Help WIth building an MBC

[TalonRacer024]

OK i am building my MBC. Here are the peices i have. (plus another hose barb).

1) Since i had to use bushings will this effect anything?
2) How do i drill the hole/thread the elbow so the adjuster screw will go into it?
3)Does this spring look ok?
4)On vfaq.com it show the nut on the top of the elbow. I assume you use this for threading? How do you get it to stay there?

THanks

 

[TalonRacer024]

anyone?

 

[crashed97tsi]

you need a tap, bring the piece to a sears or ace hardware and ask for the tap for that screw. Then drill a guide hole in the elbow piece, then drill the hole that the tap requires. Then thread the tap with a tap wrench. Mine was a little different but i 'think' that will work

later

 

[TalonRacer024]

How tight does the screw have to be inside of the controller. The screw i have right now is really strong and i am worried it might be to strong.

 

[TalonRacer024]

i mean spring my bad

 

[BoostinAWD]

just test it, make sure you put the ball in first, it acts as a seal until your boost sorce makes enough pressure to push it up and open the wastegate.

You be surprised how many people i've seen who have put the spring in first.

 

[BatmanGSX]

That spring will suck.

 

[TalonRacer024]

oh great dsm wiseman if you feel the need to tell me the spring sucks could you explain as to why and give me a recomendation for a better one.

 

[LAZPNO]

Spring wise, that spring looks like it's gonna be wayyyy too stiff for the setup, unless u plan on runnin 18+ boost. I'm remaking mine one more time before i decide to buy one... eww nevermind, not buying one. but yea, that spring looks like it's gonna be extremely stiff. it's up 2 u if u decide to use it or not, but i'd have it tested first. i.e. take it to a tire shop and have them hook it up to a pressure regulated air supply to see when the spring gives and let's the air through. also, don't forget to drill the lil hole in the side of it, i forgot on mine, and it wouldn't hold boost for anything. afterwards though, it worked fine.

 

[TalonRacer024]

ok so what kinda spring should i use? Anyone have any ideas or any pics of one that they used

 

[BatmanGSX]

Okay, heres the thing with the spring. It's too damn stiff and short, what this will do is offer poor adjustability, with no preload you will have stock boost, then with a little you will have 18psi all the sudden and then with another little quarter turn you will have 25psi. You need a softer spring. It's not easy making an MBC just because you will probably have to experiment three or four times with different springs. We can't tell you what spring to get because everyone makes their MBCs with different fittings and stuff and length becomes an issue. You need a combo of the right stiffness and the right length.

 

[LASERLX]

i use a spring like that and i can only get 20 psi plus with it

hehe 21 psi with the 14b feels good though

 

[AWD_ENVY]

Originally posted by LASERLX

hehe 21 psi with the 14b feels good though

Yeah.... it blow nice hot air... ....

 

[TalonRacer024]

what kinda spring should i use? One out of a clicky pen(something that loose) or something between that and the one i have

 

[ModInProgress]

talonracer .. i dont no if im sure y yyour making a mbc like this.. i made mine with just a valve that i bought from homedepot... i looked for the tube that gos from the compressor housing to the wastgate acuater .. now once you find this follow the tube that "T"s from that tube up to the boost solniod..that tube is the one you want to cut..cut it and put a "t"barb in the cut now you should have a boost selnoid tube with a t in it..ok from the t run a tube to a convienient spot... at the end of this tube put the simple valve that you wuold purchase from homedepot .. the vavle has 2 openings on one end insert your tube in it the other opening can be left how it is... now what you have done is allow the boost pressure (that the senoid reeds and then tells the wastegate to open) to leak out there fore giving the selnoid a false reading and making it think your only still at 10 psi when you can be at 12-25 psi .. the valve i have is very sensitive about a quarter turn is about 2-3 psi but its very good too have.. any questions?

 

[Bohrn]

Batman is right. Spring is too stiff.

Funny, 3rd time I am writing this today at this site alone!

stiff spring = pain in the arse to adjust. Its like 1/256th of a turn = 2psi of boost. take off, shift to second, build boost, over boost to 22 psi, lift like hell, slow heart rate down, pull car over, tweak it a bit looser(just a bit mind you) shut hood, get back in, take off, shift to second, build boost, wait for it, still waiting, oh joy, 10psi!

Hammer on the brakes, jump out,pop the hood, GENTLY tweak it tighter, close it up, jump back in, wait for the whole line of traffic to go buy, endure the frowns of all the old people in Century's, wait till there is room, take off, get second again, build boost, and hit 19 psi. Ok, close, we are getting there

repeat 2 or 3 more times, till you finally get a close proximity to 15 psi, accounting for spikes, and such.

Then you remember that you need to try this in 3rd gear where there si some load on the system. Oh, now go and find a spot where you can run 90+ mph, repeatedly, and safely. Oh #@%#@%#@%#@%, the sun just went behind the mountains. Arg.

We love this stuff. Right??

hehe, best of luck, and use a softer spring. I got mine at a welding supply place, they just had a few dozen springs in a couple of boxes. Cost me less than $14 canadian for the whole thing.