Carpokes Porsche Forum

Tom & Members,

I'm ready to get a MBC "ball & spring" type controller for my stock wastegate. There are so many out there on ebay/Amazon. Is there one that you would recommend? I have John Vitesse's V-MAF+ set up with K26/8 turbo.

Also, once I'm ready to install:
1) I connect from the banjo bolt to the MBC
2) from the MBC to the top of the stock WG

3) What do I do with the hose/tube that was originally attached to the banjo bolt?
4) What do I do with the hose/tube that was originally attached to the top of the WG?

*those two hose/tubes that were originally attached go to the Cycling valve*

Thanks again !

You might consider adding a Tial dual port wastegate while you are at it. Original stock wastegates all tend to be worn out by now.

Not sure if you have a piggyback with your VR stuff, but @Fast951 has an inexpensive electronic boost controller you can add if so. I use an original Profec boost controller -- it's much like a manual controller in a lot of ways (turn knob up for more boost, down for less) and I recommend it highly if you can find one....

If you want a simple MBC, I'd go with a tried and true version, like this one at paragon:
https://www.paragon-products.com/Variab ... mbc-25.htm

It's the LR kit, but Paragon has always been quite helpful before and after making a sale. It comes with installation/routing instructions.

As for hose routing, I kept the 3-pipe spider manifold under the intake and repurpose it to route the new hoses. So the original banjo bolt hose still goes to the same place. But on the other end of that pipe, with the CV removed, you can plumb that boost signal to the wastegate (or thru the mbc and then on to the wastegate). If you don't need the return line to the j-boot, you can cap that off at the back of the 3-pipe manifold too, or at the j-boot if you don't need it to look stock. Make sense?

Is this the line at the j-boot (now the vitesse MAF pipe).

https://www.punishment-racing.com/the-b ... ontroller/

Some other thoughts for 2022

Some brands I had not seen before…..not that I was ever looking.

I am thinking of trying the Turbosmart dual if I don’t go full Stand-alone from Chris White when I get to that point.

I have a LR piece but I am not putting it back in.

Thanks!

If you are using a single port WG (stock WG), then you need a ball and spring type MBC. For a dual port WG, you need a bleeder type MBC.

For the ball & spring, try finding a ceramic ball. I have seen them on eBay, but availability may be an issue.

Bleeder type MBC is a mini air regulator, same as the ones used on your shop air compressor.

The Vitesse J-pipe has 3 fittings:
- Crankcase vent hose
- BOV
- Emissions hose

The CV has 3 hoses:
- IN pressure: from IC pipe.
- OUT signal: to top of WG.
- VENT: to J-boot or shared fitting at J-pipe (emissions port).


99.9% of customers no longer use the stock CV. For those that do use the CV, they "T" the CV vent hose with the emissions hose so they can share the same port on the J-pipe (nearest the turbo).

In your pictures you point to the "emission hose port". When eliminating the CV, you disconnect the CV vent hose (and plug it). Remove the "T" fitting, the emission hose must remain connected to the J-pipe.

Ideally when going to an MBC or EBC, you want to remove the CV and its associated hoses. If you prefer to keep the CV, just disconnect and plug its hoses. Make sure to disconnect the CV electrical plug.

When using an MBC, you may need to adjust your MBC setting when the external temps change. If you set your boost on a 80-90F day, you will over boost when temps drop to 30-40F. So must be careful.
At the same time, if you set boost when it's cold outside, boost will drop when temps are hot.

An EBC works much better than a MBC. But a MBC is inexpensive (less than $30).

Hope this helps.

Great thank you. That is exactly what i did last night prior to reading this. Can't wait to give is a test ride. Thanks again!.

+1 on EBC over MBC

+2 on EBC over MBC.

I had the "black knob" in the past and other MBCs.

I bought this a year ago for about $275: https://gfb.com.au/products/boost-contr ... er-detail/
I highly recommend it for ease of use and quality. There are several youtube videos from the company and users that are helpful as far as setup and good information that explains the "why" and "how".