DIY Manual Boost Controller - under $100 TT

RS200

Hey guys, well i got a tubo XS manual boost controller, well that was made so shitty that they used a brass bolt to controll boost, so of course the allen key ripped the brass bolt up nad then i had to sue an extractor to remove the brass screw, well thats a custom fine thread bolt, so i tried to re-tap the thing, the tap broke and i started thinking, man i could make a better one for cheaper...

2 mins on google later and i found this link:

http://www.geocities.com/chmwatson/FAQs/mbc.html

now i hate manual boost controllers, but i dont have the cash to buy a $2400+ TT on a Profec B right now, so till then i am willing to try something...

so i went to LP Marine and Peaks got all this for under $65 TT

1/4" NPT Tee (I'll refer to it as the 'Body')
1/4" Male NPT plug
1/4" Female NPT x 3/16" hose barb
1/4" Male NPT x 3/16" hose barb
5/16"-18 x 1 1/2" SHCS (I'll refer to it as a 'Bolt') (I actually purchased mine from Peaks)
5/16-18 Jam Nut (I actually purchased mine from Peaks)
1/4" dia ball bearing (I actually purchased mine from Peaks)
Spring ~ 1.69" lg x 3/16" dia

this is how it is assembled

i still have to get the 1/4" male plug tapped 5/16-18 for the bolt...

ut it works pretty simple, you increase the tension on the spring by turning the bolt clockwise/righty-tighty, this increases presure on the ball bearing through the spring, that means more boost will be needed to move the ball bearing up and allow the boost signal to reach the wastegate...

you just got to make sure that with the sring all the way expanded your wastetgate functions as normal, openeing at its normal boost level/spring rate, and when you turn the screw in small incriments, you increase the ppresure on the ball bearing, raising the boost,

i'll be testing it once i get it tapped and ready and will post pics of mine assembled and installed.

check out the link for more information.

A-1 Superior Tech · Posted: Wed Oct 06, 2004 4:11 pm Post subject:

yea a mechanic did tell me about that, i was going to try it this week Cool

RS200 · Posted: Wed Oct 06, 2004 4:29 pm Post subject:

mine should be working by this evening... i'll try it our briefly to about 11psi or so, i cant use it over that till i get the car on the dyno...

InDeForest · Posted: Wed Oct 06, 2004 4:32 pm Post subject:

Oh i love it, i woulda done this if id seen it months ago. Hell i might still do it for kicks.
Actually, why does he have it between the actuator and BOV why not between the compressor nipple and actuator.

A-1 Superior Tech · Posted: Wed Oct 06, 2004 6:22 pm Post subject:

CA19, lemme no how it works, i wont mind making one tommorow and trying it out right away or so, and have boost raise ready for sunday lol....but a mechanic tell me it have one where you get this knob thingy yuh connect a line to and out and yuh could manually set it inside the car

X2 · Posted: Wed Oct 06, 2004 6:49 pm Post subject:

I'll tell ya how it works... not reliably..hehehe

I built one like that a while back (similar)... tried it... spiked from 12 all the way to 17psi and I had a heartattack.... thank god I was running a built motor at the time !

I haven't found a good BC on the market yet... my turbo XS MBC did the same shift and my buddy's greddy EBC spikes too... lorse. Maybe this one will hold low boost well ? Good luck meng... keep us up to date if you try it.

**Edit... read the whole link... not the very same one I built... but I still fraid MBC's nonetheless... Laughing

RS200 · Posted: Thu Oct 07, 2004 11:54 am Post subject:

i didn't hook it up yet as LP Marince is completing the work for me today (tapping and drilling the plug)

InDeForest · Posted: Thu Oct 07, 2004 2:08 pm Post subject:

Well I was thinking about this some more, and figured the bleed hole can have an effect on spiking, when the ball opens and the air rushing by, on its way to the actuator, bleeds out the hole, this lost air is whats causeing the actuator to open at later boost than its internal spring pressure, if its too big , youre gonna need more compressor boost put the same pressure on the actuator.
My point is anyway, that you could also change the size of the bleeder hole, if you think its too big, put a drop of solder on the mouth of it and you can smear in a smaller hole, if you know solder you what i mean.
Other thing i thought about is how well that ball bearing seals inside that barb fitting, gotta be snug

ninjaboost · Posted: Thu Oct 07, 2004 2:29 pm Post subject:

I have a few concerns......... cant wait to hear the results............

I too have made MBC's (the fellars who were at the dyno when I tested my car will confirm) and my last one which is somewhat similar to this, hardly spikes sometimes 1 or 2psi max..... and I could live with that Mr. Green

ps. it only spikes when I try to run more than 15psi and it cost me around TT$100

nash · Posted: Thu Oct 07, 2004 2:49 pm Post subject:

I like the idea there,goes to show how much can be done at home !!! Idea

RS200 · Posted: Thu Oct 07, 2004 3:47 pm Post subject:

well it worked... Very Happy

worked ok too, took me two trips up and down the main road, set to 12psi, no spiking, it slowly raises to 12psi and i can hear the wastegate open at about 9psi or so which is the regular wastegate setting/spring.

but after getting silly with a lil more boost in the rain - i head a exhast leak, the bolts on the manifold->turbo rattled loose, gotta wait for the car to cool, re-tighten them, drive home, put on the mech gloves and tighten them while they are hot... i think i'll use some lock-tight this time, and a breaker bar Twisted Evil

RS200 · Posted: Thu Oct 07, 2004 3:49 pm Post subject:

total cost was about $80 TT for everything Cool

A-1 Superior Tech · Posted: Thu Oct 07, 2004 4:27 pm Post subject:

sweeeeet

Toysport · Posted: Thu Oct 07, 2004 5:11 pm Post subject:

Sticky please?

speed demon · Posted: Thu Oct 07, 2004 5:32 pm Post subject:

brilliant god damn so what the 2400 was for please explain cause i dont know

Quicksilver · Posted: Thu Oct 07, 2004 9:53 pm Post subject:

I played with a couple setups like this..... the one on the car right now cost me TT$12 Laughing

.... the 'ball bearing' type is more effective than the cheaper bleed type though.

Quicksilver · Posted: Thu Oct 07, 2004 9:54 pm Post subject:

delete

ninjaboost · Posted: Fri Oct 08, 2004 8:58 am Post subject:

RS200 · Posted: Fri Oct 08, 2004 3:06 pm Post subject:

InDeForest · Posted: Sat Oct 09, 2004 5:57 am Post subject:

Ahh, how could I have forgotten to compare it to this.
http://www.dawesdevices.com/boost.html