MBC ?'s........

[GrungeAholicVR4]

I have a MBC on my VR-4, but that stock piece of shit wanna be "boost gauge" lol, I have an MAFT version 2.0, and performance DN Y-pipe, a lil exhaust work, and a heavy duty clutch(not like it has anything to do with boost), but I got the boost controller for free, I know it works, but on most MBC's, how much of a turn equals a lb of boost? just a guestimate, because on saturday theres a big run and its kinda personal, and i wanna have a lil more than my stock boost of 12psi, what do yall think would be safe, a quater turn? a full turn? I know this isnt safe because of no way to tell what it is running boost wise, but I need some quick horses to help kick ass, how much boost do you MBC user get out of a full turn usually? Thanks,

Matt

[GreekPower]

if u can run it at 14.5 or 15psi thats the max the stock turbos can take and ull run fast i bet

[Hotshot8792]

your gonna need an aftermarket boost gauge, you can find some for $25

[GrungeAholicVR4]

Originally Posted by GreekPower

if u can run it at 14.5 or 15psi thats the max the stock turbos can take and ull run fast i bet

Im aware of what the stock turbos and intercoolers alow the safest boost to be, I need to know some "guestimates" of what one turn on a MBC or a 1/4 turn equals in boost increase. Thats it, thanks though, I preciate your time and help.

Always,
Matt

[GrungeAholicVR4]

Originally Posted by Hotshot8792

your gonna need an aftermarket boost gauge, you can find some for $25

I was afraid of that, do you think I could do a full turn just for one drag and not hurt anything? whats your opinion....

Thanks,
Matt

[talskinyguy]

with no gauge you wont know what your running, if your willing to take that chance, than have fun. But there is no way in hell I would mess with a MBC without a gauage.

[youngvr4]

i second that

[BB1970]

i third that, one full turn of a mbc could give you up to around an extra 25psi maybe more!!!!!!! asta la vista baby!!!!!!!!!!!!!! goodbye internals. Dont play with it unless you can guage it accurately.

[Igovert500]

I've never heard of one turn giving you 25 extra psi. However, I also haven't even heard of everyone out there, and all it takes is just 1 or 2 psi too much and you can destroy your engine.
Matt do you know exactly what type of MBC/brand you have. I have heard a full turn uping it 2 or 3 psi on one I was looking at...but then again, there is a huge range over all the mbc's available for our cars, so I really wouldn't take a guess. If you get knock...kiss your pistons goodbye. Get the new boost gauge first. Good luck. - geoff

[BB1970]

even a fraction of a turn about (5mm) on my mbc gives me about 3 psi but i have to admit it is not a proper controller specified for that job in mind. maybe thats why.

[Igovert500]

I dunno, I don't have one, I just remembered 2-3psi on one that I was reading about a few days ago. For this very reason...it's a bad idea.

[BB1970]

i think the ones made specifically for the purpose enable you to fine tune the boost a lot easier, ive just got a glamorous pond air valve! it works fine.
gonna upgrade soon so saw no point in laying out on something im gonna throw away later if you know what i mean.

[alan92rttt]

I think putting a MBC on a car without an aftermarket boost guage is one of the worst ides I've ever heard.

At full open you'd be running wastegate preasure which is 6psi. You'll need several turns just to get to stockl levels. With no wayy to monitor boost it would be easy to run too much and blow your engine to peices.

Go get an aftermarket guage and do it safely.

[GrungeAholicVR4]

Originally Posted by alan92rttt

I think putting a MBC on a car without an aftermarket boost guage is one of the worst ides I've ever heard.

At full open you'd be running wastegate preasure which is 6psi. You'll need several turns just to get to stockl levels. With no wayy to monitor boost it would be easy to run too much and blow your engine to peices.

Go get an aftermarket guage and do it safely.

Not at all, with at all the back, or closed,which mine is,its the same as not having it on there for your info. Not to be an ass or anything,but geez, idk what kind of controller you have that negates stock boost values without turning the increase boost knob....thats pretty fucked up. Because I am running stock boost right now, no knock,no nothing, no fuel cut, no rpm or mas cut. And the MBC was a free gift from a friend, its a uni-controller, cant remember what brand it is, but it is definetely on stock boost, sorry to disapoint you....

[alan92rttt]

A REAL MBC removes the stock controler from the loop.

A bleeder valve bleeds vacument from the system fooling the stock controller into thinking your running less boost then you really are.

If your using the stock controller you are using a bleeder valve.
Checjk these sites for the differance between an MBC and a Bleeder Valve.
http://techdata.mi3si.org/bleedervalve.htm
http://johnmonnin.netfirms.com/Boostcontrol.html


"I am running stock boost right now, no knock,no nothing" If your don't have a datalogger how do you know your not getting knock?