What's up guys? I've had my Forge MBC for about a week now. I just found some time this morning to put it in. The mounting hardware that came with it is worthless unless you plan to mount it with a ziptie, but that's not the reason for this post. I installed the MBC into the car (replacing my old MBC) in what I think is the proper direction. I would not really know because there were no instructions or labels to tell me which line to hook up to which nipple. No biggie, I'm a big kid and can figure it out... So I install it, and turn it one click in the " + " direction and go for a drive to see where I'm at. When boost climbs to 25psi I let off the throttle and think, ok, I must have the lines backwards. So I switch them around and go out again. 4psi. Ok, now I think I'm moving in the right direction. I continue to turn it in the " + " direction after going out to see where I'm at. So after about another hour of driving around and testing it I can only get 14psi out of the MBC no matter how many clicks I turn it in the " + " direction. This is pretty frustrating.

Things to know: My boost source is right after the turbo, I DO NOT have it connected to the BOV vacuum source. T-Bolt clamps everywhere, and the car has been pressure tested to 25psi, so it's not a leak. I'm using the spring that came inside the unit, the additional spring that also comes with it is still in the box.

If anyone has experience with this MBC please let me know. Or hell, if anyone from Forge wants to chime in and help out that would be great also.

Cheers,

Greg

 

My first guess is the boost gauge. It's not even possible to run less than 11psi, because that's the minimum the wastegate will allow. If you saw 4psi, I'd be worried about factors other than the MBC.

The first scenario you gave was exactly what happens when the lines are backwards. The 2nd scenario sounds like you had it just right but were seeing 7 less psi than you should have.

 

It's not the gauge, and I say this for a few reasons. 1. The gauge is less than a week old. 2. The boost controller I built from Home Depot parts works like a champ (and has for over 2 years) and I can boost 20psi all day long with it.

It's pretty easy to diagnose a boost controller when you have one that works and one that isnt working. Thanks for the reply though.

EDIT: Also, the wastegate will let you run whatever you have the boost set at. It wont let you run any more than 11psi if it's disconnected.

 

Ah, I didn't know that. For the rest of us, whenever we install an MBC, even turned all the way out completely wide open, it never boosts less than 11psi. I've never heard of someone being able to make it go lower than the minimum stiffness of the wastegate...

 

Sorry, I'm still on the stock turbo and actuator. The 3076 doesnt go in until this week.

 

No one else out there has the Forge MBC?

 

did you try the other spring?

 

I have to agree here, sorry...

On stock turbo, it shouldn't boost less than that.

 

Stiffer spring will fix your problem...link below is how I intalled my Unos.
http://www.moto7.net/photos//displayimage.php?pos=-215

 

Tried it, didnt work. Thanks though. Forge is awesome. They are sending me a new MBC on exhange. Should be good after that.

 

I fail to see how one of those MBC's could go bad

With the stiff spring it should be good for 30 psi

Its fairly easy to install - I may consider doing a write up on how to install

 

I think Mike did a write up today on it just in case any one has a problem with installing the UNOS. Get back to this in the AM.

 

I worked up a brief set of "instructions" for the install of the unit after receiving a phone call from Greg concerning his issue.

I think the problems he is experiencing are an isolated incident and I am working with him to get it corrected.

Keep in mind, this product is a universal component applicable for numerous vehicles, so the instructions are also universal and generic in nature to accomodate installation on any application.

I'll post it up here soon!

 

Before installing this product, please be aware of your vehicle’s OEM boost control system and routing of vacuum/pressure lines. These intricate details are specific to each application and will effect the installation, mounting location, and tuning of this product on your vehicle.




Ref. 1 - This port on the UNOS manual boost controller is the inlet of the unit and needs to have a pressure source taken directly from the outlet of the turbo or from the intake manifold. We highly recommend that the source be taken from the outlet of the turbo or the intercooler piping as close to the turbo outlet as possible, but the intake manifold can be used if no turbo outlet source is available.
__________________________________________________ ________________

Ref. 2 - This port on the UNOS manual boost controller is the outlet of the unit and is to have a pressure line connected to the pressure reference on the wastegate actuator or external wastegate, depending upon the application.
__________________________________________________ ________________

Please DO NOT install the UNOS manual boost controller in the opposite orientation or with the inlet and outlet ports connected to the opposite sources from those that are recommended above. Doing so will prevent the unit from operating properly and may cause damage to the mechanical components of the engine or turbocharger if not installed correctly immediately.

If you have any specific questions or concerns about the installation of this product, please contact your preferred Forge Motorsport authorized dealer, your vehicle’s tuner, or you may contact us directly.


Forge Motorsport
6536 Pinecastle Blvd. Suite C
Orlando FL 32809

(t) 407.447.5363 (f) 407.447.5361 (e) sales@forgemotorsport.com

 

The stiffer spring has the boost swinging to 25 so I'm going back to the soft spring. The reason I went to the stiffer spring is because, when leak testing at lower boost levels, I heard the MBC sputtering.

Is the spring install as easy as taking the old one out and dropping in the new??? This seems that straightforward. Why would I get a weird sputter or flutter from the MBC?

Thanks! Sorry for the hijack, but seems pertinent ...