Help with boost!

[Pelletier8]

I just installed a boost controller, it was kinda tricky to figure out since it never came with instructions. But when I gave the knob a few (3-4) turns and hammered it to see a difference, I felt a misfire around 4k rpm..I turned the controller all the way off and this continued. After turning my car off and scratching my nuts, I tried again with the controller off. No misfire but seeing a huge increase in boost..something is wrong. Tune? Controller installed wrong? Idk..you tell me!

[Steve in Chicago]

What were you boosting to before the MBC was installed? What are you boosting to with the MBC installed and turned all the way down? How much boost do you plan on dialing in?

If you don't have a boost gauge, you're doing it wrong and I'll be expecting to see you start a new thread soon called "What happened to my engine?".

[Pelletier8]

My gauge is on the way, I figured I could throw the BC on and use it very lightly in the meantime. I hope to run about 15-17#. Im new to the whole car scene, im more into my truck..so as im sure you can tell, I need help

[Pelletier8]

Idk if it helps but here's what I've done for "mods":
K&N
BOV
full straight pipe
Boost gauge (in mail)
Turbo timer (in mail)

[Steve in Chicago]

I'm not a fan of the K&N filters on these cars. Placing an oiled air filter mere inches upstream of the MAF sensor is asking for a contaminated MAF. Plus, you're not going to out-flow the stock filter. Did you go with a drop-in filter or cone? If a cone, that's another mistake. The stock air box is actually a well designed and functional Cold Air Intake.

These cars are largely MAF based when it comes to fueling and other decisions the ECM makes. These cars are set up to use a Diverter Valve, not a BOV. Most BOV's throw off the MAF readings. On these cars, a BOV gets you that Phhhsssst sound and probably a CEL and messed up fuel trims. Your best bang for the buck is to upgrade to the Audi TT 225hp Diverter Valve (also known as the 710N valve). These go for around $45 and will hold the boost your K03 turbo can put out.

You don't need a turbo timer.

The MBC will get you into trouble if you don't know what you're doing (especially on the AEB engine).

A good first step is performance software. A "chip" or "flash" from a reputable company will get you the boost your after. It'll also have the fueling and timing maps to go with the increased airflow. Well known brands are APR, GIAC, Unitronics.

When I first got my Passat, I was in the same shoes you are in now. I had experience with other vehicles but didn't know much about these cars yet. Before you make any more modifications, do as much reading as you can. Check out PassatWorld and do reading there too. The more you know, the more you'll get in return for your money and effort.

[911_fan]

Wow, so you put a MBC on an AEB motor (with no limp mode protection) and cranked up your psi with no boost/wideband AFR gauges? Not very smart.

[Pelletier8]

Thanks Steve, and I used a drop in not a cone. And 911_fan, I really don't know much about these cars..I could tell you everything there is to know about my truck. I've got an 87 Toyota 4x4 Sr5 turbo 5 speed (look it up, they exist) with a 7 inch lift, 35x12.5x15 tires, full posi rear, scissor bed (that dumps too), quick release doors (like a jeep) and a removable sunroof. Its an inline 4 with 4.30 gears front and back. Header, turbo, straight pipe exhaust. Drop it into 4 low, put it in 1st and dump the clutch and you can rip wheelies all day long.

[911_fan]

You need to realize that AEB engines are not equipped with the same boost protection measures the 2000+ motors have. You seriously run the risk of leaning out your engine with what you are doing...essentially blind...right now. You would be smart and remove that MBC and at least wait till you have a boost gauge installed to set your boost, and a wideband air/fuel gauge to monitor your fueling. Or do it the safer way and get a chip tune.

[DB_VW]

You need to realize that AEB engines are not equipped with the same boost protection measures the 2000+ motors have. You seriously run the risk of leaning out your engine with what you are doing...essentially blind...right now. You would be smart and remove that MBC and at least wait till you have a boost gauge installed to set your boost, and a wideband air/fuel gauge to monitor your fueling. Or do it the safer way and get a chip tune.

+1 on chip tune.

And as for the K&N filter, just don't oil it

[Pelletier8]

Yeah, I took the controller off, I think im just gunna say screw that..is that bov really a bad idea?

[Steve in Chicago]

What are you trying to get with a BOV? If it's more performance, that isn't going to happen. Matter of fact, you may get just the opposite.

If it's just the sound you're after, get the Forge Splitter valve. That one will get you the Psshhhhhtt sound and not confuse your ECM.

Your AEB engine has a manifold-vacuum controlled valve. Any time the manifold vacuum is high enough, the valve opens.

A Diverter Valve opens a path from after the turbo to before the turbo. No air enters or leaves the system when the DV opens.

A BOV opens a path from after the turbo to atmosphere. When you lift-off after boosting, air leaves the system. When driving at small throttle openings or idling, manifold vacuum will be high and the valve will open. During these times, air will be entering the system.

The system is designed so the MAF measures all the air entering the system and the ECM goes by that data. If you have air entering or leaving the system, the ECM won't know about it and won't be able to adjust for it.

[Pelletier8]

I just like the sound lol I have one on my truck and it works and performs fine. Then again, this here is a volkswagon..so its gutta be complicated..ill look into the splitter. They run for what? Like $145? And I wont need a tune when I install it? If so ill just wait till I get a chip. What's a good chip? I see alot about the "GIAC" (whatever that is)

[Steve in Chicago]

Correct, the Forge Splitter valve does not require any special tune. You can use it with a stock engine or chipped. GIAC is a company that has developed several tunes for these cars. Other widely used tuning companies are APR and Unitronics. There are others too. Do some searches and reading as there are countless threads on this topic. It's always good if you can find a company with a local dealer. That way you have easier access to support. You may also be able to find a used and chipped ECM for your car. I got my first APR tune from the Classifieds. Your AEB engine uses the 557-P or the 558-M ECM.

[Pelletier8]

Sweet deal, thanks a lot man

[18t papa]

"Look guys I can crank my boost up super high!"

"Oh yeah? how much boost are you running?"

"I don't know I don't have a gauge."