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26 September 2007

Forge Diverter Valve

One more issue resolved.

At first I was planning on one of the ATP adapters with recirculating valve plumbed into an ATP intake. Then Eurocode came out with a package of the ATP adapter with a fake GReddy valve (or a real one at extra charge). I was unimpressed with Eurocode's marketing of the bundle, and after people tried it and problems became known, I was unimpressed with the technical aspect of it as well.

In looking for a better solution I contacted Forge, and was told that they were working on a solution that would be a fresh design, would have some manner of maintaining computer control over the valve, and would be a robust piston valve with NO rubber diaphragm to fail. Based on their reputation for quality piston-type valves, I decided to wait and see what they came up with. A few people (including me) knew what they were working on, and the design changed a little bit as time went on.

Development of the valve took quite a while, but the end result is a really slick valve that will *not* fail (unlike the clunky stock valve with its gossamer hymen of a diaphragm), works off of pressure & vacuum, and has a clever external solenoid valve arrangement to maintain computer control over what is essentially a mechanical valve. As an added bonus, the vacuum line tap has fittings to accommodate a boost gauge and another device in addition to the valve. Forge's designation for this part is FMFSITV.

When I finally ordered it, it was on backorder for a few weeks. I was really anxious to get it since my stock valve had seen better days.

The contents of the package:

The 3-port vacuum tap. You can see that there are three nipples provided - the largest-diameter one is used for the diverter valve, the smallest-diameter one would be for a boost gauge, and the third one would be for some other device, if needed. If you're just installing the valve, the small threaded plugs shown are used in place of the other two nipples. When making up that assembly, you definitely need to use Locktite Threadlocker (BLUE) to make sure everything stays together (Locktite BLUE is removable, RED is permanent, don't use RED unless you mean it):

In the upper left of the picture is the solenoid valve that controls the vacuum/pressure acting on the actual diverter valve. The thicker black tubing to the left is the used to make up the vacuum tap assembly:

The vacuum tap with the correct nipple + 2 plugs installed:

The valve itself:

It's made up of several pieces - the main valve body, the screw-off cap (ring+top), the piston, and the internal spring, coated internally with a red high-temperature lube.

They provided more than enough silicone vacuum tubing for the install:

Up on ramps, ready to start...

The original diverter valve on the turbo, viewed from below:

Turbo with diverter valve removed, seen from below. There are three bolts on the valve, don't remove the similar one on the oil line bracket just below it:

Always looking for a better way to do things, I decided not to mount the solenoid valve directly to the diverter valve. Forge claims it can be mounted anywhere within reach of the wiring harness that would plug into it, so I relocated it up to where it would be farther away from water, debris, etc. The two lengths of tubing shown attached to the base and cap fittings of the valve are 18" and 22" respectively:

I zip-tied the solenoid to the wiring chase near the ABS controller. It's more protected, easier to keep an eye on, and farther away from the heat of the turbo than if it were bolted to the diverter valve. The two tubes shown above go down to the diverter valve, and then the longer run of tubing goes to the vacuum source.

Here's the vacuum tap installed. It's very subtle when done right, very stock looking, and will be convenient to add a boost gauge later:

The valve installed on the turbo (sorry for the blurry picture, it's not the easiest spot to get a camera into):

When I removed my valve, it completely fell apart as I pulled it away from the turbo. I mean, the piston, the diaphragm, the spring, the pin, the plastic ring.... WIth the new valve in place, it's like a whole different car. MUCH more power, less lurching off the line and during shifts (of course, the dogbone insert helps with that, too). This has been another good mod for me, and highly recommended for anyone with a 2.0T FSI engine.

Subsequent to installing the valve, I asked Forge what maintenance needed to be performed on the valve, and at what intervals. Forge's response:
Valve maintenance is not necessarily a requirement though it can be done at whatever interval you choose based on various factors.

We have a test valve installed on a 1.8T Audi TT 225 in the UK which has been installed and operating for over the last 5 years without having ever been serviced once. It holds vacuum and pressure perfectly fine just as if it were brand new.

With that in mind, however, as dust, dirt or other debris may periodically enter the system, and possibly contaminate the grease inside the valve, depending upon your geographic location and/or other driving conditions, we would recommend at least checking the valve every so often, at least once a year or so, and clean and regrease it if you feel it's needed on your particular car.

We build the valves with Mobil1 fully synthetic bearing grease, however, any other brand of fully synthetic grease should suffice. We do not recommend the use of lithium grease as it can be corrosive to the o-rings inside the valve, nor do we condone using any sort of motor oil, spray lubricants or anything else aside from a fully synthetic bearing grease. The comment on the [motor] oil [is] directly meant to discourage anyone who thinks that motor oil is a "cure-all" lubricant when it is not even remotely suitable for lubricating a component like our valve [instead of the Mobil1 fully synthetic bearing grease].
(Edited for clarity - Len)

(Thanks to local Deldubs member '92rado2.8' for the use of his ramps!)

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25 September 2007

ECS Dogbone Mount Insert Installed

This particular part is available from several vendors. I preferred the one from ECS. because they include a new stretch bolt, where some of the other vendors don't. More on that below.

