xr4tic

I'm talking home porting here, nothing crazy, just matching (no polishing) the intake ports and manifold, and polishing/enlarging the exhaust ports and manifold.

I haven't seen the head up close, but I would think that since it's a modern head, it's already mostly optimized. I could be wrong though....

Has anybody done this? Suggestions?

4kq

few casting marks if any on mine. I have learned from my buddy who races top speed at the flats, you really HAVE to have a real flow bench to do it right. It is really easy to do it wrong or weaken the casting.

The "secret 1.8 mod" is the schrick cam upgrade. (Rumor has it, it flows 3xx cfm!!!) The limiting factors for this motor are the intake bend, poor sealing on the bosch valve, and the turbo size. Fix those, then the cam.

xr4tic

Are you referring to the 90 degree bends in the manifold itself, or the intake tract in general (IC, hoses, tubes, etc)?

I know it's easy to mess up while porting, which is why I wouldn't try changing the port shapes at all, just make them slightly bigger, or smooth them a little.

SKS

Check this pic out...BIG valves...www.interpreptuning.com/IMAGES/audi_head.jpg

carace

My pictures are towards the bottom of this thread.<ul><li><a href="http://forums.vwvortex.com/zerothread?id=202874">Pics of ported/gasket matched head</a></li></ul>

Žob

Hey Scott, were you able to get the A4 front brakes to fit the rear of the car?

xr4tic

Or did you do more?

Here is my plan:

I don't want to make the intake ports any bigger than I have to, so I'm just matching it to the manifold. Bigger ports slow intake velocity, which is important off-boost, but bigger ports help upper RPM power. It's also important to keep the intake ports rough to help keep the fuel suspended in the air.

As for the exhaust, since all it has is the pistons pushing the air out, bigger is better.
Also, a smooth and polished exhaust port and manifold helps keep exhaust gas hot, and then more energy goes to the turbo. Plus, it should flow better as well. The easier it is to get the air out, the quicker the turbo should spool.

SKS

I thought they really improved the big picture in car modulation. The big draw back for many would be that they had no E-brake. Didn't really bother me at all as I don't rally and I know my inspectors. Ask Corey about them, he bought mine.

Žob

So stock A4 front calipers won't fit the rear easily then?

carace

The ports were gasket matched but to do that you really do have to open the ports up some. I think he tried to open the port entrance up to the size of the gasket an slowly tapered the ports to the valves. Not much was taken off the roof of the port but there is some on the floor that was taken out to give a more direct route for the air. More straight to the valve instead of in and then down like the port floor is stock. I feel I have gained off boost power but that may be from the exhaust changes. At this point I am just extremely happy with the outcome!