TT225 intake manifold and some interesting measurements/comparisons...

[VAP]

Got the 225 intake manifold yesterday from Clair with a couple each intake and throttle-body gaskets to facilitate plumbing from the new custom Spearco intercooler.

First thing that jumps out at me is the larger size of the 225 plenum. My 180 (outside measurement) is 3" top-to-bottom, same as my 180. But the 225 is also 3" wide (as viewed from the top) whereas the 180 is only 2" wide and tapers to just 2" (you can see that in the pic to follow as I forgot to upload it first). Additionally the equal length intake port runners are 1.5" wide on the 180 and 2" on the 225 intake. These are MASSIVE differences in flow potentials between the two and a significant factor in one place the 225 gets some of it's additional ponies.

I didnt count on this little benefit. I thought they were identical with mirror image throttle body swap ( a 180 degree end-to-end swap only).

Now I'm starting to be a teensie bit concerned that maybe cylinder head ports are larger on 225 than on the 180. Not likely, but "if" that turns out to be the case its simply a matter of "gasket-matching" which was planned for this induction system anyway. Gasket matching is a process by which an Audi intake gasket is placed upon the the outlet (port) side of its mating surface and then with a die grinder/Dremel tool excess material is removed from the intake manifold until it matches the gasket port profile perfectly. Then the gasket is moved to the cylinder head and the process is repeated on the cylinder head intake ports (have to stuff the ports in cylinder head with rags first to prevent ground off aluminum slag/grit/shaving burrs from entering cylinder heads. This process is usually done in three steps on each piece from course to fine to semi-polish. You dont want a mirror sheen on intake runners but rather a soft-smooth finish similar to the cross-hatch marks in a cylinder.

Before any of this is initiated however this intake system is going out to be extrude-honed. A process which uses an abrasive content putty-like material to be extruded under pressure thru the throttle-body and out the intake runners in the direction of flow. This smooths and leaves a "directional" pattern for the flow to follow. It also radiuses and smooths any internal cast vacuum fittings and sharp objects/turns into a much smoother transition profile. The inside of the intake system as it comes from Audi has the same textured finish on the outside that it does on the inside due to its "sand casting" tecnique. Extrude honing and gasket matching should be good for somewhere in the neighborhood of 15-25 additional HP on a turbo 4 cylinder. With the larger size of this intake it is entire possible I could squeeze another 15 on top of that for a potential of 35-40 add'l ponies with no additional turbo or mechanical stresses. And with the intercooler this could jump upwards of 50 and potentially 60HP! I'm liking the sound of this.

Down side to all this is the expense and wait-time for extrude honing. Its typically a 30 day lead time once they have the manifold and its a little spendy, hovering near $100 per intake runner or nigh on $400 for me plus shipping both ways and that excrutiating wait time.

Should be interesting tho. I'll let everyone know as this unfolds. I'm still shopping extrude-hone locations fro PA to LA. I'm looking for shortest lead times more than price.

Pic in a few minutes...

[VAP]

[BZ]

AudiTT.org

[Larrytt]

Mance:

Did you get me e-mail?

PLease make sure you do some dyno runs on all of this work. It is easy for you to do since you have a TTfwd.

Thanks. Keep up the good work for all of us!


Larry's TTQ WebSite

[VAP]

But I'll get the trusty g-tech out and do some runs and conservative extrapolation. That'll have to be close enough. I may do a dyno in the future but there's alot more work to be done before I'll allow it. I'm still mid-evolution on this thing.

[eharleq]

It quite simple. The 180 is a low pressure, high static compression engine and the 225 is a high boost engine. Apples and oranges. The 180 design is optimized for total lower flow. Putting a 225 manifold on a kkk03 180 can actually lead to air stalling and inefficiency at part throttle, and may be even worse with a 04.

The initial limiting factor on this motor is the exhaust. Then the front of the intake path, and the intercooler. Sounds like a fun project.

[TTinHongKong]

180FWD/17" BBS RXII/BS S-02 PP/Pipercross Filter/PIAA/Wetterauer/Remus/GReddy Turbo gauge-A-pillar mount/Forge Motorsport recirculated dump valve/NGK Iridium Plugs/Abt steel flex brake lines/H&R coilovers
http://www.geocities.com/ttinhk/index.html

[RichP]

Your intake project is looking very good!!! Somone mentioned stalling the air charge with these mods, but I don't see it as a problem with a chipped K03.