LOL Emissions

[Dopefish]

Well I had parked the A4 in preparation to fix my now very leaky valvecover gasket. Everything went smoothly and there were no signs of sludge or oil starvation thanks to 3k synthetic oil intervals.



However, while doing so, I mulled over the fact that there are a TON of vacuum lines that are not really necessary and deal mostly with emissions which are not a factor where I live. I quickly decided to simplify the underhood area, both to clean it up a bit, maybe have a marginal improvement in airflow and to lower the overall possible failure points with increased boost pressure. I already had to replace a portion of the vacuum system two months ago that set me back $57... in retrospect, I should have just done this back then.

Here is how my engine bay looks, stock and unmolested.


Here are some images at various stages throughout my working.






Here are the remains of this little adventure...


I got bored this afternoon at work and made this little guy out of 1/8" aluminum to block the port left on the back of the head by the SAI, the original gasket was still good and was reused. Much better than the $35 it'd cost for block-off plate from a IE.


I'm going to modify the stock airbox a bit and use a K&N drop-in filter. I also ordered a test pipe to replace the cat which should give a moderate increase in power and lower spool time as well as lower my underhood temps. My timing belt is meant to come at the same time, so it'll be a busy next two weeks for the A4.

[Dopefish]

Minor update:

The valve cover gasket has been replaced, all the oil has been cleaned from the spark plug holes and new NGK BKR7E plugs have been installed (gapped to 0.032"). The wiring has been re-run and tidied up as well as most of the now unused vacuum ports have been capped off. I still have to get the appropriate size line for the brake booster, a 1" tube for the diverter valve (BOV) and block off one more port on the intake manifold.

I cleaned up some of the mess that was created from the leaky valve cover gasket but won't get too thorough until I do the timing belt. My kit is here now so installation of that will begin in a couple of weeks.



My downpipe arrived a bit ago as well. I didn't want to wait for ceramic coating but decided that leaving the pipe bare would be a bad idea. With that in mind I picked up some heatwrap and silicone spray to seal the pipe in.



I let the wrapping soak for a minute in water to loosen it up and began tightly wrapping around the pipe, overlapping about 3/8" each time. I used about 13' of wrap and made sure it was evenly dispersed with an extra wrap at each end for good measure.



Presently it is drying with two coats of the silicone coating. Hopefully I'll finish up the install tomorrow after work.

[B6Lovin]

what'd you dry it with before you put the silicone on??

i hit mine with an 1100* heat gun for some time and it was still damp... had to put it on the car and really let it bake to get it dry-dry

[Dopefish]

what'd you dry it with before you put the silicone on??

i hit mine with an 1100* heat gun for some time and it was still damp... had to put it on the car and really let it bake to get it dry-dry

Yea, I spent 20 minutes with a high-temp heat gun but it was still just ever-so-slightly damp. It was very minimal though so I went ahead and sprayed it.

[Dopefish]

Done! Sort of... I still need to clean up both the engine bay (dirt and wire routing) and the garage. At first I had a horrid stumble and couldn't get a steady idle but I found a line I forgot to cap off and all is well now. The exhaust note appears to be the same but I won't know for sure until I drive the car tomorrow. The turbo definitely states itself much more now which is a welcomed addition.







Oh I also rode in a Stage 3 B5 S4 earlier in the evening as well and OMFG! :drool: Makes me think that despite the good looks and posh interior of my B6, that I might find myself content at home with a B5 S4 one of these days.