OK someone told me to do this when I get bored so I did......



The stock ports on the intake manifolds of the turbo 2 are different in size. Where the UIM meets the LIM, the UIM ports are smaller(on mine) than the LIM ports. Opening the ports on the UIM should, in theory, allow for a larger quantity of air flow volume and velocity. Not to mention the air will be less turbulent due to the smoother transition. The desired results would be a quicker revving, smoother running engine.



Its a fairly easy process unless you're incredibly stupid.



First, remove the IC, disconnect the throttle cable, TPS, air thermosensor and vacuum lines leading to the UIM.



Second, unbolt the UIM from the LIM. Now stuff cloth rags inside the LIM to prevent debris from entering the block and making rotors go BOOM.



Here's where you need a micrometer. Take the micrometer and measure the diameters of all the intake ports on both the UIM and LIM... On mine the LIM ports were the larger of the two.... by almost 3mm



So, I wanted to increase the diameter of the UIM ports by 3mm. I did mine real scientific like, using isoceles triangles and all that ****, but you can tell by the carbon stains around the ports, where it needs to be opened up at.



Ok, once you have established the area to be ported you can use a die grinder and a carbide grinding bit, but a simple electric drill(plug-in) and a stone grinding sphere works fine too.



Now, while you are grinding the aluminum down, try to start just inside the lip and work your way towards the outside. Go slowly and don't apply a LOT of pressure, just let the grinding medium do the work.. try to grind around the entire circumference in one motion. This will keep you from leaving roughspots and hopefully provide a smooth surface. GO SLOW! It would suck if you opened up the ports too much! Once you are have sufficiently opened up the port, check for rough spots and reliefs. If there are any, don't worry you'll probly need to go over the area with some 150-200 grit sandpaper anyways. This really give the surface a satin smooth finish. Perfect for airflow!



Now slap everything back on and grab a beer, like you are Tarzan, King of the Jungle.



Any questions comments, remarks pm me.....



I'll get to the TB and wastegate porting another time...

 

do you have anything to report on the results of the modification?



BTW, are you planning on matching the rest of the intake junctions?

 

got a question........what the hell is a UIM LIM...a vietmanese person? :evil1:

 

UIM= upper intake manifold

LIM= Lower intake manifold

 

sorry ...thank you...now i see what the issue was



<---freakin noobie

 

What about a gasket. Do I need 1? If so, can I get it at the local parts place?

 

anyone ever match LIM to the motor.... just curious on if the port sizes are idenical and how the line up

 

I've seen porting to match the gaskets on everything UIM and LIM net about 9whp, no loss of low end and gains from 3k+

 

Does this apply to N/A's.Always looking for free HP!!! BT

 

Of course it will. Don't quote on an exact figure but as you say - it's essentially free. The intake on N/A cars (normally) is more sensitive than on turbo cars anyway as there isn't a big gay turbo shoving air through it, just the soft sensual whispers of vacuum from the combustion chamber.