Mark@AutoSpeed

I knew that something needed to be done to support the kind of power numbers I am after with my GT28RS S4. The OEM manifolds are poorly designed in terms of air flow path. Casting techniques further make the manifold less than desirable because of the bottom plate Audi puts on. I suspect this plate allows the manifold to be machined and later have the core ejected. Consequently there are several bosses protruding inside the manifold which disrupt air flow, not to mention it is a very rough cast finish.

A side profile also shows that that the air entering the manifold from the throttle body hits the mani floor at a harsh angle, further causing disruption and much turbulence.

I wanted to create an almost "scoop" effect to help increase port entering velocity while gaining some plenum volume. Rough calcs showed that with 2.7L and trying to achieve some mighty big ingestion to the tune of 700-800hp, would require a substantial increase in volume.

Problem, IT'S AN AUDI!, no room, so I made a comprimise and fit the maximum I could given the block tunnel and after run piping. I could have gone bigger, but figured this is a good starting point to build from.

Here is what I came up with...

<i>We start with a virgin RS4 Intake Manifold</i>
<img src="http://pictureposter.audiworld.com/93546/imani1.jpg">

<i>Machine the bottom off to allow us to port and polish it correctly</i>
<img src="http://pictureposter.audiworld.com/93546/imani2.jpg">

<i>CNC machine a billet bottom to gain volume and more importantly smooth out the flow path</i>
<img src="http://pictureposter.audiworld.com/93546/imani3.jpg">

<i>CNC Machine IAT Boss and TIG Weld on</i>
<img src="http://pictureposter.audiworld.com/93546/imani4.jpg">

<i>Take a hard look at an OEM Intake from the inside and compare to this; Huge Improvement</i>
<img src="http://pictureposter.audiworld.com/93546/imani5.jpg">

<i>Finished Product, No Mods necessary to the After Run Pump or Plumbing BTW</i>
<img src="http://pictureposter.audiworld.com/93546/imani6.jpg">

Take Care Guys.

2000SForce

thats nice... one of my goals in life is to weld like that it is a true art form

Arcteryx::Stock Rods

very nice mark....will you be making more of these?

Captain Matt, I be

beautiful work, sir.

S4orce2001

damn mark i want that and also the gt28 kit LOL

lucifa v.2.0

I hope that's not a one-off product. :-p

DAP@EPL

Very nice!

s4whatatwork

Will you be at Waterfest

str8blst

How long did this take you guys to complete? I can't even inmagine how much time was involved doing this. What kind of gains do you expect to see? Any chance you could do this to a stock Intake manifold?

Mark P

Very nice indeed!