I need to convert a REAR rotor housing to a FRONT.

The consensus seems to be that they are interchangeable except for the air injection passages to pass smog (I am in CA so this will be required unfortunately )

I talked with Rob (very very nice guy) from Pineapple and he says it's very simple, drill through the triangular port in the housing with a 1/2" bit, all the way through, avoiding the bottom exhaust stud.

Just wanted to confirm with pictures if anyone has done this and if I interpreted Rob's directions correctly.

Also, the rear housing has the port on the opposite side, would this need to be plugged once it becomes the front housing?

The pictures are labeled and orientation of the housings can be gathered from the direction of the exhaust studs.
My reference front housing is missing the upper exhaust stud and the rear housing to be converted has all studs in place.

Passage in FRONT rotor housing




Rear Housing showing no port



Where I think Rob is telling me to drill all the way through to the other side of the pocket



Opposite side of Front housing showing no port



Opposite side of Rear housing showing the port




Thanks guys! Any input would be appreciated.

 

Why do you NEED to convert ?
Why don't you get a S5 NA housing change the Exhaust port and call it a day..it's not like it's gonna make a difference ..except for the lettering on top.

 

Because it won't pass emissions without the egr port in the correct orientation. Emissions is all it really affects.

 

Edit.

 

Right, I'm in California so to pass smog I would need most of my emissions working.
This involves converting the rear housing to a front. I would like to keep from buying another front housing since I already spent money on this rear housing and its pretty nice (no chrome flaking at all or cracks near ports).

I ran some water through the port and it ends up ejecting into the actual exhaust port. There are two holes on the upper part of the exhaust port. The water flowed into the port in the "front" of the housing and out the hole toward "back" of the housing.

I'm thinking where I had originally thought I would drill should work. The air would flow into triangular port, through the hole I drilled and into the port in the "rear" of the housing, which has the port going into the exhaust port.

This will, however, connect the two holes on the side of the housing underneath the exhaust port.

Here are some pics for clarification.

FRONT Housing flow



REAR Housing flow with hole drilled

Direction goes from the left, dashed lines indicate the hole I will have drilled, it would go up into the port already existing in the rear of the housing, and out the hole in the exhaust port sleeve toward the front of the housing

 

Only used by the ACV to inject air into the #2 rotor exhaust port for dilution with air for idle/low cruise emissions control.
The auto FDs and 95 FDs have an airpump with a smaller pulley. This enables them to pump more air for exhaust dilution.
Get one of them if you have the large pulley air pump.

 

Seems like you should be sending your pics to Rob at Pineapple. He's a great guy, with decades of engine building experience. I'm sure he will let you know.

 

you are doing it correctly and it will work, we've done it before. passage is for the "port air", which is literally the air pump air that goes into the exhaust ports.

 

Thanks for the confirmation, I also emailed Rob at Pineapple and confirmed this is what he was talking about.

I tapped the hole with a 1/8" bit and went up from there. Pretty easy to drill.

Thanks for the pointers everyone!