bch5428

this is some information that has been evading me for quite some time. ive been searching various manual boost controller websites and asking on various forums, and havnt gotten an ounce of legitimate information regarding the cracking pressures of manual boost controllers. i personally prefer my aem tru-boost because its easy to use and adjust the cracking pressure for faster spool. ive seen people claim faster spool with the "insert name brand here" manual boost controllers, even shops have done this, yet they have no manufacturer or legitimate data to show for it. not that i dont believe them but its nice to know they dropped their spool time "300rpm" etc...

does anyone know where information regarding the cracking pressure of manual boost controllers is obtainable?

Bailhatch

Look at how they work and you will get your anwser...that you don't need because you love your aem deally haha.

bch5428

i was only using the tru-boost an example, simply bc the cracking pressure is adjustable and etc, like every other ebc.

so youre saying if the take ball and spring set up out of a mbc, i can determine its cracking pressure by looking at it?

Muckman

iTrader: (2)

This is one of those questions where I can promise you few if anyone on here will have the hard data your after.

I believe its all BS and marketing anyways.

418whpturboD

the wastegate is going to open when it sees the right boost it needs.. i cans see that creating faster spool the engine spools the turbo, i dont understand how that would make it faster.. if you want faster spool eighter get a smaller exh. housing or bigger motor or more compression, better cams and so on..

bch5428

or i can just get an electric boost controller.

dpetro1

ball and spring mbc's can reduce lag while the bleed type mbc's increase lag.

with the ball and spring, the internal spring can sometimes be swapped (hallman) or adjusted (turbo xs) to make it stiffer, hence blocking boost pressure for a longer period of time and decreasing lag.

to give a hypothetical situation...a normal wg w/ 10psi spring starts opening at 1psi and is full open at 10psi. with an mbc all pressure to the wg is blocked by the ball and spring until lets say 5psi. then the ball and spring opens then allowing the wg to open. so you keep all the exhaust going to the turbo for 4psi longer, thus decreasing lag

does that make sense? the mbc simply blocks all pressure to the wg from a longer period of time.

this is different from an ebc because an ebc actually applies pressure above the wg diaphragm to keep the wg closed longer, thus decreasing lag.

Muckman

iTrader: (2)

I dont see how the bleed type can "increase" lag. Since its bleeding the reference pressure to the wastegate it would delay the cracking point. This would decrease lag. However not as effectively as a ball spring type which is able to block ALL reference pressure, but still better than no boost controller at all.

Also with EBC's it depends how you plumb them. You can put them inline with the bottom port and it will act just like a standard MBC. One thing Ive never known the answer to is it more beneficial to use an EBC to control boost pressure to the top half of a wastegate or on the bottom half of the wastegate? It seems to me like the outcome would be the same.

dpetro1

hmm, your logic makes sense. but also wouldnt the "leak" be considered a boost leak as well, possibly increasing the lag. the leak is so small that it is doesnt effect overall boost pressure but does mean it would take the turbo longer to spool. does that make sense or am i coming out of left field?

well it seems the agruement for ebc's is that they can apply pressure to both sides of the diaphragm, giving better consistency and fine adjustment. i dont think you would want to use just the top half b/c that would just hold the wg closed indefinitely