VVIS vs. Non-VVIS, Would You Do It? <- I Did.

[bigdaddylee82]

Alright, more details...

This is the vacuum actuator for the VVIS that I needed to control, that's 1/8" ID hose.

I had to have a vacuum source, so I T'd the 1/4" factory vacuum port.

Here's a good look of the Tee with the manifold back on the engine, that's 3/8" ID hose.

With everything back where it's supposed to be, the vacuum T is hidden behind the Idle Air Control.

The vacuum reservoir is obviously mounted on the firewall; I cut a little rectangle out of the insulation to fit the mounting bracket directly against the firewall. I also had to remove the little gay sounding car alarm. I put a cheap Summit vacuum gauge in the reservoir, it's a real POS, reads 15 in/Hg with no vacuum applied, so I just consider 15 in/Hg to be 0 and count up from there. There is a one way check valve in the reservoir for the vacuum line from the intake manifold. So when the solenoid valve de-energizes or you turn the engine off, it keeps a "reservoir" of vacuum, who'd-a-thunk-it?

- Lee

[bigdaddylee82]

More...

Here's the solenoid valve ready to be plumbed.

The solenoid valve plumbed/wired/mounted. I mounted it to the engine torque arm, and used a modified base for a clamp on desk lamp as a mounting bracket. I ran the ground wire from the solenoid to the same bolt that the braided ground wire on the engine head attaches to.

I tapped into an unused/empty key-on/ignition hot fuse in the factory fuse block. Fuse position #4 is empty and unlabeled in my car, but still powered when the key is on. I used an inline fuse as well.

I bought a terminal block to use as a power distribution block. I was trying to keep this a clean install, instead of wires running all over the engine bay, and having any more wires coming off of the batter (+) terminal.

Here's the cheap eBay 12v relay that is switched off by the RPM switch. It's mounted tucked away behind the air filter box, attached to one of the bolts for the ignition coil mount.

- Lee

[bigdaddylee82]

More still...

The Pièce de résistance, with out this little guy, none of this would work. The RPM switch. I mounted it up out of the way on the bracketry that the ABS computer mounts to, driver side strut tower, well driver side for those who drive on the correct side of the road .

This is a pretty neat apparatus. It's adjustable for a pretty broad range of RPMs and can be set to either turn something on or off at a determined RPM. I of course have it set to turn off at 3700 RPM, this RPM was determined based on my finely tuned "seat-of-the-pants" dyno . The RPM switch is calibrated for use on 4, 6, 8, and 10 cylinder engines, the Volvo 5 cylinder gets no love. I originally thought I'd set it for a 10 cylinder and multiply by 2, but my theory wasn't panning out. I wound up setting it for a 4 cylinder and began trial & error testing. Turns out that set as a 4 cylinder and to turn off @ 5600 RPM is about 3700-3800 RPM according to my car's factory tachometer. I know there's some error/variability in both the switch and factory tach reading, but at least I've got a base line to go off of. The green LED comes on to show that the switch is receiving power, and the blue LED let's you know if the switched ground for what ever you're controlling is open or closed, i.e. blue LED on the switch is closed/on, blue LED off the switch is open/off.

When all is said and done, and working, the only thing you can actually see happen, is the very top of the VVIS actuator lever arm moving in and out down in between the intake runners for cylinder 3 and 4. Boy when it moves though, and does so when and how you want it to, it's a good feeling .

Now it's just testing, I guess I'll be hitting the on-ramps on the by-pass this evening.


- Lee

[bigdaddylee82]

So I drove around tonight, maybe 6 miles or so. I'll give it a solid, meh... I can tell it's got more pep, but it's nothing to write home about, definitely and improvement though. I kind of wish I hadn't gone from driving the Jetta around to this, now that TDI will get out of it's own way, so I kind of desensitized myself .

So I'm happy that it works, but if I had it all to do over again, ya know if I only knew then what I know now, I'd have a T5.

I should also add that not only did I get my VVIS working, but I did this too:

So, I don't know if I benefit more from the VVIS, the 960 throttle plate, or a pretty even combo of both, but I do know that gunning it in a right turn from a dead stop at a light, with the trans in "sport" the tires let out a little chirp, never had them break loose on dry pavement before. I tried to recreate it a couple of times in straight aways between stop lights, but no dice.

If you're following this thinking about doing it to your car, unless you've already got a '93 or '94 with the VVIS I don't see a real point. If you wanna go fast buy a turbo car. Having said that, I've got a few other things up my sleeve still.

I've had everything for 2-1/2" exhaust since before I blew up my original motor. I'll delete the cat, and put the exhaust on eventually. I've also thinking about putting an AEM dry cone filter on, and DIYing a huge CAI/Ram-air.

I'll get to work on a video that shows how everything works soon.

I haven't had the battery disconnected for any extended length of time, so the ECM probably still has some "learning" to do, so there may still be a little more "umph" to be found yet. Here's hoping anyway.


- Lee

[matthew1]

Interesting report, thanks Lee. Looking forward to the video. Sorry you put all the work into it and aren't blown away. Damn that Jetta.

[bigdaddylee82]

Here's the video! Everything is still working as it should, I've done a lot of interstate travel in the past week and, I've noticed that I can cruise at 75 mph at just a bit under 3000 RPM maybe 2900 RPM, I was at about 3200 RPM before getting the VVIS to work. I haven't got any proof (my odometer is dead) but I know I'm getting noticeably better fuel economy now, probably has more to do with the fact that I don't have to floor it to get going now .

Enjoy, I just put it up, so quality should improve as the Youtube robots do their thing.



- Lee