ochizon

I built an MBC, and am running a 1 3/4" long, 7/32" dia, and .030 wire gauge spring for my MBC. I was wonder ing if I went with a slightly stiffer spring, could I reduce the boost spike, or is this unrelated?

I am boosting 9 psi, spiking to 11psi, and my internal wastegate opens at 5psi w/o the MBC ( I can raise the wastegate actuation point, would that change anything)

B16CRXT

I would use a slightly stiffer spring. Dont get too stiff thouhg or it will be impossible to adjust efficiently. I made one with a hella stiff spring and it failed miserably. I need a softer spring.

ochizon

what was the gauge of the spring that was too stiff?

B16CRXT

the measurements on teh package I have say 1/4" x 1" x .035"

ochizon

damn, thats only .005" more than the spring I have...

B16CRXT

yea, and I cut it down from an inch to about 1/2" or so. maybe if you cut one of your springs down to 3/4" and did it that way, it might work. I would just try it at different lengths until it felt right. maybe try it with one or two more coils.

ochizon

What if I were to put a bleeder valve on the line from the mani to the BOV to put less pressure in the BOV? Do you think there is a way to balance that signal to allow over boost to be blown off, while still holding tight at the desired boost level

Only one way to find out, I guess...

saxxu

im playing it safe on a BC, since boost spike is somewhat related to boostcreep according to an article this is dangerous as ----, so i will suggest you to write down a decent 125 dlls BC on your x-mas list or save some money and buy it, trust me it's worth your motor

http://www.dsmtuners.com/forums/showthread.php?t=96678