My DIY on how to install A Dawes Device MBC. It's finished now w/ a diagram and pics as promised.
Original location (my forum)
Original location (my forum)
**I accept no responsibility to anything that you or the MBC do to your car. Any part of this DIY can be copied, but i'd ask that you give me some credit. Other DIYs can be found here
The MBC (manual boost control) is the idea mod for people who want more power with minimal spendings. The MBC used, and recomended, is the Dawes device hybrid boost control
Before ordering my MBC i emailed Mr. Dawes asking about the difference. The reply:
Thank you for your interest in our products! The Hybrid model uses a synthetic material in the ball/spring mechanism, which increase response. It also has a polished seat for better sealing. The basic model uses a heavier, steel ball. Both work as well or better than anything else on the market, but the Hybrid adds a bit quicker spool time.
Please feel free to ask any other questions that you may have.
==3 Bar Racing Inc.
That pretty much sold me. A few short days later i recieved the MBC. That weekend I installed it and did some testing. Preformance was well worth the trouble and costs.
***this version of the MBC install keeps the N75 in the loop***
You will deffinitally need a boost guage. that's not one of those things that you can skip over
Changing your stock diverter valve (710a, 8.8psi) with a stronger one. I am currently running the audi TT 710N (14.xx psi) It's cheep and effective.
After installing the boost guage check for any leaks in the vacuum system. Once all of these are done your ready to install
standard (silicon if you can get it) vacuum line:2 ft is plenty
smallest hose clamps you can find
Step one: After leting your car cool down (working near the turbo) pop up the hood and take out the air box assembly (top and bottem)
-start by undoing the 4 clips that hold the 2 halves together
-undo the 3 plugs (2 on the Mass air flow sensor, 1 on the N75 on the intake pipe)
-take the top off and the air filter
-undo the screw that holds the lower portion on. !!remember to go the correct way i already broke the stock screw on accident!! (M6x1 is the replacement i think)
-have a freind move the things that are in the way (lines, intake, ext)
Next the pressure relief valve
- it's this valve, it makes it a whole lot easier to get to the n75
-loosen the clamp closest to the metal pipe and the one at the base of the valve. then simply remove it (may require a bit of force)
Here's where the fun begins
-Locate the N75 valve, it has 3 gray large vacuum coming off of it.
-One goes to the waste gate (the canister looking thing between the turbo and engine block)
-The other goes to the turbo nipple. It a vacuum port coming strait off of the compressor side of the turbo. Remove the line from the n75 to the turbo nipple. ****VERY IMPORTANT: do not damage this line because you will be reusing it. The n75's nipple is infact larger than the nipple on the turbo. This line is used as a reducer from the turbo's standard size vacuum 3.5 or 4mm ( same as the one used on the boost guage) to the n75's nearly 6mm.
With the turbo nipple to n75 line removed examine it for any damage to the ends that may have occured. If the ends are slightly damaged it's ok to trim them a very little.
-Take the vacuum line that you bought and attach it to the turbo nipple. onto the other side of this vaccum line attach the strait part of the Dawes MBC. on the angled side of the MBC attach the smaller side of the previously removed line . it should be a decent fit, but not to terribly snug. attach the other side of the vacuum line to the N75. you should now have the basic layout. From TN -> strait side of the MBC-> the n75.
now that you have everything the way it should be, remove the line off of the N75, insert the clamp, and clamp that down
add the clamp in the MBC to WG line as well. reinstall the pcv, recheck of all the lines for any visiable leak potential.
Reinstall the airbox, plug the n75 and maf back in and reattach the intake. Start the car up and see if the Vac is where it should be.
--After a proper warm up take it for a quick test drive, watch your boost. Although the MBC comes from dawes set at 3 psi it also goes through the mbc (6 psi) so you should start out at around 9 psi in stock form. First thing you will notice over stock is how low and how quickly the boost builds. After a 5 mile drive or so, and you want to add more boost you can raise the pressure. You would do this buy loosening the locking nut and screwing in (making shorter) the MBC. I would turn it at no more than 1 turn at a time. the higher you raise the boost the more sensitive it is to changes.
--When i started with the MBC i ran it at ~11 psi in about 55* weather. 3 days later temperatures raised into the high 80's which seemed to increase the boost. I once spiked to 13 and settled at 12 and down to 10 at redline. This is TOO MUCH without a vagcom to be sure that everything is running properly. I backed the MBC out 3/4 of a turn and am currently running 10psi. Untill i get some vagcom readout's i'm going to leave it at this.
Finalize the setup by zip tieing down the strait side of the mbc down to the intake's loop(view last pics to see what i'm talking about) make sure that the locking nut is tight. and enjoi
**vagcom update. I order and received on from alpha-bid on ebay and planned on using rosstech freeware, but the proggy did not detect the vag-com cable as a rosstech one. I'll keep this post updated with the outcome and hopfully some vagcom graphs
**Note, these pictures are with the pcv still in place, it's actuall a whole lot easier to get to the n75**
From Turbo nipple
To MBC (starit side=TN, angled=n75)
mbc to n75
better shot vacuum going to n75
and the n75 with the wg line in pic aswell
and the finished product (minus aribox)
w/ airbox, no plastic covers