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View Full Version : MBC, N75, and elim.



.Mad Hatter.
08-09-2010, 12:33 PM
I know this has been beaten to DEATH, but I need a direct answer and could not find one.

I plan on running my Hallman Pro MBC and taking the N75 out of the equation. I know where the MBC goes, and I know I need to leave the N75 plugged in...but what about the banjo fitting that goes to the compressor housing? Hook it back up, or block off that hole.

new:

http://farm2.static.flickr.com/1131/4727231291_e370cdc51b_b.jpg

old:

http://farm5.static.flickr.com/4148/4847533623_2a2ea1713c_b.jpg

.Mad Hatter.
08-09-2010, 12:34 PM
actually...now that i think about it...what is that brass nipple for?

EuroDriven
08-09-2010, 12:43 PM
Thought it was for a WG as that is the only nipple I have on the intake of my BT. Did the turbo come as a kit with that inlet adapter/internal wastegate?

Dan[FN]6262
08-09-2010, 12:49 PM
*facepalm*

.Mad Hatter.
08-09-2010, 01:11 PM
ya im an idiot...that brass fitting is for the boost source

.Mad Hatter.
08-09-2010, 01:15 PM
i think im going to run it like this:

http://i130.photobucket.com/albums/p276/superman_006/mbc1.jpg

Seerlah
08-09-2010, 01:23 PM
You have 2 nipples on the mbc. The side one goes to the wastegate and the bottom one is the boost pressure source. That's the hose you are referring to.

Take the n75 out of the picture. Leave it electronically plugged in (not sure if you need to cap the nipples or not, but I don't see why you would need to) and zip tie it to the side somehwere. You can actually leave the n75 plugged into your throttle inlet (you have to keep it electronically plugged in) and either place caps on the 2 nipples (they sell them at Aurtozone) or run a vacuum line looping the 2 nipples. Run a vacuum line from the fitting on the turbo compressor housing (by the outlet), which is the boost pressure source, to the bottom nipple of your mbc. And run a vacuum line from your wastegate actuator to the side nipple of your mbc. And then dial it in correctly till you reach your desired max pressure.

Don't go by that diagram and get the n75 out of the picture.

.Mad Hatter.
08-09-2010, 01:25 PM
that was my initial thought...thoughts on the setup above?

Seerlah
08-09-2010, 01:31 PM
I added my little 2 cents at the end of my last post. My suggestion would be to remove the n75 from the equation, as agreeing to your original post. Your diagram is basically having you run the mbc parallel with the n75. The n75 is more headaches than it's worth. Remove it from the scenerio.

.Mad Hatter.
08-09-2010, 01:33 PM
ok deal

EuroDriven
08-09-2010, 03:17 PM
Sorry, I am retarded. You are right, I don't know what I was thinking looking at that picture. It's a boost source, I will put my flame suit on now.

I am going to run my MBC from my IM though.

black99.5a4
08-09-2010, 04:31 PM
I added my little 2 cents at the end of my last post. My suggestion would be to remove the n75 from the equation, as agreeing to your original post. Your diagram is basically having you run the mbc parallel with the n75. The n75 is more headaches than it's worth. Remove it from the scenerio.

it is a pain whch is why BT setups remove it.. but the elim is still small enough spool wise that he might run into surging.. so he's gonna run it without the n75, if he gets surge, gonna run it inline. i'm hoping Geoffs fine without it.. I still dont see why Tapp makes you plug it in and doesnt write it out completely..

Dan[FN]6262
08-12-2010, 06:30 AM
i think im going to run it like this:

http://i130.photobucket.com/albums/p276/superman_006/mbc1.jpg

thats how i ran mine on a 71R. it works great. still have throttle modulated boost, but you dont have to fuck with the wastegate if you want more than 22psi. just crank down the MBC more. [up]

Dan[FN]6262
08-12-2010, 06:31 AM
I am going to run my MBC from my IM though.

no. do not do that. you'll constantly have overboost conditions and it'll kill the life of your turbo. you'll boost spike like a mother ******.

wildbill
08-12-2010, 06:59 AM
seerlah wins again...wonder to modern science

EuroDriven
08-12-2010, 07:29 AM
5857;5565359']no. do not do that. you'll constantly have overboost conditions and it'll kill the life of your turbo. you'll boost spike like a mother ******.

Why?

wildbill
08-12-2010, 08:07 AM
no you wouldnt...the n75 is cycling...and the mbc gets set at or below spec. boost....case closed, the taper off makes you have to turn it down a pound or so

Dan[FN]6262
08-12-2010, 08:46 AM
Why?

by IM you mean Intake Manifold, right?

Mantis
08-12-2010, 09:10 AM
If you run boost source at the IM, you will most definitely overspin the turbo. There is a reason most manufacturers reference what is happening at the turbo, consider what would happen if you had a boost leak. The turbo tries to maintain boost at the intake, if you are referencing the IM then you are going to compound the issues already associated with a boost leak.

Dan[FN]6262
08-12-2010, 10:26 AM
If you run boost source at the IM, you will most definitely overspin the turbo. There is a reason most manufacturers reference what is happening at the turbo, consider what would happen if you had a boost leak. The turbo tries to maintain boost at the intake, if you are referencing the IM then you are going to compound the issues already associated with a boost leak.

THIS

EuroDriven
08-12-2010, 11:25 AM
If you run boost source at the IM, you will most definitely overspin the turbo. There is a reason most manufacturers reference what is happening at the turbo, consider what would happen if you had a boost leak. The turbo tries to maintain boost at the intake, if you are referencing the IM then you are going to compound the issues already associated with a boost leak.

Thanks never thought about it like that. I was merely picturing an ideal system with no leaks. Looks like I am not running a MBC anytime soon then.