[RESOLVED] Homemade MBC Question

[snowborder714]

When I bought my car, it had a homemade mbc on it. After doing some research, I found 2 pages that were pretty helpful.

Best way to install a MBC - DSM Forums
http://www.geocities.com/chmwatson/FAQs/mbc.html

But after I took mine apart, I noticed it was different from both of the sites. Here's a picture of mine taken apart and laid out.

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Now, I noticed mine has 2 bearing in it whereas the diagrams only have 1 (at the bottom). My MBC will run around 14 - 16psi when the spring gets turned sideways WTF (as shown below), but if you try and turn it up, I think it just gets bypassed and the wastegate takes over (only boosts to about 10 - 12psi). With the spring in vertically, it'll hit about 14 - 16psi and then if I turn it up too far, it'll do the same thing and only get 10 - 12psi. I've tried taking one of the bearings out, but I don't think the knob at the top comes in contact with the spring. Is there a problem with the MBC itself, the way it's put together, or would just getting a longer spring help? I think it's hooked up right.

Thanks!

Spring turned sideways

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Hooked up

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Spring vertical but not looking tall enough to be touched by knob

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Sorry for the long post but I want to give as much info as possible.

 

[Defiant]

I don't recall seeing one made out of a pipe fitting. Tubing hardware is usually used. Double-ball setups usually stack the balls under the spring, not separating them. And using a pipe plug for the adjuster is extremely iffy- the tapered threads won't hold an adjustment. Which is why tubing fittings are used for the body.
I'd start over for the ten bucks.

 

[snowborder714]

Ya, I've never seen one made out of those materials either. And I did try the balls/spring in all different combinations and got the same results. Thanks for the help!

Just curious if anyone else out there has anything more to add...

 

[DJYoshaBYD]

Thats how I made mine... I used the same stuff, but I used a longer, softer spring and a bigger ball bearing, and mine works wonderful

 

[snowborder714]

So you just have a spring and 1 bearing? Also, where would I be able to buy springs and bearings? Home Depot and Lowes?

 

[LordZed]

The spring is flipping sideways because the body of the MBC is to wide for that spring. It gives the spring room to turn around. He's also using two ball bearings because the spring is not long enough.
I made mine out of brass couplings from Home Depot's plumbing section. But not an actual pipe fitting like that. Like Defiant said, that top is really iffy too. I don't even see any teflon tape! Make your own. that way if it fails on you, you know you did it yourself

 

[snowborder714]

LordZed, do you happen to have any pictures of yours? Also, should I have teflon tape around the top part that screws in? Is that why you mentioned it?

 

[MyÜberFastGSX]

It's woth it to spend the $65 and get a Hallman...

 

[snowborder714]

Ya, I have been debating on whether to build one (for more experience and to say I did it) or to buy one that I know people have had success with...

 

[LordZed]

Ya, I have been debating on whether to build one (for more experience and to say I did it) or to buy one that I know people have had success with...

I don't have any pic's but I'll gladly pull it off and take it apart if you want to see it. Seriously though, if your not piss poor like I often am then just get a Hallman or something comparable. Wanna know where I got my ball bearing from? I purchased a 1.25 caster (a wheel that swivels on ball bearings) and drilled a hole in the top to extract the ball bearings. I got my spring out of a big ink pen I had. It's probably one of the most getto, but functioning MBC's ever constructed. It truly was a bit of a pain in the ass. But it's done and it works. I'd get a Hallman Pro like my friend has if I had the $125. You can adjust it from inside the cab!

Oh, and yes. Get teflon tape for the top.

 

[luvmygst]

I don't have any pic's but I'll gladly pull it off and take it apart if you want to see it. Seriously though, if your not piss poor like I often am then just get a Hallman or something comparable. Wanna know where I got my ball bearing from? I purchased a 1.25 caster (a wheel that swivels on ball bearings) and drilled a hole in the top to extract the ball bearings. I got my spring out of a big ink pen I had. It's probably one of the most getto, but functioning MBC's ever constructed. It truly was a bit of a pain in the ass. But it's done and it works. I'd get a Hallman Pro like my friend has if I had the $125. You can adjust it from inside the cab!

Oh, and yes. Get teflon tape for the top.

Dont feel bad, my bearing came out of a throw out bearing from my last clutch change, and the sping from a ball point pen. I have one on both my cars and have made 3 or 4 for my friends. They work like a charm

 

[DJYoshaBYD]

I got mine from the "extras & springs"bin at my local ACE hardware.... I used a wider pipe and the ball bearing is about 1/3 inches... I will post pics when I get the chance

 

[snowborder714]

Thanks for all the help so far from everyone! Ya know, I never even though about using a spring from a pen...I'll have to remember that.

I'd love to have a mbc that I could change in the cockpit, but right now can't justify $125 I would hate to buy a cheaper mbc and then want one of the better ones...I'm all about doing things once and done I'm definitly thinking about it for when I do get some cash (either that or electronic...but that's a whole different topic). I think I may just build another one for now and would love to see pics from anyone willing to take them!

 

[hewhoisknot]

I don't remember where I got my bearing from, but my spring came from a pen. The home mad MBC works just as good as any retail one though. Mine was able to hold fine even above 30 PSI.

BUN

 

[tkelly27]

http://www.xmission.com/~dempsey/perform/grainger.htm

my buddy has one that comes with 0-20, 20-50 and 50-100psi springs and hose barb fittings on them. 2 packs for $15 I think? I'll have to get the PN from him whenever he picks up the damn phone.

They work real well, help spool up a bunch!