rage mang

iTrader: (3)

im curious of this too i have a evo6 with a full tbe exhaust and custom tube manifold, a k&n pod filter and forge wastegate. other than that everything is stock in the engine bay my next plan of attack is a mbc is this an ok plan? i live in the philippines and we get 100octane at the pump but i dont want to mess with flashing the ecu right now i was thinking more on the line of the mbc helping me hold boost to redline does anyone object to this or have any advice thanks

sparky

iTrader: (1)

So, rage mang, do you already have your MBC or not?

Outlaw666

My evo IX is a USDM model and IV JDM...

Any thoughts about my question?

sparky

iTrader: (1)

The 1st thing that both the OP and rage mang need to do is test to establish their turbo's actual level of wastegate spring pressure. This will be the baseline. Once that baseline has been established, then we can proceed to increase(preload) the level of spring pressure ideally to a level 2-3 PSI below what the desired peak boost level is going to be.

First they are going to need to have boost gauges on their respective Evos. Establishing WG actual spring pressure is easy if they already have a MBC installed on their Evo(s). If you already have a correctly installed MBC then wastegate spring pressure can be determined by simply rotating the MBC adjustment knob out completely counterclockwise to the lowest possible setting(-).

If they are still using factory ECU/BCS boost control circuit, then they will have to disconnect two hoses: 1) that goes to the WGA at the WGA nipple. AND, 2) the hose that goes to the compressor discharge nipple, at the nipple. Then they will have to run a new hose connecting both nipples directly.

Outlaw666

What about me?

sparky

iTrader: (1)

Of course, it is your thread OP, and of course, my responses and any advice I may give is aimed at solving your boost issues first and foremost. Bear with me as I understand your urgency but I am getting there although it might not seem like it.

As they say in your neck of the woods: "Paciencia piojo, que la noche es larga."

sparky

iTrader: (1)

That whole spiel of mine(see post #19 above)regarding wastegate spring pressure is for your particular benefit.

If you already have your MBC installed we can get started immediately. If you haven't as yet installed the MBC then get yourself a 24-inch length of 4mm rubber vacuum hose and connect the compressor nipple directly to the WGA nipple. Do a WOT run in 4th gear and note the peak boost reading.

Outlaw666

I havent installed yet my MBC But I was plannning to connect it between the wastegate and the bov vaccum hose tee'ing them. And setting it to about 1.4/1.5bar on 3rd and 4th gear starting from total (-) in my Hallman Pro RX. Also I was thinking of using directly the harder spring.

What for should I see how much boost I can load conecting directly the WGA and the Turbocharger nipples?

sparky

iTrader: (1)

Nope. There are 2 ports on your MBC. You have to be real sure about how you are going to hook up and route your MBC hoses.

You are either going to source your boost reference from: 1) the nipple on the turbocharger's compressor discharge tube(j-pipe), or, 2) by splicing and "T"-ing into the hose that runs between the intake manifold(IM) and the diverter valve(DV).

Either way this hose will get routed to the reference port on your MBC which is the port directly inline axially and thus diametrically opposed to the MBC's adjustment knob.

The second port on the body of your MBC I think is called the signal port(?). But, whatever it is called, the hose connected to this other port which is located on the side of your MBC's body at right angles to the adjustment knob's centerlline gets routed directly to the nipple on the top of the WGA cannister.

The alternate routing which you mention is a no-no, my friend.

sparky

iTrader: (1)

Sorry, Outlaw666, for refering to you as the OP of this thread, when in fact, you only revived it. My mistake!

sparky

iTrader: (1)

Since you mentioned in your very first post that you want to improve "boost response", I was going to try and help you achieve quicker boost response.

The mere installation of an MBC device, without first increasing wastegate spring pressure is not necessarily, in and of itself, going to improve boost response in any significant measure.

An MBC will in some cases marginally improve response. But, if the actuator's spring pressure is too low then the MBC will only be controlling peak boost level without improving rate of spool substantially if at all.

rage mang

iTrader: (3)

i have a boost gauge it peaks consistently around 1 to 1.2 bar but it definetly tapers off around 5700 to 7300rpm i dont have a boost controller yet but i would like to hold peak boost till redline and if it will improve spool up response

sparky

iTrader: (1)

Keep in mind that holding peak boost flat out the top without any taper and improving spool-up response are two separate issues. You can solve one independently of the other.

Spool-up response is more of an actuator related, spring pressure issue, whereas holding peak boost until redline is not neccesarilly actuator related. In fact, boost taper has more to do with flow limitations of the 16G's turbine housinsg design. limitations in the turbine inlet, bypass port, and turbine exit areas are major factors.

So basically spoolup response is impacted directly by wastegate spring pressure, whereas, boost taper is related mostly to exhaust back pressure in the turbine housing .

Shoot me a PM and I'll give you a hand.

Outlaw666

I didnt know spool response and redline tapper were 2 different issues. From what I read on other threads what guys said was that conecting the MBC between the WGA and splicing and "T"-ing into the hose that runs between the intake manifold(IM) and the diverter valve(DV) improved turbo spool by 600 to 800rpms. Which didnt happen when connecting the MBC between the WGA and the Turbocharger...

Anyway I'm planning to connect my MBC as the OP of this thread did. Did u see the picture on #7? And capping all the other nipples (Turbo nipple, both solenoid nipples, intake) BTW Does it work the same as capping the solenoid nipples just bridging a hose between them?

what else should I do? Do I first should check the stock WGA spring pressure by connecting the WGA nipple directly to the Turbocharger nipple?

Thanks for sticking with me and the others and all your help bro. Please stay with us until the end of the process!!

sparky

iTrader: (1)

You can either source your MBC at the turbo's compressor discharge nipple which is where the factory does it, or you can cut the hose that runs between the diverter valve and the intake manifold and install a 3/16" brass "T".

However, there is not a 600-800 RPM difference in spool between the two sources. The IM/DV source is slightly quicker responding but it is not significant. It is just barely noticeable.