Overboosting, cant figure it out...
 

Hey guys got a quick question. On my friend's turbo LS setup, which we just got running, we cant seem to figure out why it keeps overboosting. It has a tial external gate, which I believe has a 7psi spring. We intially ran the car with a turboxs mbc, and figured that was to blame, and then ran a direct vaccume line to the wastegate. Same thing. The car hits 10+ psi in 4th at about half throttle, no more. We were affraid to go any farther. Any ideas? Is it definatley the wrong wastegate spring?

By the way, we found out the limitations of the stock fuel pump (waiting on delayed delivery for walboro). 1 Day, and its done.

thanks for ant help guys

Re:Overboosting, cant figure it out...
 

sounds like the spring is different than you thought.
only other thing is if the tubing you are using is leaking.
you can try to use a pump with gauge to find out the psi. if you have to, get another spring off ebay for $10 to be certain. they list what the psi the spring is for.

Re:Overboosting, cant figure it out...
 

wanted to add, we took the wastegate apart to install this so called 7psi spring. First one we've ever done so is there some way we could have put it back together wrong and it isnt operating right, like never opening? I dont have another one to reference, anyone got a link of how one is suppose to go together?

Whiterice: Ill check the vaccume lines tommorow. The car is running a vaccume manifold, so all of the lines ar connected in a sense. Will a leak anywhere in the system, not just the wastget line, cause trouble? Ill check all of em, i was just wodnering.

thnx again

Re:Overboosting, cant figure it out...
 

the car will always boost 2-3psi more in 4th and 5th cause the engine has more load, therefor producing more exhaust and driving the exhaust wheel faster.

Re:Overboosting, cant figure it out...
 

run a vaccum line from the turbo to the wastegate , not the intake mani to the wastegate... if not leave it as is and just add more fuel :P

Re:Overboosting, cant figure it out...
 

try to run a straight line (not shared)like RENR said.
also, does the wastegate have more than one nipple?

Re:Overboosting, cant figure it out...
 

add more to the tank ::)?

and the turbo doesnt have an outlet for vaccume, its external wastegate, i think vaccume for the intake mani should work fine

Re:Overboosting, cant figure it out...
 

Niiiiiice whiterice i think you got it, i seem to remember another nipple on the wastgate that isnt being used. I totally forgot about it. Ill plug it up tommorow and hopefully the new fuel pump will be here.

Thanks for the help man
peace

Re:Overboosting, cant figure it out...
 

the nipple on top of the wg should have nothing on it unless u are using an electronic boost controller. u want to use the one on the side. what color was the spring u instaled? was it green?

Re:Overboosting, cant figure it out...
 

hey here's a way to get an additional vacuum source from the intake manifold. worked out real good for me.
i didn't T off the PCV valve after all. i T'd off the charcoal fuel/emission filter cause it was gonna be much easier then the PCV. i did it with a plastic T edit:(platic T painted flat black) instead of the bulky brass homedepot T <-what was i thinking ::).
close up:http://www.newbieforces.com/files/wg T closeup.jpg
further away so you could see where i Td' off.
http://www.newbieforces.com/files/wg T faraway.jpg
hardly no boost spikes at all with an internal w/g. only a 1 psi boost spike on 2nd & 3rd gear. now that the waste gate isn't feeding off the fuel pressure regulator, and the BOV vacuum source, the BOV doesn't flutter on low psi (5-7psi) and the BOV sounds louder too. but the main purpose as why i did this is to avaoid buying a $40. vacuum manifold and to end of reduce the almost 3psi in boost spikes i was getting. i already drove the car for a while and it worked out good.