Unlike some of my other installations, I'm not going to do a step-by-step with pictures description of installing this part. The reason is that excellent documentation already exists from ECS (PDF). I'll just add some personal observations.

First, this thing is a lot larger than I had imagined it from pictures. I imagined it being about 3/4 as big as it actually is.

Second, it's a lot squishier than I anticipated. I thought it would be pretty much rigid, and was really surprised when I found how flexible it is. I thought, "you've *got* to be kidding - how can you push this in?" I'm not used to pushing things into a tight opening that aren't pretty rigid, no matter how much lube is involved.

With the car raised I removed the original bolt in the 'dogbone' mount. The original bolt takes a 21mm socket, and came loose much easier than I thought it should. I lubed up the insert, and lined it up on the rubber bushing. It started in pretty easily, then no amount of arm force would budge it. Time for Plan B.

Plan B was a hydraulic bottle jack. I set it against the edge of the insert and jacked it enough to push the insert in a few milimetres, then backed it off, repositioned and repeated. This worked great, and working in small increments got the whole insert firmly seated into the bushing.

The small washer goes INSIDE the hole in the insert, then the larger disk on top of it. The bolt supplied requires a 22mm socket.

If you're not familiar with stretch bolts, the idea is that the bolt is designed where the threads pull the bolt down and stretch the neck so that the head of the bolt applies extra tension against the fastening surface. It takes advantage of the tensile properties of the bolt, but at the same time it inherently weakens the bolt. Therefore, a stretch bolt must not be tightened more than spec, and must never be re-used.

The way a stretch bolt is tightened is with two separate steps: It's tightened to a specified torque value, and then 'angle torqued' for a specified amount. In the case of this bolt used in the insert, it is first tightened to 74 pounds-feet of torque, then it is rotated for an additional 90degrees (no more, no less) (expressed as 74 lbs-ft + 1/4 turn, or 74 lbs-ft + 90deg.) Tightening this bolt to 74 lbs-ft was easy enough with a torque wrench, but that last 90deg turn was a bitch. I wasn't taking any chances, so I coated the threads with LocTite Threadlocker (BLUE) before I assembled it.

Having installed the insert, I'm kicking myself for not having done it earlier. Seriously, it's the best $40 you can spend on the car. For anyone who claims that it increases any vibration, I have one question: "what are you, nuts?". This smoothed out everything quite noticeably. It idles smoother, and got rid of a lot of the lurching and generally crappy feel when starting off or shifting. When people say it improves the feel of shifts, it's not the actual 'shift' that feels any different, it's the clutch engagement *after* the shift that's improved. This is definitely $40-worth of value and improvement in feel. Now I'd like to do the full VF-Engineering engine mount kit, but I'm not sure that it has the same cost-benefit as just this insert alone.

I highly recommend this for anyone with a manual-transmission A3 (or GTI or GLI).

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I have a resolution to my failed A/C compressor saga. (previous articles: 1, 2, 3, 4, 5, 6, 7). Since my last post, it failed *again* on the 13th of August. Of course they couldn't get me in to deal with it for a week. Another failed compressor.

When I got the car back, I wasn't satisfied with how well it cooled. A few days later, it stopped cooling altogether. I don't mean inadequate cooling, I mean none at all. The low-pressure line from the compressor was ambient temperature, and not sweating. There were some green stains around the low-pressure fitting on the line so I took off the cap and saw BUBBLES OF DYE in the schraeder valve. I had an A/C gauge, so I checked the pressure and it was low.

I took the car in to the dealer, and my service writer wouldn't even talk to me. He immediately got the service manager. The service manager immediately went into CYA mode - first he tried to claim that there was nothing wrong with it, then said they'd 'check it out'. No loaner, they gave me a ride to work.

Later that day they picked me up and claimed that it was blowing 32degF at the vents (yeah, right). They had evacuated the system and recharged it from scratch. (In fact, it *has* been working nominally since that time.) He also denied there was any leak, but assured me they had 'verified' that the schraeder valve was tight. Just like before, ONLY the service manager would deal with me, and everyone else eyed me suspiciously while I was there. Hardly a welcoming customer service experience.

They also refused to cover the scratch and scuff on the rear bumper that *they* caused while it was in their care. Instead, the service manager helpfully suggested that I use their body shop when I pay for it out of pocket.

At about this time, my attorney contacted me and said that Audi had made a settlement offer. It was an absurdly low offer, and we countered with a much higher amount (the max my attorney said I could possibly get), and a request to extend the warranty to unlimited years/100k miles. Of course Audi didn't go for it, and countered with an offer midway between what they had started at and what we had countered with, plus warranty extension to 5 years/60,000 miles (up from the standard 4/50). The settlement also stipulates that I cannot sue Audi for *anything* else related to this car, and prevents me from suing the dealer either. I accepted the offer.

The cash amount is small. How small? Well, let's just say that after covering my payments for the time the car was out of service, paying to fix the bumper damage that the dealer caused, and paying insurance, there's about enough left for a bottle of water and a pack of mints. To me, the warranty extension is more important: if they keep screwing up the compressor repair, they'll keep paying to repair it for a longer period of time. Also, Audi had to pay my attorney's fees, so it's a decently symbolic pound of flesh.


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