So by now it's kind of a well known thing that the cast ports on the Stillen IC's are restrictive due to the thickness of the metal. Here are some pics of then stock. 2" ports, but the inside is reduced because of the cast port.
 So the fix that people have been doing is to cut off the cast port, weld on a new 2" thinner walled pipe for the port and clean up the inside of the end housing as well to help increase flow. Member Aliaz has had this done to his. I believe he has flow result comparisons as well. Since this my 2nd go around with the Stillens, I figured I better have this mod done. So I took them to my local shop that did my plenum work for my 60mm tbs. They were shying away from using the 2" thinned walled pipe as they didn't want to risk having it crush when clamping the connecting hoses on. So we decided to use a 2.5" pipe with a thicker wall. Obviously this gives me an even larger port. Also if in the future I decide to look into some 2.5" IC piping I'll be ready to go. Here is the first go around. I'll explain why I say "first" in a few.
 As you can see, the ports are so much larger you can see the mounting bolt locations that are cast into the design on the inside. And although the pics makes the insides look somewhat rough, they are very smooth. You can kinda see where they did some metal forming on the outlet port to help with flow and to also fit the larger pipe. So I took them home and started mounting them up. With then having larger ports they needed to reduce down in size to mount to the stock IC pipes. For the inlet side, things get pretty tight. The stock pipe comes off a 45 degree bend, then uses a 45 hose to join to the IC. I found these 2"-2.5" reducing silicone 45's online so I picked up a set.
 Everything mounted up, but there was a slight issue. Because of the 45 bend and the long port on the IC itself, the hose wanted to have a slight kink in it where it reduces. Easy fix. I took the IC back to the shop and had them chop the port down shorter. Then as you can see in the pic above I cut a section of the hose out as well. Both of these mods allowed the reducing section be pulled away from the IC pipe and get rid of the kink in the hose.
 The rear section was pretty easy as well. I used a reducer, a metal coupler and a section silicone hose to replace the factory hose. I kept this section 2.5" as long as I could instead of putting the reducer right on the IC and going 2" out from there. This should help smooth out the flow of air coming out of that port due to the tight corner has to travel around. I could have gone with either option though.
 Here's the overall set up
 And on the car
 JackB nimble JackB quick JackB can suck my dick =P - james-lee 11/02/01
Arrogance is the #1 weapon against Supra Owners - MikeH 08/06/02
Dallas with a Z: I like the bulge dude 05/02/03
Bezbefootball: Does dick have anything for me? 10/21/03 |
Pics and write up of my modified Stillen ICs. - 
