Brainz

So I've been meaning to pressure test my intake tract on my 7TT.

Realized it was super easy when I had the rear wheels off this past weekend. I measured the compressor outlets and headed to Homie Depot for some parts.

Here's what you need:
1 1/2" Sched 40 PVC Plug
1 1/2" x 1/2" Sched 40 PVC Reducer/plug
1/2 to 3/8 brass reducer nut
1/4" male air fitting (has 3/8" NPT thread)

Brainz

I measured the spouts on the turbo compressor outlets. Theres a groove that needs to be filed/ground/cut into the PVC fittings so that they won't get shot out of the hose under pressure.

I used a small lathe to turn a 5mm wide x 1mm deep groove 7mm from the end of each PVC fitting. These dimensions mirrored the spouts on the turbo. You could probably do this with a file.

Here's some pics that show you the completed pieces:

Brainz

I put a plug on each charge hose and used regulated compressed air to start pressurizing the system. I started at 10 psi and worked my way up to about 25psi (the gauge reads high as the valve is closed in the pics).

I did learn that one of my Norma clamps that secures the intercooler hose to the turbo was not able to be fully tightened and would leak at just 10 psi. I put a new clamp on and found no other leaks.

Job done. Much easier than expected and only cost ~$10 in materials.

Hope that helps someone.

saabin

^ Very nice work, If I didn't already have a set that I got from Markski (I like yours better, BTW) I would build these..I have to use 2 hose clamps so that I'm absolutely sure the plug is in.. I had one come out at 12psi once before and it scared the crap outta me :-)

I bet you could make a bunch of these and sell them to fellow RLers..

Brainz

Thanks! I've got no interest in manufacturing/selling -- too many other projects.

While having a lathe made this a breeze, I think you could easily do it with just a file. If you've got a drill press or a Dremel, you could also likely make something workable. PVC is pretty soft, and the groove is only 1mm deep, so material removal is pretty quick.

Catorce

Nice work bro.

RennKit-Dave

lliejk

Just don't put your face anywhere near it. I have a similar setup to use on my Audi turbos, no grooves, testing to about 20 PSI and no blowouts, but they can and do happen. So pay attention to the direction they could blow and make sure nothing fragile, like your face or hands, are in the way.

Thanks for the info, makes it easy to mock a set of these up for testing, and with turbos, leakage is a killer.

Ed

RennKit-Dave

Now that's smart advice. So many ways to get hurt working on a car, especially one up in the air.

saabin

^ I'm not a huge user of safety glasses (I have several pair in the toolchest), but this is one of the times I put them on without fail.

pfbz

A few wraps Gorilla tape (or similar) around the fittings and a few strokes with sandpaper to rough up the tape makes them much less slick and less likely to pop out. It definitely WILL get your attention if one blows out!

911.Forever

Brainz, thanks for the DIY and appreciate your post. Sounds like a fun little project I'll tackle.

Johnny DB

Thanks for posting!

Brainz

Truth be told I did have a blowout at ~15psi with the faulty Norma clamp -- the clamp would only tighten so much before the worm would skip teeth on the band and tighten no further.

As I was standing behind the car when it happened it wasn't full code brown, but it definitely got my attention. Eye pro and/or a face shield is highly recommended.

In my case the fitting that slipped was the one in the picture with the air hose on it (and the non-factory clamp). As such, it was quickly arrested by the weight of the hose and didn't fly around the garage.

Also, if you're going to do this job, you may consider pre-ordering some additional "Norma 40-60 x 9mm" clamps -- [NORMA 01266704050-000-0541]. These clamps sit right behind the rear tires and get a little mangy. I found a guy on Ebay selling 6 clamps for ~$8 shipped. At that price they're good spares to have, not just for Porsche -- lots of European cars use them on cooling system hoses.

Brainz

One other quick thought: If you're running factory intercoolers like me, do not go crazy with the test pressure. I heard some faint creaking noises from the intercoolers as I got up around 25psi and it spooked me. It's probably best to only test up to your max boost pressure or maybe a few psi higher. My guess is that 20psi is plenty high for folks on stock ICs. I don't want anyone blowing off an end tank.