unit. It is flush with the face of the flange and pressed in before being bent from the looks of it. It curls up and toward the passenger side. I have no idea why that was done. Lastly, there is the charge temp sensor threaded into a boss which is unused, but still remains on the production unit.
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I didn't realize until I began to take pictures for comparison purposes that I grabbed my two piece that had been poorly ported before my purchase. Although it was a real bargain, and not hogged out too far to be saved, it makes this comparison more difficult. There has certainly been some material removed on the production piece, but one can still clearly see how much less the humps intrude into the runners. That makes sense, as the outside measures well over .1" more on the proto intake.
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Note the orientation of the knock sensor on the prototype piece. It would have been much easier to swap them out if it would have remained at this angle.
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One less port on the back side of the proto unit too. There is also a huge difference in the portion which sticks out to hold the wiring bracket for the AIS and TPS. No boss on the back top side of the TB flange is present and it shows how much smaller the neck is than the stock piece. If you know the differences in the flange size.
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These photos help to illustrate the differences between the size of the neck leading to their respective plenums. The proto piece is much more pinched off and abrupt. This would not be good for porting at all. With how easy it can be to go through the casting on the stock piece, I would think this prototype intake would require a lot of welding to make a satisfactory transition. It may not be noticeable, but the proto plenum is significantly narrower when measured from the front near the valve cover to the back of it near the firewall. It's not a huge difference, but given the length of that piece it probably makes a surprising difference in overall volume. Again, not good at all when trying to make power.
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While there are a couple different casting numbers on the prototype piece, one being on the bottom side of the lower, and the other on the under side of the plenum piece, that's all you get compared to the stocker. The Pentastar, firing order, "normal" casting numbers, cylinder numbers, and Ace/co. logo are all missing.
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If you haven't noticed it yet, another huge difference between the two is the extra bolt on the back side to hold the middle rear portion of the top piece to the lower on the production unit.
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Some small details, which may not be that apparent are the casting flash in a few places on the proto unit. they are very rough indeed.
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Other than that, the arches in the casting where the runners meet the head are a different shape, and as I've mentioned, the runners are physically larger on the prototype unit on the lower half. It's a mixed bag on the upper half of the top piece for both. Some parts seem wider, and others narrower.
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At the end of the day, I'm sure a lot of people are wondering which would have been better for overall performance. I'm of the opinion that we're much better off with the stock piece. Not only does it have a cool 4th rib, and 5Digits has definitely taught us that more ribs on an intake are better. Not to get too math nerdy, but it's not even a linear relationship. The more ribs one has on their intake, the exponentially better. In all seriousness, the added plenum volume of the stock piece, combined with the better throat area at the entry to the plenum will carry the day. Sure, there is less area to work with in the intake at the pinch points where they clearances for the bolts, but with a few dabs of tig glue, one can completely remove those humps if socket cap screws are used. I actually can't imagine what work would need to be done to this prototype piece go achieve the same plenum entry possible by welding up the passenger side of the TB flange before porting.

I think the final word on this piece is that it's a cool piece of history, and certainly better than the one piece intake. It might find its way onto the Turbomom van in the next year or so, but that will be up to my wife when it comes time. Until then it will sit atop the two piece intake pile in the basement; oldest and still king of the hill.

Having some insight on the development history would be cool. But I might be one of a few that find those details interesting.

Wouldn't Stu Davis know the history on this really well?

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Originally Posted by Reaper1

Wouldn't Stu Davis know the history on this really well?

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I believe he would have exceptional insight into this. If anyone knows how to signal him, that would be great. I'll see if I can find his thread on the engine development, but I'm still having a hard time finding the CS racer derlrin control arm bushings posts, you mentioned, so you might be up for this one.

We all find it interesting!!

Here's a link with some great discussion.

Thanks
Randy

http://www.turbo-mopar.com/forums/sh...ight=STU+DAVIS

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Originally Posted by Saturn Five

Having some insight on the development history would be cool. But I might be one of a few that find those details interesting.

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Wow, awesome read. I love seeing “preproduction” stuff or at least prototype factory parts... i need to check into this “5th rib” intake yall speak of...

~Mark