IE 2.5L 5 Cylinder Engine Dyno Project - Part Two

For the last few months, we've been working on various products for the VW / Audi 2.5L. After successfully installing it on our engine dyno, and getting the bone stock engine running on a Vi-Pec V88 ECU, we were able to start development work.
Since then, we've been working steadily on developing parts. Principally, our engineering staff has been working on a short runner intake manifold. So far, with just the addition of the manifold, we have been able to bump power output by about 40 horsepower- however development work continues. First we look at the valve sizes, cam lift curves, and other engine characteristics, and determine a baseline runner size and length. Then a manifold is carefully computer designed around these characteristics, and flow optimized using CFD.
However, this is basically just a rough draft... It's not too carefully detailed, as many changes are expected during the development phase. This model is taken and chopped into parts which make it modular. This allows us to create new prototype sections and test changes to the plenum, lowers, or runners, without creating entirely new prototypes every time. We call these development mules...
Next, our engineers use our Stratasys 3d printer to create functional, full scale prototypes out of ABS plastic... Through experience, we have determined the proper process to successfully run these parts directly on the engine. This gives us engine dyno power and flow results long before any designs are committed. Many companies would outsource this work and print only one manifold prototype to check fitment. In contrast, we typically will test as many as 20 refinements to a manifold design- everything from runner length, shape, size, and injector placement is checked... Below are some prototype parts from the development process of this 2.5L VW Part... Check them out!
Rapid prototyped ABS development mule on our VW 2.5L test engine... Note the modular construction.
Here are some of the sections by themselves... You can see this particular one features a large diameter velocity stack with a very generous corner radius. Below it is a runner section- notice the injector placement is different- one is stock, the other one moved upstream somewhat. These sections are printed layer by layer out of actual ABS plastic... We have even used them on boosted engines before.

With the parts ready to go and assembled, dyno testing is the next main stage. We have been testing different configurations and designs for this manifold for several months now, and are getting close to finalized results. By using a programmable aftermarket ecu, we can ensure that the test conditions are fair for each run. Our dyno controls and measures dozens of data channels as well, including airflow, EGT, air/fuel ratio, oil and water temps, fuel flows, and much more. This gives our engineers the data required to determine how to proceed next!

Eventually, all of this will be combined into a finalized version of the manifold, and made ready for production. That version will be fully detailed out and optimized. A final complete manifold will be printed to check fitment on the car and confirm final power numbers before it goes to casting. Make sure to bookmark our blog for future updates as progress continues towards the final goal- tearing up the streets with a beautiful, American designed, engineered AND manufactured manifold!



  • Admin

    Thanks Jeff,
    The manifolds will be available in raw casting or in a black powder coat finish. If you would like a different color the raw casting will powder coat very easily, a local coater to you should be able to handle the job easily. Thanks for the kind words!


  • Jeff Crouch

    Sounds like you guys were able to cut costs without cutting corners. Impressive! I may invest in one of these well developed IM for my 2.5. Would there be a possibility for other color options for the manifold?
    I know a car community that would love to see products from Integrated Engineering. The only IM for them is a Cosworth piece.

  • Admin

    Aaron, as of right now these will not work on 2.5L engines with hydraulic power steering pumps. It will work with all 2.5L engines with magnetic power steering. We may be able to offer a kit to re-locate the power steering pumps on those vehicles at some point in the future, depending on how cost effective it might be.

  • Aaron

    Is this going to be only for the old 2.5 motor or the newer one? I believe the newer one has something to the left of the engine that blocks space that the older motor had available.

  • Tyler Nixon

    hey guys i’m loving the process. i know for myself being stage 2 turbo i really like the idea of having a CAST manifold. can you speak of the benefits of going with a cast manifold over a tig welded sheet built mani? overall to me i like the look of a nice cast unit and can’t wait to see what price point you guys come to the market with. i’m sure you’ll sell more if its “fair” i surely trust your knowledge with the 2.5 and look forward to ordering MANY parts very soon (internals?)

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