2001.5 Inlet manifold

[MCB]

Thought I would start a new thread as interest is taking over another one and this could be interesting.

Already posted so copied again here:

All credit for this post to Dave Pramanik AW.com:

There are three different manifolds used on the 2.7T engine...

078 133 201 AE
078 133 201 AC
078 133 201 BC

The AE manifold is the original boxy one that is used on the 2000 and early 2001 6-spd S4s. The BC manifold is the later manifold with the smaller plenum and better intake ports and is used on all of the 01.5+ S4s and later A6 and allroads.

The AC manifold is used on the tiptronic 00 S4s and the early allroads and A6 2.7Ts. It has the plenum and runner design of the later BC manifold but vacuum port connections similar to the AE manifold.

So '00 and early '01 S4s who want to upgrade to the newer style manifold should have an easier time using the AC one so that all of the vacuum ports don't have to be replaced.

A few photos...

[MCB]

More photos

[MCB]

More photos

[s4woody]

it would ave been nice to have seen the AC/BC manifold before it was ported..just to see how far the intake tubes come into view..so is the RS4 manifold the same as the AC/BC manifold..?

[JonnyX]

RS4 manifold, I would think, has larger ports. I think the design is the same as BC though.
May have longer runners as well - need a side by side really.

From questions in the other thread, the AC manifold still has the F-hose but does have vacuum port
connections which are compatible with what you already have. The F-hose is POP to get rid of anyway
if you really want to.

[yorkie]

Excuse my ignorance but what is the problem with the F-hose anyway?

[MCB]

Woody

it would ave been nice to have seen the AC/BC manifold before it was ported..just to see how far the intake tubes come into view

I think the ports have just been smoothed - not cut back - take a look at the top view, so I think we can see the differance.

[shineydave]

it splits on a regular basis and allows the turbos to overspin causing tears the size you have never cried before. untill you get the bill for repairing it of course.

[MCB]

Excellent summary Dave - you’ve done the vac test equip - now can you move onto the steel f-hose?

[buzzard]

I'm surprised that if folks are spending a wad on custom exhaust manifolds-- that they didn't have also a custom inlet tract.
anyone any good at gas flow simulation and volumetric efficiency? perfect gas flow will result in max in and then max out. giving more power available.
unless ,of course, that the 2001.5 is as good as it gets.
key features in fsi tech have been on inlet development, coorect me if i'm wrong.
i am presuming that the plenum area will be a balance point where combined pressure from each turbo will be distributed equally where it is required.
has anyone ran the two sides of the engine individually , creating two- three cylinder engines (by separating the induction.)???

PS mint pics MCB

[ZeroK66]

Unfortunately I was not aware when doing my conversion that my manifold was different to the 2001.5, I have now ordered one with Vag Parts for 180+VAT & delivery. Not a bad price... I will take some pics when I get it.

[JonnyX]

Unfortunately I was not aware when doing my conversion that my manifold was different to the 2001.5, I have now ordered one with Vag Parts for 180+VAT & delivery. Not a bad price... I will take some pics when I get it.

Who are you going to get to fit it? I don't think it will mate up with your
existing vacuum tubing very well (your current manifold will have 3 ports
connected at the rear). When I have seen it discussed on AW it is like this:

http://forums.audiworld.com/s4/msgs/1233434.phtml

That doesn't sound DIY to me. If I were you, I would get in touch with vagparts
and see if they will see you the AC rev part instead. Unless of course Mihnea
or Doug have a sneaky way of getting this done easily.

[ZeroK66]

Doug will be fitting this. They have done this on Mihnea's car. They are aware of the new plumbing involved, its no easy job, but they are confident they can do it. I will be leaving it in their capable hands.

Question is.. do I have it tidies up and the ports smoothed off a little, or I leave it as is. Mihnea has obv over 500 on a stock manifold.

[S4TAN]

What sort of power gains (if any) could be had by installing the AC rev IM on a MY2000 car with stock turbos/intercoolers/fueling etc - but with MRC custom map and catback single 3" exhaust?

(My cars build date is 11/99 but i've been told this is considered as a 'MY2000' ...)

[ZeroK66]

I think gains are only really seen on K04 cars at the top end... as it flows better. K03's I dont think can flow enough to take advantage of it. Maybe 10HP if you were lucky? I am guessing on a good K04 car you may see 20HP? My main reason is just the F-Hose thing - which I know can be avoided with a collector, but I dont fancy that.