Materials needed:

1 x 1/8" NPT 1/4" Barbed Nipple (Male Fitting)
1 x 1/8" NPT 1/4" Barbed Nipple (Female Fitting)
1 x 3/16" Ball Bearing
1 x Utility Spring
2 x 1/2" Hose Clamps

The barbed fittings are used from compressors, but you should screw them onto each other so that you have a nipple on each end. The spring and ball bearing go inside so that essentially the spring presses on the ball bearing firmly against the inside of one of the fittings to seal the hole off. If the spring is too short, you can pull on it to make it a little bit longer, but if its too long, you can cut a big of the spring off, enough so that the spring presses against the fitting. Once everything is in together, you will be able to adjust the boost by simply turning the fittings together. this is an effective way to manipulate boost manually, all for under 5$

do you have pictures of it
dirk

yes i too would like to see a diagram of this or at least the parts just to finish off my imagination before such a $5 venture...

Pictures make the world go round. :)

.........interesting,,,,,,,,,,,,,,,,,,pics please---------please

Have a look at this site, it explains the procedure just as above and it also has pics.

http://www.c-speedracing.com/howto/mbc/mbc.php

You could also go to Harbor Freight and buy an air regulator for ~$3 and the same two male and female barbed nipples for ~$.99 each, thread one on to each side and there you go.

Made this one today.. Very good idea and I see how it works, but, I got really bad boost spiking..

Wastegate = 7psi, and I slowly up'd the boost with the homemade mbc,

Spike to 10, back down to 7-8 ish
spike to 13, back down to 7-9 ish
Spike to 16, back down to 7-9 ish

Anyone have any ideas?

Try using a stiffer spring and readjust the fittings for the same boost. This should give you smoother open/close of the mbc. Also make sure the surface the ball is pressing against inside the fitting is clean and smooth. If it's dinged up or rough at all use a tapered honing stone (like the ones you use in a dremmel tool) to clean it up, or better yet, jsut go back to the hardware store and buy one that has a nice clean finish inside.

Made this one today.. Very good idea and I see how it works, but, I got really bad boost spiking..

Wastegate = 7psi, and I slowly up'd the boost with the homemade mbc,

Spike to 10, back down to 7-8 ish
spike to 13, back down to 7-9 ish
Spike to 16, back down to 7-9 ish

Anyone have any ideas?

pressure regulators work good too... but I notice some spiking in third and fourth gear!

Made this one today.. Very good idea and I see how it works, but, I got really bad boost spiking..

Wastegate = 7psi, and I slowly up'd the boost with the homemade mbc,

Spike to 10, back down to 7-8 ish
spike to 13, back down to 7-9 ish
Spike to 16, back down to 7-9 ish

Anyone have any ideas?

Buy a Hallman Pro? :)

Iv got an apexi avcr, but thanks :)

Just wanted a feel for the car at higher boost before putting the avcr in. Im thinking about selling the car and dont want to put the avcr in unless I decide to keep it.. If that makes sense lol

can't find the ball bearing anywhere where i live

Not sure bout others, but I found it didnt work very well anyways in my gtir.. Real bad spike, then back down to standard boost...

how much will it let you boost???